Ziqiang Guan

Journal Article bioRxiv · September 5, 2024 A broad chemical genetics screen in Mycobacterium tuberculosis (Mtb) to identify inhibitors of established or previously untapped targets for therapeutic development yielded compounds (BRD-8000.3 and BRD-9327) that inhibit the essential efflux pump EfpA. T ... Full text Link to item Cite

Lipid discovery enabled by sequence statistics and machine learning.

Journal Article bioRxiv · August 19, 2024 Bacterial membranes are complex and dynamic, arising from an array of evolutionary pressures. One enzyme that alters membrane compositions through covalent lipid modification is MprF. We recently identified that Streptococcus agalactiae MprF synthesizes ly ... Full text Link to item Cite

Structures of trehalose-6-phosphate synthase, Tps1, from the fungal pathogen Cryptococcus neoformans: A target for antifungals.

Journal Article Proc Natl Acad Sci U S A · August 6, 2024 Invasive fungal diseases are a major threat to human health, resulting in more than 1.5 million annual deaths worldwide. The arsenal of antifungal therapeutics remains limited and is in dire need of drugs that target additional biosynthetic pathways that a ... Full text Link to item Cite

Structures of trehalose-6-phosphate synthase, Tps1, from the fungal pathogen Cryptococcus neoformans : a target for novel antifungals.

Preprint · June 5, 2024 Full text Link to item Cite

Streptococcus agalactiae glycolipids promote virulence by thwarting immune cell clearance.

Journal Article Sci Adv · May 31, 2024 Streptococcus agalactiae [group B Streptococcus (GBS)] is a leading cause of neonatal meningitis, with late-onset disease (LOD) occurring after gastrointestinal tract colonization in infants. Bacterial membrane lipids are essential for host-pathogen intera ... Full text Link to item Cite

Spatial organization of bacterial sphingolipid synthesis enzymes.

Journal Article J Biol Chem · May 2024 Sphingolipids are produced by nearly all eukaryotes where they play significant roles in cellular processes such as cell growth, division, programmed cell death, angiogenesis, and inflammation. While it was previously believed that sphingolipids were quite ... Full text Link to item Cite

Pneumonic Plague Protection Induced by a Monophosphoryl Lipid A Decorated Yersinia Outer-Membrane-Vesicle Vaccine.

Journal Article Small · April 2024 A new Yersinia pseudotuberculosis mutant strain, YptbS46, carrying the lpxE insertion and pmrF-J deletion is constructed and shown to exclusively produce monophosphoryl lipid A (MPLA) having adjuvant properties. Outer membrane vesicles (OMVs) isolated from ... Full text Link to item Cite

A bacterial vesicle-based pneumococcal vaccine against influenza-mediated secondary Streptococcus pneumoniae pulmonary infection.

Journal Article Mucosal Immunol · April 2024 Streptococcus pneumoniae (Spn) is a common pathogen causing a secondary bacterial infection following influenza, which leads to severe morbidity and mortality during seasonal and pandemic influenza. Therefore, there is an urgent need to develop bacterial v ... Full text Link to item Cite

Lipid discovery enabled by sequence statistics and machine learning

Preprint · February 22, 2024 Full text Cite

Structure and Function of ArnD. A Deformylase Essential for Lipid A Modification with 4-Amino-4-deoxy-l-arabinose and Polymyxin Resistance.

Journal Article Biochemistry · October 17, 2023 Covalent modification of lipid A with 4-deoxy-4-amino-l-arabinose (Ara4N) mediates resistance to cationic antimicrobial peptides and polymyxin antibiotics in Gram-negative bacteria. The proteins required for Ara4N biosynthesis are encoded in the pmrE and a ... Full text Link to item Cite

Preclinical safety and efficacy characterization of an LpxC inhibitor against Gram-negative pathogens.

Journal Article Sci Transl Med · August 9, 2023 The UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase LpxC is an essential enzyme in the biosynthesis of lipid A, the outer membrane anchor of lipopolysaccharide and lipooligosaccharide in Gram-negative bacteria. The development of LpxC-targeting a ... Full text Link to item Cite

Characterization of an evolutionarily distinct bacterial ceramide kinase from Caulobacter crescentus.

Journal Article J Biol Chem · July 2023 A common feature among nearly all gram-negative bacteria is the requirement for lipopolysaccharide (LPS) in the outer leaflet of the outer membrane. LPS provides structural integrity to the bacterial membrane, which aids bacteria in maintaining their shape ... Full text Link to item Cite

HexSDF Is Required for Synthesis of a Novel Glycolipid That Mediates Daptomycin and Bacitracin Resistance in C. difficile.

Journal Article mBio · April 25, 2023 Clostridioides difficile is a Gram-positive opportunistic pathogen responsible for 250,000 hospital-associated infections, 12,000 hospital-associated deaths, and $1 billion in medical costs in the United States each year. There has been recent interest in ... Full text Link to item Cite

Critical role of the RpoE stress response pathway in polymyxin resistance of Escherichia coli.

Journal Article J Antimicrob Chemother · March 2, 2023 OBJECTIVES: Polymyxins, including colistin, are the drugs of last resort to treat MDR bacterial infections in humans. In-depth understanding of the molecular basis and regulation of polymyxin resistance would provide new therapeutic opportunities to combat ... Full text Link to item Cite

Structure and dynamics of the essential endogenous mycobacterial polyketide synthase Pks13.

Journal Article Nat Struct Mol Biol · March 2023 The mycolic acid layer of the Mycobacterium tuberculosis cell wall is essential for viability and virulence, and the enzymes responsible for its synthesis are targets for antimycobacterial drug development. Polyketide synthase 13 (Pks13) is a module encodi ... Full text Link to item Cite

AepG is a glucuronosyltransferase involved in acidic exopolysaccharide synthesis and contributes to environmental adaptation of Haloarcula hispanica.

Journal Article J Biol Chem · February 2023 The attachment of a sugar to a hydrophobic lipid carrier is the first step in the biosynthesis of many glycoconjugates. In the halophilic archaeon Haloarcula hispanica, HAH_1206, renamed AepG, is a predicted glycosyltransferase belonging to the CAZy Group ... Full text Link to item Cite

Structure and dynamics of the essential endogenous mycobacterial polyketide synthase Pks13.

Journal Article bioRxiv · January 28, 2023 Mycobacterium tuberculosis is currently the leading cause of death by any bacterial infection1. The mycolic acid layer of the cell wall is essential for viability and virulence, and the enzymes responsible for its synthesis are therefore front line targets ... Full text Link to item Cite

Agl28 and Agl29 are key components of a Halobacterium salinarum N-glycosylation pathway.

Journal Article FEMS Microbiol Lett · January 17, 2023 Although Halobacterim salinarum provided the first example of N-glycosylation outside the Eukarya, only recently has attention focused on delineating the pathway responsible for the assembly of the N-linked tetrasaccharide decorating selected proteins in t ... Full text Link to item Cite

Parkin coordinates mitochondrial lipid remodeling to execute mitophagy.

Journal Article EMBO Rep · December 6, 2022 Autophagy has emerged as the prime machinery for implementing organelle quality control. In the context of mitophagy, the ubiquitin E3 ligase Parkin tags impaired mitochondria with ubiquitin to activate autophagic degradation. Although ubiquitination is es ... Full text Link to item Cite

An N-linked tetrasaccharide from Halobacterium salinarum presents a novel modification, sulfation of iduronic acid at the O-3 position.

Journal Article Carbohydr Res · November 2022 Halobacterium salinarum, a halophilic archaeon that grows at near-saturating salt concentrations, provided the first example of N-glycosylation outside Eukarya. Yet, almost 50 years later, numerous aspects of such post-translational protein processing in t ... Full text Link to item Cite

Structural basis for inhibition and regulation of a chitin synthase from Candida albicans.

Journal Article Nat Struct Mol Biol · July 2022 Chitin is an essential component of the fungal cell wall. Chitin synthases (Chss) catalyze chitin formation and translocation across the membrane and are targets of antifungal agents, including nikkomycin Z and polyoxin D. Lack of structural insights into ... Full text Link to item Cite

Caulobacter lipid A is conditionally dispensable in the absence of fur and in the presence of anionic sphingolipids.

Journal Article Cell Rep · May 31, 2022 Lipid A, the membrane-anchored portion of lipopolysaccharide (LPS), is an essential component of the outer membrane (OM) of nearly all Gram-negative bacteria. Here we identify regulatory and structural factors that together render lipid A nonessential in C ... Full text Link to item Cite

Convergent evolution of bacterial ceramide synthesis.

Journal Article FASEB J · May 2022 Bacteria synthesize numerous types of sphingolipids with various physiological functions. Despite their roles in mediating host inflammation, cellular differentiation, and protection from environmental stress, their biosynthetic pathway remains undefined s ... Full text Link to item Cite

Structural basis of NPR1 in activating plant immunity.

Journal Article Nature · May 2022 NPR1 is a master regulator of the defence transcriptome induced by the plant immune signal salicylic acid1-4. Despite the important role of NPR1 in plant immunity5-7, understanding of its regulatory mechanisms has been hindered by a l ... Full text Cite

Remodeling Yersinia pseudotuberculosis to generate a highly immunogenic outer membrane vesicle vaccine against pneumonic plague.

Journal Article Proc Natl Acad Sci U S A · March 15, 2022 SignificanceYersinia pestis, the etiologic agent of plague, has been responsible for high mortality in several epidemics throughout human history. This plague bacillus has been used as a biological weapon during human history and is currently one of the de ... Full text Link to item Cite

Convergent evolution of bacterial ceramide synthesis.

Journal Article Nat Chem Biol · March 2022 The bacterial domain produces numerous types of sphingolipids with various physiological functions. In the human microbiome, commensal and pathogenic bacteria use these lipids to modulate the host inflammatory system. Despite their growing importance, thei ... Full text Link to item Cite

Identification of a novel cationic glycolipid in Streptococcus agalactiae that contributes to brain entry and meningitis.

Journal Article PLoS Biol · February 2022 Bacterial membrane lipids are critical for membrane bilayer formation, cell division, protein localization, stress responses, and pathogenesis. Despite their critical roles, membrane lipids have not been fully elucidated for many pathogens. Here, we report ... Full text Link to item Cite

Distinct Regions of the Haloferax volcanii Dolichol Phosphate-Mannose Synthase AglD Mediate the Assembly and Subsequent Processing of the Lipid-Linked Mannose.

Journal Article J Bacteriol · January 18, 2022 Haloferax volcanii AglD is currently the only archaeal dolichol phosphate (DolP)-mannose synthase shown to participate in N-glycosylation. However, the relation between AglD and Pyrococcus furiosus PF0058, the only archaeal DolP-mannose synthase for which ... Full text Link to item Cite

Hemochromatosis drives acute lethal intestinal responses to hyperyersiniabactin-producing Yersinia pseudotuberculosis.

