51
|
Maleki H, Maurer MM, Ronaghi N, Valentine SJ. Ion Mobility, Hydrogen/Deuterium Exchange, and Isotope Scrambling: Tools to Aid Compound Identification in ‘Omics Mixtures. Anal Chem 2017; 89:6399-6407. [PMID: 28505408 DOI: 10.1021/acs.analchem.7b00075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Hossein Maleki
- Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Megan M. Maurer
- Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Nima Ronaghi
- Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Stephen J. Valentine
- Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
52
|
Hamuro Y. Regio-Selective Intramolecular Hydrogen/Deuterium Exchange in Gas-Phase Electron Transfer Dissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:971-977. [PMID: 28194737 DOI: 10.1007/s13361-017-1612-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 12/29/2016] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
Protein backbone amide hydrogen/deuterium exchange mass spectrometry (HDX-MS) typically utilizes enzymatic digestion after the exchange reaction and before MS analysis to improve data resolution. Gas-phase fragmentation of a peptic fragment prior to MS analysis is a promising technique to further increase the resolution. The biggest technical challenge for this method is elimination of intramolecular hydrogen/deuterium exchange (scrambling) in the gas phase. The scrambling obscures the location of deuterium. Jørgensen's group pioneered a method to minimize the scrambling in gas-phase electron capture/transfer dissociation. Despite active investigation, the mechanism of hydrogen scrambling is not well-understood. The difficulty stems from the fact that the degree of hydrogen scrambling depends on instruments, various parameters of mass analysis, and peptide analyzed. In most hydrogen scrambling investigations, the hydrogen scrambling is measured by the percentage of scrambling in a whole molecule. This paper demonstrates that the degree of intramolecular hydrogen/deuterium exchange depends on the nature of exchangeable hydrogen sites. The deuterium on Tyr amide of neurotensin (9-13), Arg-Pro-Tyr-Ile-Leu, migrated significantly faster than that on Ile or Leu amides, indicating the loss of deuterium from the original sites is not mere randomization of hydrogen and deuterium but more site-specific phenomena. This more precise approach may help understand the mechanism of intramolecular hydrogen exchange and provide higher confidence for the parameter optimization to eliminate intramolecular hydrogen/deuterium exchange during gas-phase fragmentation. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Yoshitomo Hamuro
- ExSAR Corporation, 11 Deer Park Drive, Suite 103, Monmouth Junction, NJ, 08852, USA.
| |
Collapse
|
53
|
Jhan SY, Huang LJ, Wang TF, Chou HH, Chen SH. Dimethyl Labeling Coupled with Mass Spectrometry for Topographical Characterization of Primary Amines on Monoclonal Antibodies. Anal Chem 2017; 89:4255-4263. [PMID: 28257187 DOI: 10.1021/acs.analchem.7b00320] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Site-specific solvent accessibility of the primary amines (mainly lysine or the N-termini) on proteins is of great interest in many research areas because amines are an important functional group for protein conjugation. In this study, we coupled dimethyl labeling via reductive amination with liquid chromatography-mass spectrometry (LC-MS) to fully characterize the solvent accessibility of lysine residues and the N-termini on human immunoglobulin G (IgG). Circular dichroism (CD) and fluorescence spectroscopy revealed that dimethyl labeling did not alter the conformation of the native IgG molecule. Based on intact protein measurements, up to 28 (light chain) and 66 (heavy chain) dimethyl tags, covering all lysine residues and the N-termini, were sequentially incorporated into IgG molecules in 1000 s. All labeled sites were identified and quantified by a bottom-up proteomics approach. Some highly exposed hot-spots (for example, the N-termini of both the heavy and the light chains) and some buried sites (for example, K415 in the heavy chain and K39 in the light chain) were unambiguously revealed. This method was also used to characterize aggregation-induced structural changes in IgGs by increasing the temperature. Substantial changes in the labeling percentage of many lysine sites were observed, indicating a non-native aggregation triggered by thermal stress. Due to high labeling yields and the van der Waals surface of the labeling reagents being comparable to that of water, dimethyl labeling is a highly promising technique for probing the amine's surface topography of proteins. It can also be used as a complementary approach to other methods for resolving the higher-order structure of proteins by LC-MS.
