1
|
Weston M, Hu H, Li X. PSPI: A deep learning approach for prokaryotic small protein identification. Front Genet 2024; 15:1439423. [PMID: 39050248 PMCID: PMC11266045 DOI: 10.3389/fgene.2024.1439423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Accepted: 06/18/2024] [Indexed: 07/27/2024] Open
Abstract
Small Proteins (SPs) are pivotal in various cellular functions such as immunity, defense, and communication. Despite their significance, identifying them is still in its infancy. Existing computational tools are tailored to specific eukaryotic species, leaving only a few options for SP identification in prokaryotes. In addition, these existing tools still have suboptimal performance in SP identification. To fill this gap, we introduce PSPI, a deep learning-based approach designed specifically for predicting prokaryotic SPs. We showed that PSPI had a high accuracy in predicting generalized sets of prokaryotic SPs and sets specific to the human metagenome. Compared with three existing tools, PSPI was faster and showed greater precision, sensitivity, and specificity not only for prokaryotic SPs but also for eukaryotic ones. We also observed that the incorporation of (n, k)-mers greatly enhances the performance of PSPI, suggesting that many SPs may contain short linear motifs. The PSPI tool, which is freely available at https://www.cs.ucf.edu/∼xiaoman/tools/PSPI/, will be useful for studying SPs as a tool for identifying prokaryotic SPs and it can be trained to identify other types of SPs as well.
Collapse
Affiliation(s)
- Matthew Weston
- Department of Computer Science, University of Central Florida, Orlando, FL, United States
| | - Haiyan Hu
- Department of Computer Science, University of Central Florida, Orlando, FL, United States
| | - Xiaoman Li
- Burnett School of Biomedical Science, College of Medicine, University of Central Florida, Orlando, FL, United States
| |
Collapse
|
2
|
Beals J, Hu H, Li X. A survey of experimental and computational identification of small proteins. Brief Bioinform 2024; 25:bbae345. [PMID: 39007598 PMCID: PMC11247407 DOI: 10.1093/bib/bbae345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/27/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024] Open
Abstract
Small proteins (SPs) are typically characterized as eukaryotic proteins shorter than 100 amino acids and prokaryotic proteins shorter than 50 amino acids. Historically, they were disregarded because of the arbitrary size thresholds to define proteins. However, recent research has revealed the existence of many SPs and their crucial roles. Despite this, the identification of SPs and the elucidation of their functions are still in their infancy. To pave the way for future SP studies, we briefly introduce the limitations and advancements in experimental techniques for SP identification. We then provide an overview of available computational tools for SP identification, their constraints, and their evaluation. Additionally, we highlight existing resources for SP research. This survey aims to initiate further exploration into SPs and encourage the development of more sophisticated computational tools for SP identification in prokaryotes and microbiomes.
Collapse
Affiliation(s)
- Joshua Beals
- Burnett School of Biomedical Science, University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816, United States
| | - Haiyan Hu
- Department of Computer Science, University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816, United States
| | - Xiaoman Li
- Burnett School of Biomedical Science, University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816, United States
| |
Collapse
|
3
|
Kamalakshan A, Jamuna NA, Chittilappilly Devassy AM, Mandal S. Dual Optical Response Strategy for the Detection of Cytochrome c Using Highly Luminescent Lanthanide-Based Nanotubular Sensor Arrays. ACS APPLIED BIO MATERIALS 2024; 7:2460-2471. [PMID: 38517347 DOI: 10.1021/acsabm.4c00077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Here, we demonstrate a label-free dual optical response strategy for the detection of cytochrome c (Cyt c) with ultrahigh sensitivity using highly luminescent lanthanides containing inorganic-organic hybrid nanotubular sensor arrays. These sensor arrays are formed by the sequential incorporation of the photosensitizers 2,3-dihydroxynaphthalene (DHN) or 1,10-phenanthroline (Phen), and trivalent lanthanide terbium ions (Tb3+) into sodium lithocholate (NaLC) nanotube templates. Our sensing platform relies on the detection and quantification of Cyt c in solution by providing dual photoluminescence quenching responses from the nanotubular hybrid arrays in the presence of Cyt c. The large quenching of the sensitized Tb3+ emission within the DHN/Phen-Tb3+-NaLC nanotubular sensor arrays caused by the strong binding of the photosensitizers to Cyt c provides an important signal response for the selective detection of Cyt c. This long-lived lanthanide emission response-based sensing strategy can be highly advantageous for the detection of Cyt c in a cellular environment eliminating background fluorescence and scattering signals through time-gated measurements. The DHN containing nanotubular sensor arrays (DHN-NaLC and DHN-Tb3+-NaLC) provide an additional quenching response characterized by a unique spectral valley splitting with quantized quenching dip on the DHN fluorescence emission. This spectral quenching dip resulting from efficient FRET between the protein bound DHN photosensitizer and the heme group of Cyt c serves as an important means for specific detection and quantification of Cyt c in the concentration range of 0-30 μM with a low detection limit of around 20 nM.