Journal Article Proc Natl Acad Sci U S A · January 11, 2022 Hemachromatosis (iron-overload) increases host susceptibility to siderophilic bacterial infections that cause serious complications, but the underlying mechanisms remain elusive. The present study demonstrates that oral infection with hyperyersiniabactin ( ... Full text Link to item Cite

Revisiting N-glycosylation in Halobacterium salinarum: Characterizing a dolichol phosphate- and glycoprotein-bound tetrasaccharide.

Journal Article Glycobiology · December 30, 2021 Although Halobacterium salinarum provided the first example of N-glycosylation outside the Eukarya, much regarding such post-translational modification in this halophilic archaea remains either unclear or unknown. The composition of an N-linked glycan deco ... Full text Link to item Cite

Outer Membrane Vesicles Displaying a Heterologous PcrV-HitA Fusion Antigen Promote Protection against Pulmonary Pseudomonas aeruginosa Infection.

Journal Article mSphere · October 27, 2021 Along with surging threats and antibiotic resistance of Pseudomonas aeruginosa in health care settings, it is imperative to develop effective vaccines against P. aeruginosa infection. In this study, we used an Asd (aspartate-semialdehyde dehydrogenase)-bas ... Full text Link to item Cite

Recombinant Pseudomonas Bionanoparticles Induce Protection against Pneumonic Pseudomonas aeruginosa Infection.

Journal Article Infect Immun · October 15, 2021 To develop an effective Pseudomonas aeruginosa outer-membrane-vesicle (OMV) vaccine, we eliminated multiple virulence factors from a wild-type (WT) P. aeruginosa strain, PA103, to generate a recombinant strain, PA-m14. Strain PA-m14 was tailored with a pSM ... Full text Link to item Cite

Lipid diversity in clostridia.

Journal Article Biochim Biophys Acta Mol Cell Biol Lipids · September 2021 Studies of the lipidomes of twenty-one species of clostridia have revealed considerable diversity. Even among those species now defined as Clostridium sensu stricto, which are related to Clostridium butyricum, the type species, lipid analysis has shown tha ... Full text Link to item Cite

Identification of the Flavobacterium johnsoniae cysteate-fatty acyl transferase required for capnine synthesis and for efficient gliding motility.

Journal Article Environ Microbiol · May 2021 Sulfonolipids (SLs) are bacterial lipids that are structurally related to sphingolipids. Synthesis of this group of lipids seems to be mainly restricted to Flavobacterium, Cytophaga and other members of the phylum Bacteroidetes. These lipids have a wide ra ... Full text Link to item Cite

Streptococcus pneumoniae, S. pyogenes and S. agalactiae membrane phospholipid remodelling in response to human serum.

Journal Article Microbiology (Reading) · May 2021 Streptococcus pneumoniae, S. pyogenes (Group A Streptococcus; GAS) and S. agalactiae (Group B Streptococcus; GBS) are major aetiological agents of diseases in humans. The cellular membrane, a crucial site in host-pathogen interactions, is poorly characteri ... Full text Link to item Cite

Critical Role of 3'-Downstream Region of pmrB in Polymyxin Resistance in Escherichia coli BL21(DE3).

Journal Article Microorganisms · March 22, 2021 Polymyxins, such as colistin and polymyxin B, are the drugs used as a last resort to treat multidrug-resistant Gram-negative bacterial infections in humans. Increasing colistin resistance has posed a serious threat to human health, warranting in-depth mech ... Full text Link to item Cite

Streptococcus pneumoniae, S. mitis, and S. oralis Produce a Phosphatidylglycerol-Dependent, ltaS-Independent Glycerophosphate-Linked Glycolipid.

Journal Article mSphere · February 24, 2021 Lipoteichoic acid (LTA) is a Gram-positive bacterial cell surface polymer that participates in host-microbe interactions. It was previously reported that the major human pathogen Streptococcus pneumoniae and the closely related oral commensals S. mitis and ... Full text Link to item Cite

Streptococcus pneumoniae,S. pyogenes, andS. agalactiaemembrane phospholipid remodeling in response to human serum

Preprint · January 28, 2021 Full text Cite

Identifying Components of a Halobacterium salinarum N-Glycosylation Pathway.

Journal Article Front Microbiol · 2021 Whereas N-glycosylation is a seemingly universal process in Archaea, pathways of N-glycosylation have only been experimentally verified in a mere handful of species. Toward expanding the number of delineated archaeal N-glycosylation pathways, the involveme ... Full text Link to item Cite

Regulation of glial size by eicosapentaenoic acid through a novel Golgi apparatus mechanism.

Journal Article PLoS Biol · December 2020 Coordination of cell growth is essential for the development of the brain, but the molecular mechanisms underlying the regulation of glial and neuronal size are poorly understood. To investigate the mechanisms involved in glial size regulation, we used Cae ... Full text Link to item Cite

Phospholipid distribution in the cytoplasmic membrane of Gram-negative bacteria is highly asymmetric, dynamic, and cell shape-dependent.

Journal Article Sci Adv · June 2020 The distribution of phospholipids across the inner membrane (IM) of Gram-negative bacteria is unknown. We demonstrate that the IMs of Escherichia coli and Yersinia pseudotuberculosis are asymmetric, with a 75%/25% (cytoplasmic/periplasmic leaflet) distribu ... Full text Link to item Cite

A2E Distribution in RPE Granules in Human Eyes.

Journal Article Molecules · March 20, 2020 A2E (N-retinylidene-N-retinylethanolamine) is a major fluorophore in the RPE (retinal pigment epithelium). To identify and characterize A2E-rich RPE lipofuscin, we fractionated RPE granules from human donor eyes into five fractions (F1-F5 in ascending orde ... Full text Link to item Cite

MESH1 is a cytosolic NADPH phosphatase that regulates ferroptosis.

Journal Article Nat Metab · March 2020 Critical to the bacterial stringent response is the rapid relocation of resources from proliferation toward stress survival through the respective accumulation and degradation of (p)ppGpp by RelA and SpoT homologues. While mammalian genomes encode MESH1, a ... Full text Open Access Link to item Cite

Quantifying lipofuscin in retinal pigment epithelium in vivo by visible-light optical coherence tomography-based multimodal imaging.

Journal Article Sci Rep · February 19, 2020 Lipofuscin in the retinal pigment epithelium (RPE) is the major source of fundus autofluorescence (FAF). A technical challenge to accurately quantify the FAF intensities, thus the lipofuscin concentration, is to compensate the light attenuation of RPE mela ... Full text Open Access Link to item Cite

Outer Membrane Vesiculation Facilitates Surface Exchange and In Vivo Adaptation of Vibrio cholerae.

Journal Article Cell Host Microbe · February 12, 2020 Gram-negative bacteria release outer membrane vesicles into the external milieu to deliver effector molecules that alter the host and facilitate virulence. Vesicle formation is driven by phospholipid accumulation in the outer membrane and regulated by the ... Full text Open Access Link to item Cite

Human UDP-galactose 4'-epimerase (GALE) is required for cell-surface glycome structure and function.

Journal Article J Biol Chem · January 31, 2020 Glycan biosynthesis relies on nucleotide sugars (NSs), abundant metabolites that serve as monosaccharide donors for glycosyltransferases. In vivo, signal-dependent fluctuations in NS levels are required to maintain normal cell physiology and are dysregulat ... Full text Open Access Link to item Cite

Ornithine Lipids in Burkholderia spp. Pathogenicity.

Journal Article Front Mol Biosci · 2020 The genus Burkholderia sensu lato is composed of a diverse and metabolically versatile group of bacterial species. One characteristic thought to be unique for the genus Burkholderia is the presence of two forms each (with and without 2-hydroxylation) of th ... Full text Open Access Link to item Cite

Identification of a novel cationic glycolipid inStreptococcus agalactiaethat contributes to brain entry and meningitis

Preprint · 2020 Full text Cite

Streptococcus pneumoniae,S. mitis, andS. oralisproduce a phosphatidylglycerol-dependent,ltaS-independent glycerophosphate-linked glycolipid

Preprint · 2020 Full text Cite

Ether lipid metabolism by AADACL1 regulates platelet function and thrombosis.

Journal Article Blood Adv · November 26, 2019 We previously reported the discovery of a novel lipid deacetylase in platelets, arylacetamide deacetylase-like 1 (AADACL1/NCEH1), and that its inhibition impairs agonist-induced platelet aggregation, Rap1 GTP loading, protein kinase C (PKC) activation, and ... Full text Link to item Cite

Phosphatidylcholine Biosynthesis in Mitis Group Streptococci via Host Metabolite Scavenging.

Journal Article J Bacteriol · November 15, 2019 The mitis group streptococci include the major human pathogen Streptococcus pneumoniae and the opportunistic pathogens Streptococcus mitis and Streptococcus oralis, which are human oral cavity colonizers and agents of bacteremia and infective endocarditis ... Full text Open Access Link to item Cite

Investigation of the conserved reentrant membrane helix in the monotopic phosphoglycosyl transferase superfamily supports key molecular interactions with polyprenol phosphate substrates.

Journal Article Arch Biochem Biophys · October 30, 2019 Long-chain polyprenol phosphates feature in membrane-associated glycoconjugate biosynthesis pathways across domains of life. These unique amphiphilic molecules are best known as substrates of polytopic membrane proteins, including polyprenol-phosphate phos ... Full text Link to item Cite

Lipidomic Analysis of Clostridium cadaveris and Clostridium fallax.

Journal Article Lipids · August 2019 The lipidomes of Clostridium fallax and Clostridium cadaveris were studied using thin-layer chromatography (TLC) and normal phase liquid chromatography/mass spectrometry (NPLC/MS). Both species contain diradylglycerol (DRG), monohexosyldiradylglycerol (MHD ... Full text Link to item Cite

The Lipid A 1-Phosphatase, LpxE, Functionally Connects Multiple Layers of Bacterial Envelope Biogenesis.

Journal Article mBio · June 18, 2019 Although distinct lipid phosphatases are thought to be required for processing lipid A (component of the outer leaflet of the outer membrane), glycerophospholipid (component of the inner membrane and the inner leaflet of the outer membrane), and undecapren ... Full text Open Access Link to item Cite

Visualizing conformation transitions of the Lipid II flippase MurJ.

Journal Article Nat Commun · April 15, 2019 The biosynthesis of many polysaccharides, including bacterial peptidoglycan and eukaryotic N-linked glycans, requires transport of lipid-linked oligosaccharide (LLO) precursors across the membrane by specialized flippases. MurJ is the flippase for the lipi ... Full text Link to item Cite

Caulobacter crescentus Adapts to Phosphate Starvation by Synthesizing Anionic Glycoglycerolipids and a Novel Glycosphingolipid.

Journal Article mBio · April 2, 2019 Caulobacter crescentus adapts to phosphate starvation by elongating its cell body and a polar stalk structure. The stalk is an extension of the Gram-negative envelope containing inner and outer membranes as well as a peptidoglycan cell wall. Cellular elong ... Full text Open Access Link to item Cite

Identifying a novel connection between the fungal plasma membrane and pH-sensing.