Collapse
Affiliation(s)
- Sin-Yi Jhan
- Department of Chemistry, National Cheng Kung University , No. 1 College Road, Tainan 701, Taiwan, Republic of China
| | - Li-Juan Huang
- Department of Chemistry, National Cheng Kung University , No. 1 College Road, Tainan 701, Taiwan, Republic of China
| | - Tzu-Fan Wang
- Department of Chemistry, National Cheng Kung University , No. 1 College Road, Tainan 701, Taiwan, Republic of China
| | - Ho-Hsuan Chou
- Department of Chemistry, National Cheng Kung University , No. 1 College Road, Tainan 701, Taiwan, Republic of China
| | - Shu-Hui Chen
- Department of Chemistry, National Cheng Kung University , No. 1 College Road, Tainan 701, Taiwan, Republic of China
| |
Collapse
|
54
|
Hamuro Y. Determination of Equine Cytochrome c Backbone Amide Hydrogen/Deuterium Exchange Rates by Mass Spectrometry Using a Wider Time Window and Isotope Envelope. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:486-497. [PMID: 28108962 DOI: 10.1007/s13361-016-1571-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/02/2016] [Accepted: 11/27/2016] [Indexed: 06/06/2023]
Abstract
A new strategy to analyze amide hydrogen/deuterium exchange mass spectrometry (HDX-MS) data is proposed, utilizing a wider time window and isotope envelope analysis of each peptide. While most current scientific reports present HDX-MS data as a set of time-dependent deuteration levels of peptides, the ideal HDX-MS data presentation is a complete set of backbone amide hydrogen exchange rates. The ideal data set can provide single amide resolution, coverage of all exchange events, and the open/close ratio of each amide hydrogen in EX2 mechanism. Toward this goal, a typical HDX-MS protocol was modified in two aspects: measurement of a wider time window in HDX-MS experiments and deconvolution of isotope envelope of each peptide. Measurement of a wider time window enabled the observation of deuterium incorporation of most backbone amide hydrogens. Analysis of the isotope envelope instead of centroid value provides the deuterium distribution instead of the sum of deuteration levels in each peptide. A one-step, global-fitting algorithm optimized exchange rate and deuterium retention during the analysis of each amide hydrogen by fitting the deuterated isotope envelopes at all time points of all peptides in a region. Application of this strategy to cytochrome c yielded 97 out of 100 amide hydrogen exchange rates. A set of exchange rates determined by this approach is more appropriate for a patent or regulatory filing of a biopharmaceutical than a set of peptide deuteration levels obtained by a typical protocol. A wider time window of this method also eliminates false negatives in protein-ligand binding site identification. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Yoshitomo Hamuro
- ExSAR Corporation, 11 Deer Park Drive, Suite 103, Monmouth Junction, NJ, 08852, USA.
| |
Collapse
|
55
|
Sysoeva TA. Assessing heterogeneity in oligomeric AAA+ machines. Cell Mol Life Sci 2017; 74:1001-1018. [PMID: 27669691 PMCID: PMC11107579 DOI: 10.1007/s00018-016-2374-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 09/13/2016] [Accepted: 09/19/2016] [Indexed: 10/20/2022]
Abstract
ATPases Associated with various cellular Activities (AAA+ ATPases) are molecular motors that use the energy of ATP binding and hydrolysis to remodel their target macromolecules. The majority of these ATPases form ring-shaped hexamers in which the active sites are located at the interfaces between neighboring subunits. Structural changes initiate in an active site and propagate to distant motor parts that interface and reshape the target macromolecules, thereby performing mechanical work. During the functioning cycle, the AAA+ motor transits through multiple distinct states. Ring architecture and placement of the catalytic sites at the intersubunit interfaces allow for a unique level of coordination among subunits of the motor. This in turn results in conformational differences among subunits and overall asymmetry of the motor ring as it functions. To date, a large amount of structural information has been gathered for different AAA+ motors, but even for the most characterized of them only a few structural states are known and the full mechanistic cycle cannot be yet reconstructed. Therefore, the first part of this work will provide a broad overview of what arrangements of AAA+ subunits have been structurally observed focusing on diversity of ATPase oligomeric ensembles and heterogeneity within the ensembles. The second part of this review will concentrate on methods that assess structural and functional heterogeneity among subunits of AAA+ motors, thus bringing us closer to understanding the mechanism of these fascinating molecular motors.
