Scholars@Duke
Terrence Gilbert Oas

Terrence Gilbert Oas

Professor of Biochemistry
Biochemistry
oas@duke.edu
Duke Box 3711, Durham, NC 27710
230C Nanaline Duke, Durham, NC 27710

Selected Publications

Efficient enumeration and visualization of helix-coil ensembles.

Journal Article Biophys J · February 6, 2024 Helix-coil models are routinely used to interpret circular dichroism data of helical peptides or predict the helicity of naturally-occurring and designed polypeptides. However, a helix-coil model contains significantly more information than mean helicity a ... Full text Link to item Cite

Efficient Enumeration and Visualization of Helix-coil Ensembles.

Journal Article bioRxiv · September 17, 2023 Helix-coil models are routinely used to interpret CD data of helical peptides or predict the helicity of naturally-occurring and designed polypeptides. However, a helix-coil model contains significantly more information than mean helicity alone, as it defi ... Full text Open Access Link to item Cite

Multiple Modes of Zinc Binding to Histatin 5 Revealed by Buffer-Independent Thermodynamics.

Journal Article Inorg Chem · May 8, 2023 Histatin 5 (Hist5) is an antimicrobial peptide found in human saliva as part of the innate immune system. Hist5 can bind several metal ions in vitro, and Zn2+ has been shown to function as an inhibitory switch to regulate the peptide's biological activity ... Full text Link to item Cite

Exposing Hidden High-Affinity RNA Conformational States.

Journal Article J Am Chem Soc · January 15, 2020 RNA recognition frequently results in conformational changes that optimize intermolecular binding. As a consequence, the overall binding affinity of RNA to its binding partners depends not only on the intermolecular interactions formed in the bound state b ... Full text Link to item Cite

Injectable tissue integrating networks from recombinant polypeptides with tunable order.

Journal Article Nat Mater · December 2018 Emergent properties of natural biomaterials result from the collective effects of nanoscale interactions among ordered and disordered domains. Here, using recombinant sequence design, we have created a set of partially ordered polypeptides to study emergen ... Full text Link to item Cite

Author Correction: Injectable tissue integrating networks from recombinant polypeptides with tunable order.

Journal Article Nat Mater · December 2018 In the version of this Article originally published, one of the authors' names was incorrectly given as Jeffery Schaal; it should have been Jeffrey L. Schaal. This has been corrected in all versions of the Article. ... Full text Link to item Cite

Continuous Interdomain Orientation Distributions Reveal Components of Binding Thermodynamics.

Journal Article J Mol Biol · September 14, 2018 The flexibility of biological macromolecules is an important structural determinant of function. Unfortunately, the correlations between different motional modes are poorly captured by discrete ensemble representations. Here, we present new ways to both re ... Full text Link to item Cite

Continuous interdomain orientation distributions reveal components of binding thermodynamics

Journal Article · October 11, 2017 1 Abstract The flexibility of biological macromolecules is an important structural determinant of function. Unfortunately, the correlations between different motional modes are poorly captured by discrete ensemble representations. Here, we present new ways ... Full text Cite

Spontaneous Unfolding-Refolding of Fibronectin Type III Domains Assayed by Thiol Exchange: THERMODYNAMIC STABILITY CORRELATES WITH RATES OF UNFOLDING RATHER THAN FOLDING.

Journal Article J Biol Chem · January 20, 2017 Globular proteins are not permanently folded but spontaneously unfold and refold on time scales that can span orders of magnitude for different proteins. A longstanding debate in the protein-folding field is whether unfolding rates or folding rates correla ... Full text Open Access Link to item Cite

Electrostatic Energetics of Bacillus subtilis Ribonuclease P Protein Determined by Nuclear Magnetic Resonance-Based Histidine pKa Measurements.

Journal Article Biochemistry · September 8, 2015 The pKa values of ionizable groups in proteins report the free energy of site-specific proton binding and provide a direct means of studying pH-dependent stability. We measured histidine pKa values (H3, H22, and H105) in the unfolded (U), intermediate (I), ... Full text Open Access Link to item Cite

Conformational kinetics reveals affinities of protein conformational states.

