Scholars@Duke
Robert David Stevens

Robert David Stevens

Adjunct Assistant Professor of Medicine
Medicine, Endocrinology, Metabolism, and Nutrition
steve018@mc.duke.edu
Box 104775, Rm 47-205, 300 N. Duke Street, Durham, NC 27701
300 N. Duke Street, 47-205, Durham, NC 27701

Selected Publications

Cord Blood Metabolomics: Association With Newborn Anthropometrics and C-Peptide Across Ancestries.

Journal Article J Clin Endocrinol Metab · October 1, 2019 CONTEXT: Newborn adiposity is associated with childhood obesity. Cord blood metabolomics is one approach that can be used to understand early-life contributors to adiposity and insulin resistance. OBJECTIVE: To determine the association of cord blood metab ... Full text Link to item Cite

Disrupted Maturation of the Microbiota and Metabolome among Extremely Preterm Infants with Postnatal Growth Failure.

Journal Article Sci Rep · June 3, 2019 Growth failure during infancy is a major global problem that has adverse effects on long-term health and neurodevelopment. Preterm infants are disproportionately affected by growth failure and its effects. Herein we found that extremely preterm infants wit ... Full text Link to item Cite

Maternal metabolites during pregnancy are associated with newborn outcomes and hyperinsulinaemia across ancestries.

Journal Article Diabetologia · March 2019 AIMS/HYPOTHESIS: We aimed to determine the association of maternal metabolites with newborn adiposity and hyperinsulinaemia in a multi-ethnic cohort of mother-newborn dyads. METHODS: Targeted and non-targeted metabolomics assays were performed on fasting a ... Full text Link to item Cite

Respiratory Phenomics across Multiple Models of Protein Hyperacylation in Cardiac Mitochondria Reveals a Marginal Impact on Bioenergetics.

Journal Article Cell Rep · February 5, 2019 Acyl CoA metabolites derived from the catabolism of carbon fuels can react with lysine residues of mitochondrial proteins, giving rise to a large family of post-translational modifications (PTMs). Mass spectrometry-based detection of thousands of acyl-PTMs ... Full text Link to item Cite

Adverse Effects of Fenofibrate in Mice Deficient in the Protein Quality Control Regulator, CHIP.

Journal Article J Cardiovasc Dev Dis · August 15, 2018 We previously reported how the loss of CHIP expression (Carboxyl terminus of Hsc70-Interacting Protein) during pressure overload resulted in robust cardiac dysfunction, which was accompanied by a failure to maintain ATP levels in the face of increased ener ... Full text Link to item Cite

Physiological mechanisms of sustained fumagillin-induced weight loss.

Journal Article JCI Insight · March 8, 2018 Current obesity interventions suffer from lack of durable effects and undesirable complications. Fumagillin, an inhibitor of methionine aminopeptidase-2, causes weight loss by reducing food intake, but with effects on weight that are superior to pair-feedi ... Full text Link to item Cite

Targeted Metabolomics Demonstrates Distinct and Overlapping Maternal Metabolites Associated With BMI, Glucose, and Insulin Sensitivity During Pregnancy Across Four Ancestry Groups.

Journal Article Diabetes Care · July 2017 OBJECTIVE: We used targeted metabolomics in pregnant mothers to compare maternal metabolite associations with maternal BMI, glycemia, and insulin sensitivity. RESEARCH DESIGN AND METHODS: Targeted metabolomic assays of clinical metabolites, amino acids, an ... Full text Link to item Cite

Maternal BMI and Glycemia Impact the Fetal Metabolome.

Journal Article Diabetes Care · July 2017 OBJECTIVE: We used targeted metabolomics to determine associations of maternal BMI and glucose levels with cord blood metabolites and associations of cord blood metabolites with newborn birth weight and adiposity in mother-offspring dyads. RESEARCH DESIGN ... Full text Link to item Cite

SIRT4 Is a Lysine Deacylase that Controls Leucine Metabolism and Insulin Secretion.

Journal Article Cell Metab · April 4, 2017 Sirtuins are NAD+-dependent protein deacylases that regulate several aspects of metabolism and aging. In contrast to the other mammalian sirtuins, the primary enzymatic activity of mitochondrial sirtuin 4 (SIRT4) and its overall role in metabolic control h ... Full text Link to item Cite

A Class of Reactive Acyl-CoA Species Reveals the Non-enzymatic Origins of Protein Acylation.

Journal Article Cell Metab · April 4, 2017 The mechanisms underlying the formation of acyl protein modifications remain poorly understood. By investigating the reactivity of endogenous acyl-CoA metabolites, we found a class of acyl-CoAs that undergo intramolecular catalysis to form reactive interme ... Full text Link to item Cite

Associations of maternal BMI and insulin resistance with the maternal metabolome and newborn outcomes.

Journal Article Diabetologia · March 2017 AIMS/HYPOTHESIS: Maternal obesity increases the risk for large-for-gestational-age birth and excess newborn adiposity, which are associated with adverse long-term metabolic outcomes in offspring, probably due to effects mediated through the intrauterine en ... Full text Link to item Cite

Mixture model normalization for non-targeted gas chromatography/mass spectrometry metabolomics data.

Journal Article BMC Bioinformatics · February 2, 2017 BACKGROUND: Metabolomics offers a unique integrative perspective for health research, reflecting genetic and environmental contributions to disease-related phenotypes. Identifying robust associations in population-based or large-scale clinical studies dema ... Full text Link to item Cite

Association of Plasma Small-Molecule Intermediate Metabolites With Age and Body Mass Index Across Six Diverse Study Populations.

Journal Article J Gerontol A Biol Sci Med Sci · November 2016 BACKGROUND: Older age and obesity are associated with metabolic dysregulation; the mechanism by which these factors impact metabolism across the lifespan is important, but relatively unknown. We evaluated a panel of amino acids (AAs) and acylcarnitines (AC ... Full text Link to item Cite

Metabolomic Profiling Identifies Novel Circulating Biomarkers of Mitochondrial Dysfunction Differentially Elevated in Heart Failure With Preserved Versus Reduced Ejection Fraction: Evidence for Shared Metabolic Impairments in Clinical Heart Failure.

Journal Article J Am Heart Assoc · July 29, 2016 BACKGROUND: Metabolic impairment is an important contributor to heart failure (HF) pathogenesis and progression. Dysregulated metabolic pathways remain poorly characterized in patients with HF and preserved ejection fraction (HFpEF). We sought to determine ... Full text Open Access Link to item Cite

Branched-chain amino acid restriction in Zucker-fatty rats improves muscle insulin sensitivity by enhancing efficiency of fatty acid oxidation and acyl-glycine export.

Journal Article Mol Metab · July 2016 OBJECTIVE: A branched-chain amino acid (BCAA)-related metabolic signature is strongly associated with insulin resistance and predictive of incident diabetes and intervention outcomes. To better understand the role that this metabolite cluster plays in obes ... Full text Link to item Cite

Metabolic Networks and Metabolites Underlie Associations Between Maternal Glucose During Pregnancy and Newborn Size at Birth.

Journal Article Diabetes · July 2016 Maternal metabolites and metabolic networks underlying associations between maternal glucose during pregnancy and newborn birth weight and adiposity demand fuller characterization. We performed targeted and nontargeted gas chromatography/mass spectrometry ... Full text Link to item Cite

Research Resource: Roles for Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 (CaMKK2) in Systems Metabolism.

Journal Article Mol Endocrinol · May 2016 A number of epidemiological studies have implicated calcium (Ca(2+)) signaling as a major factor in obesity that contributes to aberrant systems metabolism. Somewhat paradoxically, obesity correlates with decreased circulating Ca(2+) levels, leading to inc ... Full text Link to item Cite

The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-Induced Lysine Acetylation of Mitochondrial Proteins.

Journal Article Cell Rep · January 12, 2016 Lysine acetylation (AcK), a posttranslational modification wherein a two-carbon acetyl group binds covalently to a lysine residue, occurs prominently on mitochondrial proteins and has been linked to metabolic dysfunction. An emergent theory suggests mitoch ... Full text Link to item Cite

Impact of combined resistance and aerobic exercise training on branched-chain amino acid turnover, glycine metabolism and insulin sensitivity in overweight humans.