Collapse
Affiliation(s)
- Adithya Kamalakshan
- Department of Chemistry, National Institute of Technology, Tiruchirappalli, Tamil Nadu 620015, India
| | - Nidhi Anilkumar Jamuna
- Department of Chemistry, National Institute of Technology, Tiruchirappalli, Tamil Nadu 620015, India
| | | | - Sarthak Mandal
- Department of Chemistry, National Institute of Technology, Tiruchirappalli, Tamil Nadu 620015, India
| |
Collapse
|
4
|
Smith J, Carillo S, Kulkarni A, Redman E, Yu K, Bones J. Rapid characterization of adeno-associated virus (AAV) capsid proteins using microchip ZipChip CE-MS. Anal Bioanal Chem 2024; 416:1069-1084. [PMID: 38102410 PMCID: PMC10800304 DOI: 10.1007/s00216-023-05097-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/17/2023]
Abstract
Adeno-associated viruses (AAVs) are viral vectors used as delivery systems for gene therapies. Intact protein characterization of AAV viral capsid proteins (VPs) and their post-translational modifications is critical to ensuring product quality. In this study, microchip-based ZipChip capillary electrophoresis-mass spectrometry (CE-MS) was applied for the rapid characterization of AAV intact VPs, specifically full and empty viral capsids of serotypes AAV6, AAV8 and AAV9, which was accomplished using 5 min of analysis time. Low levels of dimethyl sulfoxide (4%) in the background electrolyte (BGE) improved MS signal quality and component detection. A sensitivity evaluation revealed consistent detection of VP proteoforms when as little as 2.64 × 106 viral particles (≈26.4 picograms) were injected. Besides the traditional VP proteoforms used for serotype identification, multiple VP3 variants were detected, including truncated VP3 variants most likely generated by leaky scanning as well as unacetylated and un-cleaved VP3 proteoforms. Phosphorylation, known to impact AAV transduction efficiency, was also seen in all serotypes analysed. Additionally, low abundant fragments originating from either N- or C-terminus truncation were detected. As the aforementioned VP components can impact product quality and efficacy, the ZipChip's ability to rapidly characterize them illustrates its strength in monitoring product quality during AAV production.
Collapse
Affiliation(s)
- Josh Smith
- Characterisation and Comparability Laboratory, The National Institute for Bioprocessing Research and Training, Foster Avenue, Mount Merrion, A94 X099, Co. Dublin, Ireland
| | - Sara Carillo
- Characterisation and Comparability Laboratory, The National Institute for Bioprocessing Research and Training, Foster Avenue, Mount Merrion, A94 X099, Co. Dublin, Ireland
| | - Aditya Kulkarni
- 908 Devices Inc., 645 Summer Street #201, Boston, MA, 02210, USA
| | - Erin Redman
- 908 Devices Inc., 511 Davis Dr Suite 450, Morrisville, NC, 27560, USA
| | - Kate Yu
- 908 Devices Inc., 645 Summer Street #201, Boston, MA, 02210, USA
| | - Jonathan Bones
- Characterisation and Comparability Laboratory, The National Institute for Bioprocessing Research and Training, Foster Avenue, Mount Merrion, A94 X099, Co. Dublin, Ireland.