Journal Article Proc Natl Acad Sci U S A · July 28, 2015 Most biological reactions rely on interplay between binding and changes in both macromolecular structure and dynamics. Practical understanding of this interplay requires detection of critical intermediates and determination of their binding and conformatio ... Full text Open Access Link to item Cite

Suppression of conformational heterogeneity at a protein-protein interface.

Journal Article Proc Natl Acad Sci U S A · July 21, 2015 Staphylococcal protein A (SpA) is an important virulence factor from Staphylococcus aureus responsible for the bacterium's evasion of the host immune system. SpA includes five small three-helix-bundle domains that can each bind with high affinity to many h ... Full text Open Access Link to item Cite

Multiscale conformational heterogeneity in staphylococcal protein a: possible determinant of functional plasticity.

Journal Article Structure · October 7, 2014 The Staphylococcus aureus virulence factor staphylococcal protein A (SpA) is a major contributor to bacterial evasion of the host immune system, through high-affinity binding to host proteins such as antibodies. SpA includes five small three-helix-bundle d ... Full text Open Access Link to item Cite

The statistical conformation of a highly flexible protein: small-angle X-ray scattering of S. aureus protein A.

Journal Article Structure · August 5, 2014 Staphylococcal protein A (SpA) is a multidomain protein consisting of five globular IgG binding domains separated by a conserved six- to nine-residue flexible linker. We collected SAXS data on the N-terminal protein-binding half of SpA (SpA-N) and construc ... Full text Open Access Link to item Cite

Ligand concentration regulates the pathways of coupled protein folding and binding.

Journal Article J Am Chem Soc · January 22, 2014 Featured Publication Coupled ligand binding and conformational change plays a central role in biological regulation. Ligands often regulate protein function by modulating conformational dynamics, yet the order in which binding and conformational change occurs are often hotly d ... Full text Link to item Cite

Mapping mechanical properties of organic thin films by force-modulation microscopy in aqueous media.

Journal Article Beilstein J Nanotechnol · 2012 The mechanical properties of organic and biomolecular thin films on surfaces play an important role in a broad range of applications. Although force-modulation microscopy (FMM) is used to map the apparent elastic properties of such films with high lateral ... Full text Link to item Cite

Multiple ligand-specific conformations of the β2-adrenergic receptor.

Journal Article Nat Chem Biol · August 21, 2011 Seven-transmembrane receptors (7TMRs), also called G protein-coupled receptors (GPCRs), represent the largest class of drug targets, and they can signal through several distinct mechanisms including those mediated by G proteins and the multifunctional adap ... Full text Link to item Cite

A miniaturized technique for assessing protein thermodynamics and function using fast determination of quantitative cysteine reactivity.

Journal Article Proteins · April 2011 Protein thermodynamic stability is a fundamental physical characteristic that determines biological function. Furthermore, alteration of thermodynamic stability by macromolecular interactions or biochemical modifications is a powerful tool for assessing th ... Full text Link to item Cite

Probing the folding intermediate of Bacillus subtilis RNase P protein by nuclear magnetic resonance.

Journal Article Biochemistry · November 9, 2010 Featured Publication Protein folding intermediates are often imperative for overall folding processes and consequent biological functions. However, the low population and transient nature of the intermediate states often hinder their biochemical and biophysical characterizatio ... Full text Open Access Link to item Cite

Osmolyte-induced folding of an intrinsically disordered protein: folding mechanism in the absence of ligand.

Journal Article Biochemistry · June 29, 2010 Featured Publication Understanding the interconversion between thermodynamically distinguishable states present in a protein folding pathway provides not only the kinetics and energetics of protein folding but also insights into the functional roles of these states in biologic ... Full text Open Access Link to item Cite

Picomole-scale characterization of protein stability and function by quantitative cysteine reactivity.

Journal Article Proc Natl Acad Sci U S A · March 16, 2010 The Gibbs free energy difference between native and unfolded states ("stability") is one of the fundamental characteristics of a protein. By exploiting the thermodynamic linkage between ligand binding and stability, interactions of a protein with small mol ... Full text Link to item Cite

Conformational selection or induced fit: a flux description of reaction mechanism.