Journal Article Diabetologia · October 2015 AIMS/HYPOTHESES: Obesity is associated with decreased insulin sensitivity (IS) and elevated plasma branched-chain amino acids (BCAAs). The purpose of this study was to investigate the relationship between BCAA metabolism and IS in overweight (OW) individua ... Full text Link to item Cite

ACLY and ACC1 Regulate Hypoxia-Induced Apoptosis by Modulating ETV4 via α-ketoglutarate.

Journal Article PLoS Genet · October 2015 In order to propagate a solid tumor, cancer cells must adapt to and survive under various tumor microenvironment (TME) stresses, such as hypoxia or lactic acidosis. To systematically identify genes that modulate cancer cell survival under stresses, we perf ... Full text Open Access Link to item Cite

Increased palmitate intake: higher acylcarnitine concentrations without impaired progression of β-oxidation.

Journal Article J Lipid Res · September 2015 Palmitic acid (PA) is associated with higher blood concentrations of medium-chain acylcarnitines (MCACs), and we hypothesized that PA may inhibit progression of FA β-oxidation. Using a cross-over design, 17 adults were fed high PA (HPA) and low PA/high ole ... Full text Link to item Cite

Carnitine Acetyltransferase Mitigates Metabolic Inertia and Muscle Fatigue during Exercise.

Journal Article Cell Metab · July 7, 2015 Acylcarnitine metabolites have gained attention as biomarkers of nutrient stress, but their physiological relevance and metabolic purpose remain poorly understood. Short-chain carnitine conjugates, including acetylcarnitine, derive from their corresponding ... Full text Link to item Cite

Muscle-Specific Overexpression of PGC-1α Does Not Augment Metabolic Improvements in Response to Exercise and Caloric Restriction.

Journal Article Diabetes · May 2015 This study used mice with muscle-specific overexpression of PGC-1α, a transcriptional coactivator that promotes mitochondrial biogenesis, to determine whether increased oxidative potential facilitates metabolic improvements in response to lifestyle modific ... Full text Link to item Cite

Effect of aerobic training on the host systemic milieu in patients with solid tumours: an exploratory correlative study.

Journal Article Br J Cancer · March 3, 2015 BACKGROUND: Few studies have investigated the effects of exercise on modulation of host factors in cancer patients. We investigated the efficacy of chronic aerobic training on multiple host-related effector pathways in patients with solid tumours. PATIENTS ... Full text Link to item Cite

Effect of aerobic training on the host systemic milieu in patients with solid tumours: An exploratory correlative study

Journal Article British Journal of Cancer · March 3, 2015 Background: Few studies have investigated the effects of exercise on modulation of host factors in cancer patients. We investigated the efficacy of chronic aerobic training on multiple host-related effector pathways in patients with solid tumours.Patients ... Full text Cite

Metabolomic profile associated with insulin resistance and conversion to diabetes in the Insulin Resistance Atherosclerosis Study.

Journal Article J Clin Endocrinol Metab · March 2015 CONTEXT: Metabolomic profiling of amino acids and acylcarnitines has revealed consistent patterns associated with metabolic disease. OBJECTIVE: This study used metabolomic profiling to identify analytes associated with insulin sensitivity (SI) and conversi ... Full text Link to item Cite

Sex differences in biomarkers associated with insulin resistance in obese adolescents: metabolomic profiling and principal components analysis.

Journal Article J Clin Endocrinol Metab · December 2014 OBJECTIVE: Obesity and insulin resistance (IR) predispose to type 2 diabetes mellitus. Yet only half of obese adolescents have IR and far fewer progress to type 2 diabetes mellitus. We hypothesized that amino acid and fatty acid metabolites may serve as bi ... Full text Link to item Cite

Metabolite signatures of exercise training in human skeletal muscle relate to mitochondrial remodelling and cardiometabolic fitness.

Journal Article Diabetologia · November 2014 AIMS/HYPOTHESIS: Targeted metabolomic and transcriptomic approaches were used to evaluate the relationship between skeletal muscle metabolite signatures, gene expression profiles and clinical outcomes in response to various exercise training interventions. ... Full text Link to item Cite

Energy metabolic reprogramming in the hypertrophied and early stage failing heart: a multisystems approach.

Journal Article Circ Heart Fail · November 2014 BACKGROUND: An unbiased systems approach was used to define energy metabolic events that occur during the pathological cardiac remodeling en route to heart failure (HF). METHODS AND RESULTS: Combined myocardial transcriptomic and metabolomic profiling were ... Full text Link to item Cite

Long-echo time MR spectroscopy for skeletal muscle acetylcarnitine detection.

Journal Article J Clin Invest · November 2014 Animal models suggest that acetylcarnitine production is essential for maintaining metabolic flexibility and insulin sensitivity. Because current methods to detect acetylcarnitine involve biopsy of the tissue of interest, noninvasive alternatives to measur ... Full text Link to item Cite

Hepatic SRC-1 activity orchestrates transcriptional circuitries of amino acid pathways with potential relevance for human metabolic pathogenesis.

Journal Article Mol Endocrinol · October 2014 Disturbances in amino acid metabolism are increasingly recognized as being associated with, and serving as prognostic markers for chronic human diseases, such as cancer or type 2 diabetes. In the current study, a quantitative metabolomics profiling strateg ... Full text Link to item Cite

Fatty acid elongase-5 (Elovl5) regulates hepatic triglyceride catabolism in obese C57BL/6J mice.

Journal Article J Lipid Res · July 2014 Nonalcoholic fatty liver disease is a major public health concern in the obese and type 2 diabetic populations. The high-fat lard diet induces obesity and fatty liver in C57BL/6J mice and suppresses expression of the PPAR-target gene, FA elongase 5 (Elovl5 ... Full text Link to item Cite

Severe acute malnutrition in childhood: hormonal and metabolic status at presentation, response to treatment, and predictors of mortality.

Journal Article J Clin Endocrinol Metab · June 2014 OBJECTIVE: Malnutrition is a major cause of childhood morbidity and mortality. To identify and target those at highest risk, there is a critical need to characterize biomarkers that predict complications prior to and during treatment. METHODS: We used targ ... Full text Link to item Cite

Mechanical unloading promotes myocardial energy recovery in human heart failure.

Journal Article Circ Cardiovasc Genet · June 2014 BACKGROUND: Impaired bioenergetics is a prominent feature of the failing heart, but the underlying metabolic perturbations are poorly understood. METHODS AND RESULTS: We compared metabolomic, gene transcript, and protein data from 6 paired samples of faili ... Full text Link to item Cite

Postprandial metabolite profiles reveal differential nutrient handling after bariatric surgery compared with matched caloric restriction.

Journal Article Ann Surg · April 2014 BACKGROUND: Roux-en-Y gastric bypass (RYGB) surgery results in exaggerated postprandial insulin and incretin responses and increased susceptibility to hypoglycemia. OBJECTIVE: We examined whether these features are due to caloric restriction (CR) or altere ... Full text Link to item Cite

Targeted metabolomics connects thioredoxin-interacting protein (TXNIP) to mitochondrial fuel selection and regulation of specific oxidoreductase enzymes in skeletal muscle.

Journal Article J Biol Chem · March 21, 2014 Thioredoxin-interacting protein (TXNIP) is an α-arrestin family member involved in redox sensing and metabolic control. Growing evidence links TXNIP to mitochondrial function, but the molecular nature of this relationship has remained poorly defined. Herei ... Full text Link to item Cite

Dietary intake of palmitate and oleate has broad impact on systemic and tissue lipid profiles in humans.

Journal Article Am J Clin Nutr · March 2014 BACKGROUND: Epidemiologic evidence has suggested that diets with a high ratio of palmitic acid (PA) to oleic acid (OA) increase risk of cardiovascular disease (CVD). OBJECTIVE: To gain additional insights into the relative effect of dietary fatty acids and ... Full text Link to item Cite

Validation of the association between a branched chain amino acid metabolite profile and extremes of coronary artery disease in patients referred for cardiac catheterization.