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, D04 V1W8, Ireland.
| |
Collapse
|
5
|
Shi X, Liu C, Zheng W, Cao X, Li W, Zhang D, Zhu J, Zhang X, Chen Y. Proteomic Analysis Revealed the Potential Role of MAGE-D2 in the Therapeutic Targeting of Triple-Negative Breast Cancer. Mol Cell Proteomics 2024; 23:100703. [PMID: 38128647 PMCID: PMC10835320 DOI: 10.1016/j.mcpro.2023.100703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023] Open
Abstract
Among all the molecular subtypes of breast cancer, triple-negative breast cancer (TNBC) is the most aggressive one. Currently, the clinical prognosis of TNBC is poor because there is still no effective therapeutic target. Here, we carried out a combined proteomic analysis involving bioinformatic analysis of the proteome database, label-free quantitative proteomics, and immunoprecipitation (IP) coupled with mass spectrometry (MS) to explore potential therapeutic targets for TNBC. The results of bioinformatic analysis showed an overexpression of MAGE-D2 (melanoma antigen family D2) in TNBC. In vivo and in vitro experiments revealed that MAGE-D2 overexpression could promote cell proliferation and metastasis. Furthermore, label-free quantitative proteomics revealed that MAGE-D2 acted as a cancer-promoting factor by activating the PI3K-AKT pathway. Moreover, the outcomes of IP-MS and cross-linking IP-MS demonstrated that MAGE-D2 could interact with Hsp70 and prevent Hsp70 degradation, but evidence for their direct interaction is still lacking. Nevertheless, MAGE-D2 is a potential therapeutic target for TNBC, and blocking MAGE-D2 may have important therapeutic implications.
Collapse
Affiliation(s)
- Xiaoyu Shi
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Chunyan Liu
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Weimin Zheng
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Xiao Cao
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Wan Li
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Dongxue Zhang
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Jianhua Zhu
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Xian Zhang
- School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Yun Chen
- School of Pharmacy, Nanjing Medical University, Nanjing, China; State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing, China; Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Nanjing, China.
| |
Collapse
|
6
|
Kaltashov IA, Ivanov DG, Yang Y. Mass spectrometry-based methods to characterize highly heterogeneous biopharmaceuticals, vaccines, and nonbiological complex drugs at the intact-mass level. MASS SPECTROMETRY REVIEWS 2024; 43:139-165. [PMID: 36582075 PMCID: PMC10307928 DOI: 10.1002/mas.21829] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
The intact-mass MS measurements are becoming increasingly popular in characterization of a range of biopolymers, especially those of interest to biopharmaceutical industry. However, as the complexity of protein therapeutics and other macromolecular medicines increases, the new challenges arise, one of which is the high levels of structural heterogeneity that are frequently exhibited by such products. The very notion of the molecular mass measurement loses its clear and intuitive meaning when applied to an extremely heterogenous system that cannot be characterized by a unique mass, but instead requires that a mass distribution be considered. Furthermore, convoluted mass distributions frequently give rise to unresolved ionic signal in mass spectra, from which little-to-none meaningful information can be extracted using standard approaches that work well for homogeneous systems. However, a range of technological advances made in the last decade, such as the hyphenation of intact-mass MS measurements with front-end separations, better integration of ion mobility in MS workflows, development of an impressive arsenal of gas-phase ion chemistry tools to supplement MS methods, as well as the revival of the charge detection MS and its triumphant entry into the field of bioanalysis already made impressive contributions towards addressing the structural heterogeneity challenge. An overview of these techniques is accompanied by critical analysis of the strengths and weaknesses of different approaches, and a brief overview of their applications to specific classes of biopharmaceutical products, vaccines, and nonbiological complex drugs.