Journal Article Proc Natl Acad Sci U S A · August 18, 2009 Featured Publication The mechanism of ligand binding coupled to conformational changes in macromolecules has recently attracted considerable interest. The 2 limiting cases are the "induced fit" mechanism (binding first) or "conformational selection" (conformational change firs ... Full text Link to item Cite

PHYS 26-When folding is coupled to binding: How do we tell which comes first?

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 17, 2008 Link to item Cite

Dynamics of backbone conformational heterogeneity in Bacillus subtilis ribonuclease P protein.

Journal Article Biochemistry · December 25, 2007 Featured Publication Interconversion of protein conformations is imperative to function, as evidenced by conformational changes associated with enzyme catalytic cycles, ligand binding and post-translational modifications. In this study, we used 15N NMR relaxation experiments t ... Full text Link to item Cite

Statistical estimation of statistical mechanical models: helix-coil theory and peptide helicity prediction.

Journal Article J Comput Biol · December 2007 Featured Publication Analysis of biopolymer sequences and structures generally adopts one of two approaches: use of detailed biophysical theoretical models of the system with experimentally-determined parameters, or largely empirical statistical models obtained by extracting p ... 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

Force-induced prolyl cis-trans isomerization in elastin-like polypeptides.

Journal Article J Am Chem Soc · May 23, 2007 Elastin-like polypeptides (ELPs) are stimulus-responsive polymers that contain repeats of five amino acids, Val-Pro-Gly-Xaa-Gly (VPGXG), where Xaa is a guest residue that can be any amino acid with the exception of proline. While studying the conformationa ... Full text Link to item Cite

Backbone dynamics of the monomeric lambda repressor denatured state ensemble under nondenaturing conditions.

Journal Article Biochemistry · February 6, 2007 Featured Publication Oxidizing two native methionine residues predominantly populates the denatured state of monomeric lambda repressor (MetO-lambdaLS) under nondenaturing conditions. NMR was used to characterize the secondary structure and dynamics of MetO-lambdaLS in standar ... Full text Link to item Cite

Folding mechanism of a multiple independently-folding domain protein: double B domain of protein A.

Journal Article Biochemistry · October 10, 2006 The antibody binding properties of staphylococcal protein A (SpA) can be attributed to the presence of five highly homologous domains (E, D, A, B, and C). Although the folding of the B domain of protein A (BdpA) is well-characterized, the folding behavior ... Full text Link to item Cite

Ligation-state hydrogen exchange: coupled binding and folding equilibria in ribonuclease P protein.

Journal Article J Am Chem Soc · June 21, 2006 Featured Publication Bacillus subtilis ribonuclease P protein (P protein) is predominantly unfolded (D) at physiological pH and low ionic strength; however, small molecule anionic ligands (e.g., sulfate) directly bind to and stabilize the folded state (NL2). Because the D + 2L ... Full text Link to item Cite

Methionine oxidation of monomeric lambda repressor: the denatured state ensemble under nondenaturing conditions.

Journal Article Protein Sci · March 2006 Although poorly understood, the properties of the denatured state ensemble are critical to the thermodynamics and the kinetics of protein folding. The most relevant conformations to cellular protein folding are the ones populated under physiological condit ... Full text Link to item Cite

Thermodynamic characterization of the osmolyte- and ligand-folded states of Bacillus subtilis ribonuclease P protein.

Journal Article Biochemistry · October 4, 2005 Featured Publication In Bacillus subtilis, P protein is the noncatalytic component of ribonuclease P (RNase P) that is critical for achieving maximal nuclease activity under physiological conditions. P protein is predominantly unfolded (D) at neutral pH and low ionic strength; ... Full text Link to item Cite

Activation dependent conformational changes in beta-arrestin 2

Conference BIOPHYSICAL JOURNAL · January 1, 2005 Link to item Cite

Kinetic role of helix caps in protein folding is context-dependent.

Journal Article Biochemistry · April 6, 2004 Secondary structure punctuation through specific backbone and side chain interactions at the beginning and end of alpha-helices has been proposed to play a key role in hierarchical protein folding mechanisms [Baldwin, R. L., and Rose, G. D. (1999) Trends B ... Full text Link to item Cite

Fast and faster: a designed variant of the B-domain of protein A folds in 3 microsec.