Journal Article Atherosclerosis · January 2014 OBJECTIVE: To validate independent associations between branched-chain amino acids (BCAA) and other metabolites with coronary artery disease (CAD). METHODS: We conducted mass-spectrometry-based profiling of 63 metabolites in fasting plasma from 1983 sequen ... Full text Link to item Cite

Effects of HIV infection on the metabolic and hormonal status of children with severe acute malnutrition.

Journal Article PLoS One · 2014 BACKGROUND: HIV infection occurs in 30% of children with severe acute malnutrition in sub-Saharan Africa. Effects of HIV on the pathophysiology and recovery from malnutrition are poorly understood. METHODS: We conducted a prospective cohort study of 75 sev ... Full text Link to item Cite

Metabolomics reveals broad-scale metabolic perturbations in hyperglycemic mothers during pregnancy.

Journal Article Diabetes Care · 2014 OBJECTIVE To characterize metabolites across the range of maternal glucose by comparing metabolomic profiles of mothers with high and low fasting plasma glucose (FPG). RESEARCH DESIGN AND METHODS We compared fasting serum from an oral glucose tolerance tes ... Full text Link to item Cite

SIRT5 regulates the mitochondrial lysine succinylome and metabolic networks.

Journal Article Cell Metab · December 3, 2013 Reversible posttranslational modifications are emerging as critical regulators of mitochondrial proteins and metabolism. Here, we use a label-free quantitative proteomic approach to characterize the lysine succinylome in liver mitochondria and its regulati ... Full text Link to item Cite

Race and sex differences in small-molecule metabolites and metabolic hormones in overweight and obese adults.

Journal Article OMICS · December 2013 In overweight/obese individuals, cardiometabolic risk factors differ by race and sex categories. Small-molecule metabolites and metabolic hormone levels might also differ across these categories and contribute to risk factor heterogeneity. To explore this ... Full text Link to item Cite

Branched chain amino acids are novel biomarkers for discrimination of metabolic wellness.

Journal Article Metabolism · July 2013 OBJECTIVE: To identify novel biomarkers through metabolomic profiles that distinguish metabolically well (MW) from metabolically unwell (MUW) individuals, independent of body mass index (BMI). MATERIALS/METHODS: This study was conducted as part of the Meas ... Full text Link to item Cite

Metabolomic profiling reveals a role for caspase-2 in lipoapoptosis.

Journal Article J Biol Chem · May 17, 2013 The accumulation of long-chain fatty acids (LCFAs) in non-adipose tissues results in lipid-induced cytotoxicity (or lipoapoptosis). Lipoapoptosis has been proposed to play an important role in the pathogenesis of several metabolic diseases, including non-a ... Full text Link to item Cite

A lipidomics analysis of the relationship between dietary fatty acid composition and insulin sensitivity in young adults.

Journal Article Diabetes · April 2013 Relative to diets enriched in palmitic acid (PA), diets rich in oleic acid (OA) are associated with reduced risk of type 2 diabetes. To gain insight into mechanisms underlying these observations, we applied comprehensive lipidomic profiling to specimens co ... Full text Link to item Cite

Pathogenesis of A⁻β⁺ ketosis-prone diabetes.

Journal Article Diabetes · March 2013 A⁻β⁺ ketosis-prone diabetes (KPD) is an emerging syndrome of obesity, unprovoked ketoacidosis, reversible β-cell dysfunction, and near-normoglycemic remission. We combined metabolomics with targeted kinetic measurements to investigate its pathophysiology. ... Full text Link to item Cite

Branched-chain amino acids alter neurobehavioral function in rats.

Journal Article Am J Physiol Endocrinol Metab · February 15, 2013 Recently, we have described a strong association of branched-chain amino acids (BCAA) and aromatic amino acids (AAA) with obesity and insulin resistance. In the current study, we have investigated the potential impact of BCAA on behavioral functions. We de ... Full text Link to item Cite

Research resource: tissue- and pathway-specific metabolomic profiles of the steroid receptor coactivator (SRC) family.

Journal Article Mol Endocrinol · February 2013 The rapidly growing family of transcriptional coregulators includes coactivators that promote transcription and corepressors that harbor the opposing function. In recent years, coregulators have emerged as important regulators of metabolic homeostasis, inc ... Full text Link to item Cite

Suppression of oxidative stress by β-hydroxybutyrate, an endogenous histone deacetylase inhibitor.

Journal Article Science · January 11, 2013 Concentrations of acetyl-coenzyme A and nicotinamide adenine dinucleotide (NAD(+)) affect histone acetylation and thereby couple cellular metabolic status and transcriptional regulation. We report that the ketone body d-β-hydroxybutyrate (βOHB) is an endog ... Full text Link to item Cite

Metabolomic analysis reveals extended metabolic consequences of marginal vitamin B-6 deficiency in healthy human subjects.

Journal Article PLoS One · 2013 Marginal deficiency of vitamin B-6 is common among segments of the population worldwide. Because pyridoxal 5'-phosphate (PLP) serves as a coenzyme in the metabolism of amino acids, carbohydrates, organic acids, and neurotransmitters, as well as in aspects ... Full text Link to item Cite

Skeletal muscle Nur77 expression enhances oxidative metabolism and substrate utilization.

Journal Article J Lipid Res · December 2012 Mitochondrial dysfunction has been implicated in the pathogenesis of type 2 diabetes. Identifying novel regulators of mitochondrial bioenergetics will broaden our understanding of regulatory checkpoints that coordinate complex metabolic pathways. We previo ... Full text Link to item Cite

Analysis of serum metabolic profiles in women with endometrial cancer and controls in a population-based case-control study.

Journal Article J Clin Endocrinol Metab · September 2012 CONTEXT: Endometrial cancer is associated with metabolic disturbances related to its underlying risk factors, including obesity and diabetes. Identifying metabolite biomarkers associated with endometrial cancer may have value for early detection, risk asse ... Full text Link to item Cite

Rapid and weight-independent improvement of glucose tolerance induced by a peptide designed to elicit apoptosis in adipose tissue endothelium.

Journal Article Diabetes · September 2012 A peptide designed to induce apoptosis of endothelium in white adipose tissue (WAT) decreases adiposity. The goal of this work is to determine whether targeting of WAT endothelium results in impaired glucose regulation as a result of impaired WAT function. ... Full text Link to item Cite

Daily Variation of Serum Acylcarnitines and Amino Acids.

Journal Article Metabolomics · August 2012 To characterize daily variation of amino acids (AAs) and acylcarnitines (ACs) in response to feeding and activity, we measured serum metabolites at various times and after various activities during the day. Subjects were admitted overnight for serial serum ... Full text Link to item Cite

Thyroid hormone stimulates hepatic lipid catabolism via activation of autophagy.

Journal Article J Clin Invest · July 2012 For more than a century, thyroid hormones (THs) have been known to exert powerful catabolic effects, leading to weight loss. Although much has been learned about the molecular mechanisms used by TH receptors (TRs) to regulate gene expression, little is kno ... Full text Link to item Cite

Muscle-specific deletion of carnitine acetyltransferase compromises glucose tolerance and metabolic flexibility.

Journal Article Cell Metab · May 2, 2012 The concept of "metabolic inflexibility" was first introduced to describe the failure of insulin-resistant human subjects to appropriately adjust mitochondrial fuel selection in response to nutritional cues. This phenomenon has since gained increasing reco ... Full text Link to item Cite

Ablation of steroid receptor coactivator-3 resembles the human CACT metabolic myopathy.

Journal Article Cell Metab · May 2, 2012 Oxidation of lipid substrates is essential for survival in fasting and other catabolic conditions, sparing glucose for the brain and other glucose-dependent tissues. Here we show Steroid Receptor Coactivator-3 (SRC-3) plays a central role in long chain fat ... Full text Link to item Cite

Baseline metabolomic profiles predict cardiovascular events in patients at risk for coronary artery disease.

Journal Article Am Heart J · May 2012 BACKGROUND: Cardiovascular risk models remain incomplete. Small-molecule metabolites may reflect underlying disease and, as such, serve as novel biomarkers of cardiovascular risk. METHODS: We studied 2,023 consecutive patients undergoing cardiac catheteriz ... Full text Link to item Cite

Metabolic profiles predict adverse events after coronary artery bypass grafting.