Collapse
Affiliation(s)
- Igor A. Kaltashov
- Department of Chemistry, University of Massachusetts-Amherst, Amherst MA 01003
| | - Daniil G. Ivanov
- Department of Chemistry, University of Massachusetts-Amherst, Amherst MA 01003
| | | |
Collapse
|
7
|
Cheung See Kit M, Cropley TC, Bleiholder C, Chouinard CD, Sobott F, Webb IK. The role of solvation on the conformational landscape of α-synuclein. Analyst 2023; 149:125-136. [PMID: 37982746 PMCID: PMC10760066 DOI: 10.1039/d3an01680c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
Native ion mobility mass spectrometry has been used extensively to characterize ensembles of intrinsically disordered protein (IDP) conformers, but the extent to which the gaseous measurements provide realistic pictures of the solution conformations for such flexible proteins remains unclear. Therefore, we systematically studied the relationship between the solution and gaseous structural ensembles by measuring electrospray charge state and collision cross section (CCS) distributions for cationic and anionic forms of α-synuclein (αSN), an anionic protein in solution, as well as directly probed gas phase residue to residue distances via ion/ion reactions between gaseous α-synuclein cations and disulfonic acid linkers that form strong electrostatic bonds. We also combined results from in-solution protein crosslinking identified from native tandem mass spectrometry (MS/MS) with an initial αSN ensemble generated computationally by IDPConformerGenerator to generate an experimentally restrained solution ensemble of αSN. CCS distributions were directly calculated for the solution ensembles determined by NMR and compared to predicted gaseous conformers. While charge state and collision cross section distributions are useful for qualitatively describing the relative structural dynamics of proteins and major conformational changes induced by changes to solution states, the predicted and measured gas phase conformers include subpopulations that are significantly different than those expected from completely "freezing" solution conformations and preserving them in the gas phase. However, insights were gained on the various roles of solvent in stabilizing various conformers for extremely dynamic proteins like α-synuclein.
Collapse
Affiliation(s)
- Melanie Cheung See Kit
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
| | - Tyler C Cropley
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Christian Bleiholder
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
| | | | - Frank Sobott
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Ian K Webb
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| |
Collapse
|
8
|
Koy C, Glocker UM, Danquah BD, Glocker MO. Native and compactly folded in-solution conformers of pepsin are revealed and distinguished by mass spectrometric ITEM-TWO analyses of gas-phase pepstatin A - pepsin complex binding strength differences. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2023; 29:303-312. [PMID: 37259551 DOI: 10.1177/14690667231178999] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Pepsin, because of its optimal activity at low acidic pH, has gained importance in mass spectrometric proteome research as a readily available and easy-to-handle protease. Pepsin has also been study object of protein higher-order structure analyses, but questions about how to best investigate pepsin in-solution conformers still remain. We first determined dependencies of pepsin ion charge structures on solvent pH which indicated the in-solution existence of (a) natively folded pepsin (N) which by nanoESI-MS analysis gave rise to a narrow charge state distribution with an 11-fold protonated most intense ion signal, (b) unfolded pepsin (U) with a rather broad ion charge state distribution whose highest ion signal carried 25 protons, and (c) a compactly folded pepsin conformer (C) with a narrow charge structure and a 12-fold protonated ion signal in the center of its charge state envelope. Because pepsin is a protease, unfolded pepsin became its own substrate in solution at pH 6.6 since at this pH some portion of pepsin maintained a compact/native fold which displayed enzymatic activity. Subsequent mass spectrometric ITEM-TWO analyses of pepstatin A - pepsin complex dissociation reactions in the gas phase confirmed a very strong binding of pepstatin A by natively folded pepsin (N). ITEM-TWO further revealed the existence of two compactly folded in-solution pepsin conformers (Ca and Cb) which also were able to bind pepstatin A. Binding strengths of the respective compactly folded pepsin conformer-containing complexes could be determined and apparent gas phase complex dissociation constants and reaction enthalpies differentiated these from each other and from the pepstatin A - pepsin complex which had been formed from natively folded pepsin. Thus, ITEM-TWO turned out to be well suited to pinpoint in-solution pepsin conformers by interrogating quantitative traits of pepstatin A - pepsin complexes in the gas phase.