Journal Article Protein Sci · April 2004 We have introduced the mutation glycine 29 to alanine, designed to increase the rate of protein folding, into the B-domain of protein A (BdpA). From NMR lineshape analysis, we find the G29A mutation increases the folding rate constant by threefold; the fol ... Full text Link to item Cite

Probing the folding and unfolding dynamics of secondary and tertiary structures in a three-helix bundle protein.

Journal Article Biochemistry · March 30, 2004 Fast relaxation kinetics studies of the B-domain of staphylococcal protein A were performed to characterize the folding and unfolding of this small three-helix bundle protein. The relaxation kinetics were initiated using a laser-induced temperature jump an ... Full text Link to item Cite

Microsecond folding dynamics of the F13W G29A mutant of the B domain of staphylococcal protein A by laser-induced temperature jump.

Journal Article Proc Natl Acad Sci U S A · March 16, 2004 The small size (58 residues) and simple structure of the B domain of staphylococcal protein A (BdpA) have led to this domain being a paradigm for theoretical studies of folding. Experimental studies of the folding of BdpA have been limited by the rapidity ... Full text Link to item Cite

Identification of a residue critical for maintaining the functional conformation of BPTI.

Journal Article J Mol Biol · October 17, 2003 The effects of amino acid replacements on the backbone dynamics of bovine pancreatic trypsin inhibitor (BPTI) were examined using 15N NMR relaxation experiments. Previous studies have shown that backbone amide groups within the trypsin-binding region of th ... Full text Link to item Cite

Quantitative protein stability measurement in living bacteria

Journal Article Proceedings 50th ASMS Conference on Mass Spectrometry and Allied Topics · December 1, 2002 Hydrogen exchange detected by MALDI mass spectrometry was used to measure the thermodynamic stability of proteins. The stability of the N-terminal domain measured in vitro, qualitatively correlated with its degradation because the folding kinetics of the p ... Cite

A general mass spectrometry-based method for the quantitation of protein-ligand binding interactions in solution

Journal Article Proceedings 50th ASMS Conference on Mass Spectrometry and Allied Topics · December 1, 2002 The protein-ligand binding interactions in solution were investigated using mass spectrometry. The H/D exchange and mass spectrometry-based technique termed as stability of unpurified proteins by rates of H/D exchange (SUPREX) was developed to evaluate the ... Cite

A general mass spectrometry-based assay for the quantitation of protein-ligand binding interactions in solution.

Journal Article J Am Chem Soc · September 4, 2002 A new method that utilizes matrix-assisted laser desorption/ionization (MALDI) mass spectrometry and exploits the hydrogen/deuterium (H/D) exchange properties of proteins was developed for measuring the thermodynamic properties of protein-ligand complexes ... Full text Link to item Cite

Mechanism of fast protein folding.

Journal Article Annu Rev Biochem · 2002 An explosion of in vitro experimental data on the folding of proteins has revealed many examples of folding in the millisecond or faster timescale, often occurring in the absence of stable intermediate states. We review experimental methods for measuring f ... Full text Link to item Cite

Quantitative protein stability measurement in vivo.

Journal Article Nat Struct Biol · October 2001 Featured Publication The equilibrium between the native and denatured states of a protein can be key to its function and regulation. Traditionally, the folding equilibrium constant has been measured in vitro using purified protein and simple buffers. However, the biological en ... Full text Link to item Cite

Phosphorylation of RNA polymerase II CTD fragments results in tight binding to the WW domain from the yeast prolyl isomerase Ess1.

Journal Article Biochemistry · July 24, 2001 The yeast prolyl isomerase, Ess1, has recently been shown to interact via its WW domain with the hyperphosphorylated form of the RNA polymerase II C-terminal domain (CTD). We have investigated folding of the Ess1 WW domain and its binding to peptides repre ... Full text Link to item Cite

Preorganized secondary structure as an important determinant of fast protein folding.