Journal Article J Thorac Cardiovasc Surg · April 2012 OBJECTIVE: Clinical models incompletely predict the outcomes after coronary artery bypass grafting. Novel molecular technologies can identify biomarkers to improve risk stratification. We examined whether metabolic profiles can predict adverse events in pa ... Full text Link to item Cite

Deletion of CaMKK2 from the liver lowers blood glucose and improves whole-body glucose tolerance in the mouse.

Journal Article Mol Endocrinol · February 2012 Ca(2+)/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is a member of the Ca(2+)/CaM-dependent protein kinase family that is expressed abundantly in brain. Previous work has revealed that CaMKK2 knockout (CaMKK2 KO) mice eat less due to a central ner ... Full text Link to item Cite

Branched-chain amino acid levels are associated with improvement in insulin resistance with weight loss.

Journal Article Diabetologia · February 2012 AIMS/HYPOTHESIS: Insulin resistance (IR) improves with weight loss, but this response is heterogeneous. We hypothesised that metabolomic profiling would identify biomarkers predicting changes in IR with weight loss. METHODS: Targeted mass spectrometry-base ... Full text Link to item Cite

Caloric restriction alters the metabolic response to a mixed-meal: results from a randomized, controlled trial.

Journal Article PLoS One · 2012 OBJECTIVES: To determine if caloric restriction (CR) would cause changes in plasma metabolic intermediates in response to a mixed meal, suggestive of changes in the capacity to adapt fuel oxidation to fuel availability or metabolic flexibility, and to dete ... Full text Open Access Link to item Cite

Mig-6 plays a critical role in the regulation of cholesterol homeostasis and bile acid synthesis.

Journal Article PLoS One · 2012 The disruption of cholesterol homeostasis leads to an increase in cholesterol levels which results in the development of cardiovascular disease. Mitogen Inducible Gene 6 (Mig-6) is an immediate early response gene that can be induced by various mitogens, s ... Full text Link to item Cite

Metabolomic profiling reveals mitochondrial-derived lipid biomarkers that drive obesity-associated inflammation.

Journal Article PLoS One · 2012 Obesity has reached epidemic proportions worldwide. Several animal models of obesity exist, but studies are lacking that compare traditional lard-based high fat diets (HFD) to "Cafeteria diets" (CAF) consisting of nutrient poor human junk food. Our previou ... Full text Link to item Cite

Effect of heparin administration on metabolomic profiles in samples obtained during cardiac catheterization.

Journal Article Circ Cardiovasc Genet · December 2011 BACKGROUND: Metabolic profiling holds promise for early detection of coronary artery disease and assessing risk for ischemic events. Heparin is frequently administered (1) to treat acute coronary syndromes; and (2) during routine cardiac catheterization pr ... Full text Link to item Cite

SIRT3 deficiency and mitochondrial protein hyperacetylation accelerate the development of the metabolic syndrome.

Journal Article Mol Cell · October 21, 2011 Acetylation is increasingly recognized as an important metabolic regulatory posttranslational protein modification, yet the metabolic consequence of mitochondrial protein hyperacetylation is unknown. We find that high-fat diet (HFD) feeding induces hepatic ... Full text Link to item Cite

Metabolic remodeling of human skeletal myocytes by cocultured adipocytes depends on the lipolytic state of the system.

Journal Article Diabetes · July 2011 OBJECTIVE: Adipocyte infiltration of the musculoskeletal system is well recognized as a hallmark of aging, obesity, and type 2 diabetes. Intermuscular adipocytes might serve as a benign storage site for surplus lipid or play a role in disrupting energy hom ... Full text Link to item Cite

Plasma acylcarnitines are associated with physical performance in elderly men.

Journal Article J Gerontol A Biol Sci Med Sci · May 2011 BACKGROUND: Metabolic profiling might provide insight into the biologic underpinnings of disability in older adults. METHODS: A targeted mass spectrometry-based platform was used to identify and quantify 45 plasma acylcarnitines in 77 older men with a mean ... Full text Link to item Cite

Differential metabolic impact of gastric bypass surgery versus dietary intervention in obese diabetic subjects despite identical weight loss.

Journal Article Sci Transl Med · April 27, 2011 Glycemic control is improved more after gastric bypass surgery (GBP) than after equivalent diet-induced weight loss in patients with morbid obesity and type 2 diabetes mellitus. We applied metabolomic profiling to understand the mechanisms of this better m ... Full text Link to item Cite

Effect of caloric restriction with and without exercise on metabolic intermediates in nonobese men and women.

Journal Article J Clin Endocrinol Metab · February 2011 OBJECTIVES: The objective of the study was to evaluate whether serum concentrations of metabolic intermediates are related to adiposity and insulin sensitivity (Si) in overweight healthy subjects and compare changes in metabolic intermediates with similar ... Full text Link to item Cite

Short-term effects of dietary fatty acids on muscle lipid composition and serum acylcarnitine profile in human subjects.

Journal Article Obesity (Silver Spring) · February 2011 In cultured cells, palmitic acid (PA) and oleic acid (OA) confer distinct metabolic effects, yet, unclear, is whether changes in dietary fat intake impact cellular fatty acid (FA) composition. We hypothesized that short-term increases in dietary PA or OA w ... Full text Link to item Cite

Exercise-induced changes in metabolic intermediates, hormones, and inflammatory markers associated with improvements in insulin sensitivity.

Journal Article Diabetes Care · January 2011 OBJECTIVE: To understand relationships between exercise training-mediated improvements in insulin sensitivity (S(I)) and changes in circulating concentrations of metabolic intermediates, hormones, and inflammatory mediators. RESEARCH DESIGN AND METHODS: Ta ... Full text Open Access Link to item Cite

Acylcarnitines: analysis in plasma and whole blood using tandem mass spectrometry.

Journal Article Methods Mol Biol · 2011 The acylcarnitine profile is a diagnostic test for inherited disorders of fatty acid and branched-chain amino acid catabolism. Patients with this type of metabolic disorder accumulate disease-specific acylcarnitines that correlate with the acyl coenzyme A ... Full text Link to item Cite

The coactivator SRC-1 is an essential coordinator of hepatic glucose production.

Journal Article Cell Metab · December 1, 2010 Gluconeogenesis makes a major contribution to hepatic glucose production, a process critical for survival in mammals. In this study, we identify the p160 family member, SRC-1, as a key coordinator of the hepatic gluconeogenic program in vivo. SRC-1-null mi ... Full text Link to item Cite

Comprehensive Metabolic Analysis for Understanding of Disease

Journal Article · December 1, 2010 Comprehensive measurement of intermediary metabolites and changes in metabolic activity lead to the improved detection and understanding of diseases. Metabolomics is increasingly getting integrated with genomic and transcriptomic profiling methods. This ch ... Full text Cite

Dissecting the in vivo metabolic potential of two human gut acetogens.

Journal Article J Biol Chem · July 16, 2010 Fermenting microbial communities generate hydrogen; its removal through the production of acetate, methane, or hydrogen sulfide modulates the efficiency of energy extraction from available nutrients in many ecosystems. We noted that pathway components for ... Full text Link to item Cite

Adipose acyl-CoA synthetase-1 directs fatty acids toward beta-oxidation and is required for cold thermogenesis.

Journal Article Cell Metab · July 7, 2010 Long-chain acyl-CoA synthetase-1 (ACSL1) contributes 80% of total ACSL activity in adipose tissue and was believed to be essential for the synthesis of triacylglycerol. We predicted that an adipose-specific knockout of ACSL1 (Acsl1(A-/-)) would be lipodyst ... Full text Link to item Cite

Association of a peripheral blood metabolic profile with coronary artery disease and risk of subsequent cardiovascular events.

Journal Article Circ Cardiovasc Genet · April 2010 BACKGROUND: Molecular tools may provide insight into cardiovascular risk. We assessed whether metabolites discriminate coronary artery disease (CAD) and predict risk of cardiovascular events. METHODS AND RESULTS: We performed mass-spectrometry-based profil ... Full text Open Access Link to item Cite

Insulin resistance is associated with a metabolic profile of altered protein metabolism in Chinese and Asian-Indian men.