Journal Article Mol Microbiol · August 2018 The mechanisms by which micro-organisms sense and internalize extracellular pH signals are not completely understood. One example of a known external pH-sensing process is the fungal-specific Rim/Pal signal transduction pathway. Fungi, such as the opportun ... Full text Open Access Link to item Cite

Nonsyndromic Retinitis Pigmentosa in the Ashkenazi Jewish Population: Genetic and Clinical Aspects.

Journal Article Ophthalmology · May 2018 PURPOSE: To analyze the genetic and clinical findings in retinitis pigmentosa (RP) patients of Ashkenazi Jewish (AJ) descent, aiming to identify genotype-phenotype correlations. DESIGN: Cohort study. PARTICIPANTS: Retinitis pigmentosa patients from 230 fam ... Full text Link to item Cite

The phospholipid-repair system LplT/Aas in Gram-negative bacteria protects the bacterial membrane envelope from host phospholipase A2 attack.

Journal Article J Biol Chem · March 2, 2018 Secretory phospholipases A2 (sPLA2s) are potent components of mammalian innate-immunity antibacterial mechanisms. sPLA2 enzymes attack bacteria by hydrolyzing bacterial membrane phospholipids, causing membrane disorganization and cell lysis. However, most ... Full text Open Access Link to item Cite

Reduced Chlorhexidine and Daptomycin Susceptibility in Vancomycin-Resistant Enterococcus faecium after Serial Chlorhexidine Exposure.

Journal Article Antimicrob Agents Chemother · January 2018 Vancomycin-resistant Enterococcus faecium strains (VREfm) are critical public health concerns because they are among the leading causes of hospital-acquired bloodstream infections. Chlorhexidine (CHX) is a bisbiguanide cationic antiseptic that is routinely ... Full text Link to item Cite

Gene deletions leading to a reduction in the number of cyclopentane rings in Sulfolobus acidocaldarius tetraether lipids.

Journal Article FEMS Microbiol Lett · January 1, 2018 The cell membrane of (hyper)thermophilic archaea, including the thermoacidophile Sulfolobus acidocaldarius, incorporates dibiphytanylglycerol tetraether lipids. The hydrophobic cores of such tetraether lipids can include up to eight cyclopentane rings. Pre ... Full text Open Access Link to item Cite

Long-Chain Polyprenols Promote Spore Wall Formation in Saccharomyces cerevisiae.

Journal Article Genetics · December 2017 Dolichols are isoprenoid lipids of varying length that act as sugar carriers in glycosylation reactions in the endoplasmic reticulum. In Saccharomyces cerevisiae, there are two cis-prenyltransferases that synthesize polyprenol-an essential precursor to dol ... Full text Link to item Cite

Methionine metabolism is essential for SIRT1-regulated mouse embryonic stem cell maintenance and embryonic development.

Journal Article EMBO J · November 2, 2017 Methionine metabolism is critical for epigenetic maintenance, redox homeostasis, and animal development. However, the regulation of methionine metabolism remains unclear. Here, we provide evidence that SIRT1, the most conserved mammalian NAD+-dependent pro ... Full text Link to item Cite

Knowns and unknowns of membrane lipid synthesis in streptomycetes.

Journal Article Biochimie · October 2017 Bacteria belonging to the genus Streptomyces are among the most prolific producers of antibiotics. Research on cellular membrane biosynthesis and turnover is lagging behind in Streptomyces compared to related organisms like Mycobacterium tuberculosis. Whil ... Full text Link to item Cite

Assembling Glycan-Charged Dolichol Phosphates: Chemoenzymatic Synthesis of a Haloferax volcanii N-Glycosylation Pathway Intermediate.

Journal Article Bioconjug Chem · September 20, 2017 N-glycosylation, the covalent attachment of glycans to select protein target Asn residues, is a post-translational modification performed by all three domains of life. In the halophilic archaea Haloferax volcanii, in which understanding of this universal p ... Full text Link to item Cite

Lipid sugar carriers at the extremes: The phosphodolichols Archaea use in N-glycosylation.

Journal Article Biochim Biophys Acta Mol Cell Biol Lipids · June 2017 N-glycosylation, a post-translational modification whereby glycans are covalently linked to select Asn residues of target proteins, occurs in all three domains of life. Across evolution, the N-linked glycans are initially assembled on phosphorylated cytopl ... Full text Link to item Cite

Impaired photoreceptor functions in the NgBR(R290H/R290H) mouse

Conference INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE · June 1, 2017 Link to item Cite

Streptococcus mitis and S. oralis Lack a Requirement for CdsA, the Enzyme Required for Synthesis of Major Membrane Phospholipids in Bacteria.

Journal Article Antimicrob Agents Chemother · May 2017 Synthesis and integrity of the cytoplasmic membrane are fundamental to cellular life. Experimental evolution studies have hinted at unique physiology in the Gram-positive bacteria Streptococcus mitis and S. oralis These organisms commonly cause bacteremia ... Full text Open Access Link to item Cite

Editorial for Special Issue on lipid methodology.

Journal Article Anal Biochem · May 1, 2017 Full text Link to item Cite

Streptococcus mitis and Streptococcus oralis Mutate an 'Essential'" Gene Upon Exposure to Daptomycin

Conference FASEB JOURNAL · April 1, 2017 Link to item Cite

1,2-Diacylglycerol choline phosphotransferase catalyzes the final step in the unique Treponema denticola phosphatidylcholine biosynthesis pathway.

Journal Article Mol Microbiol · March 2017 Treponema denticola synthesizes phosphatidylcholine through a licCA-dependent CDP-choline pathway identified only in the genus Treponema. However, the mechanism of conversion of CDP-choline to phosphatidylcholine remained unclear. We report here characteri ... Full text Open Access Link to item Cite

In Vivo and in Vitro Synthesis of Phosphatidylglycerol by an Escherichia coli Cardiolipin Synthase.

Journal Article J Biol Chem · November 25, 2016 Phosphatidylglycerol (PG) makes up 5-20% of the phospholipids of Escherichia coli and is essential for growth in wild-type cells. PG is synthesized from the dephosphorylation of its immediate precursor, phosphatidylglycerol phosphate (PGP) whose synthase i ... Full text Open Access Link to item Cite

The cellular lipids of Romboutsia.

Journal Article Biochim Biophys Acta · September 2016 We have examined the lipids of three isolates, Romboutsia lituseburensis, Romboutsia ilealis, and Romboutsia sp. strain FRIFI, of the newly described genus Romboutsia by two-dimensional thin-layer chromatography (2D-TLC) and by liquid chromatography/mass s ... Full text Open Access Link to item Cite

N-glycosylation in the thermoacidophilic archaeon Sulfolobus acidocaldarius involves a short dolichol pyrophosphate carrier.

Journal Article FEBS Lett · September 2016 N-glycosylation is a post-translational modification that occurs across evolution. In the thermoacidophilic archaea Sulfolobus acidocaldarius, glycoproteins are modified by an N-linked tribranched hexasaccharide reminiscent of the N-glycans assembled in Eu ... Full text Open Access Link to item Cite

Discovery of the Elusive UDP-Diacylglucosamine Hydrolase in the Lipid A Biosynthetic Pathway in Chlamydia trachomatis.

Journal Article mBio · March 22, 2016 Constitutive biosynthesis of lipid A via the Raetz pathway is essential for the viability and fitness of Gram-negative bacteria, includingChlamydia trachomatis Although nearly all of the enzymes in the lipid A biosynthetic pathway are highly conserved acro ... Full text Open Access Link to item Cite

NgBR is essential for endothelial cell glycosylation and vascular development.

Journal Article EMBO Rep · February 2016 NgBR is a transmembrane protein identified as a Nogo-B-interacting protein and recently has been shown to be a subunit required for cis-prenyltransferase (cisPTase) activity. To investigate the integrated role of NgBR in vascular development, we have chara ... Full text Open Access Link to item Cite

Substrate Selectivity of Lysophospholipid Transporter LplT Involved in Membrane Phospholipid Remodeling in Escherichia coli.

Journal Article J Biol Chem · January 29, 2016 Lysophospholipid transporter (LplT) was previously found to be primarily involved in 2-acyl lysophosphatidylethanolamine (lyso-PE) recycling in Gram-negative bacteria. This work identifies the potent role of LplT in maintaining membrane stability and integ ... Full text Link to item Cite

Structure of the polyisoprenyl-phosphate glycosyltransferase GtrB and insights into the mechanism of catalysis.

Journal Article Nat Commun · January 5, 2016 The attachment of a sugar to a hydrophobic polyisoprenyl carrier is the first step for all extracellular glycosylation processes. The enzymes that perform these reactions, polyisoprenyl-glycosyltransferases (PI-GTs) include dolichol phosphate mannose synth ... Full text Open Access Link to item Cite

Chemoenzymatic Assembly of Bacterial Glycoconjugates for Site-Specific Orthogonal Labeling.

Journal Article J Am Chem Soc · October 7, 2015 The cell surfaces of bacteria are replete with diverse glycoconjugates that play pivotal roles in determining how bacteria interact with the environment and the hosts that they colonize. Studies to advance our understanding of these interactions rely on th ... Full text Link to item Cite

Discovery of a bifunctional acyltransferase responsible for ornithine lipid synthesis in Serratia proteamaculans.

Journal Article Environ Microbiol · May 2015 Ornithine lipids (OLs) are phosphorus-free membrane lipids that can be formed by many bacteria but that are absent from archaea and eukaryotes. A function for OLs in stress conditions and in host-bacteria interactions has been shown in some bacteria. Some ... Full text Link to item Cite

Biomarkers of NAFLD progression: a lipidomics approach to an epidemic.

Journal Article J Lipid Res · March 2015 The spectrum of nonalcoholic fatty liver disease (NAFLD) includes steatosis, nonalcoholic steatohepatitis (NASH), and cirrhosis. Recognition and timely diagnosis of these different stages, particularly NASH, is important for both potential reversibility an ... Full text Link to item Cite

N-Linked Glycans Are Assembled on Highly Reduced Dolichol Phosphate Carriers in the Hyperthermophilic Archaea Pyrococcus furiosus.

Journal Article PLoS One · 2015 In all three domains of life, N-glycosylation begins with the assembly of glycans on phosphorylated polyisoprenoid carriers. Like eukaryotes, archaea also utilize phosphorylated dolichol for this role, yet whereas the assembled oligosaccharide is transferr ... Full text Link to item Cite

Clostridium difficile contains plasmalogen species of phospholipids and glycolipids.

Journal Article Biochim Biophys Acta · October 2014 Analysis of the polar lipids of many pathogenic and non-pathogenic clostridia has revealed the presence of plasmalogens, alk-1'-enyl ether-containing phospholipids and glycolipids. An exception to this finding so far has been Clostridium difficile, an impo ... Full text Link to item Cite

Kdo hydroxylase is an inner core assembly enzyme in the Ko-containing lipopolysaccharide biosynthesis.