Journal Article Nat Struct Biol · June 2001 The folding and unfolding kinetics of the B-domain of staphylococcal protein A, a small three-helix bundle protein, were probed by NMR. The lineshape of a single histidine resonance was fit as a function of denaturant to give folding and unfolding rate con ... Full text Link to item Cite

Linked folding and anion binding of the Bacillus subtilis ribonuclease P protein.

Journal Article Biochemistry · March 6, 2001 Ribonuclease P (RNase P) is the endoribonuclease responsible for the 5'-maturation of precursor tRNA transcripts. In bacteria, RNase P is composed of a catalytic RNA subunit and an associated protein subunit that enhances the substrate specificity of the h ... Full text Link to item Cite

A quantitative, high-throughput screen for protein stability.

Journal Article Proc Natl Acad Sci U S A · July 18, 2000 Featured Publication In proteomic research, it is often necessary to screen a large number of polypeptides for the presence of stable structure. Described here is a technique (referred to as SUPREX, stability of unpurified proteins from rates of H/D exchange) for measuring the ... Full text Link to item Cite

Novel disulfide engineering in human carbonic anhydrase II using the PAIRWISE side-chain geometry database.

Journal Article Protein Sci · April 2000 An analysis of the pairwise side-chain packing geometries of cysteine residues observed in high-resolution protein crystal structures indicates that cysteine pairs have pronounced orientational preferences due to the geometric constraints of disulfide bond ... Full text Link to item Cite

Mechanism of folding fast: Experimental and theoretical studies of monomeric lambda repressor.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 26, 2000 Link to item Cite

Reinterpretation of GCN4-p1 folding kinetics: partial helix formation precedes dimerization in coiled coil folding.

Journal Article J Mol Biol · June 4, 1999 The folding of coiled coil peptides has traditionally been interpreted in terms of native dimer and unfolded monomers. Calculations using AGADIR and experimental studies of fragments suggest that the monomers of the coiled coil peptide, GCN4-p1, contain si ... Full text Link to item Cite

Contribution of a buried hydrogen bond to lambda repressor folding kinetics.

Journal Article Biochemistry · May 25, 1999 A hydrogen bond between the buried residues Asp 14 and Ser 77 in monomeric lambda repressor has been removed by mutation of these residues to alanine. Double mutant cycles show that the interaction stabilizes the native state of the protein by 1.5 kcal/mol ... Full text Link to item Cite

Determinants of backbone dynamics in native BPTI: cooperative influence of the 14-38 disulfide and the Tyr35 side-chain.

Journal Article J Mol Biol · December 18, 1998 15Nitrogen relaxation experiments were used to characterize the backbone dynamics of two modified forms of bovine pancreatic trypsin inhibitor (BPTI). In one form, the disulfide between Cys14 and Cys38 in the wild-type protein was selectively reduced and m ... Full text Link to item Cite

The structural distribution of cooperative interactions in proteins: analysis of the native state ensemble.

Journal Article Proc Natl Acad Sci U S A · August 18, 1998 Cooperative interactions link the behavior of different amino acid residues within a protein molecule. As a result, the effects of chemical or physical perturbations to any given residue are propagated to other residues by an intricate network of interacti ... Full text Link to item Cite

Folding kinetics of a fluorescent variant of monomeric lambda repressor.

Journal Article Biochemistry · June 23, 1998 A tryptophan-containing variant of monomeric lambda repressor has been made, and its folding kinetics were analyzed at 20 degreesC using fluorescence stopped-flow and dynamic NMR. Equilibrium denaturation curves obtained by circular dichroism, fluorescence ... Full text Link to item Cite

Protein folding dynamics: quantitative comparison between theory and experiment.

Journal Article Biochemistry · April 21, 1998 The development of a quantitative kinetic scheme is a central goal in mechanistic studies of biological phenomena. For fast-folding proteins, which lack experimentally observable kinetic intermediates, a quantitative kinetic scheme describing the order and ... Full text Link to item Cite

ALASKA: A Mathematica package for two-state kinetic analysis of protein folding reactions

Journal Article Journal of Biomolecular NMR · January 1, 1998 A Mathematica package (ALASKA) has been developed to simplify the measurement of protein folding kinetics by analysis of 1H NMR lineshape analysis. This package reads NMR data in ASCII format and can simulate an aromatic 1 NMR spectrum with or without line ... Full text Cite

Enhanced protein flexibility caused by a destabilizing amino acid replacement in BPTI.