Journal Article Diabetologia · April 2010 AIMS/HYPOTHESIS: Insulin resistance (IR) is associated with obesity, but can also develop in individuals with normal body weight. We employed comprehensive profiling methods to identify metabolic events associated with IR, while controlling for obesity. ME ... Full text Link to item Cite

Leptin therapy in insulin-deficient type I diabetes.

Journal Article Proc Natl Acad Sci U S A · March 16, 2010 In nonobese diabetic mice with uncontrolled type 1 diabetes, leptin therapy alone or combined with low-dose insulin reverses the catabolic state through suppression of hyperglucagonemia. Additionally, it mimics the anabolic actions of insulin monotherapy a ... Full text Link to item Cite

SIRT3 regulates mitochondrial fatty-acid oxidation by reversible enzyme deacetylation.

Journal Article Nature · March 4, 2010 Sirtuins are NAD(+)-dependent protein deacetylases. They mediate adaptive responses to a variety of stresses, including calorie restriction and metabolic stress. Sirtuin 3 (SIRT3) is localized in the mitochondrial matrix, where it regulates the acetylation ... Full text Link to item Cite

Activation of nuclear receptor CAR ameliorates diabetes and fatty liver disease.

Journal Article Proc Natl Acad Sci U S A · November 3, 2009 Constitutive androstane receptor CAR (NR1I3) has been identified as a central mediator of coordinate responses to xenobiotic and endobiotic stress. Here we use leptin-deficient mice (ob/ob) and ob/ob, CAR(-/-) double mutant mice to identify a metabolic rol ... Full text Link to item Cite

Relationships between circulating metabolic intermediates and insulin action in overweight to obese, inactive men and women.

Journal Article Diabetes Care · September 2009 OBJECTIVE: To determine whether circulating metabolic intermediates are related to insulin resistance and beta-cell dysfunction in individuals at risk for type 2 diabetes. RESEARCH DESIGN AND METHODS: In 73 sedentary, overweight to obese, dyslipidemic indi ... Full text Link to item Cite

Carnitine insufficiency caused by aging and overnutrition compromises mitochondrial performance and metabolic control.

Journal Article J Biol Chem · August 21, 2009 In addition to its essential role in permitting mitochondrial import and oxidation of long chain fatty acids, carnitine also functions as an acyl group acceptor that facilitates mitochondrial export of excess carbons in the form of acylcarnitines. Recent e ... Full text Link to item Cite

Increased insulin sensitivity in mice lacking collectrin, a downstream target of HNF-1alpha.

Journal Article Mol Endocrinol · June 2009 Collectrin is a downstream target of the transcription factor hepatocyte nuclear factor-1alpha (HNF-1alpha), which is mutated in maturity-onset diabetes of the young subtype 3 (MODY3). Evidence from transgenic mouse models with collectrin overexpression in ... Full text Link to item Cite

Metabolomic profiling reveals distinct patterns of myocardial substrate use in humans with coronary artery disease or left ventricular dysfunction during surgical ischemia/reperfusion.

Journal Article Circulation · April 7, 2009 BACKGROUND: Human myocardial metabolism has been incompletely characterized in the setting of surgical cardioplegic arrest and ischemia/reperfusion. Furthermore, the effect of preexisting ventricular state on ischemia-induced metabolic derangements has not ... Full text Link to item Cite

A branched-chain amino acid-related metabolic signature that differentiates obese and lean humans and contributes to insulin resistance.

Journal Article Cell Metab · April 2009 Metabolomic profiling of obese versus lean humans reveals a branched-chain amino acid (BCAA)-related metabolite signature that is suggestive of increased catabolism of BCAA and correlated with insulin resistance. To test its impact on metabolic homeostasis ... Full text Link to item Cite

A convenient LC-MS method for assessment of glucose kinetics in vivo with D-[13C6]glucose as a tracer.

Journal Article Clin Chem · March 2009 BACKGROUND: The isotope-labeled intravenous glucose tolerance test (IVGTT) combined with computer modeling is widely used to derive parameters related to glucose metabolism in vivo. Most of these methods involve use of either (2)H(2)-labeled or (13)C(1)-la ... Full text Link to item Cite

Moderate dietary vitamin B-6 restriction raises plasma glycine and cystathionine concentrations while minimally affecting the rates of glycine turnover and glycine cleavage in healthy men and women.

Journal Article J Nutr · March 2009 Glycine is a precursor of purines, protein, glutathione, and 1-carbon units as 5,10-methylenetetrahydrofolate. Glycine decarboxylation through the glycine cleavage system (GCS) and glycine-serine transformation by serine hydroxymethyltransferase (SHMT) req ... Full text Link to item Cite

Metabolic profiling of PPARalpha-/- mice reveals defects in carnitine and amino acid homeostasis that are partially reversed by oral carnitine supplementation.

Journal Article FASEB J · February 2009 Peroxisome proliferator-activated receptor-alpha (PPARalpha) is a master transcriptional regulator of beta-oxidation and a prominent target of hypolipidemic drugs. To gain deeper insights into the systemic consequences of impaired fat catabolism, we used q ... Full text Link to item Cite

The STEDMAN project: biophysical, biochemical and metabolic effects of a behavioral weight loss intervention during weight loss, maintenance, and regain.

Journal Article OMICS · February 2009 The Study of the Effects of Diet on Metabolism and Nutrition (STEDMAN) Project uses comprehensive metabolic profiling to probe biochemical mechanisms of weight loss in humans. Measurements at baseline, 2 and 4 weeks, 6 and 12 months included diet, body com ... Full text Link to item Cite

High heritability of metabolomic profiles in families burdened with premature cardiovascular disease.

Journal Article Mol Syst Biol · 2009 Integration of genetic and metabolic profiling holds promise for providing insight into human disease. Coronary artery disease (CAD) is strongly heritable, but the heritability of metabolomic profiles has not been evaluated in humans. We performed quantita ... Full text Link to item Cite

Genetic networks of liver metabolism revealed by integration of metabolic and transcriptional profiling.

Journal Article PLoS Genet · March 14, 2008 Although numerous quantitative trait loci (QTL) influencing disease-related phenotypes have been detected through gene mapping and positional cloning, identification of the individual gene(s) and molecular pathways leading to those phenotypes is often elus ... Full text Link to item Cite

Mitochondrial overload and incomplete fatty acid oxidation contribute to skeletal muscle insulin resistance.

Journal Article Cell Metab · January 2008 Previous studies have suggested that insulin resistance develops secondary to diminished fat oxidation and resultant accumulation of cytosolic lipid molecules that impair insulin signaling. Contrary to this model, the present study used targeted metabolomi ... Full text Link to item Cite

Increased lipid accumulation and insulin resistance in transgenic mice expressing DGAT2 in glycolytic (type II) muscle.

Journal Article Am J Physiol Endocrinol Metab · December 2007 Insulin resistance and type 2 diabetes are frequently accompanied by lipid accumulation in skeletal muscle. However, it is unknown whether primary lipid deposition in skeletal muscle is sufficient to cause insulin resistance or whether the type of muscle f ... Full text Link to item Cite

Genetic diversity of coastal bottlenose dolphins revealed by structurally and functionally diverse hemoglobins.

Journal Article Gene · August 15, 2007 Studies of structure-function relationships in the respiratory proteins of marine mammals revealed unexpected variations in the number and types of hemoglobins (Hbs) present in coastal bottlenose dolphins, Tursiops truncatus. We obtained blood samples from ... Full text Link to item Cite

Dissociation of hepatic steatosis and insulin resistance in mice overexpressing DGAT in the liver.

Journal Article Cell Metab · July 2007 Hepatic steatosis, the accumulation of lipids in the liver, is widely believed to result in insulin resistance. To test the causal relationship between hepatic steatosis and insulin resistance, we generated mice that overexpress acyl-CoA:diacylglycerol acy ... Full text Link to item Cite

Chemical knockout of pantothenate kinase reveals the metabolic and genetic program responsible for hepatic coenzyme A homeostasis.