Collapse
Affiliation(s)
- Tatyana A Sysoeva
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
| |
Collapse
|
56
|
|
57
|
Wang B, Liu J, Cao J, Wang H, Guan X, Wei Z, Guo X. Investigation of c ions formed by N-terminally charged peptides upon collision-induced dissociation. JOURNAL OF MASS SPECTROMETRY : JMS 2016; 51:989-997. [PMID: 27537939 DOI: 10.1002/jms.3841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 08/16/2016] [Indexed: 06/06/2023]
Abstract
Peptide fragments such as b and y sequence ions generated upon low-energy collision-induced dissociation have been routinely used for tandem mass spectrometry (MS/MS)-based peptide/protein identification. The underlying formation mechanisms have been studied extensively and described within the literature. As a result, the 'mobile proton model' and 'pathways in competition model' have been built to interpret a majority of peptide fragmentation behavior. However, unusual peptide fragments which involve unfamiliar fragmentation pathways or various rearrangement reactions occasionally appear in MS/MS spectra, resulting in confused MS/MS interpretations. In this work, a series of unfamiliar c ions are detected in MS/MS spectra of the model peptides having an N-terminal Arg or deuterohemin group upon low-energy collision-induced dissociation process. Both the protonated Arg and deuterohemin group play an important role in retention of a positive charge at the N-terminus that is remote from the cleavage sites. According to previous reports and our studies involving amino acid substitutions and hydrogen-deuterium exchange, we propose a McLafferty-type rearrangement via charge-remote fragmentation as the potential mechanism to explain the formation of c ions from precursor peptide ions or unconventional b ions. Density functional theory calculations are also employed in order to elucidate the proposed fragmentation mechanisms. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Bing Wang
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Jinrong Liu
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Jungang Cao
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Huixin Wang
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Xinshu Guan
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Zhonglin Wei
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Xinhua Guo
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China.
| |
Collapse
|
58
|
Sowole MA, Simpson S, Skovpen YV, Palmer DRJ, Konermann L. Evidence of Allosteric Enzyme Regulation via Changes in Conformational Dynamics: A Hydrogen/Deuterium Exchange Investigation of Dihydrodipicolinate Synthase. Biochemistry 2016; 55:5413-22. [PMID: 27604304 DOI: 10.1021/acs.biochem.6b00764] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Dihydrodipicolinate synthase is a tetrameric enzyme of the diaminopimelate pathway in bacteria and plants. The protein catalyzes the condensation of pyruvate (Pyr) and aspartate semialdehyde en route to the end product lysine (Lys). Dihydrodipicolinate synthase from Campylobacter jejuni (CjDHDPS) is allosterically inhibited by Lys. CjDHDPS is a promising antibiotic target, as highlighted by the recent development of a potent bis-lysine (bisLys) inhibitor. The mechanism whereby Lys and bisLys allosterically inhibit CjDHDPS remains poorly understood. In contrast to the case for other allosteric enzymes, crystallographically detectable conformational changes in CjDHDPS upon inhibitor binding are very minor. Also, it is difficult to envision how Pyr can access the active site; the available X-ray data seemingly imply that each turnover step requires diffusion-based mass transfer through a narrow access channel. This study employs hydrogen/deuterium exchange mass spectrometry for probing the structure and dynamics of CjDHDPS in a native solution environment. The deuteration kinetics reveal that the most dynamic protein regions are in the direct vicinity of the substrate access channel. This finding is consistent with the view that transient opening/closing fluctuations facilitate access of the substrate to the active site. Under saturating conditions, both Lys and bisLys cause dramatically reduced dynamics in the inhibitor binding region. In addition, rigidification extends to regions close to the substrate access channel. This finding strongly suggests that allosteric inhibitors interfere with conformational fluctuations that are required for CjDHDPS substrate turnover. In particular, our data imply that Lys and bisLys suppress opening/closing events of the access channel, thereby impeding diffusion of the substrate into the active site. Overall, this work illustrates why allosteric control does not have to be associated with crystallographically detectable large-scale transitions. Our experiments provide evidence that in CjDHDPS allostery is mediated by changes in the extent of thermally activated conformational fluctuations.
Collapse
Affiliation(s)
- Modupeola A Sowole
- Department of Chemistry, The University of Western Ontario , London, Ontario N6A 5B7, Canada
| | - Sarah Simpson
- Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Yulia V Skovpen
- Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - David R J Palmer
- Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario , London, Ontario N6A 5B7, Canada
| |
Collapse
|
59
|
Probing the dynamic regulation of peripheral membrane proteins using hydrogen deuterium exchange-MS (HDX-MS). Biochem Soc Trans 2016; 43:773-86. [PMID: 26517882 DOI: 10.1042/bst20150065] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Many cellular signalling events are controlled by the selective recruitment of protein complexes to membranes. Determining the molecular basis for how lipid signalling complexes are recruited, assembled and regulated on specific membrane compartments has remained challenging due to the difficulty of working in conditions mimicking native biological membrane environments. Enzyme recruitment to membranes is controlled by a variety of regulatory mechanisms, including binding to specific lipid species, protein-protein interactions, membrane curvature, as well as post-translational modifications. A powerful tool to study the regulation of membrane signalling enzymes and complexes is hydrogen deuterium exchange-MS (HDX-MS), a technique that allows for the interrogation of protein dynamics upon membrane binding and recruitment. This review will highlight the theory and development of HDX-MS and its application to examine the molecular basis of lipid signalling enzymes, specifically the regulation and activation of phosphoinositide 3-kinases (PI3Ks).