Journal Article Biochem Biophys Res Commun · September 26, 2014 The lipopolysaccharide (LPS) isolated from certain important Gram-negative pathogens including a human pathogen Yersinia pestis and opportunistic pathogens Burkholderia mallei and Burkholderia pseudomallei contains d-glycero-d-talo-oct-2-ulosonic acid (Ko) ... Full text Link to item Cite

Mutation of Nogo-B receptor, a subunit of cis-prenyltransferase, causes a congenital disorder of glycosylation.

Journal Article Cell Metab · September 2, 2014 Dolichol is an obligate carrier of glycans for N-linked protein glycosylation, O-mannosylation, and GPI anchor biosynthesis. cis-prenyltransferase (cis-PTase) is the first enzyme committed to the synthesis of dolichol. However, the proteins responsible for ... Full text Link to item Cite

Characterization of the Vibrio cholerae VolA surface-exposed lipoprotein lysophospholipase.

Journal Article J Bacteriol · April 2014 Bacterial lipases play important roles in bacterial metabolism and environmental response. Our laboratory recently discovered that a novel lipoprotein lysophospholipase, VolA, localizes on the surface of the Gram-negative aquatic pathogen Vibrio cholerae. ... Full text Link to item Cite

Photoreceptor degeneration in the DHDDS K42EK42E mouse

Conference INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE · April 1, 2014 Link to item Cite

Abnormal synaptic transmission between photoreceptors and bipolar cells in DHDDSK42E/K42E mice

Conference INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE · April 1, 2014 Link to item Cite

Substrate promiscuity: AglB, the archaeal oligosaccharyltransferase, can process a variety of lipid-linked glycans.

Journal Article Appl Environ Microbiol · January 2014 Across evolution, N-glycosylation involves oligosaccharyltransferases that transfer lipid-linked glycans to selected Asn residues of target proteins. While these enzymes catalyze similar reactions in each domain, differences exist in terms of the chemical ... Full text Link to item Cite

Crystal Structure of MraY, an Essential Membrane Enzyme for Bacterial Cell Wall Synthesis

Conference Biophysical Journal · January 2014 Full text Cite

Aberrant dolichol chain lengths as biomarkers for retinitis pigmentosa caused by impaired dolichol biosynthesis.

Journal Article J Lipid Res · December 2013 We observed a characteristic shortening of plasma and urinary dolichols in retinitis pigmentosa (RP) patients carrying K42E and T206A mutations in the dehydrodolichol diphosphate synthase (DHDDS) gene, using liquid chromatography-mass spectrometry. Dolicho ... Full text Link to item Cite

Two distinct N-glycosylation pathways process the Haloferax volcanii S-layer glycoprotein upon changes in environmental salinity.

Journal Article mBio · November 5, 2013 UNLABELLED: N-glycosylation in Archaea presents aspects of this posttranslational modification not seen in either Eukarya or Bacteria. In the haloarchaeon Haloferax volcanii, the surface (S)-layer glycoprotein can be simultaneously modified by two differen ... Full text Link to item Cite

Crystal structure of MraY, an essential membrane enzyme for bacterial cell wall synthesis.

Journal Article Science · August 30, 2013 MraY (phospho-MurNAc-pentapeptide translocase) is an integral membrane enzyme that catalyzes an essential step of bacterial cell wall biosynthesis: the transfer of the peptidoglycan precursor phospho-MurNAc-pentapeptide to the lipid carrier undecaprenyl ph ... Full text Link to item Cite

Daptomycin-resistant Enterococcus faecalis diverts the antibiotic molecule from the division septum and remodels cell membrane phospholipids.

Journal Article mBio · July 23, 2013 UNLABELLED: Treatment of multidrug-resistant enterococci has become a challenging clinical problem in hospitals around the world due to the lack of reliable therapeutic options. Daptomycin (DAP), a cell membrane-targeting cationic antimicrobial lipopeptide ... Full text Link to item Cite

The polar lipids of Clostridium psychrophilum, an anaerobic psychrophile.

Journal Article Biochim Biophys Acta · June 2013 We have examined the polar lipids of Clostridium psychrophilum, a recently characterized psychrophilic Clostridium isolated from an Antarctic microbial mat. Lipids were extracted from cells grown near the optimal growth temperature (+5°C) and at -5°C, and ... Full text Link to item Cite

An ethanolamine-phosphate modified glycolipid in Clostridium acetobutylicum that responds to membrane stress.

Journal Article Biochim Biophys Acta · June 2013 Two phosphorus-containing glycolipids have previously been observed in Clostridium acetobutylicum. We had shown that the concentration of one of them increases in response to increased unsaturation of the membrane lipid hydrocarbon chains, suggesting a pot ... Full text Link to item Cite

The outer surface lipoprotein VolA mediates utilization of exogenous lipids by Vibrio cholerae.

Journal Article mBio · May 14, 2013 UNLABELLED: Previous work from our laboratory showed that the Gram-negative aquatic pathogen Vibrio cholerae can take up a much wider repertoire of fatty acids than other Gram-negative organisms. The current work elaborated on the ability of V. cholerae to ... Full text Link to item Cite

Agrobacteria lacking ornithine lipids induce more rapid tumour formation.

Journal Article Environ Microbiol · March 2013 Ornithine lipids (OLs) are phosphorus-free membrane lipids that are widespread among Gram-negative bacteria. Their basic structure consists of a 3-hydroxy fatty acyl group attached in amide linkage to the α-amino group of ornithine and a second fatty acyl ... Full text Link to item Cite

Lipid modification gives rise to two distinct Haloferax volcanii S-layer glycoprotein populations.

Journal Article Biochim Biophys Acta · March 2013 The S-layer glycoprotein is the sole component of the protein shell surrounding Haloferax volcanii cells. The deduced amino acid sequence of the S-layer glycoprotein predicts the presence of a C-terminal membrane-spanning domain. However, several earlier o ... Full text Link to item Cite

Mutants resistant to LpxC inhibitors by rebalancing cellular homeostasis.

Journal Article J Biol Chem · February 22, 2013 LpxC, the deacetylase that catalyzes the second and committed step of lipid A biosynthesis in Escherichia coli, is an essential enzyme in virtually all gram-negative bacteria and is one of the most promising antibiotic targets for treatment of multidrug-re ... Full text Link to item Cite

AglQ is a novel component of the Haloferax volcanii N-glycosylation pathway.

Journal Article PLoS One · 2013 N-glycosylation is a post-translational modification performed by members of all three domains of life. Studies on the halophile Haloferax volcanii have offered insight into the archaeal version of this universal protein-processing event. In the present st ... Full text Link to item Cite

Negative control of mast cell degranulation and the anaphylactic response by the phosphatase lipin1.

Journal Article Eur J Immunol · January 2013 Mast cells play a critical role in the pathogenesis of allergic diseases; however, how mast cell function is regulated is still not well understood. Both phosphatidic acid (PA) and diacylglycerol (DAG) are important secondary messengers involved in mast ce ... Full text Link to item Cite

Crystal structure of MraY, an essential membrane enzyme for bacterial cell wall synthesis

Journal Article Science · 2013 MraY (phospho-MurNAc-pentapeptide translocase) is an integral membrane enzyme that catalyzes an essential step of bacterial cell wall biosynthesis: the transfer of the peptidoglycan precursor phospho-MurNAc-pentapeptide to the lipid carrier undecaprenyl ph ... Full text Cite

Discovery of a cardiolipin synthase utilizing phosphatidylethanolamine and phosphatidylglycerol as substrates.

Journal Article Proc Natl Acad Sci U S A · October 9, 2012 Depending on growth phase and culture conditions, cardiolipin (CL) makes up 5-15% of the phospholipids in Escherichia coli with the remainder being primarily phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). In E. coli, the cls and ybhO genes (r ... Full text Link to item Cite

Lipid diversity among botulinum neurotoxin-producing clostridia.

Journal Article Microbiology (Reading) · October 2012 Clostridium botulinum has been classified into four groupings (groups I to IV) based on physiological characteristics and 16S rRNA sequencing. We have examined the lipid compositions of 11 representative strains of C. botulinum and a strain of Clostridium ... Full text Link to item Cite

AglR is required for addition of the final mannose residue of the N-linked glycan decorating the Haloferax volcanii S-layer glycoprotein.

Journal Article Biochim Biophys Acta · October 2012 BACKGROUND: Recent studies of Haloferax volcanii have begun to elucidate the steps of N-glycosylation in Archaea, where this universal post-translational modification remains poorly described. In Hfx. volcanii, a series of Agl proteins catalyzes the assemb ... Full text Link to item Cite

Role of unusual P loop ejection and autophosphorylation in HipA-mediated persistence and multidrug tolerance.

Journal Article Cell Rep · September 27, 2012 HipA is a bacterial serine/threonine protein kinase that phosphorylates targets, bringing about persistence and multidrug tolerance. Autophosphorylation of residue Ser150 is a critical regulatory mechanism of HipA function. Intriguingly, Ser150 is not loca ... Full text Link to item Cite

Probing conformational changes in human DNA topoisomerase IIα by pulsed alkylation mass spectrometry.

Journal Article J Biol Chem · July 20, 2012 Type II topoisomerases are essential enzymes for solving DNA topological problems by passing one segment of DNA duplex through a transient double-strand break in a second segment. The reaction requires the enzyme to precisely control DNA cleavage and gate ... Full text Link to item Cite

A predicted geranylgeranyl reductase reduces the ω-position isoprene of dolichol phosphate in the halophilic archaeon, Haloferax volcanii.

Journal Article Biochim Biophys Acta · June 2012 In N-glycosylation in both Eukarya and Archaea, N-linked oligosaccharides are assembled on dolichol phosphate prior to transfer of the glycan to the protein target. However, whereas only the α-position isoprene subunit is saturated in eukaryal dolichol pho ... Full text Link to item Cite

Diversity in prokaryotic glycosylation: an archaeal-derived N-linked glycan contains legionaminic acid.

Journal Article Mol Microbiol · May 2012 VP4, the major structural protein of the haloarchaeal pleomorphic virus, HRPV-1, is glycosylated. To define the glycan structure attached to this protein, oligosaccharides released by β-elimination were analysed by mass spectrometry and nuclear magnetic re ... Full text Link to item Cite

Life with too much polyprenol: polyprenol reductase deficiency.

Journal Article Mol Genet Metab · April 2012 Congenital disorders of glycosylation (CDG) are caused by a dysfunction of glycosylation, an essential step in the manufacturing process of glycoproteins. This paper focuses on a 6-year-old patient with a new type of CDG-I caused by a defect of the steroid ... Full text Link to item Cite

A Mitochondrial Lipid Phosphatase in Cell Metabolism and Membrane Organization

Journal Article FASEB JOURNAL · April 1, 2012 Open Access Link to item Cite

Protein glycosylation as an adaptive response in Archaea: growth at different salt concentrations leads to alterations in Haloferax volcanii S-layer glycoprotein N-glycosylation.