Journal Article J Mol Biol · May 30, 1997 A genetically engineered variant of bovine pancreatic trypsin inhibitor (Y35G BPTI) has been shown previously by X-ray crystallography to have a three-dimensional structure dramatically different from that of the wild-type protein, particularly in the prot ... Full text Link to item Cite

The energy landscape of a fast-folding protein mapped by Ala-->Gly substitutions.

Journal Article Nat Struct Biol · April 1997 A moderately stable protein with typical folding kinetics unfolds and refolds many times during its cellular lifetime. In monomeric lambda repressor this process is extremely rapid, with an average folded state lifetime of only 30 milliseconds. A thermosta ... Full text Link to item Cite

Microsecond protein folding through a compact transition state.

Journal Article J Mol Biol · October 25, 1996 Dynamic NMR methods have been employed to measure the folding and unfolding rate constants of two extremely fast-folding proteins. lambda 6-85, a truncated, monomeric form of the N-terminal domain of lambda repressor, refolds with a lifetime of approximate ... 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

Heat and cold denatured states of monomeric lambda repressor are thermodynamically and conformationally equivalent.

Journal Article Biochemistry · May 21, 1996 Although the denaturation of proteins by low temperatures is a well-documented phenomenon, little is known about the molecular details of the process. In this study, the parameters describing the denaturation thermodynamics of residues 6-85 of the N-termin ... Full text Link to item Cite

Heat and cold denatured states of monomeric λ represser are thermodynamically and conformationally equivalen

Journal Article Biochemistry · May 21, 1996 Although the denaturation of proteins by low temperatures is a well-documented phenomenon, little is known about the molecular details of the process. In this study, the parameters describing the denaturation thermodynamics of residues 6-85 of the N-termin ... Cite

Submillisecond folding of monomeric lambda repressor.

Journal Article Proc Natl Acad Sci U S A · July 18, 1995 Featured Publication The folding kinetics of a truncated form of the N-terminal domain of phage lambda repressor [lambda 6-85] has been investigated by using the technique of dynamic NMR. lambda 6-85 has been shown previously to fold in a purely two-state fashion. This allows ... Full text Link to item Cite

Structure and stability of monomeric lambda repressor: NMR evidence for two-state folding.

Journal Article Biochemistry · March 28, 1995 The absence of equilibrium intermediates in protein folding reactions (i.e., two-state folding) simplifies thermodynamic and kinetic analyses but is difficult to prove rigorously. We demonstrate a sensitive method for detecting partially folded species bas ... Full text Link to item Cite

An Anionic Diplatinum DNA Photocleavage Agent: Chemical Mechanism and Footprinting of λ Repressor

Journal Article Journal of the American Chemical Society · January 1, 1995 The dσ* → pσ excited state of Pt2(pop)44– (1, pop = P2O5H22–) elicits frank scission of double-stranded DNA as assayed by high-resolution gel electrophoresis. The photoreaction of 1 and a 5′-32P-labeled 25-mer duplex produces a surprisingly even ladder of ... Full text Cite

Propensity for a leucine zipper-like domain of human immunodeficiency virus type 1 gp41 to form oligomers correlates with a role in virus-induced fusion rather than assembly of the glycoprotein complex.

Journal Article Proc Natl Acad Sci U S A · December 20, 1994 For a number of viruses, oligomerization is a critical component of envelope processing and surface expression. Previously, we reported that a synthetic peptide (DP-107) corresponding to the putative leucine zipper region (aa 553-590) of the transmembrane ... Full text Link to item Cite

ANTIVIRAL ACTIVITY AND MECHANISM OF INHIBITION OF GP41 DERIVED SYNTHETIC PEPTIDES

Conference AIDS RESEARCH AND HUMAN RETROVIRUSES · August 1, 1994 Link to item Cite

A PEPTIDE INHIBITOR OF HIV-1 REPLICATION - CORRELATION BETWEEN SOLUTION STRUCTURE AND VIRAL INHIBITION

Conference JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY · June 1, 1993 Link to item Cite

A synthetic peptide inhibitor of human immunodeficiency virus replication: correlation between solution structure and viral inhibition.

