Hydrogen Exchange Mass Spectrometry for Studying Protein-ligand Interactions

Hydrogen Exchange Mass Spectrometry for Studying Protein-ligand Interactions
Author: Modupeola A. Sowole
Publisher:
Total Pages: 354
Release: 2015
Genre:
ISBN:
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Hydrogen deuterium exchange (HDX) coupled with mass spectrometry is widely used for probing protein structure and dynamics. Protein-ligand interactions usually induce a reduction in the measured HDX rates an effect that may be ascribed to stabilization of the protein structure. This work aims to improve the general understanding of the changes in HDX patterns associated with ligand binding. We initially applied HDX for studying differences between oxy -hemoglobin (Oxy- Hb) and aquomet-hemoglobin (Chapter 2). The results show that the and subunits respond differently to the oxy to aquomet transition with the heme binding pocket being destabilized in both cases. The results suggest that enhanced structural dynamics in the heme binding pocket may have adverse effects on heme-protein interactions. Chapter 3 focuses on the different scenarios that can be encountered in an HDX experiment upon ligand binding. Myoglobin and hemoglobin were used as model systems, focusing on the oxy and deoxy states of both proteins. Our results demons trate that ligand binding can be stabilizing or destabilizing, leading to decreased or increased HDX rates respectively. In Chapters 4 HDX was used to probe the changes in structural dynamics of caseinolytic protease P (ClpP), an antibiotic drug target, after binding ADEP antibiotics. The mechanism of ADEP binding and the N-terminal structure of ClpP is not well understood with conflicting x-ray structures reported in literature. Our findings demonstrate that the N- terminus of ClpP remains quite unstructured after ADEP binding, while belt region undergoes tightening. Pin 1, a peptidyl prolyl isomerase, binding to a cyclic peptide inhibitor was studied in Chapter 5. Characterization of Pin1-CRYPEVEIC interactions by ot her techniques has been difficult. This study demonstrates that binding of the inhibitor triggers an overall stabilization of Pin 1. We identify a loop that interacts with basic sites of the ligand and that becomes destabilized upon ligand binding. This destabilization is ascribed to steric clashes between the peptide inhibitor and the protein.

Hydrogen Exchange Mass Spectrometry of Proteins

Hydrogen Exchange Mass Spectrometry of Proteins
Author: David D. Weis
Publisher: John Wiley & Sons
Total Pages: 376
Release: 2016-01-11
Genre: Science
ISBN: 1118703693
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Hydrogen exchange mass spectrometry is widely recognized for its ability to probe the structure and dynamics of proteins. The application of this technique is becoming widespread due to its versatility for providing structural information about challenging biological macromolecules such as antibodies, flexible proteins and glycoproteins. Although the technique has been around for 25 years, this is the first definitive book devoted entirely to the topic. Hydrogen Exchange Mass Spectrometry of Proteins: Fundamentals, Methods and Applications brings into one comprehensive volume the theory, instrumentation and applications of Hydrogen Exchange Mass Spectrometry (HX-MS) - a technique relevant to bioanalytical chemistry, protein science and pharmaceuticals. The book provides a solid foundation in the basics of the technique and data interpretation to inform readers of current research in the method, and provides illustrative examples of its use in bio- and pharmaceutical chemistry and biophysics In-depth chapters on the fundamental theory of hydrogen exchange, and tutorial chapters on measurement and data analysis provide the essential background for those ready to adopt HX-MS. Expert users may advance their current understanding through chapters on methods including membrane protein analysis, alternative proteases, millisecond hydrogen exchange, top-down mass spectrometry, histidine exchange and method validation. All readers can explore the diversity of HX-MS applications in areas such as ligand binding, membrane proteins, drug discovery, therapeutic protein formulation, biocomparability, and intrinsically disordered proteins.

Mass Spectrometry of Protein Interactions

Mass Spectrometry of Protein Interactions
Author: Kevin Downard
Publisher: John Wiley & Sons
Total Pages: 153
Release: 2007-08-24
Genre: Science
ISBN: 047014632X
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The authoritative guide to analyzing protein interactions by mass spectrometry Mass spectrometry (MS) is playing an increasingly important role in the study of protein interactions. Mass Spectrometry of Protein Interactionspresents timely and definitive discussions of the diverse range of approaches for studying protein interactions by mass spectrometry with an extensive set of references to the primary literature. Each chapter is written by authors or teams of authors who are international authorities in their fields. This leading reference text: * Discusses the direct detection of protein interactions through electrospray ionization (ESI-MS); ion mobility analysis; and matrix-assisted laser desorption/ionization (MALDI-MS) * Covers the indirect analysis of protein interactions through hydrogen-deuterium exchange (HX-MS); limited proteolysis; cross-linking; and radial probe (RP-MS) * Guides researchers in the use of mass spectrometry in structural biology, biochemistry, and protein science to map and define the huge number and diversity of protein interactions * Reviews the latest discoveries and applications and addresses new and ongoing challenges This is a comprehensive reference for researchers in academia and industry engaged in studies of protein interactions and an excellent text for graduate and postgraduate students.