Collapse
Affiliation(s)
- Cornelia Koy
- Proteome Center Rostock, Medical Faculty and Natural Science Faculty, University of Rostock, Rostock, Germany
| | - Ursula M Glocker
- Proteome Center Rostock, Medical Faculty and Natural Science Faculty, University of Rostock, Rostock, Germany
| | - Bright D Danquah
- Proteome Center Rostock, Medical Faculty and Natural Science Faculty, University of Rostock, Rostock, Germany
| | - Michael O Glocker
- Proteome Center Rostock, Medical Faculty and Natural Science Faculty, University of Rostock, Rostock, Germany
| |
Collapse
|
9
|
Luan M, Hou Z, Zhang B, Ma L, Yuan S, Liu Y, Huang G. Inter-Domain Repulsion of Dumbbell-Shaped Calmodulin during Electrospray Ionization Revealed by Molecular Dynamics Simulations. Anal Chem 2023; 95:8798-8806. [PMID: 37309130 DOI: 10.1021/acs.analchem.2c05630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The mechanisms whereby protein ions are released from nanodroplets at the liquid-gas interface have continued to be controversial since electrospray ionization (ESI) mass spectrometry was widely applied in biomolecular structure analysis in solution. Several viable pathways have been proposed and verified for single-domain proteins. However, the ESI mechanism of multi-domain proteins with more complicated and flexible structures remains unclear. Herein, dumbbell-shaped calmodulin was chosen as a multi-domain protein model to perform molecular dynamics simulations to investigate the structural evolution during the ESI process. For [Ca4CAM], the protein followed the classical charge residue model. As the inter-domain electrostatic repulsion increased, the droplet was found to split into two sub-droplets, while stronger-repulsive apo-calmodulin unfolded during the early evaporation stage. We designated this novel ESI mechanism as the domain repulsion model, which provides new mechanistic insights into further exploration of proteins containing more domains. Our results suggest that greater attention should be paid to the effect of domain-domain interactions on structure retention during liquid-gas interface transfer when mass spectrometry is used as the developing technique in gas phase structural biology.
Collapse
Affiliation(s)
- Moujun Luan
- Department of Cardiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Zhuanghao Hou
- Department of Cardiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Buchun Zhang
- Department of Cardiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
| | - Likun Ma
- Department of Cardiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
| | - Siming Yuan
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
- Department of Pharmacy, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
| | - Yangzhong Liu
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
- Department of Pharmacy, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
| | - Guangming Huang
- Department of Cardiology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| |
Collapse
|
10
|
Saurabh S, Nadendla K, Purohit SS, Sivakumar PM, Cetinel S. Fuzzy Drug Targets: Disordered Proteins in the Drug-Discovery Realm. ACS OMEGA 2023; 8:9729-9747. [PMID: 36969402 PMCID: PMC10034788 DOI: 10.1021/acsomega.2c07708] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Intrinsically disordered proteins (IDPs) and regions (IDRs) form a large part of the eukaryotic proteome. Contrary to the structure-function paradigm, the disordered proteins perform a myriad of functions in vivo. Consequently, they are involved in various disease pathways and are plausible drug targets. Unlike folded proteins, that have a defined structure and well carved out drug-binding pockets that can guide lead molecule selection, the disordered proteins require alternative drug-development methodologies that are based on an acceptable picture of their conformational ensemble. In this review, we discuss various experimental and computational techniques that contribute toward understanding IDP "structure" and describe representative pursuances toward IDP-targeting drug development. We also discuss ideas on developing rational drug design protocols targeting IDPs.