Journal Article Environ Microbiol · March 2012 To cope with life in hypersaline environments, halophilic archaeal proteins are enriched in acidic amino acids. This strategy does not, however, offer a response to transient changes in salinity, as would post-translational modifications. To test this hypo ... Full text Link to item Cite

Daptomycin resistance in enterococci is associated with distinct alterations of cell membrane phospholipid content.

Journal Article PLoS One · 2012 BACKGROUND: The lipopeptide antibiotic, daptomycin (DAP) interacts with the bacterial cell membrane (CM). Development of DAP resistance during therapy in a clinical strain of Enterococcus faecalis was associated with mutations in genes encoding enzymes inv ... Full text Link to item Cite

A Mitochondrial Lipid Phosphatase in Cell Metabolism and Membrane Organization

Conference FASEB JOURNAL · 2012 Cite

Liquid chromatography/tandem mass spectrometry of dolichols and polyprenols, lipid sugar carriers across evolution.

Journal Article Biochim Biophys Acta · November 2011 Across evolution, dolichols and polyprenols serve as sugar carriers in biosynthetic processes that include protein glycosylation and lipopolysaccharide biogenesis. Liquid chromatography coupled with electrospray ionization mass spectrometry offers a powerf ... Full text Link to item Cite

Non-enzymatically derived minor lipids found in Escherichia coli lipid extracts.

Journal Article Biochim Biophys Acta · November 2011 Electrospray ionization mass spectrometry is a powerful technique to analyze lipid extracts especially for the identification of new lipid metabolites. A hurdle to lipid identification is the presence of solvent contaminants that hinder the identification ... Full text Link to item Cite

Identification of self-lipids presented by CD1c and CD1d proteins.

Journal Article J Biol Chem · October 28, 2011 The CD1 family consists of five proteins that are related to the peptide-presenting MHC class I family. T cells can recognize the presentation of both foreign and self-derived lipids on four CD1 family members. The identities of the self-lipids capable of ... Full text Link to item Cite

The thermoacidophilic archaeon Sulfolobus acidocaldarius contains an unusually short, highly reduced dolichyl phosphate.

Journal Article Biochim Biophys Acta · October 2011 Polyprenoids, polymers containing varied numbers of isoprene subunits, serve numerous roles in biology. In Eukarya, dolichyl phosphate, a phosphorylated polyprenol bearing a saturated α-end isoprene subunit, serves as the glycan carrier during N-glycosylat ... Full text Link to item Cite

Dietary isothiocyanate-induced apoptosis via thiol modification of DNA topoisomerase IIα.

Journal Article J Biol Chem · September 23, 2011 Studies in animal models have indicated that dietary isothiocyanates (ITCs) exhibit cancer preventive activities through carcinogen detoxification-dependent and -independent mechanisms. The carcinogen detoxification-independent mechanism of cancer preventi ... Full text Link to item Cite

Different routes to the same ending: comparing the N-glycosylation processes of Haloferax volcanii and Haloarcula marismortui, two halophilic archaea from the Dead Sea.

Journal Article Mol Microbiol · September 2011 Recent insight into the N-glycosylation pathway of the haloarchaeon, Haloferax volcanii, is helping to bridge the gap between our limited understanding of the archaeal version of this universal post-translational modification and the better-described eukar ... Full text Link to item Cite

Pathway for lipid A biosynthesis in Arabidopsis thaliana resembling that of Escherichia coli.

Journal Article Proc Natl Acad Sci U S A · July 12, 2011 The lipid A moiety of Escherichia coli lipopolysaccharide is a hexa-acylated disaccharide of glucosamine that makes up the outer monolayer of the outer membrane. Arabidopsis thaliana contains nuclear genes encoding orthologs of key enzymes of bacterial lip ... Full text Link to item Cite

Glyco-engineering in Archaea: differential N-glycosylation of the S-layer glycoprotein in a transformed Haloferax volcanii strain.

Journal Article Microb Biotechnol · July 2011 Archaeal glycoproteins present a variety of N-linked glycans not seen elsewhere. The ability to harness the agents responsible for this unparalleled diversity offers the possibility of generating glycoproteins bearing tailored glycans, optimized for specif ... Full text Link to item Cite

Mitochondrial phosphatase PTPMT1 is essential for cardiolipin biosynthesis.

Journal Article Cell Metab · June 8, 2011 PTPMT1 was the first protein tyrosine phosphatase found localized to the mitochondria, but its biological function was unknown. Herein, we demonstrate that whole body deletion of Ptpmt1 in mice leads to embryonic lethality, suggesting an indispensable role ... Full text Link to item Cite

Platensimycin and platencin congeners from Streptomyces platensis.

Journal Article J Nat Prod · March 25, 2011 Platensimycin (1a) and platencin (2) are inhibitors of FabF and FabF/H bacterial fatty acid synthase. The discovery of natural congeners is an approach that can render a better understanding of the structure-function relationships of complex natural produc ... Full text Link to item Cite

Hydroxylated ornithine lipids increase stress tolerance in Rhizobium tropici CIAT899.

Journal Article Mol Microbiol · March 2011 Ornithine lipids (OLs) are widespread among Gram-negative bacteria. Their basic structure consists of a 3-hydroxy fatty acyl group attached in amide linkage to the α-amino group of ornithine and a second fatty acyl group ester-linked to the 3-hydroxy posit ... Full text Link to item Cite

Structural characterization of the polar lipids of Clostridium novyi NT. Further evidence for a novel anaerobic biosynthetic pathway to plasmalogens.

Journal Article Biochim Biophys Acta · March 2011 A study of the polar lipids of Clostridium novyi NT has revealed the presence of phosphatidylethanolamine (PE) and cardiolipin as major phospholipids with smaller amounts of phosphatidylglycerol (PG), lysyl-PG and alanyl-PG. Other minor phospholipids inclu ... Full text Link to item Cite

Three phosphatidylglycerol-phosphate phosphatases in the inner membrane of Escherichia coli.

Journal Article J Biol Chem · February 18, 2011 The phospholipids of Escherichia coli consist mainly of phosphatidylethanolamine, phosphatidylglycerol (PG), and cardiolipin. PG makes up ∼25% of the cellular phospholipid and is essential for growth in wild-type cells. PG is synthesized on the inner surfa ... Full text Link to item Cite

Identification of a chloroform-soluble membrane miniprotein in Escherichia coli and its homolog in Salmonella typhimurium.

Journal Article Anal Biochem · February 15, 2011 Two homologous 29 amino acid-long highly hydrophobic membrane miniproteins were identified in the Bligh-Dyer lipid extracts of Escherichia coli and Salmonella typhimurium using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The amino acid seque ... Full text Link to item Cite

Remodelling of the Vibrio cholerae membrane by incorporation of exogenous fatty acids from host and aquatic environments.

Journal Article Mol Microbiol · February 2011 The Gram-negative bacteria Vibrio cholerae poses significant public health concerns by causing an acute intestinal infection afflicting millions of people each year. V. cholerae motility, as well as virulence factor expression and outer membrane protein pr ... Full text Link to item Cite

A mouse macrophage lipidome.

Journal Article J Biol Chem · December 17, 2010 We report the lipidomic response of the murine macrophage RAW cell line to Kdo(2)-lipid A, the active component of an inflammatory lipopolysaccharide functioning as a selective TLR4 agonist and compactin, a statin inhibitor of cholesterol biosynthesis. Ana ... Full text Link to item Cite

Distinct glycan-charged phosphodolichol carriers are required for the assembly of the pentasaccharide N-linked to the Haloferax volcanii S-layer glycoprotein.

Journal Article Mol Microbiol · December 2010 In Archaea, dolichol phosphates have been implicated as glycan carriers in the N-glycosylation pathway, much like their eukaryal counterparts. To clarify this relation, highly sensitive liquid chromatography/mass spectrometry was employed to detect and cha ... Full text Link to item Cite

Expression of functional bacterial undecaprenyl pyrophosphate synthase in the yeast rer2{Delta} mutant and CHO cells.

Journal Article Glycobiology · December 2010 During evolution the average chain length of polyisoprenoid glycosyl carrier lipids increased from C55 (prokaryotes) to C75 (yeast) to C95 (mammalian cells). In this study, the ability of the E. coli enzyme, undecaprenyl pyrophosphate synthase (UPPS), to c ... Full text Link to item Cite

Lipidomics reveals a remarkable diversity of lipids in human plasma.

Journal Article J Lipid Res · November 2010 The focus of the present study was to define the human plasma lipidome and to establish novel analytical methodologies to quantify the large spectrum of plasma lipids. Partial lipid analysis is now a regular part of every patient's blood test and physician ... Full text Link to item Cite

AglJ adds the first sugar of the N-linked pentasaccharide decorating the Haloferax volcanii S-layer glycoprotein.

Journal Article J Bacteriol · November 2010 Like the Eukarya and Bacteria, the Archaea also perform N glycosylation. Using the haloarchaeon Haloferax volcanii as a model system, a series of Agl proteins involved in the archaeal version of this posttranslational modification has been identified. In t ... Full text Link to item Cite

Distinct granuloma responses in C57BL/6J and BALB/cByJ mice in response to pristane.

Journal Article Int J Exp Pathol · October 2010 Granuloma formation is an inflammatory response of the host against invading pathogens or indigestible substances. We generated mesenteric oil granulomas by injecting pristane into the peritoneal cavity (PC) of mice, and compared oil granuloma formation in ... Full text Link to item Cite

Subcellular organelle lipidomics in TLR-4-activated macrophages.

Journal Article J Lipid Res · September 2010 Lipids orchestrate biological processes by acting remotely as signaling molecules or locally as membrane components that modulate protein function. Detailed insight into lipid function requires knowledge of the subcellular localization of individual lipids ... Full text Link to item Cite

Plasticity of lipid-protein interactions in the function and topogenesis of the membrane protein lactose permease from Escherichia coli.

Journal Article Proc Natl Acad Sci U S A · August 24, 2010 Phosphatidylcholine (PC) has been widely used in place of naturally occurring phosphatidylethanolamine (PE) in reconstitution of bacterial membrane proteins. However, PC does not support native structure or function for several reconstituted transport prot ... Full text Link to item Cite

SRD5A3 is required for converting polyprenol to dolichol and is mutated in a congenital glycosylation disorder.

Journal Article Cell · July 23, 2010 N-linked glycosylation is the most frequent modification of secreted and membrane-bound proteins in eukaryotic cells, disruption of which is the basis of the congenital disorders of glycosylation (CDGs). We describe a new type of CDG caused by mutations in ... Full text Link to item Cite

Molecular characterization of the cis-prenyltransferase of Giardia lamblia.

Journal Article Glycobiology · July 2010 Giardia lamblia, the protist that causes diarrhea, makes an Asn-linked-glycan (N-glycan) precursor that contains just two sugars (GlcNAc(2)) attached by a pyrophosphate linkage to a polyprenol lipid. Because the candidate cis-prenyltransferase of Giardia a ... Full text Link to item Cite

A phosphoethanolamine-modified glycosyl diradylglycerol in the polar lipids of Clostridium tetani.