Application of Hydrogen Deuterium Exchange Mass Spectrometry in Protein-ligand and Protein-protein Interactions

Application of Hydrogen Deuterium Exchange Mass Spectrometry in Protein-ligand and Protein-protein Interactions
Author: Siqi Guan
Publisher:
Total Pages: 322
Release: 2016
Genre:
ISBN:
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Proteins are not static objects. They have a great variety of internal motions with different amplitudes and different timescales. These internal motions play an important role in catalytic processes. Therefore, the existence of an intimate relationship between protein dynamics and protein function is widely accepted. Due to the significance of protein dynamics, techniques have been developed to study protein dynamics including nuclear magnetic resonance (NMR) spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and mass spectrometry (MS). Compared with NMR and EPR spectroscopy, MS has less stringent sample requirements, including protein concentration and protein size. Moreover, the mass accuracy, sensitivity, and faster data analysis also have contributed to the rapid growth of MS based techniques. Hydrogen-deuterium exchange mass spectrometry (HDX-MS), a combination of HPLC and MS, has become a common and sensitive tool to probe protein structural flexibility and solution dynamics. In this dissertation, HDX-MS was applied to study dynamic changes of proteins due to substrate binding and protein-protein interactions. The GT-A glycosyltransferase glucosyl-3-phosphoglycerate synthase from Mycobacterium tuberculosis (MtGpgS) catalyzes the first step of biosynthesis of 6-O-methylglucose lipopolysaccharides (MGLPs), which are essential to growth and existence of mycobacterium. The HDX-MS data revealed that the two substrates UDP-glucose (UDPG) and 3-phosphoglycerate (3PGA) can bind to MtGpgS independently, disagreeing with the previous proposal that 3PGA can only bind to MtGpgS after UDPG. Moreover, 3PGA was found to bind to or allosterically affect the UDPG binding site. Furthermore, the HDX-MS data revealed that MtGpgS may provide a necessary conformation for UDPG binding, while it goes through a large conformational change on 3PGA binding. The GT-B glycosyltransferase MshA from Corynebacterium glutamicum (CgMshA) catalyzes the initial step of mycothiol biosynthesis. A large conformational change was observed in CgMshA on nucleotide binding by superimposing APO structure of CgMshA and complex structure with UDP. HDX-MS was utilized to study conformational changes of CgMshA on substrate binding from the aspect of dynamics, providing a complementary to static structures. The HDX-MS data showed that both substrates uridine diphosphate glucose-N-acetylglucosamine (UDP-GlcNAc) and 1-L-myo-inositol-1-phosphate (I1P) can bind to CgMshA independently, but the I1P binding is not productive since it binds to an uncorrect site. Moreover, the I1P binding can lead to dynamic changes of CgMshA, while only UDP-GlcNAc can induce the major conformational change of CgMshA. Furthermore, the 3PGA binding cannot induce further dynamic changes of CgMshA in the presence of UDP. HDX-MS was also employed to study dynamic changes of protein complex SufBC2D from Escherichia coli on ADP/Mg2+ binding. This complex is responsible for Fe-S cluster assembly under oxidative stress. The crystal structure of SufBC2D complex has been determined, while little dynamic information is known. So HDX-MS was applied to study dynamic changes of the SufBC2D complex. The HDX-MS data revealed that SufC has a significant conformational change, which may be required by ATP binding and hydrolysis. Moreover, SufB and SufD are detected to have dynamic changes due to SufC conformational changes. These dynamic changes suggest that SufB-SufD protomer may have a conformational change in order to provide a suitable conformation for Fe-S cluster assembly. This work demonstrates that HDX-MS can be effectively used to study protein-ligand and protein-protein interactions, as well as the accompanying changes in structural dynamics. HDX-MS data detects substrate binding mechanism and conformational changes that are not available through x-ray crystallography. With these advantages, HDX-MS has been applied in study of protein structure and dynamics, studying protein-ligand and protein-protein interactions, protein folding, as well as protein therapeutics discovery and development.