Journal Article Chem Biol · March 2007 Coenzyme A (CoA) is the major acyl group carrier in intermediary metabolism. Hopantenate (HoPan), a competitive inhibitor of the pantothenate kinases, was used to chemically antagonize CoA biosynthesis. HoPan dramatically reduced liver CoA and mice develop ... Full text Link to item Cite

The neurosteroid allopregnanolone is reduced in prefrontal cortex in Alzheimer's disease.

Journal Article Biol Psychiatry · December 15, 2006 BACKGROUND: Few data are currently available investigating neurosteroids (NS) in Alzheimer's disease (AD). The NS allopregnanolone may be decreased in serum and plasma in patients with AD, but it is unclear if allopregnanolone is also reduced in brain. Bec ... Full text Link to item Cite

A pyruvate cycling pathway involving cytosolic NADP-dependent isocitrate dehydrogenase regulates glucose-stimulated insulin secretion.

Journal Article J Biol Chem · October 13, 2006 Glucose-stimulated insulin secretion (GSIS) from pancreatic islet beta-cells is central to control of mammalian fuel homeostasis. Glucose metabolism mediates GSIS in part via ATP-regulated K+ (KATP) channels, but multiple lines of evidence suggest particip ... Full text Link to item Cite

Neuroactive steroids are altered in schizophrenia and bipolar disorder: relevance to pathophysiology and therapeutics.

Journal Article Neuropsychopharmacology · June 2006 Evidence suggests that neuroactive steroids may be candidate modulators of schizophrenia pathophysiology and therapeutics. We therefore investigated neuroactive steroid levels in post-mortem brain tissue from subjects with schizophrenia, bipolar disorder, ... Full text Link to item Cite

New PEG-ylated Mn(III) porphyrins approaching catalytic activity of SOD enzyme.

Journal Article Dalton Trans · January 28, 2006 Two new tri(ethyleneglycol)-derivatized Mn(III) porphyrins were synthesized with the aim of increasing their bioavailability, and blood-circulating half-life. These are Mn(III) tetrakis(N-(1-(2-(2-(2-methoxyethoxy)ethoxy)ethyl)pyridinium-2-yl)porphyrin, Mn ... Full text Link to item Cite

Overproduction of alpha chains provides a proton-insensitive component to the bluefish hemoglobin system.

Journal Article J Biol Chem · December 9, 2005 Expression of alpha and beta chains and their post-translational assembly into alpha(2)beta(2) tetramers is fundamental to the formation and function of most vertebrate hemoglobins. There is a strong evolutionary bias that favors expression of equal amount ... Full text Link to item Cite

The Study of the Effects of Diet on Metabolism and Nutrition (STEDMAN) weight loss project: Rationale and design.

Journal Article Contemp Clin Trials · December 2005 This paper outlines the rationale and design of the Study of the Effects of Diet on Metabolism and Nutrition (STEDMAN) weight loss project, in which detailed biologic profiling of three hundred and fifty obese individuals (body mass index (BMI): 30-50 kg/m ... Full text Link to item Cite

Nitric oxide represses arabidopsis flowering

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2005 Link to item Cite

Elevated stearoyl-CoA desaturase-1 expression in skeletal muscle contributes to abnormal fatty acid partitioning in obese humans.

Journal Article Cell Metab · October 2005 Obesity and type 2 diabetes are strongly associated with abnormal lipid metabolism and accumulation of intramyocellular triacylglycerol, but the underlying cause of these perturbations are yet unknown. Herein, we show that the lipogenic gene, stearoyl-CoA ... Full text Link to item Cite

New Mn(III) porphyrins with high superoxide disproportionating ability

Conference FREE RADICAL BIOLOGY AND MEDICINE · January 1, 2005 Link to item Cite

Nitric oxide represses the Arabidopsis floral transition.

Journal Article Science · September 24, 2004 The correct timing of flowering is essential for plants to maximize reproductive success and is controlled by environmental and endogenous signals. We report that nitric oxide (NO) repressed the floral transition in Arabidopsis thaliana. Plants treated wit ... Full text Link to item Cite

New class of potent catalysts of O2.-dismutation. Mn(III) ortho-methoxyethylpyridyl- and di-ortho-methoxyethylimidazolylporphyrins.

Journal Article Dalton Trans · June 7, 2004 Three new Mn(III) porphyrin catalysts of O2.-dismutation (superoxide dismutase mimics), bearing ether oxygen atoms within their side chains, were synthesized and characterized: Mn(III) 5,10,15,20-tetrakis[N-(2-methoxyethyl)pyridinium-2-yl]porphyrin (MnTMOE ... Full text Link to item Cite

Hypertension and impaired glycine handling in mice lacking the orphan transporter XT2.

Journal Article Mol Cell Biol · May 2004 A family of orphan transporters has been discovered that are structurally related to the Na(+)-Cl(-)-dependent neurotransmitter transporters, including the dopamine transporter. One member of this family, the mouse XT2 gene, is predominantly expressed in t ... Full text Link to item Cite

Hepatic expression of malonyl-CoA decarboxylase reverses muscle, liver and whole-animal insulin resistance.

Journal Article Nat Med · March 2004 Lipid infusion or ingestion of a high-fat diet results in insulin resistance, but the mechanism underlying this phenomenon remains unclear. Here we show that, in rats fed a high-fat diet, whole-animal, muscle and liver insulin resistance is ameliorated fol ... Full text Link to item Cite

ENU mutagenesis identifies mice with mitochondrial branched-chain aminotransferase deficiency resembling human maple syrup urine disease.

Journal Article J Clin Invest · February 2004 Tandem mass spectrometry was applied to detect derangements in the pathways of amino acid and fatty acid metabolism in N-ethyl-N-nitrosourea-treated (ENU-treated) mice. We identified mice with marked elevation of blood branched-chain amino acids (BCAAs), k ... Full text Link to item Cite

Improving bioavailibility of SOD mimics

Conference FREE RADICAL BIOLOGY AND MEDICINE · January 1, 2004 Link to item Cite

A comparison of in vitro acylcarnitine profiling methods for the diagnosis of classical and variant short chain acyl-CoA dehydrogenase deficiency.

Journal Article Clin Chim Acta · November 2003 BACKGROUND: Homozygosity and compound heterozygosity for the short chain acyl-CoA dehydrogenase (SCAD) gene sequence variants 625G-->A and 511C-->T are associated with ethylmalonic aciduria (EMA), a biochemical indicator of SCAD deficiency. The clinical an ... Full text Link to item Cite

Analysis of a glucose tetrasaccharide elevated in Pompe disease by stable isotope dilution-electrospray ionization tandem mass spectrometry.

Journal Article Anal Biochem · May 15, 2003 Patients with glycogen storage disease type II (GSD II) typically excrete increased amounts of a glycogen-derived glucose tetrasaccharide, Glcalpha1-6Glcalpha1-4Glcalpha1-4Glc (Glc(4)), in the urine. With the advent of a new enzyme replacement therapy for ... Full text Link to item Cite

Isomeric oligosaccharide analysis using hydrophilic interaction LC-ESI-MS/MS

Journal Article Proceedings 50th ASMS Conference on Mass Spectrometry and Allied Topics · December 1, 2002 A hydrophilic interaction liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS/MS) method was established for the separation and analysis of hexose tetrasaccharide linkage isomers in urine, plasma and blood spots. Using the LC-ESI-MS/ ... Cite

An LC-MS/MS method for determination of glycosaminoglycan content of urine for the diagnosis of mucopolysaccharidoses

Journal Article Proceedings 50th ASMS Conference on Mass Spectrometry and Allied Topics · December 1, 2002 A quantitative liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) is developed to measure the characterstic disaccharide derived from glycosaminoglycans (GAG) by partial methanolysis. The results show that methanolysis replace the sulphat ... Cite

Responses of normal and sickle cell hemoglobin to S-nitroscysteine: implications for therapeutic applications of NO in treatment of sickle cell disease.