Collapse
|
60
|
Leitner A. Cross-linking and other structural proteomics techniques: how chemistry is enabling mass spectrometry applications in structural biology. Chem Sci 2016; 7:4792-4803. [PMID: 30155128 PMCID: PMC6016523 DOI: 10.1039/c5sc04196a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 04/25/2016] [Indexed: 01/05/2023] Open
Abstract
The biological function of proteins is heavily influenced by their structures and their organization into assemblies such as protein complexes and regulatory networks. Mass spectrometry (MS) has been a key enabling technology for high-throughput and comprehensive protein identification and quantification on a proteome-wide scale. Besides these essential contributions, MS can also be used to study higher-order structures of biomacromolecules in a variety of ways. In one approach, intact proteins or protein complexes may be directly probed in the mass spectrometer. Alternatively, various forms of solution-phase chemistry are used to introduce modifications in intact proteins and localizing these modifications by MS analysis at the peptide level is used to derive structural information. Here, I will put a spotlight on the central role of chemistry in such mass spectrometry-based methods that bridge proteomics and structural biology, with a particular emphasis on chemical cross-linking of protein complexes.
Collapse
Affiliation(s)
- Alexander Leitner
- Department of Biology , Institute of Molecular Systems Biology , ETH Zurich , Auguste-Piccard-Hof 1 , 8093 Zurich , Switzerland .
| |
Collapse
|
61
|
Sarpe V, Rafiei A, Hepburn M, Ostan N, Schryvers AB, Schriemer DC. High Sensitivity Crosslink Detection Coupled With Integrative Structure Modeling in the Mass Spec Studio. Mol Cell Proteomics 2016; 15:3071-80. [PMID: 27412762 DOI: 10.1074/mcp.o116.058685] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Indexed: 01/21/2023] Open
Abstract
The Mass Spec Studio package was designed to support the extraction of hydrogen-deuterium exchange and covalent labeling data for a range of mass spectrometry (MS)-based workflows, to integrate with restraint-driven protein modeling activities. In this report, we present an extension of the underlying Studio framework and provide a plug-in for crosslink (XL) detection. To accommodate flexibility in XL methods and applications, while maintaining efficient data processing, the plug-in employs a peptide library reduction strategy via a presearch of the tandem-MS data. We demonstrate that prescoring linear unmodified peptide tags using a probabilistic approach substantially reduces search space by requiring both crosslinked peptides to generate sparse data attributable to their linear forms. The method demonstrates highly sensitive crosslink peptide identification with a low false positive rate. Integration with a Haddock plug-in provides a resource that can combine multiple sources of data for protein modeling activities. We generated a structural model of porcine transferrin bound to TbpB, a membrane-bound receptor essential for iron acquisition in Actinobacillus pleuropneumoniae Using mutational data and crosslinking restraints, we confirm the mechanism by which TbpB recognizes the iron-loaded form of transferrin, and note the requirement for disparate sources of restraint data for accurate model construction. The software plugin is freely available at www.msstudio.ca.
Collapse
Affiliation(s)
- Vladimir Sarpe
- From the ‡Department of Biochemistry and Molecular Biology
| | | | - Morgan Hepburn
- From the ‡Department of Biochemistry and Molecular Biology
| | - Nicholas Ostan
- ¶Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Alberta, T2N 1N4, Canada
| | - Anthony B Schryvers
- From the ‡Department of Biochemistry and Molecular Biology, ¶Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Alberta, T2N 1N4, Canada
| | - David C Schriemer
- From the ‡Department of Biochemistry and Molecular Biology, §Department of Chemistry,
| |
Collapse
|
62
|
Vahidi S, Konermann L. Probing the Time Scale of FPOP (Fast Photochemical Oxidation of Proteins): Radical Reactions Extend Over Tens of Milliseconds. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1156-64. [PMID: 27067899 DOI: 10.1007/s13361-016-1389-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/09/2016] [Accepted: 03/14/2016] [Indexed: 05/11/2023]
Abstract
Hydroxyl radical (⋅OH) labeling with mass spectrometry detection reports on protein conformations and interactions. Fast photochemical oxidation of proteins (FPOP) involves ⋅OH production via H2O2 photolysis by UV laser pulses inside a flow tube. The experiments are conducted in the presence of a scavenger (usually glutamine) that shortens the ⋅OH lifetime. The literature claims that FPOP takes place within 1 μs. This ultrafast time scale implies that FPOP should be immune to labeling-induced artifacts that may be encountered with other techniques. Surprisingly, the FPOP time scale has never been validated in direct kinetic measurements. Here we employ flash photolysis for probing oxidation processes under typical FPOP conditions. Bleaching of the reporter dye cyanine-5 (Cy5) served as readout of the time-dependent radical milieu. Surprisingly, Cy5 oxidation extends over tens of milliseconds. This time range is four orders of magnitude longer than expected from the FPOP literature. We demonstrate that the glutamine scavenger generates metastable secondary radicals in the FPOP solution, and that these radicals lengthen the time frame of Cy5 oxidation. Cy5 and similar dyes are widely used for monitoring the radical dose experienced by proteins in solution. The measured Cy5 kinetics thus strongly suggest that protein oxidation in FPOP extends over a much longer time window than previously thought (i.e., many milliseconds instead of one microsecond). The optical approach developed here should be suitable for assessing the performance of future FPOP-like techniques with improved temporal labeling characteristics. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Siavash Vahidi
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada.