Collapse
Affiliation(s)
- Suman Saurabh
- Molecular
Sciences Research Hub, Department of Chemistry, Imperial College London, London W12 0BZ, U.K.
| | - Karthik Nadendla
- Center
for Misfolding Diseases, Yusuf Hamied Department of Chemistry, Lensfield
Road, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Shubh Sanket Purohit
- Department
of Clinical Haematology, Sahyadri Superspeciality
Hospital, Pune, Maharashtra 411038, India
| | - Ponnurengam Malliappan Sivakumar
- Institute
of Research and Development, Duy Tan University, Da Nang 550000, Vietnam
- School
of Medicine and Pharmacy, Duy Tan University, Da Nang 550000, Vietnam
- Nanotechnology
Research and Application Center (SUNUM), Sabanci University, Istanbul 34956, Turkey
| | - Sibel Cetinel
- Nanotechnology
Research and Application Center (SUNUM), Sabanci University, Istanbul 34956, Turkey
- Faculty of
Engineering and Natural Sciences, Molecular Biology, Genetics and
Bioengineering Program, Sabanci University, Istanbul 34956, Turkey
| |
Collapse
|
11
|
Shao X, Huang Y, Wang G. Microfluidic devices for protein analysis using intact and top‐down mass spectrometry. VIEW 2022. [DOI: 10.1002/viw.20220032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Xinyang Shao
- Institute for Cell Analysis Shenzhen Bay Laboratory Shenzhen China
- Biomedical Pioneering Innovation Center Peking University Beijing China
- Peking‐Tsinghua Center for Life Sciences Peking University Beijing China
| | - Yanyi Huang
- Institute for Cell Analysis Shenzhen Bay Laboratory Shenzhen China
- Biomedical Pioneering Innovation Center Peking University Beijing China
- Peking‐Tsinghua Center for Life Sciences Peking University Beijing China
- College of Chemistry and Molecular Engineering and Beijing National Laboratory for Molecular Sciences Peking University Beijing China
| | - Guanbo Wang
- Institute for Cell Analysis Shenzhen Bay Laboratory Shenzhen China
- Biomedical Pioneering Innovation Center Peking University Beijing China
| |
Collapse
|
12
|
Prabhu GRD, Yang TH, Shiu RT, Witek HA, Urban PL. Scanning pH-metry for Observing Reversibility in Protein Folding. Biochemistry 2022; 61:2377-2389. [PMID: 36251331 DOI: 10.1021/acs.biochem.2c00453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
One of the main factors affecting protein structure in solution is pH. Traditionally, to study pH-dependent conformational changes in proteins, the concentration of the H+ ions is adjusted manually, complicating real-time analyses, hampering dynamic pH regulation, and consequently leading to a limited number of tested pH levels. Here, we present a programmable device, a scanning pH-meter, that can automatically generate different types of pH ramps and waveforms in a solution. A feedback loop algorithm calculates the required flow rates of the acid/base titrants, allowing one, for example, to generate periodic pH sine waveforms to study the reversibility of protein folding by fluorescence spectroscopy. Interestingly, for some proteins, the fluorescence intensity profiles recorded in such a periodically oscillating pH environment display hysteretic behavior indicating an asymmetry in the sequence of the protein unfolding/refolding events, which can most likely be attributed to their distinct kinetics. Another useful application of the scanning pH-meter concerns coupling it with an electrospray ionization mass spectrometer to observe pH-induced structural changes in proteins as revealed by their varying charge-state distributions. We anticipate a broad range of applications of the scanning pH-meter developed here, including protein folding studies, determination of the optimum pH for achieving maximum fluorescence intensity, and characterization of fluorescent dyes and other synthetic materials.