Journal Article J Lipid Res · July 2010 The polar lipids of the anaerobic bacterium Clostridium tetani, the causative agent of tetanus, have been examined by two-dimensional thin layer chromatography, ESI mass spectrometry, and NMR spectroscopy. Plasmalogen and di- and tetra-acylated species of ... Full text Link to item Cite

Application of electrospray ionization mass spectrometry to characterize glycerophospholipids in Francisella tularensis subsp. novicida

Journal Article International Journal of Mass Spectrometry · April 27, 2010 Francisella tularensis is a highly infectious human pathogen that can cause tularemia, but little is known about the lipid composition in membranes of this bacterium. Our recent study has shown that lipid A in membranes of F. tularensis subsp. novicida is ... Full text Cite

Application of proteomic marker ensembles to subcellular organelle identification.

Journal Article Mol Cell Proteomics · February 2010 Compartmentalization of biological processes and the associated cellular components is crucial for cell function. Typically, the location of a component is revealed through a co-localization and/or co-purification with an organelle marker. Therefore, the i ... Full text Link to item Cite

Sinorhizobium meliloti phospholipase C required for lipid remodeling during phosphorus limitation.

Journal Article Proc Natl Acad Sci U S A · January 5, 2010 Rhizobia are Gram-negative soil bacteria able to establish nitrogen-fixing root nodules with their respective legume host plants. Besides phosphatidylglycerol, cardiolipin, and phosphatidylethanolamine, rhizobial membranes contain phosphatidylcholine (PC) ... Full text Link to item Cite

Isolation, structure and biological activities of platensimycin B4 from Streptomyces platensis.

Journal Article J Antibiot (Tokyo) · December 2009 Platensimycin and platencin are inhibitors of FabF and FabF/H bacterial fatty acid synthesis enzymes, respectively. Discovery of natural congeners provides one of the ways to understand the relationship of chemical structure and biological function. Effort ... Full text Link to item Cite

Cardiolipin and the osmotic stress responses of bacteria.

Journal Article Biochim Biophys Acta · October 2009 Cells control their own hydration by accumulating solutes when they are exposed to high osmolality media and releasing solutes in response to osmotic down-shocks. Osmosensory transporters mediate solute accumulation and mechanosensitive channels mediate so ... Full text Link to item Cite

Discovering novel brain lipids by liquid chromatography/tandem mass spectrometry.

Journal Article J Chromatogr B Analyt Technol Biomed Life Sci · September 15, 2009 Discovery and structural elucidation of novel brain lipids hold great promise in revealing new lipid functions in the brain and in understanding the biochemical mechanisms underlying brain physiology and pathology. The revived interests in searching for no ... Full text Link to item Cite

Correction to uridine-based inhibitors as new leads for antibiotics targeting Escherichia coli LpxC (Biochemistry (2009) 48, (3068) DOI: 10.1021/bi900167q)

Journal Article Biochemistry · August 18, 2009 Full text Cite

A eukaryote-like cardiolipin synthase is present in Streptomyces coelicolor and in most actinobacteria.

Journal Article J Biol Chem · June 26, 2009 Cardiolipin (CL) is an anionic membrane lipid present in bacteria, plants, and animals, but absent from archaea. It is generally thought that bacteria use an enzyme belonging to the phospholipase D superfamily as cardiolipin synthase (Cls) catalyzing a rev ... Full text Link to item Cite

Uridine-based inhibitors as new leads for antibiotics targeting Escherichia coli LpxC.

Journal Article Biochemistry · April 14, 2009 The UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase LpxC catalyzes the committed reaction of lipid A (endotoxin) biosynthesis in Gram-negative bacteria and is a validated antibiotic target. Although several previously described compounds bind to ... Full text Link to item Cite

Discovery of new biosynthetic pathways: the lipid A story.

Journal Article J Lipid Res · April 2009 The outer monolayer of the outer membrane of Gram-negative bacteria consists of the lipid A component of lipopolysaccharide (LPS), a glucosamine-based saccharolipid that is assembled on the inner surface of the inner membrane. The first six enzymes of the ... Full text Link to item Cite

Identification of undecaprenyl phosphate-beta-D-galactosamine in Francisella novicida and its function in lipid A modification.

Journal Article Biochemistry · February 17, 2009 Francisella tularensis is a highly infectious pathogen that causes tularemia. Francisella lipid A contains an unusual galactosamine (GalN) unit, attached to its 1-phosphate moiety. Two genes, flmF2 and flmK, are required for the addition of GalN to Francis ... Full text Link to item Cite

Biosynthesis of undecaprenyl phosphate-galactosamine and undecaprenyl phosphate-glucose in Francisella novicida.

Journal Article Biochemistry · February 17, 2009 Lipid A of Francisella tularensis subsp. novicida contains a galactosamine (GalN) residue linked to its 1-phosphate group. As shown in the preceding paper, this GalN unit is transferred to lipid A from the precursor undecaprenyl phosphate-beta-D-GalN. A sm ... Full text Link to item Cite

Purification and mutagenesis of LpxL, the lauroyltransferase of Escherichia coli lipid A biosynthesis.

Journal Article Biochemistry · August 19, 2008 Escherichia coli lipid A is a hexaacylated disaccharide of glucosamine with secondary laurate and myristate chains on the distal unit. Hexaacylated lipid A is a potent agonist of human Toll-like receptor 4, whereas its tetra- and pentaacylated precursors a ... Full text Link to item Cite

Dolichyl-phosphate-glucose is used to make O-glycans on glycoproteins of Trichomonas vaginalis.

Journal Article Eukaryot Cell · August 2008 Trichomonas vaginalis, the protist that causes vaginal itching, has a huge genome with numerous gene duplications. Recently we found that Trichomonas has numerous genes encoding putative dolichyl-phosphate-glucose (Dol-P-Glc) synthases (encoded by ALG5 gen ... Full text Link to item Cite

Phosphorylation analysis of G protein-coupled receptor by mass spectrometry: identification of a phosphorylation site in V2 vasopressin receptor.

Journal Article Anal Chem · August 1, 2008 Phosphorylation plays vital roles in the regulation and function of the V2 vasopressin receptor (V2R), a G protein-coupled receptor (GPCR) that is responsible for maintaining water homeostasis in the kidney. Through a combination of immunoaffinity purifica ... Full text Link to item Cite

Mechanistic studies of eukaryotic topoisomerase II: a cysteine footprinting and FRET approach

Conference FASEB JOURNAL · April 1, 2008 Link to item Cite

An inner membrane dioxygenase that generates the 2-hydroxymyristate moiety of Salmonella lipid A.

Journal Article Biochemistry · March 4, 2008 The lipid A residues of certain Gram-negative bacteria, including most strains of Salmonella and Pseudomonas, are esterified with one or two secondary S-2-hydroxyacyl chains. The S-2 hydroxylation process is O 2-dependent in vivo, but the relevant enzymati ... Full text Link to item Cite

Identification of N-acylphosphatidylserine molecules in eukaryotic cells.

Journal Article Biochemistry · December 18, 2007 While profiling the lipidome of the mouse brain by mass spectrometry, we discovered a novel family of N-acylphosphatidylserine (N-acyl-PS) molecules. These N-acyl-PS species were enriched by DEAE-cellulose column chromatography, and they were then characte ... Full text Link to item Cite

An undecaprenyl phosphate-aminoarabinose flippase required for polymyxin resistance in Escherichia coli.

Journal Article J Biol Chem · December 7, 2007 Modification of lipid A with the 4-amino-4-deoxy-L-arabinose (L-Ara4N) moiety is required for resistance to polymyxin and cationic antimicrobial peptides in Escherichia coli and Salmonella typhimurium. An operon of seven genes (designated pmrHFIJKLM in S. ... Full text Link to item Cite

The lipid lysyl-phosphatidylglycerol is present in membranes of Rhizobium tropici CIAT899 and confers increased resistance to polymyxin B under acidic growth conditions.

Journal Article Mol Plant Microbe Interact · November 2007 Lysyl-phosphatidylglycerol (LPG) is a well-known membrane lipid in several gram-positive bacteria but is almost unheard of in gram-negative bacteria. In Staphylococcus aureus, the gene product of mprF is responsible for LPG formation. Low pH-inducible gene ... Full text Link to item Cite

Isolation, structure, and coccidiostat activity of coccidiostatin A.

Journal Article J Nat Prod · August 2007 Coccidiosis is one of the more common and costly diseases in poultry that is caused by various Eimeria species. In our quest to discover coccidiostats from natural products, we discovered a microbial fermentation extract that exhibited in vivo anticoccidia ... Full text Link to item Cite

The active conformation of beta-arrestin1: direct evidence for the phosphate sensor in the N-domain and conformational differences in the active states of beta-arrestins1 and -2.

Journal Article J Biol Chem · July 20, 2007 beta-Arrestins are multifunctional adaptor proteins that regulate seven transmembrane-spanning receptor (7TMR) desensitization and internalization and also initiate alternative signaling pathways. Studies have shown that beta-arrestins undergo a conformati ... Full text Link to item Cite

Identification and quantification of dolichol and dolichoic acid in neuromelanin from substantia nigra of the human brain.

Journal Article J Lipid Res · July 2007 Neuromelanin (NM) isolated from the substantia nigra of the human brain is found to contain a series of dolichoic acids (dol-CA) containing 14-20 isoprene units. This is the first observation of dol-CA in a natural system. Using internally spiked nor-dolic ... Full text Link to item Cite

Attenuated virulence of a Francisella mutant lacking the lipid A 4'-phosphatase.

Journal Article Proc Natl Acad Sci U S A · March 6, 2007 Francisella tularensis causes tularemia, a highly contagious disease of animals and humans, but the virulence features of F. tularensis are poorly defined. F. tularensis and the related mouse pathogen Francisella novicida synthesize unusual lipid A molecul ... Full text Link to item Cite

Analysis of ubiquinones, dolichols, and dolichol diphosphate-oligosaccharides by liquid chromatography-electrospray ionization-mass spectrometry.

Journal Article Methods Enzymol · 2007 Prenols, a class of lipids formed by the condensation of five carbon isoprenoids, have important roles in numerous metabolic pathways of the eukaryotic cell. Prenols are found in the cell as free alcohols, such as dolichol, or can be attached to vitamins, ... Full text Link to item Cite

Modification of cysteine 111 in human Cu,Zn-superoxide dismutase.

Journal Article Free Radic Biol Med · December 15, 2006 Human Cu,Zn-superoxide dismutase (hSOD1) has 4 cysteines per subunit. Cys57 and Cys148 are involved in an intrasubunit disulfide bond, while Cys6 and Cys111 are free. Cys6 is buried within the protein while Cys111 is on the surface, near the dimer interfac ... Full text Link to item Cite

Structure and biosynthesis of free lipid A molecules that replace lipopolysaccharide in Francisella tularensis subsp. novicida.