| |
Collapse
|
63
|
Zhang X. Instant Integrated Ultradeep Quantitative-structural Membrane Proteomics Discovered Post-translational Modification Signatures for Human Cys-loop Receptor Subunit Bias. Mol Cell Proteomics 2016; 15:3665-3684. [PMID: 27073180 DOI: 10.1074/mcp.m114.047514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 11/17/2015] [Indexed: 12/31/2022] Open
Abstract
Neurotransmitter ligand-gated ion channels (LGICs) are widespread and pivotal in brain functions. Unveiling their structure-function mechanisms is crucial to drive drug discovery, and demands robust proteomic quantitation of expression, post-translational modifications (PTMs) and dynamic structures. Yet unbiased digestion of these modified transmembrane proteins-at high efficiency and peptide reproducibility-poses the obstacle. Targeting both enzyme-substrate contacts and PTMs for peptide formation and detection, we devised flow-and-detergent-facilitated protease and de-PTM digestions for deep sequencing (FDD) method that combined omni-compatible detergent, tandem immobilized protease/PNGase columns, and Cys-selective reduction/alkylation, to achieve streamlined ultradeep peptide preparation within minutes not days, at high peptide reproducibility and low abundance-bias. FDD transformed enzyme-protein contacts into equal catalytic travel paths through enzyme-excessive columns regardless of protein abundance, removed products instantly preventing inhibition, tackled intricate structures via sequential multiple micro-digestions along the flow, and precisely controlled peptide formation by flow rate. Peptide-stage reactions reduced steric bias; low contamination deepened MS/MS scan; distinguishing disulfide from M oxidation and avoiding gain/loss artifacts unmasked protein-endogenous oxidation states. Using a recent interactome of 285-kDa human GABA type A receptor, this pilot study validated FDD platform's applicability to deep sequencing (up to 99% coverage), H/D-exchange and TMT-based structural mapping. FDD discovered novel subunit-specific PTM signatures, including unusual nontop-surface N-glycosylations, that may drive subunit biases in human Cys-loop LGIC assembly and pharmacology, by redefining subunit/ligand interfaces and connecting function domains.
Collapse
Affiliation(s)
- Xi Zhang
- From the ‡Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, .,§Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
64
|
Wessels HJCT, de Almeida NM, Kartal B, Keltjens JT. Bacterial Electron Transfer Chains Primed by Proteomics. Adv Microb Physiol 2016; 68:219-352. [PMID: 27134025 DOI: 10.1016/bs.ampbs.2016.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Electron transport phosphorylation is the central mechanism for most prokaryotic species to harvest energy released in the respiration of their substrates as ATP. Microorganisms have evolved incredible variations on this principle, most of these we perhaps do not know, considering that only a fraction of the microbial richness is known. Besides these variations, microbial species may show substantial versatility in using respiratory systems. In connection herewith, regulatory mechanisms control the expression of these respiratory enzyme systems and their assembly at the translational and posttranslational levels, to optimally accommodate changes in the supply of their energy substrates. Here, we present an overview of methods and techniques from the field of proteomics to explore bacterial electron transfer chains and their regulation at levels ranging from the whole organism down to the Ångstrom scales of protein structures. From the survey of the literature on this subject, it is concluded that proteomics, indeed, has substantially contributed to our comprehending of bacterial respiratory mechanisms, often in elegant combinations with genetic and biochemical approaches. However, we also note that advanced proteomics offers a wealth of opportunities, which have not been exploited at all, or at best underexploited in hypothesis-driving and hypothesis-driven research on bacterial bioenergetics. Examples obtained from the related area of mitochondrial oxidative phosphorylation research, where the application of advanced proteomics is more common, may illustrate these opportunities.