Probing Protein-ligand Interactions Via Solution Phase Hydrogen Exchange Mass Spectrometry

Probing Protein-ligand Interactions Via Solution Phase Hydrogen Exchange Mass Spectrometry
Author: Stefan Theo Esswein
Publisher:
Total Pages: 220
Release: 2010
Genre:
ISBN:
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Mass spectrometry is a versatile, sensitive and fast technique with which to probe biophysical properties in biological systems and one of the most important analytical tools in the multidisciplinary field of proteomics. The study of nativestate proteins and their complexes in the gas-phase is well established and direct infusion electrospray ionisation mass spectrometry (DI-ESI-MS) techniques are becoming increasingly popular as a tool for screening and determining quantitative information on protein-protein and protein-ligand interactions. However, complexes retained by ESI-MS are not always representative of those in solution and care must be taken in interpreting purely gas-phase results. This thesis details modification and advancement of solution phase techniques devised by Gross et al. utilising ESI-MS and Fitzgerald et al. applying matrix assisted laser desorption ionisation (MALDI)-MS termed PLIMSTEX (protein-ligand interactions by mass spectrometry, titration and hydrogen-deuterium-exchange)[1] and SUPREX (Stability of unpurified proteins from rates of H/D exchange)[2] to quantify these interactions with regards to high throughput analysis. The first part of this thesis describes the different developmental stages of the devised HPLC-front ends and their optimisation with myoglobin and insulin. The successfully developed HPLC-front end in conjunction with PLIMSTEX and SUPREX and ESI-MS then gets tested with self expressed and purified cyclophilin A(CypA)- cyclosporin A (CsA) system, followed by a test screen with potential CypA binding ligands. Dissociation constants (Kd's) within one order of magnitude to reported values are determined. In the third part of this thesis the application of the devised ESI-SUPREX methodology has been applied to anterior gradient 2 (AGr2) and the factor H complement control proteins module 19-20 (fH19-20) exhibiting binding potential to a taggedhexapeptide and a synthetic pentasaccharide, respectively, resulting in thermodynamical data for these protein-ligand interactions. For the AGr2 system another dimension of investigation has been added by temperature controlling the devised ESI-SUPREX approach, revealing a phase transition in the protein at higher temperatures. The final part of this thesis describes the application of the ESI-SUPREX methodology to probe folding properties of CypA in the presence of the self expressed and purified E. coli chaperonin groEL. Thereby the denaturing properties of groEL have been emphasised along with the stabilisation of a denatured CypA species.

Mass Spectrometry Analysis for Protein-Protein Interactions and Dynamics

Mass Spectrometry Analysis for Protein-Protein Interactions and Dynamics
Author: M. Chance
Publisher: John Wiley & Sons
Total Pages: 325
Release: 2008-09-22
Genre: Science
ISBN: 0470258861
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Presents a wide variety of mass spectrometry methods used to explore structural mechanisms, protein dynamics and interactions between proteins. Preliminary chapters cover mass spectrometry methods for examining proteins and are then followed by chapters devoted to presenting very practical, how-to methods in a detailed way. Includes footprinting and plistex specifically, setting this book apart from the competition.

Investigating Protein-carbohydrate Interactions with Hydrogen/deuterium Exchange Mass Spectrometry (HDX-MS)

Investigating Protein-carbohydrate Interactions with Hydrogen/deuterium Exchange Mass Spectrometry (HDX-MS)
Author: Jingjing Zhang
Publisher:
Total Pages: 7
Release: 2014
Genre: Carbohydrates
ISBN:
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The application of hydrogen/deuterium exchange mass spectrometry (HDX-MS) to investigating protein-carbohydrate interactions is described. Proteins from three bacterial toxins, the B subunit homopentamers of Cholera toxin (CTB5) and Shiga toxin type 1 (Stx1B5) and a fragment of Clostridium difficile toxin A (TcdA-A2), and their interactions with native carbohydrate receptors, GM1 pentasaccharide (GM1-os), Pk trisaccharide and CD-grease, respectively, were first served as model systems for this study. The results suggested that HDX-MS can serve as a useful tool for localizing the ligand binding sites in carbohydrate-binding proteins. Following this, HDX-MS measurements were applied to explore the existence of distinct HMOs binding sites on toxins. Altogether, two toxins were studied, CTB5 and TcdA-A2, and their interactions with HMOs, 2'-fucosyllactose (2'-FL) and lacto-N-tetraose (LNT), respectively. For CTB5 and its interaction with 2'-FL, a novel binding site was localized for 2'-FL, different from the one for native receptor GM1-os. For TcdA-A2 and its interaction with LNT, however, the localized binding site was the same as its native carbohydrate receptor CD-grease. A HDX-MS based titration method Protein-Ligand Interactions in solution by Mass Spectrometry, Titration and hydrogen/deuterium Exchange (PLIMSTEX), was also applied to CTB5 and its interactions GM1-os, to test the reliability of using peptides as indicators to obtain the protein-carbohydrate binding affinities. The average apparent association constant measured for the addition of GM1-os to CTB at pH 7.0 and 20 °C was found to be (1.6 ± 0.2) * 106 M-1. This is in reasonable agreement with the reported value of (3.2 ± 0.2) * 106 M-1, which was measured using direct ESI-MS assay at pH 6.9 and room temperature.