Journal Article Biochemistry · December 5, 2006 Francisella tularensis subsp. novicida U112 phospholipids, extracted without hydrolysis, consist mainly of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and two lipid A species, designated A1 and A2. These lipid A species, present in ... Full text Link to item Cite

Electron capture dissociation mass spectrometry in characterization of peptides and proteins.

Journal Article Biotechnol Lett · July 2006 Electron capture dissociation (ECD) represents one of the most recent and significant advancements in tandem mass spectrometry (MS/MS) for the identification and characterization of polypeptides. In comparison with the conventional fragmentation techniques ... Full text Link to item Cite

Expression cloning of three Rhizobium leguminosarum lipopolysaccharide core galacturonosyltransferases.

Journal Article J Biol Chem · May 5, 2006 The lipid A and core regions of the lipopolysaccharide in Rhizobium leguminosarum, a nitrogen-fixing plant endosymbiont, are strikingly different from those of Escherichia coli. In R. leguminosarum lipopolysaccharide, the inner core is modified with three ... Full text Link to item Cite

Isolation and insecticidal/anthelmintic activity of xanthonol, a novel bis-xanthone, from a non-sporulating fungal species.

Journal Article J Antibiot (Tokyo) · May 2006 Xanthonol, a novel dimeric xanthone, was isolated from a fermentation broth of a non-sporulating fungal species using Sephadex LH20 followed by HPLC and the structure elucidated by spectral analysis. Xanthonol exhibited insecticidal and anthelmintic activi ... Full text Link to item Cite

Highly substituted terphenyls as inhibitors of parasite cGMP-dependent protein kinase activity.

Journal Article J Nat Prod · April 2006 Parasite cGMP-dependent protein kinase (PKG) is one of the validated biochemical targets for the treatment of coccidiosis. We screened our library of natural product extracts for inhibitors of parasite PKG for the discovery of anticoccidial leads. Terferol ... Full text Link to item Cite

Conformational changes in beta-arrestin1: The importance of beta-arrestin1's N-domain

Conference FASEB JOURNAL · March 6, 2006 Link to item Cite

Identification of candidate substrates for ectodomain shedding by the metalloprotease-disintegrin ADAM8.

Journal Article Biol Chem · March 2006 ADAM proteases are type I transmembrane proteins with extracellular metalloprotease domains. As for most ADAM family members, ADAM8 (CD156a, MS2) is involved in ectodomain shedding of membrane proteins and is linked to inflammation and neurodegeneration. T ... Full text Link to item Cite

A slow, tight-binding inhibitor of the zinc-dependent deacetylase LpxC of lipid A biosynthesis with antibiotic activity comparable to ciprofloxacin.

Journal Article Biochemistry · December 20, 2005 The zinc-dependent enzyme LpxC catalyzes the deacetylation of UDP-3-O-acyl-GlcNAc, the first committed step of lipid A biosynthesis. Lipid A is an essential component of the outer membranes of most Gram-negative bacteria, including Escherichia coli, Salmon ... Full text Link to item Cite

Solution structure of the Set2-Rpb1 interacting domain of human Set2 and its interaction with the hyperphosphorylated C-terminal domain of Rpb1.

Journal Article Proc Natl Acad Sci U S A · December 6, 2005 The phosphorylation state of the C-terminal repeat domain (CTD) of the largest subunit of RNA polymerase II changes as polymerase transcribes a gene, and the distinct forms of the phospho-CTD (PCTD) recruit different nuclear factors to elongating polymeras ... Full text Link to item Cite

New fungal metabolite geranylgeranyltransferase inhibitors with antifungal activity.

Journal Article Nat Prod Res · December 2005 Geranylgeranyltransferase I (GGTase I) catalyzes the post-translational transfer of lyophilic diterpenoid geranylgeranyl to the cysteine residue of proteins terminating with a CaaX motif such as Rho1p and Cdc42p. It has been shown that GGTase I activity is ... Full text Link to item Cite

A new method for the synthesis of 1,4,5-oxadiazocines and its application in the structure modification of natural products

Journal Article Tetrahedron Letters · November 14, 2005 A new method for the synthesis of eight-membered heterocyclic 1,4,5-oxadiazocines has been described from β-diketone and β,β,β-triketone with an acidic α-hydrogen. The method entails the reaction of a di- or triketone with 2-hydroxyethylhydrazine and an al ... Full text Cite

Isolation and structures of novel fungal metabolites as chemokine receptor (CCR2) antagonists.

Journal Article J Antibiot (Tokyo) · November 2005 The chemokine receptor, CCR2, is predominantly expressed on monocytes/macrophages, and on a subset of memory T cells. It binds to several CC type chemokines of the monocyte chemoattractant protein (MCP) family of which MCP-1 exhibits the highest affinity. ... Full text Link to item Cite

Extraction and identification by mass spectrometry of undecaprenyl diphosphate-MurNAc-pentapeptide-GlcNAc from Escherichia coli.

Journal Article Anal Biochem · October 15, 2005 Undecaprenyl diphosphate-MurNAc-pentapeptide-GlcNAc (lipid II) is extracted from Escherichia coli cells by utilizing its unusual pH-dependent solubility property in a Bligh-Dyer system, and identified by electrospray ionization mass spectrometry in conjunc ... Full text Link to item Cite

Anthrabenzoxocinones from Streptomyces sp. as liver X receptor ligands and antibacterial agents.

Journal Article J Nat Prod · September 2005 Liver X receptors (LXR) are nuclear hormone receptors that play a critical role in cholesterol homeostasis. They regulate the expression of the ABCA1 gene, which mediates the efflux of cholesterol out of cells. LXR agonists are expected to increase cholest ... Full text Link to item Cite

Steroidal and triterpenoidal fungal metabolites as ligands of liver X receptors.

Journal Article J Antibiot (Tokyo) · September 2005 Cholesterol homeostasis is tightly controlled process that involves a variety of regulators including liver X receptors (LXR). Agonists of LXR are expected to increase cholesterol efflux, lower LDL, and raise HDL levels. Screening of a natural product libr ... Full text Link to item Cite

Electron capture dissociation mass spectrometry in characterization of post-translational modifications.

Journal Article Biochem Biophys Res Commun · August 19, 2005 Electron capture dissociation (ECD) represents a significant advance in tandem mass spectrometry for the identification and characterization of post-translational modifications (PTMs) of polypeptides. In comparison with the conventional fragmentation techn ... Full text Link to item Cite

Diterpenoid, steroid, and triterpenoid agonists of liver X receptors from diversified terrestrial plants and marine sources.

Journal Article J Nat Prod · August 2005 It has been demonstrated that liver X receptors (LXR) play a significant role in cholesterol homeostasis. Agonists of LXR are expected to increase cellular cholesterol efflux, lower LDL, and raise HDL levels. Screening of a natural product library of plant ... Full text Link to item Cite

Guttiferone I, a new prenylated benzophenone from Garcinia humilis as a liver X receptor ligand.

Journal Article J Nat Prod · April 2005 Liver X receptors (LXR) have been implicated in cholesterol homeostasis. Agonists of LXR are expected to increase cholesterol efflux, lower LDL, and raise HDL levels. Screening of a natural product library of plant extracts using a LXR-SPA binding assay an ... Full text Link to item Cite

Tenellones A and B from a Diaporthe sp.: two highly substituted benzophenone inhibitors of parasite cGMP-dependent protein kinase activity.

Journal Article J Nat Prod · April 2005 Parasite cGMP-dependent protein kinase (PKG) has been recently validated as a biochemical target for the treatment of coccidiosis. To discover new anticoccidial leads, we have screened our library of natural product extracts for inhibitors of parasite PKG. ... Full text Link to item Cite

Modulation of human nuclear receptor LRH-1 activity by phospholipids and SHP.

Journal Article Nat Struct Mol Biol · April 2005 The human nuclear receptor liver receptor homolog 1 (hLRH-1) plays an important role in the development of breast carcinomas. This orphan receptor is efficiently downregulated by the unusual co-repressor SHP and has been thought to be ligand-independent. W ... Full text Link to item Cite

Kinetic analysis of the zinc-dependent deacetylase in the lipid A biosynthetic pathway.

Journal Article Biochemistry · February 1, 2005 The first committed step of lipid A biosynthesis in Gram-negative bacteria is catalyzed by the zinc-dependent hydrolase LpxC that removes an acetate from the nitrogen at the 2' '-position of UDP-3-O-acyl-N-acetylglucosamine. Recent structural characterizat ... Full text Link to item Cite

Discovery of structurally diverse natural product antagonists of chemokine receptor CXCR3.

Journal Article Mol Divers · 2005 The chemokines (CXCL9, CXCL10 and CXCL11) and associated CXCR3 receptor are expressed during the inflammatory process from multiple sclerosis, atherosclerosis or organ transplantation resulting in the recruitment of lymphocytes leading to tissue damage. It ... Full text Link to item Cite

Isolation and structure of antagonists of chemokine receptor (CCR5).

Journal Article J Nat Prod · June 2004 Human CCR5 is a G-coupled receptor that binds to the envelope protein gp120 and CD4 and mediates the HIV-1 viral entry into the cells. The blockade of this binding by a small molecule receptor antagonist could lead to a new mode of action agent for HIV-1 a ... Full text Link to item Cite

Application and Study of Fine-silty Sand Control Technique for Unconsolidation Quaternary Sand Gas Reservoir, Sebei Qinghai

Conference SPE International Formation Damage Control Symposium Proceedings · May 12, 2004 Sebei Gas Field is in the northeast of Caidam Basin, Qinghai, China. Its main pay-zone is unconsolidation quaternary fine-silty and dirty sandstones with serious sand production. A series of technique of comprehensive sand control with fiber-resin coated s ... Cite

Isolation, structure, absolute stereochemistry, and HIV-1 integrase inhibitory activity of integrasone, a novel fungal polyketide.

Journal Article J Nat Prod · May 2004 HIV-1 integrase is a critical enzyme for replication of HIV, and its inhibition is one of the most promising new drug targets for anti-retroviral therapy with potentially significant advantages over existing therapies. In this Note, the isolation, structur ... Full text Link to item Cite

Application and Study of Fine-silty Sand Control Technique for Unconsolidation Quaternary Sand Gas Reservoir, Sebei Qinghai

Conference SPE International Formation Damage Control Symposium Proceedings · January 1, 2004 Full text Cite

Isolation, structure, and HIV-1-integrase inhibitory activity of structurally diverse fungal metabolites.