Collapse
Affiliation(s)
- H J C T Wessels
- Nijmegen Center for Mitochondrial Disorders, Radboud Proteomics Centre, Translational Metabolic Laboratory, Radboud University Medical Center, Nijmegen, The Netherlands
| | - N M de Almeida
- Institute of Water and Wetland Research, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - B Kartal
- Institute of Water and Wetland Research, Radboud University Nijmegen, Nijmegen, The Netherlands; Laboratory of Microbiology, Ghent University, Ghent, Belgium
| | - J T Keltjens
- Institute of Water and Wetland Research, Radboud University Nijmegen, Nijmegen, The Netherlands.
| |
Collapse
|
65
|
Elferich J, Williamson DM, David LL, Shinde U. Determination of Histidine pKa Values in the Propeptides of Furin and Proprotein Convertase 1/3 Using Histidine Hydrogen-Deuterium Exchange Mass Spectrometry. Anal Chem 2015; 87:7909-17. [PMID: 26110992 PMCID: PMC4903077 DOI: 10.1021/acs.analchem.5b01721] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Propeptides of proprotein convertases regulate activation of their protease domains by sensing the organellar pH within the secretory pathway. Earlier experimental work highlighted the importance of a conserved histidine residue within the propeptide of a widely studied member, furin. A subsequent evolutionary analysis found an increase in histidine content within propeptides of secreted eukaryotic proteases compared with their prokaryotic orthologs. However, furin activates in the trans-golgi network at a pH of 6.5 while a paralog, proprotein convertase 1/3, activates in secretory vesicles at a pH of 5.5. It is unclear how a conserved histidine can mediate activation at two different pH values. In this manuscript, we measured the pKa values of histidines within the propeptides of furin and proprotein convertase 1/3 using a histidine hydrogen-deuterium exchange mass spectrometry approach. The high density of histidine residues combined with an abundance of basic residues provided challenges for generation of peptide ions with unique histidine residues, which were overcome by employing ETD fragmentation. During this analysis, we found slow hydrogen-deuterium exchange in residues other than histidine at basic pH. Finally, we demonstrate that the pKa of the conserved histidine in proprotein convertase 1/3 is acid-shifted compared with furin and is consistent with its lower pH of activation.
Collapse
Affiliation(s)
- Johannes Elferich
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239, United States
| | - Danielle M. Williamson
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239, United States
| | - Larry L. David
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239, United States
| | - Ujwal Shinde
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239, United States
| |
Collapse
|
66
|
Burns KM, Sarpe V, Wagenbach M, Wordeman L, Schriemer DC. HX-MS2 for high performance conformational analysis of complex protein states. Protein Sci 2015; 24:1313-24. [PMID: 26009873 DOI: 10.1002/pro.2707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/05/2015] [Accepted: 05/14/2015] [Indexed: 01/15/2023]
Abstract
Water-mediated hydrogen exchange (HX) processes involving the protein main chain are sensitive to structural dynamics and molecular interactions. Measuring deuterium uptake in amide bonds provides information on conformational states, structural transitions and binding events. Increasingly, deuterium levels are measured by mass spectrometry (MS) from proteolytically generated peptide fragments of large molecular systems. However, this bottom-up method has limited spectral capacity and requires a burdensome manual validation exercise, both of which restrict analysis of protein systems to generally less than 150 kDa. In this study, we present a bottom-up HX-MS(2) method that improves peptide identification rates, localizes high-quality HX data and simplifies validation. The method combines a new peptide scoring algorithm (WUF, weighted unique fragment) with data-independent acquisition of peptide fragmentation data. Scoring incorporates the validation process and emphasizes identification accuracy. The HX-MS(2) method is illustrated using data from a conformational analysis of microtubules treated with dimeric kinesin MCAK. When compared to a conventional Mascot-driven HX-MS method, HX-MS(2) produces two-fold higher α/β-tubulin sequence depth at a peptide utilization rate of 74%. A Mascot approach delivers a utilization rate of 44%. The WUF score can be constrained by false utilization rate (FUR) calculations to return utilization values exceeding 90% without serious data loss, indicating that automated validation should be possible. The HX-MS(2) data confirm that N-terminal MCAK domains anchor kinesin force generation in kinesin-mediated depolymerization, while the C-terminal tails regulate MCAK-tubulin interactions.