Journal Article Biophys Chem · July 10, 2002 Factors which govern transnitrosation reactions between hemoglobin (Hb) and low molecular weight thiols may define the extent to which S-nitrosated Hb (SNO-Hb) plays a role in NO in the control of blood pressure and other NO-dependent reactions. We show th ... Full text Link to item Cite

Heme redox properties of S-nitrosated hemoglobin A0 and hemoglobin S: implications for interactions of nitric oxide with normal and sickle red blood cells.

Journal Article J Biol Chem · April 26, 2002 S-Nitrosated hemoglobin is remarkably stable and can be cycled between deoxy, oxygenated, or oxidized forms without significant loss of NO. Here we show that S-nitrosation of adult human hemoglobin (Hb A(0)) or sickle cell Hb (Hb S) results in an increased ... Full text Link to item Cite

Manganese(III) meso-tetrakis(ortho-N-alkylpyridyl)porphyrins. Synthesis, characterization, and catalysis of O2/·- dismutation

Journal Article Journal of the Chemical Society, Dalton Transactions · January 1, 2002 A series of ortho isomers of meso-tetrakis(N-alkylpyridyl)porphyrins (alkyl being methyl, ethyl, n-propyl, n-butyl, n-hexyl, and n-octyl) and their Mn(III) complexes were synthesized and characterized by elemental analysis, uv/vis spectroscopy, electrospra ... Full text Cite

Manganese(III) biliverdin IX dimethyl ester: a powerful catalytic scavenger of superoxide employing the Mn(III)/Mn(IV) redox couple.

Journal Article Inorg Chem · February 12, 2001 A manganese(III) complex of biliverdin IX dimethyl ester, (MnIIIBVDME)2, was prepared and characterized by elemental analysis, UV/vis spectroscopy, cyclic voltammetry, chronocoulometry, electrospray mass spectrometry, freezing-point depression, magnetic su ... Full text Link to item Cite

Aqueous solution speciation of Fe(III) complexes with dihydroxamate siderophores alcaligin and rhodotorulic acid and synthetic analogues using electrospray ionization mass spectrometry.

Journal Article Inorg Chem · January 1, 2001 Aqueous solutions of Fe3+ complexes of cyclic (alcaligin) and linear (rhodotorulic acid) dihydroxamate siderophores and synthetic linear eight-carbon-chain and two-carbon-chain dihydroxamic acids ([CH3N(OH)C=O)]2(CH2)n; H2Ln; n = 2 and 8) were investigated ... Full text Link to item Cite

An LDI-TOF and ESI mass spectrometry study of a series of β-substituted cationic metalloporphyrins

Journal Article Journal of Porphyrins and Phthalocyanines · January 1, 2001 A series of β-halogenated cationic metalloporphyrins were analyzed by LDI-TOF and ESI-MS. Although LDI-TOFMS reveals to be a good tool for the characterization of this family of metal-complexes, including the redox state of the metal, ESI-MS indicates in a ... Full text Cite

Electrospray mass spectrometry of isomeric tetrakis(N-alkylpyridyl)porphyrins and their manganese(III) and iron(III) complexes

Journal Article Journal of Porphyrins and Phthalocyanines · January 1, 2000 Manganese(III) complexes of isomeric tetrakis(N-alkylpyridyl)porphyrins (N-alkyl = N-methyl, M or N-ethyl, E), MnTM(E)-2(3,4)-PyP5+, are being developed as superoxide dismutase (SOD) mimics. Simultaneously, techniques for their purification, identification ... Full text Cite

Electrospray mass spectrometry of isomeric tetrakis(N-alkylpyridyl)porphyrins and their manganese(III) and iron(III) complexes

Journal Article Journal of Porphyrins and Phthalocyanines · January 1, 2000 Manganese(III) complexes of isomeric tetrakis(N-alkylpyridyl)porphyrins (N-alkyl = N-methyl, M or N-ethyl, E), MnTM(E)-2(3,4)-PyP5+, are being developed as superoxide dismutase (SOD) mimics. Simultaneously, techniques for their purification, identification ... Full text Cite

Effects of S-nitrosation on oxygen binding by normal and sickle cell hemoglobin.

Journal Article J Biol Chem · August 27, 1999 S-Nitrosated hemoglobin (SNO-Hb) is of interest because of the allosteric control of NO delivery from SNO-Hb made possible by the conformational differences between the R- and T-states of Hb. To better understand SNO-Hb, the oxygen binding properties of S- ... Full text Link to item Cite

Fe(III) dissociation mechanisms for dohydroxamic acid siderophore complexes.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 22, 1999 Link to item Cite

Ternary complex structure of human HGPRTase, PRPP, Mg2+, and the inhibitor HPP reveals the involvement of the flexible loop in substrate binding.

Journal Article Protein Sci · May 1999 Site-directed mutagenesis was used to replace Lys68 of the human hypoxanthine phosphoribosyltransferase (HGPRTase) with alanine to exploit this less reactive form of the enzyme to gain additional insights into the structure activity relationship of HGPRTas ... Full text Link to item Cite

Protonation of the neutral repeats of the RNA polymerase II CTD.

Journal Article Biochem Biophys Res Commun · April 7, 1998 The CTD (carboxy-terminal repeat domain) of the largest subunit of RNA Polymerase II in most eukaryotes consists of from 26 to 52 seven amino acid repeats, the consensus sequence of which is YSPTSPS. Even though this consensus repeat does not contain resid ... Full text Link to item Cite

Surface structure of human mucin using X-ray photoelectron spectroscopy.

Journal Article Biospectroscopy · 1998 X-ray photoelectron spectroscopy (XPS) is a surface sensitive analytical technique that measures the binding energy of electrons in atoms and molecules on the surface of a material. XPS was used to determine the distribution of the oligosaccharide side cha ... Full text Link to item Cite

Evidence for a novel O-linked sialylated trisaccharide on Ser-248 of human plasminogen 2.

Journal Article J Biol Chem · March 14, 1997 Human plasminogen, the inactive precursor of plasmin, exists in two major glycoforms. Plasminogen 1 contains an N-linked oligosaccharide at Asn-289 and an O-linked oligosaccharide at Thr-345. Plasminogen 2 is known to contain only an O-linked oligosacchari ... Full text Link to item Cite

Identification of five hemoglobins in B6C3F1 mice by mass spectrometry and sequence analysis.

Journal Article Int J Biochem Cell Biol · December 1996 The aim of the work is to identify and characterize the hemoglobins found in B6C3F1 mice using mass spectrometry. The primary structures are compared to those reported for BALB/c mice. Individual hemoglobin chains were isolated by reverse-phase high perfor ... Full text Link to item Cite

High-level misincorporation of lysine for arginine at AGA codons in a fusion protein expressed in Escherichia coli.

Journal Article J Mol Biol · October 4, 1996 The expression of eukaryotic genes in Escherichia coli is one of the most frequently used tools of modern science. The arginine codon AGA is a common codon in eukaryotic genes but is particularly rare in E. coli. We report here 36 to 42% misincorporation o ... Full text Link to item Cite

Phytol metabolites are circulating dietary factors that activate the nuclear receptor RXR.

Journal Article Mol Biol Cell · August 1996 RXR is a nuclear receptor that plays a central role in cell signaling by pairing with a host of other receptors. Previously, 9-cis-retinoic acid (9cRA) was defined as a potent RXR activator. Here we describe a unique RXR effector identified from organic ex ... Full text Link to item Cite

Purification and characterization of the Cu,Zn SOD from Escherichia coli.

Journal Article Free Radic Biol Med · 1996 The periplasmic Cu,Zn superoxide dismutase has been purified to homogeneity by a procedure, which depended upon osmotic shock followed by two chromatographic columns. Its subunit weight, determined by electrospray ionization mass spectrometry, was found to ... Full text Link to item Cite

Processive post-translational modification. Vitamin K-dependent carboxylation of a peptide substrate.