Journal Article J Ind Microbiol Biotechnol · December 2003 HIV-1 integrase is a critical enzyme for replication of HIV, and its inhibition is one of the most promising new drug strategies for anti-retroviral therapy, with potentially significant advantages over existing therapies. In this report, a series of HIV-1 ... Full text Link to item Cite

Isolation, Structure, and HIV-1 Integrase Inhibitory Activity of Xanthoviridicatin E and F, Two Novel Fungal Metabolites Produced by Penicillium chrysogenum

Journal Article Helvetica Chimica Acta · November 20, 2003 HIV-1 Integrase is a critical enzyme for replication of HIV, and its inhibition is one of the most promising new drug targets for anti-retroviral therapy with potentially significant advantages over existing therapies. Xanthoviridicatins E (1) and F (2) ar ... Full text Cite

Detection and characterization of methionine oxidation in peptides by collision-induced dissociation and electron capture dissociation.

Journal Article J Am Soc Mass Spectrom · June 2003 Electron capture dissociation (ECD) and collision-induced dissociation (CID), the two complementary fragmentation techniques, are demonstrated to be effective in the detection and localization of the methionine sulfoxide [Met(O)] residues in peptides using ... Full text Link to item Cite

Isolation and insecticidal activity of mellamide from Aspergillus melleus.

Journal Article J Ind Microbiol Biotechnol · April 2003 Mellamide, a novel indole amide, was isolated from a fermentation of Aspergillus melleus using silica gel and high-performance liquid chromatographic methods. This allowed its separation from three known antiparasitic compounds (ochratoxin A, viomellin and ... Full text Link to item Cite

Isolation, structure, and HIV-1 integrase inhibitory activity of Cytosporic acid, a fungal metabolite produced by a Cytospora sp.

Journal Article J Nat Prod · April 2003 HIV-1 integrase is a critical enzyme for replication of HIV, and its inhibition has the potential to lead to an anti-retroviral therapy that has advantages over existing therapies. Cytosporic acid (1) is a polyketide-derived novel natural product that was ... Full text Link to item Cite

The unanticipated loss of SO2 from sulfonamides in collision-induced dissociation.

Journal Article Rapid Commun Mass Spectrom · 2003 A potent and selective sulfonamide beta3 agonist with an excellent pharmacokinetic profile has recently been synthesized. During the analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS) of metabolites of the sulfonamide N-[4-[2-(2-hydroxy- ... Full text Link to item Cite

Identification and localization of the fatty acid modification in ghrelin by electron capture dissociation.

Journal Article J Am Soc Mass Spectrom · December 2002 Electron capture dissociation (ECD) has been demonstrated to be an effective fragmentation technique for characterizing the site and structure of the fatty acid modification in ghrelin, a 28-residue growth-hormone-releasing peptide that has an unusual este ... Full text Link to item Cite

Localization and characterization of peptide acylation with Ester linkage by electron capture dissociation FTICR/MS

Journal Article Proceedings 50th ASMS Conference on Mass Spectrometry and Allied Topics · December 1, 2002 The localization and characterization of peptide acylation with ester linkage by electron capture dissociation FTICR/MS were discussed. The electron capture dissociation (ECD) FTICR/MS were applied to ghrelin, a 28-residue acylated growth-hormone-releasing ... Cite

Durhamycin A, a potent inhibitor of HIV Tat transactivation.

Journal Article J Nat Prod · August 2002 Tat is a small HIV protein essential for both viral replication and the progression of HIV disease. In our efforts to discover Tat inhibitors from natural product screening of microbial fermentation extracts, we discovered durhamycin A (1) as a potent inhi ... Full text Link to item Cite

Integramides A and B, two novel non-ribosomal linear peptides containing nine C(alpha)-methyl amino acids produced by fungal fermentations that are inhibitors of HIV-1 integrase.

Journal Article Org Lett · May 2, 2002 [structure: see text]. Integramides A and B are two novel 16-mer linear peptides rich in C(alpha)-methyl amino acids that were isolated from fungal extracts of Dendrodochium sp. by employing a bioassay-guided isolation procedure using recombinant HIV-1 int ... Full text Link to item Cite

Enzymatic deglycosylation of enfumafungin, a triterpene glycoside natural product, and its chemically synthesized analogues

Journal Article Journal of Molecular Catalysis - B Enzymatic · November 20, 2001 A panel of 27 commercial enzymes was screened for the deglycosylation of a triterpene glycoside (enfumafungin), an antifungal natural product with a novel mechanism of action that bears an ester, a hemi-acetal and a carboxylic acid functionalities in its s ... Full text Cite

Solvation of acylium fragment ions in electrospray ionization quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry.

Journal Article J Mass Spectrom · March 2001 In electrospray ionization (ESI) quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry, certain fragment ions (e.g. acylium ions) generated either during the ion transportation process (in the source interface region) or in th ... Full text Link to item Cite

Isolation and structure elucidation of coleophomones A and B, novel inhibitors of bacterial cell wall transglycosylase

Journal Article Tetrahedron Letters · November 4, 2000 The discovery, structure and absolute stereochemistry of coleophomones A and B are described, two structurally novel natural products that inhibit bacterial transglycosylase activity. Coleophomone A represents a new ring system, containing a highly condens ... Full text Cite

Gaseous conformational structures of cytochrome c

Journal Article Journal of the American Chemical Society · May 20, 1998 Solution folding of a protein removes major sections of it from their aqueous environment. Complete removal, by forming water-free gaseous protein ions with electrospray ionization/mass spectrometry, profoundly changes the conformation of cytochrome c. Of ... Full text Cite

Creatine kinase: essential arginine residues at the nucleotide binding site identified by chemical modification and high-resolution tandem mass spectrometry.

Journal Article Proc Natl Acad Sci U S A · March 31, 1998 Phenylglyoxal is an arginine-specific reagent that inactivates creatine kinase (CK). Previous results suggest that modification of the dimeric enzyme at a single arginine residue per subunit causes complete inactivation accompanied by the loss of nucleotid ... Full text Link to item Cite

DNA sequencing with blackbody infrared radiative dissociation of electrosprayed ions

Journal Article International Journal of Mass Spectrometry and Ion Processes · January 1, 1997 As shown by Williams for positive multiply-charged ions, negative electrosprayed ions trapped in a Fourier-transform ion cyclotron resonance mass spectrometer can be dissociated efficiently with BIRD. For a 50-mer DNA, an ion cell wall temperature of 90°C ... Full text Cite

Double stranded DNA sequencing by tandem mass spectrometry

Journal Article International Journal of Mass Spectrometry and Ion Processes · January 1, 1997 Electrospray ionization produces far more abundant molecular ions for double stranded (ds) DNA than for single stranded (ss) and accurate molecular masses can provide the base composition of dsDNA. This study shows that the Fourier-transform mass spectra o ... Full text Cite

Broadband quadrupolar axialization of large multiply charged ions to enhance measurement and minimize conformational restrictions.

Journal Article J Mass Spectrom · May 1996 For high-resolution Fourier transform mass spectrometry of electrosprayed proteins, the signal-to-noise ratio of measuring nozzle-skimmer fragment ions can be improved substantially by their broadband quadrupolar axialization (QA), even without increasing ... Full text Link to item Cite

193 nm photodissociation of larger multiply-charged biomolecules

Journal Article International Journal of Mass Spectrometry and Ion Processes · January 1, 1996 In contrast to most ion dissociation methods, 193 nm ultraviolet photodissociation of electrosprayed melittin (2.8 kDa) and ubiquitin (8.6 kDa) molecular ions yields new c and z ions (backbone amine bond dissociation) that provide additional sequence infor ... Full text Cite

High performance detection of biomolecules using a high magnetic field electrospray ionization source/Fourier transform ion cyclotron resonance mass spectrometer

Journal Article Review of Scientific Instruments · December 1, 1995 An improved, high-performance version of the concentric vacuum chamber design is shown for forming ions at high pressure in a strong magnetic field and detecting them in an adjacent Fourier transform ion cyclotron resonance mass spectrometry (FTICR) trappe ... Full text Cite

Real-time monitoring of the gas phase reactions of a single ion population using the remeasurement experiment in Fourier transform ion cyclotron resonance mass spectrometry.

Journal Article Anal Chem · April 15, 1995 A single population of multiply charged protein ions formed by electrospray ionization is held in a trapped ion cell and remeasured continuously by Fourier transform ion cyclotron resonance (FTICR) mass spectrometry while undergoing multiple reactions with ... Full text Link to item Cite

Cell geometry considerations for the Fourier transform ion cyclotron resonance mass spectrometry remeasurement experiment.

Journal Article Anal Chem · January 15, 1995 Three cell geometries, closed cubic, closed elongated, and open elongated, are evaluated for optimum remeasurement performance in the Fourier transform ion cyclotron resonance mass spectrometry (FTICR) experiment. The advantages and disadvantages of each c ... Full text Link to item Cite

Remeasurement at high resolving power in fourier transform ion cyclotron resonance mass spectrometry

Journal Article Journal of the American Society for Mass Spectrometry · January 1, 1995 The Fourier transform ion cyclotron resonance mass spectrometry remeasurement experiment is demonstrated and evaluated under high resolution conditions. Signal-to-noise enhancement is observed for isotopically resolved bovine insulin peaks at a resolution ... Full text Cite

Charge state assignment from schiff‐base adducts in low resolution electrospray mass spectra of protein mixtures and dissociation products

Journal Article Journal of Mass Spectrometry · January 1, 1995 Schiff‐bases formed by reaction between ketones and free amine sites in proteins yield mass‐shifted ions that are useful in assigning charge states in low resolution electrospray ionization mass spectra of mixtures and dissociation products. The technique ... Full text Cite

Selective generation of charge-cependent/independent ion energy distributions from a heated capillary electrospray source

Journal Article Journal of the American Society for Mass Spectrometry · January 1, 1994 Retarding grid and Fourier transform ion cyclotron resonance (FTICR) mass spectrometry variable trap potential measurements are performed to determine factors that contribute to the kinetic energy distribution of ions formed in an electrospray source that ... Full text Cite

Remeasurement of electrosprayed proteins in the trapped ion cell of a Fourier transform ion cyclotron resonance mass spectrometer.

Journal Article Anal Chem · June 1, 1993 A single population of multiply charged protein ions formed by electrospray ionization (ESI) is subjected to multiple Fourier transform ion cyclotron resonance (FTICR) excitation and detection events without promoting ion loss from the trapped ion cell. Th ... Full text Link to item Cite

Concentric tube vacuum chamber for high magnetic field, high-pressure ionization in a fourier transform ion cyclotron resonance mass spectrometer

Journal Article Journal of the American Society for Mass Spectrometry · January 1, 1993 A new differential pumping design for external source Fourier transform ion cyclotron resonance mass spectrometry is described. A network of concentric tubes of increasing diameter terminates at a series of conductance limits across which a pressure from a ... Full text Cite

Electrochemistry of C60 films: Quartz crystal microbalance and mass spectrometric studies

Journal Article Journal of Physical Chemistry · January 1, 1992 The incorporation of tetra-n-butylammonium (TBA+) upon electroreduction of films of C60 on an electrode in MeCN solutions was studied by electrochemical quartz crystal microbalance (EQCM) and laser desorption mass spectrometry (LDMS) methods. EQCM allowed ... Full text Cite