Journal Article Proc Natl Acad Sci U S A · November 1, 1992 A peptide designated DP-107 was synthesized containing amino acid residues 558-595 of the envelope glycoprotein gp160 of human immunodeficiency virus type 1 strain LAI (HIV-1LAI). Algorithms for secondary structure have predicted that this region of the en ... Full text Link to item Cite

STRUCTURE AND ENERGETICS OF CONCANAVALIN A-OLIGOSACCHARIDE BINDING

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 23, 1992 Link to item Cite

Inhibition of thermolysin by phosphonamidate transition-state analogues: measurement of 31P-15N bond lengths and chemical shifts in two enzyme-inhibitor complexes by solid-state nuclear magnetic resonance.

Journal Article Biochemistry · October 2, 1990 31P and 15N chemical shifts and 31P-15N bond lengths have been measured with solid-state NMR techniques in two inhibitors of thermolysin, carbobenzoxy-Glyp-L-Leu-L-Ala (ZGpLA) and carbobenzoxy-L-Phep-L-Leu-L-Ala (ZFpLA), both as free lithium salts and when ... Full text Link to item Cite

Secondary structure of a leucine zipper determined by nuclear magnetic resonance spectroscopy.

Journal Article Biochemistry · March 27, 1990 Previous work has shown that a synthetic peptide corresponding to the leucine zipper region of the yeast transcriptional activator GCN4 forms a stable dimer of alpha-helices and that the helices are oriented in a parallel manner. Two-dimensional nuclear ma ... Full text Link to item Cite

PEPTIDE MODELS AND THE FOLDING OF BPTI

Journal Article BIOPHYSICAL JOURNAL · February 1, 1990 Link to item Cite

Peptides from conus venoms which affect ca+plus; entry into neurons

Journal Article Toxin Reviews · January 1, 1990 The venoms of fish-hunting Conus contain paralytic conotoxins and an unprecedented variety of other biologically-active peptides. Particularly noteworthy are peptides which inhibit calcium entry into neurons, the conantokins and w-conotoxins which target N ... Full text Cite

A PROTEIN FOLDING INTERMEDIATE ANALOG - DESIGN, SYNTHESIS, AND CHARACTERIZATION

Conference PROTEIN FOLDING : DECIPHERING THE SECOND HALF OF THE GENETIC CODE · January 1, 1990 Link to item Cite

Selective NMR detection of 13C15N dipole pairs in solid samples

Journal Article Journal of Magnetic Resonance (1969) · February 1, 1989 Full text Cite

Enhancement of the effect of small anisotropies in magic-angle spinning nuclear magnetic resonance

Journal Article Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases · December 1, 1988 A variety of novel methods in magic-angle spinning NMR is described. The effects have in common the enhancement of the influence of small anisotropies on the NMR spectrum by deliberate intervention, i.e. either by applying pulses, carefully chosen continuo ... Full text Cite

A peptide model of a protein folding intermediate.

Journal Article Nature · November 3, 1988 It is difficult to determine the structures of protein folding intermediates because folding is a highly cooperative process. A disulphide-bonded peptide pair, designed to mimic the first crucial intermediate in the folding of bovine pancreatic trypsin inh ... Full text Link to item Cite

A new iterative least-squares method for the extraction of NMR parameters from nonideal powder patterns

Journal Article Journal of Magnetic Resonance (1969) · January 1, 1988 A new approach to fitting powder patterns via nonlinear least-squares analysis is described. This fitting method is designed to be particularly sensitive to the frequencies of important features and insensitive to discrepancies in intensity between calcula ... Full text Cite

Rotary resonance recoupling of dipolar interactions in solid-state nuclear magnetic resonance spectroscopy

Journal Article The Journal of Chemical Physics · January 1, 1988 A new resonance effect in solid-state nuclear magnetic resonance (NMR) is described. The effect involves a combination of magic-angle sample rotation with irradiation of a heteronuclear spin system at the Larmor frequency of one of the spin species. If the ... Full text Cite