Journal Article J Biol Chem · December 22, 1995 Mass spectrometry has been used to demonstrate that vitamin K-dependent carboxylation is a processive post-translational modification (i.e. multiple carboxylations occur during a single association between enzyme and substrate). Purified vitamin K-dependen ... Full text Link to item Cite

A Monomer-to-Dimer Shift in a Series of 1:1 Ferric Dihydroxamates Probed by Electrospray Mass Spectrometry

Journal Article Inorganic Chemistry · December 1, 1994 Electrospray mass spectrometry (ESMS) was used to determine the stoichiometry of a series of 1:1 iron(III) complexes with model dihydroxamic acids H2L, [CH3N(OH)C(O)]2(CH2)n, and with the natural dihydroxamate siderophore rhodotorulic acid, RA. Parent (or ... Full text Cite

Acrylamide in polyacrylamide gels can modify proteins during electrophoresis.

Journal Article Anal Biochem · October 1994 Many notable discoveries have resulted from the characterization or purification of compounds by electrophoresis. The results reported here show that when polyacrylamide gels are used as the support matrix for electrophoresis, proteins can be modified by r ... Full text Link to item Cite

Characterization of Mn(III) complexes of linear and cyclic desferrioxamines as mimics of superoxide dismutase activity.

Journal Article Arch Biochem Biophys · May 1, 1994 The green complex of Mn(III) with desferrioxamine B has been prepared by air oxidation of Mn(II) in the presence of the ligand or by reaction of Mn(OH)3, or of MnO2, with the ligand. The resultant complex was purified by ion-exchange chromatography and sho ... Full text Link to item Cite

Electrospray Mass Spectrometry Study of 1:1 Ferric Dihydroxamates

Journal Article Inorganic Chemistry · March 1, 1994 Full text Cite

The acceptor substrate specificity of porcine submaxillary UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase is dependent on the amino acid sequences adjacent to serine and threonine residues.

Journal Article J Biol Chem · November 5, 1993 The acceptor substrate specificity of a pure polypeptide N-acetylgalactosaminyltransferase has been examined with synthetic polypeptides with sequences identical, or similar to those found in porcine mucin or human erythropoietin. The sequences adjacent to ... Link to item Cite

Escherichia coli produces linoleic acid during late stationary phase.

Journal Article J Bacteriol · September 1993 Escherichia coli produces linoleic acid in the late stationary phase. This was the case whether the cultures were grown aerobically or anaerobically on a supplemented glucose-salts medium. The linoleic acid was detected by thin-layer chromatography and was ... Full text Link to item Cite

Proton magnetic resonance studies of the aggregation of taurine-conjugated bile salts.

Journal Article J Lipid Res · January 1992 The concentration dependence of the 500 MHz 1H-NMR spectra of taurocholate, taurochenodeoxycholate, taurodeoxycholate, and the monosulfate esters of taurochenodeoxycholate has been examined at 0.154 M NaCl in D2O. The resonances of the C18, C19, and C21 me ... Link to item Cite

Calcium binding by monosulfate esters of taurochenodeoxycholate.

Journal Article J Lipid Res · April 1991 The effect of sulfate esterification of the 3 alpha- or 7 alpha-hydroxyl groups of taurochenodeoxycholate on calcium binding was studied at 0.154 M NaCl in the presence and absence of phosphatidylcholine using a calcium electrode. For comparison, similar s ... Link to item Cite

Effects of monosulfate esters of taurochenodeoxycholate on bile flow and biliary lipids in hamsters.

Journal Article J Lipid Res · May 1989 The effect of the 3 alpha- and 7 alpha-monosulfate esters of taurochenodeoxycholate on bile flow and biliary lipids was compared to the effect of unsulfated taurochenodeoxycholate. Test bile salts were infused directly into the portal circulation through a ... Link to item Cite

CALCIUM-BINDING BY MONOSULFATE ESTERS OF TAUROCHENODEOXYCHOLATE

Journal Article CLINICAL RESEARCH · April 1, 1989 Link to item Cite

Fat digestion in patients with bile acid malabsorption but minimal steatorrhea.

Journal Article Dig Dis Sci · May 1980 Patients with an interrupted enterohepatic circulation of bile acids and minimal or no steatorrhea were studied to determine if their fat absorption was aided by compensatory mechanisms which delivered increased amounts of lipid to the aqueous phase of pos ... Full text Link to item Cite

The laboratory method as a variable in the interpretation of serum bilirubin fractionation.

Journal Article Gastroenterology · May 1980 Fractionation of the serum bilirubin into direct and indirect-reacting components has been used in the differentiation of patients with hepatobiliary disease from those with unconjugated hyperbilirubinemia. Previous studies have shown that patients with in ... Link to item Cite

The laboratory method as a variable in the interpretation of serum bilirubin fractionation

Journal Article Gastroenterology · January 1, 1980 Fractionation of the serum bilirubin into direct and indirect-reacting components has been used in the differentiation of patients with hepatobiliary disease from those with unconjugated hyperbilirubinemia. Previous studies have shown that patients with in ... Full text Cite

ESR STUDY OF THE AZO-COMPOUND PHOTOINITIATED POLYMERIZATION OF METHACRYLONITRILE

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · January 1, 1979 Link to item Cite

The sources of rat biliary cholesterol and bile acid.

Journal Article J Lipid Res · September 1978 The precursor sources of bile acid and bile neutral sterol were evaluated in the rat using Triparanol to inhibit the terminal reduction in the synthesis of cholesterol. During the initial period of Triparanol administration, the accumulation of hepatic des ... Link to item Cite

Lymph-node bacilliform bodies resembling those of Whipple's disease in a patient without intestinal involvement.

Journal Article Ann Intern Med · July 1978 A 38-year-old man developed symptoms of arthalgias and arthritis, lymphadenopathy, and weight loss. An axillary lymph-node biopsy was done in the diagnostic study; a periodic acid Schiff stain, done for evidence of fungal infection, showed periodic acid Sc ... Full text Link to item Cite

EPR study of the photoinitiated polymerization of styrene

Journal Article Journal of Magnetic Resonance (1969) · January 1, 1978 Using previously described continuous-flow procedures, we have studied, using electron paramagnetic resonance, the photolysis by near-ultraviolet radiation of dilute solutions of three symmetrical aliphatic azo compounds [RN : NR with R- equal to {A figure ... Full text Cite

An electron spin resonance study of cholestane spin label in aqueous mixtures of biliary lipids.

Journal Article J Lipid Res · July 1977 The effect of cholesterol on the fluidity of the phospholipid matrix in mixed micelles derived from bile salts and lecithin has been determined by the paramagnetic probe technique. It was found that correlation times for the cholestane spin label were disc ... Link to item Cite

GEL-PERMEATION OF AGGREGATES FORMED BY BILIARY LIPIDS

Journal Article GASTROENTEROLOGY · January 1, 1977 Link to item Cite

Magnetic nonequivalence in radicals from acrylic derivatives

Journal Article Journal of Magnetic Resonance (1969) · January 1, 1975 Full text Cite

Electron paramagnetic resonance study of the photoinitiated polymerization of methacrylonitrile

Journal Article The Journal of Physical Chemistry · January 1, 1975 Using previously detailed continuous-flow techniques, we have studied by electron paramagnetic resonance, EPR, the photolysis of 2,2′-azobis(2-methylpropionitrile), RN:NR, in solution at ca. 25°. The solvents used were toluene, methacrylonitrile, and tolue ... Full text Cite

Electron paramagnetic resonance spectroscopic study of the photoinitiated polymerization of alkyl methacrylates

Journal Article Journal of Physical Chemistry · January 1, 1972 Within a continuous-flow system, dilute oxygen-free solutions of 2,2′-azobis[isobutyronitrile], RN:NR, have been irradiated with near-ultraviolet mercury radiation, this occurring as the liquid passed through the cavity of an X-band electron paramagnetic r ... Full text Cite

Electron paramagnetic resonance spectroscopic study of radical cations from hydrazine, methylhydrazine, and dimethylhydrazines

Journal Article The Journal of Physical Chemistry · January 1, 1971 The substrates hydrazine, methylhydrazine, 1,1-dimethylhydrazine, and 1,2-dimethylhydrazine have been investigated in turn within an aqueous continuous-flow system at 25 ± 2° using the titanous chloride-hydrogen peroxide radical-generating method. For each ... Full text Cite