Collapse
Affiliation(s)
- Kyle M Burns
- Department of Biochemistry and Molecular Biology and the Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada, T2N 4N1
| | - Vladimir Sarpe
- Department of Biochemistry and Molecular Biology and the Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada, T2N 4N1
| | - Mike Wagenbach
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington, 98195-7290
| | - Linda Wordeman
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington, 98195-7290
| | - David C Schriemer
- Department of Biochemistry and Molecular Biology and the Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada, T2N 4N1
| |
Collapse
|
67
|
Donohoe GC, Arndt JR, Valentine SJ. Online deuterium hydrogen exchange and protein digestion coupled with ion mobility spectrometry and tandem mass spectrometry. Anal Chem 2015; 87:5247-54. [PMID: 25893550 DOI: 10.1021/acs.analchem.5b00277] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Online deuterium hydrogen exchange (DHX) and pepsin digestion (PD) is demonstrated using drift tube ion mobility spectrometry (DTIMS) coupled with linear ion trap (LTQ) mass spectrometry (MS) with electron transfer dissociation (ETD) capabilities. DHX of deuterated ubiquitin, followed by subsequent quenching and digestion, is performed within ∼60 s, yielding 100% peptide sequence coverage. The high reproducibility of the IMS separation allows spectral feature matching between two-dimensional IMS-MS datasets (undeuterated and deuterated) without the need for dataset alignment. Extracted ion drift time distributions (XIDTDs) of deuterated peptic peptides are mobility-matched to corresponding XIDTDs of undeuterated peptic peptides that were identified using collision-induced dissociation (CID). Matching XIDTDs allows a straightforward identification and deuterium retention evaluation for labeled peptides. Aside from the mobility separation, the ion trapping capabilities of the LTQ, combined with ETD, are demonstrated to provide single-residue resolution. Deuterium retention for the c- series ions across residues M(1)-L(15) and N(25)-R(42) are in good agreement with the known secondary structural elements within ubiquitin.
Collapse
Affiliation(s)
- Gregory C Donohoe
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - James R Arndt
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Stephen J Valentine
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
68
|
Keppel TR, Weis DD. Mapping residual structure in intrinsically disordered proteins at residue resolution using millisecond hydrogen/deuterium exchange and residue averaging. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:547-554. [PMID: 25481641 DOI: 10.1007/s13361-014-1033-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/16/2014] [Accepted: 10/16/2014] [Indexed: 06/04/2023]
Abstract
Measurement of residual structure in intrinsically disordered proteins can provide insights into the mechanisms by which such proteins undergo coupled binding and folding. The present work describes an approach to measure residual structure in disordered proteins using millisecond hydrogen/deuterium (H/D) exchange in a conventional bottom-up peptide-based workflow. We used the exchange mid-point, relative to a totally deuterated control, to quantify the rate of H/D exchange in each peptide. A weighted residue-by-residue average of these midpoints was used to map the extent of residual structure at near single-residue resolution. We validated this approach both by simulating a disordered protein and experimentally using the p300 binding domain of ACTR, a model disordered protein already well-characterized by other approaches. Secondary structure elements mapped in the present work are in good agreement with prior nuclear magnetic resonance measurements. The new approach was somewhat limited by a loss of spatial resolution and subject to artifacts because of heterogeneities in intrinsic exchange. Approaches to correct these limitations are discussed.
Collapse
Affiliation(s)
- Theodore R Keppel
- Department of Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
| | | |
Collapse
|
69
|
Iacob RE, Krystek SR, Huang RYC, Wei H, Tao L, Lin Z, Morin PE, Doyle ML, Tymiak AA, Engen JR, Chen G. Hydrogen/deuterium exchange mass spectrometry applied to IL-23 interaction characteristics: potential impact for therapeutics. Expert Rev Proteomics 2015; 12:159-69. [PMID: 25711416 DOI: 10.1586/14789450.2015.1018897] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
IL-23 is an important therapeutic target for the treatment of inflammatory diseases. Adnectins are targeted protein therapeutics that are derived from domain III of human fibronectin and have a similar protein scaffold to antibodies. Adnectin 2 was found to bind to IL-23 and compete with the IL-23/IL-23R interaction, posing a potential protein therapeutic. Hydrogen/deuterium exchange mass spectrometry and computational methods were applied to probe the binding interactions between IL-23 and Adnectin 2 and to determine the correlation between the two orthogonal methods. This review summarizes the current structural knowledge about IL-23 and focuses on the applicability of hydrogen/deuterium exchange mass spectrometry to investigate the higher order structure of proteins, which plays an important role in the discovery of new and improved biotherapeutics.
Collapse
Affiliation(s)
- Roxana E Iacob
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
70
|
Yu L, Zhang L, Sun Y. Protein behavior at surfaces: Orientation, conformational transitions and transport. J Chromatogr A 2015; 1382:118-34. [DOI: 10.1016/j.chroma.2014.12.087] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 12/26/2014] [Accepted: 12/31/2014] [Indexed: 12/18/2022]
|
71
|
Engen JR, Wales TE. Analytical Aspects of Hydrogen Exchange Mass Spectrometry. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2015; 8:127-48. [PMID: 26048552 PMCID: PMC4989240 DOI: 10.1146/annurev-anchem-062011-143113] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This article reviews the analytical aspects of measuring hydrogen exchange by mass spectrometry (HX MS). We describe the nature of analytical selectivity in hydrogen exchange, then review the analytical tools required to accomplish fragmentation, separation, and the mass spectrometry measurements under restrictive exchange quench conditions. In contrast to analytical quantitation that relies on measurements of peak intensity or area, quantitation in HX MS depends on measuring a mass change with respect to an undeuterated or deuterated control, resulting in a value between zero and the maximum amount of deuterium that can be incorporated. Reliable quantitation is a function of experimental fidelity and to achieve high measurement reproducibility, a large number of experimental variables must be controlled during sample preparation and analysis. The method also reports on important qualitative aspects of the sample, including conformational heterogeneity and population dynamics.