Rotary Resonance Recoupling in Heteronuclear Spin Pair Systems

Journal Article Israel Journal of Chemistry · January 1, 1988 In solid state magic angle spinning experiments on a polycrystalline sample containing dilute heteronuclear spin pairs, the usual spectrum is insensitive to small heteronuclear couplings between the spins, and to the relative orientations of the various in ... Full text Cite

The Amide 15N Chemical Shift Tensors of Four Peptides Determined from 13C Dipole-Coupled Chemical Shift Powder Patterns

Journal Article Journal of the American Chemical Society · September 1, 1987 The15N chemical shift tensors of a homologous series of peptides of the form N-acetyl[l-13C]glycyl[15N]-X-amide (X = glycine, alanine, and tyrosine) and the unprotected dipeptide [l-13C]glycyl[15N]glycine hydrochloride have been determined from13C dipole-c ... Full text Cite

The Carbonyl 13C Chemical Shift Tensors of Five Peptides Determined from 15N Dipole-Coupled Chemical Shift Powder Patterns

Journal Article Journal of the American Chemical Society · September 1, 1987 The13C chemical shift tensors have been determined for the glycine carbonyl carbon in a homologous series of peptides of the general form N-acetyl[l-13C]glycyl-X-amide, where X was [15N]glycine, dl-[15n] <-tyrosine, l-[15n] Full text Cite

Determination of the 15N and 13C Chemical Shift Tensors of L-[13C]Alanyl-L-[15N]alanine from the Dipole-Coupled Powder Patterns

Journal Article Journal of the American Chemical Society · September 1, 1987 The13C and15N chemical shift tensors of L-[l-13C]alanyl-L-[15N]alanine have been determined from the dipole-coupled powder patterns and verified with the decoupled spectra. The principal values of the13C tensor are σ11= -115.5, σ22= -42.3, and 0–33= 33.5 p ... Full text Cite

A NEW APPROACH TO LEAST-SQUARES FITTING ANALYSIS OF NMR POWDER PATTERNS

Journal Article BIOPHYSICAL JOURNAL · February 1, 1987 Link to item Cite

Determination of the 15N and 13C chemical shift tensors of L-[13C]alanyl-L-[15N]alanine from the dipole-coupled powder patterns

Journal Article Journal of the American Chemical Society · 1987 The 13C and 15N chemical shift tensors of L-[1-13C]alanyl-L-[15N]alanine have been determined from the dipole-coupled powder patterns and verified with the decoupled spectra. The principal values of the 13C tensor are σ11 = -115.5, σ22 = -42.3, and σ33 = 3 ... Cite

N-15 AMIDE CHEMICAL-SHIFT TENSORS OF SEVERAL DIPEPTIDES

Journal Article BIOPHYSICAL JOURNAL · February 1, 1986 Link to item Cite

Assignment of Proton Amide Resonances of T4 Lysozyme by 13C and 15N Multiple Isotopic Labeling

Journal Article Journal of the American Chemical Society · January 1, 1986 The unambiguous resolution and assignment of resonances from specific protons is the major limitation in 1H NMR studies of proteins.1Heteronuclear double-resonance spectroscopy of samples labeled with stable isotopes such as 13C and l5N offers one solution ... Full text Cite

C-13 CARBONYL CHEMICAL-SHIFT TENSORS OF 3 GLYCINE DIPEPTIDES

Journal Article BIOPHYSICAL JOURNAL · January 1, 1985 Link to item Cite

ULTRAVIOLET RESONANCE RAMAN STUDIES OF PEPTIDE COMPONENTS

Conference BIOPHYSICAL JOURNAL · January 1, 1984 Link to item Cite

Comparison of Associations of Different Hydrocarbons with Clay Particles in Simulated Seawater

Journal Article Environmental Science and Technology · January 1, 1978 Some aspects of the association of hydrocarbons and smectite clay in simulated seawater were investigated using NaCl solutions in laboratory experiments. Both n-eicosane and n-eicosene displayed identical association behaviors with this clay. Association i ... Full text Cite