Collapse
Affiliation(s)
- Gurpur Rakesh D Prabhu
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu300093, Taiwan
| | - Tzu-Hsin Yang
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
| | - Ruei-Tzung Shiu
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
| | - Henryk A Witek
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu300093, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu300093, Taiwan
| | - Pawel L Urban
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
| |
Collapse
|
13
|
Santambrogio C, Ponzini E, Grandori R. Native mass spectrometry for the investigation of protein structural (dis)order. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140828. [PMID: 35926718 DOI: 10.1016/j.bbapap.2022.140828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/24/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
A central challenge in structural biology is represented by dynamic and heterogeneous systems, as typically represented by proteins in solution, with the extreme case of intrinsically disordered proteins (IDPs) [1-3]. These proteins lack a specific three-dimensional structure and have poorly organized secondary structure. For these reasons, they escape structural characterization by conventional biophysical methods. The investigation of these systems requires description of conformational ensembles, rather than of unique, defined structures or bundles of largely superimposable structures. Mass spectrometry (MS) has become a central tool in this field, offering a variety of complementary approaches to generate structural information on either folded or disordered proteins [4-6]. Two main categories of methods can be recognized. On one side, conformation-dependent reactions (such as cross-linking, covalent labeling, H/D exchange) are exploited to label molecules in solution, followed by the characterization of the labeling products by denaturing MS [7-11]. On the other side, non-denaturing ("native") MS can be used to directly explore the different conformational components in terms of geometry and structural compactness [12-16]. All these approaches have in common the capability to conjugate protein structure investigation with the peculiar analytical power of MS measurements, offering the possibility of assessing species distributions for folding and binding equilibria and the combination of both. These methods can be combined with characterization of noncovalent complexes [17, 18] and post-translational modifications [19-23]. This review focuses on the application of native MS to protein structure and dynamics investigation, with a general methodological section, followed by examples on specific proteins from our laboratory.
Collapse
Affiliation(s)
- Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy.
| | - Erika Ponzini
- Materials Science Department, University of Milano-Bicocca, Via R. Cozzi 55, 20125 Milan, Italy; COMiB Research Center, University of Milano-Bicocca, Via R. Cozzi 55, 20125 Milan, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy.
| |
Collapse
|
14
|
Fedorov II, Lineva VI, Tarasova IA, Gorshkov MV. Mass Spectrometry-Based Chemical Proteomics for Drug Target Discoveries. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:983-994. [PMID: 36180990 DOI: 10.1134/s0006297922090103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/04/2022] [Accepted: 07/06/2022] [Indexed: 06/16/2023]
Abstract
Chemical proteomics, emerging rapidly in recent years, has become a main approach to identifying interactions between the small molecules and proteins in the cells on a proteome scale and mapping the signaling and/or metabolic pathways activated and regulated by these interactions. The methods of chemical proteomics allow not only identifying proteins targeted by drugs, characterizing their toxicity and discovering possible off-target proteins, but also elucidation of the fundamental mechanisms of cell functioning under conditions of drug exposure or due to the changes in physiological state of the organism itself. Solving these problems is essential for both basic research in biology and clinical practice, including approaches to early diagnosis of various forms of serious diseases or prediction of the effectiveness of therapeutic treatment. At the same time, recent developments in high-resolution mass spectrometry have provided the technology for searching the drug targets across the whole cell proteomes. This review provides a concise description of the main objectives and problems of mass spectrometry-based chemical proteomics, the methods and approaches to their solution, and examples of implementation of these methods in biomedical research.
Collapse
Affiliation(s)
- Ivan I Fedorov
- V. L. Talrose Institute for Energy Problems of Chemical Physics, N. N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia
- Moscow Institute of Physics and Technology (National University), Dolgoprudny, Moscow Region, 141700, Russia
| | - Victoria I Lineva
- Moscow Institute of Physics and Technology (National University), Dolgoprudny, Moscow Region, 141700, Russia
| | - Irina A Tarasova
- V. L. Talrose Institute for Energy Problems of Chemical Physics, N. N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Mikhail V Gorshkov
- V. L. Talrose Institute for Energy Problems of Chemical Physics, N. N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia.