Collapse
Affiliation(s)
- John R Engen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115;
| | | |
Collapse
|
72
|
Jensen PF, Larraillet V, Schlothauer T, Kettenberger H, Hilger M, Rand KD. Investigating the interaction between the neonatal Fc receptor and monoclonal antibody variants by hydrogen/deuterium exchange mass spectrometry. Mol Cell Proteomics 2014; 14:148-61. [PMID: 25378534 DOI: 10.1074/mcp.m114.042044] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The recycling of immunoglobulins by the neonatal Fc receptor (FcRn) is of crucial importance in the maintenance of antibody levels in plasma and is responsible for the long half-lives of endogenous and recombinant monoclonal antibodies. From a therapeutic point of view there is great interest in understanding and modulating the IgG-FcRn interaction to optimize antibody pharmacokinetics and ultimately improve efficacy and safety. Here we studied the interaction between a full-length human IgG(1) and human FcRn via hydrogen/deuterium exchange mass spectrometry and targeted electron transfer dissociation to map sites perturbed by binding on both partners of the IgG-FcRn complex. Several regions in the antibody Fc region and the FcRn were protected from exchange upon complex formation, in good agreement with previous crystallographic studies of FcRn in complex with the Fc fragment. Interestingly, we found that several regions in the IgG Fab region also showed reduced deuterium uptake. Our findings indicate the presence of hitherto unknown FcRn interaction sites in the Fab region or a possible conformational link between the IgG Fc and Fab regions upon FcRn binding. Further, we investigated the role of IgG glycosylation in the conformational response of the IgG-FcRn interaction. Removal of antibody glycans increased the flexibility of the FcRn binding site in the Fc region. Consequently, FcRn binding did not induce a similar conformational stabilization of deglycosylated IgG as observed for the wild-type glycosylated IgG. Our results provide new molecular insight into the IgG-FcRn interaction and illustrate the capability of hydrogen/deuterium exchange mass spectrometry to advance structural proteomics by providing detailed information on the conformation and dynamics of large protein complexes in solution.
Collapse
Affiliation(s)
- Pernille Foged Jensen
- From the ‡Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Vincent Larraillet
- §Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Penzberg, Nonnenwald 2, 82377 Penzberg, Germany
| | - Tilman Schlothauer
- §Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Penzberg, Nonnenwald 2, 82377 Penzberg, Germany
| | - Hubert Kettenberger
- §Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Penzberg, Nonnenwald 2, 82377 Penzberg, Germany
| | - Maximiliane Hilger
- §Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Penzberg, Nonnenwald 2, 82377 Penzberg, Germany
| | - Kasper D Rand
- From the ‡Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark;
| |
Collapse
|
73
|
Song H, Olsen OH, Persson E, Rand KD. Sites involved in intra- and interdomain allostery associated with the activation of factor VIIa pinpointed by hydrogen-deuterium exchange and electron transfer dissociation mass spectrometry. J Biol Chem 2014; 289:35388-96. [PMID: 25344622 DOI: 10.1074/jbc.m114.614297] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Factor VIIa (FVIIa) is a trypsin-like protease that plays an important role in initiating blood coagulation. Very limited structural information is available for the free, inactive form of FVIIa that circulates in the blood prior to vascular injury and the molecular details of its activity enhancement remain elusive. Here we have applied hydrogen/deuterium exchange mass spectrometry coupled to electron transfer dissociation to pinpoint individual residues in the heavy chain of FVIIa whose conformation and/or local interaction pattern changes when the enzyme transitions to the active form, as induced either by its cofactor tissue factor or a covalent active site inhibitor. Identified regulatory residues are situated at key sites across one continuous surface of the protease domain spanning the TF-binding helix across the activation pocket to the calcium binding site and are embedded in elements of secondary structure and at the base of flexible loops. Thus these residues are optimally positioned to mediate crosstalk between functional sites in FVIIa, particularly the cofactor binding site and the active site. Our results unambiguously show that the conformational allosteric activation signal extends to the EGF1 domain in the light chain of FVIIa, underscoring a remarkable intra- and interdomain allosteric regulation of this trypsin-like protease.
Collapse
Affiliation(s)
- Hongjian Song
- From the Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark and
| | - Ole H Olsen
- Haemostasis Biology, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Måløv, Denmark
| | - Egon Persson
- Haemostasis Biology, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Måløv, Denmark
| | - Kasper D Rand
- From the Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark and
| |
Collapse
|