Mass Spectrometry in Biophysics

Mass Spectrometry in Biophysics
Author: Igor A. Kaltashov
Publisher: John Wiley & Sons
Total Pages: 320
Release: 2005-05-06
Genre: Science
ISBN: 0471705160
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The first systematic summary of biophysical mass spectrometrytechniques Recent advances in mass spectrometry (MS) have pushed the frontiersof analytical chemistry into the biophysical laboratory. As aresult, the biophysical community's acceptance of MS-based methods,used to study protein higher-order structure and dynamics, hasaccelerated the expansion of biophysical MS. Despite this growing trend, until now no single text has presentedthe full array of MS-based experimental techniques and strategiesfor biophysics. Mass Spectrometry in Biophysics expertly closesthis gap in the literature. Covering the theoretical background and technical aspects of eachmethod, this much-needed reference offers an unparalleled overviewof the current state of biophysical MS. Mass Spectrometry inBiophysics begins with a helpful discussion of general biophysicalconcepts and MS-related techniques. Subsequent chaptersaddress: * Modern spectrometric hardware * High-order structure and dynamics as probed by various MS-basedmethods * Techniques used to study structure and behavior of non-nativeprotein states that become populated under denaturingconditions * Kinetic aspects of protein folding and enzyme catalysis * MS-based methods used to extract quantitative information onprotein-ligand interactions * Relation of MS-based techniques to other experimental tools * Biomolecular properties in the gas phase Fully referenced and containing a helpful appendix on the physicsof electrospray mass spectrometry, Mass Spectrometry in Biophysicsalso offers a compelling look at the current challenges facingbiomolecular MS and the potential applications that will likelyshape its future.

Hydrogen Deuterium Exchange Mass Spectrometry for Protein-protein Interaction and Structural Dynamics

Hydrogen Deuterium Exchange Mass Spectrometry for Protein-protein Interaction and Structural Dynamics
Author: Harsimran Singh
Publisher:
Total Pages: 159
Release: 2013
Genre: Electronic dissertations
ISBN:
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Hydrogen deuterium exchange mass spectrometry has emerged as an important technique to probe protein structure and conformational dynamics. The rate of exchange of hydrogen with deuterium by the peptide backbone is dependent on the solvent accessibility, extent of hydrogen bonding in secondary structural elements and protein dynamics. The extent and the rate of deuterium incorporation are affected by changes in protein structure, interaction with ligand, protein-protein interaction and environmental factors such as pH and temperature. These conformational changes can be global and/or local. The increase in the mass is used to localize the deuterium incorporation after pepsin digestion of the protein and analysis by electrospray ionization mass spectrometry. In this dissertation traditional HDX-MS and a new deuterium trapping assay were used to probe the interaction sites between E. coli cysteine desulfurase SufS and acceptor protein SufE. SufS and SufE form an important part of the SUF pathway, essential for the biosynthesis of Fe-S clusters under oxidative stress and iron depletion conditions. In addition, SufE is known to stimulate SufS cysteine desulfurase activity, but the mechanism is unknown. The HDX-MS results show that the regions affected by the SufS-SufE interaction are dependent on the catalytic intermediate states of the two proteins. HDX-MS was also used to probe the conformational changes resulting upon persulfuration of SufS of Cys364 in the active site. The persulfuration of SufS not only affected regions in the active site cavity, but also had other conformational changes in more distal regions. Based on our findings a model for the interaction SufS and SufE was proposed. A mechanism for the enhancement of SufS cysteine desulfurase activity upon interaction with SufE was also postulated. In all this work demonstrates that hydrogen deuterium exchange mass spectrometry and the deuterium trapping methodology optimized for this system can be easily and effectively used to study the protein-protein interactions and the accompanying changes in structural dynamics for other proteins. Deuterium trapping was demonstrated to be fast, sensitive and reliable method to deduce the changes in solvent accessibility between two or more states of a protein. Both techniques can easily be applied to large number of protein complexes to determine the regions of interaction as well as gain mechanistic information not available through traditional methods such as X-ray crystallography and NMR.