| |
Collapse
|
15
|
Chang MJ, Ollivault-Shiflett M, Schuman R, Ngoc Nguyen S, Kaltashov IA, Bobst C, Rajagopal SP, Przedpelski A, Barbieri JT, Lees A. Genetically detoxified tetanus toxin as a vaccine and conjugate carrier protein. Vaccine 2022; 40:5103-5113. [PMID: 35871872 DOI: 10.1016/j.vaccine.2022.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/16/2022] [Accepted: 07/11/2022] [Indexed: 11/16/2022]
Abstract
Tetanus toxoid (TTxd), developed over 100 years ago, is a clinically effective, legacy vaccine against tetanus. Due to the extreme potency of native tetanus toxin, manufacturing and regulatory efforts often focus on TTxd production, standardization, and safety, rather than product modernization. Recently, a genetically detoxified, full-length tetanus toxin protein (8MTT) was reported as a tetanus vaccine alternative to TTxd (Przedpelski et al. mBio, 2020). Here we describe the production of 8MTT in Gor/MetTM E. coli, a strain engineered to have an oxidative cytoplasm, allowing for the expression of soluble, disulfide-bonded proteins. The strain was also designed to efficiently cleave N-terminal methionine, the obligatory start amino acid for E. coli expressed proteins. 8MTT was purified as a soluble protein from the cytoplasm in a two-column protocol to > 99 % purity, yielding 0.5 g of purified 8MTT/liter of fermentation broth with low endotoxin contamination, and antigenic purity of 3500 Lf/mg protein nitrogen. Mouse immunizations showed 8MTT to be an immunogenic vaccine and effective as a carrier protein for peptide and polysaccharide conjugates. These studies validate 8MTT as commercially viable and, unlike the heterogenous tetanus toxoid, a uniform carrier protein for conjugate vaccines. The development of a recombinant, genetically detoxified toxin produced in E. coli aligns the tetanus vaccine with modern manufacturing, regulatory, standardization, and safety requirements.
Collapse
Affiliation(s)
- Min-Ju Chang
- Fina Biosolutions LLC, 9430 Key West Ave, Suite 200, Rockville, MD 20850, United States
| | | | - Richard Schuman
- Antibody and Immunoassay Consultants, 9430 Key West Ave, Suite 201, Rockville, MD 20850, United States
| | - Son Ngoc Nguyen
- University of Massachusetts, 240 Thatcher Way, Life Science Laboratories N369, Amherst, MA 01003, United States
| | - Igor A Kaltashov
- University of Massachusetts, 240 Thatcher Way, Life Science Laboratories N369, Amherst, MA 01003, United States
| | - Cedric Bobst
- University of Massachusetts, 240 Thatcher Way, Life Science Laboratories N369, Amherst, MA 01003, United States
| | - Shalini P Rajagopal
- National Institute for Biological Standards and Control, Medicines and Healthcare products Regulatory Agency, Blanche Lane, South Mimms, Potters Bar EN6 3QG, UK
| | - Amanda Przedpelski
- Medical College of Wisconsin, 8701 Watertown Plank Rd., Microbiology and Immunology BSB-2830, Milwaukee, WI 53226, United States
| | - Joseph T Barbieri
- Medical College of Wisconsin, 8701 Watertown Plank Rd., Microbiology and Immunology BSB-2830, Milwaukee, WI 53226, United States
| | - Andrew Lees
- Fina Biosolutions LLC, 9430 Key West Ave, Suite 200, Rockville, MD 20850, United States
| |
Collapse
|
16
|
Li W, Chaihu L, Jiang J, Wu B, Zheng X, Dai R, Tian Y, Huang Y, Wang G, Men Y. Microfluidic Platform for Time-Resolved Characterization of Protein Higher-Order Structures and Dynamics Using Top-Down Mass Spectrometry. Anal Chem 2022; 94:7520-7527. [PMID: 35584038 DOI: 10.1021/acs.analchem.2c00077] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Characterization of protein higher-order structures and dynamics is essential for understanding the biological functions of proteins and revealing the underlying mechanisms. Top-down mass spectrometry (MS) accesses structural information at both the intact protein level and the peptide fragment level. Native top-down MS allows analysis of a protein complex's architecture and subunits' identity and modifications. Top-down hydrogen/deuterium exchange (HDX) MS offers high spatial resolution for conformational or binding interface analysis and enables conformer-specific characterization. A microfluidic chip can provide superior performance for front-end reactions useful for these MS workflows, such as flexibility in manipulating multiple reactant flows, integrating various functional modules, and automation. However, most microchip-MS devices are designed for bottom-up approaches or top-down proteomics. Here, we demonstrate a strategy for designing a microchip for top-down MS analysis of protein higher-order structures and dynamics. It is suitable for time-resolved native MS and HDX MS, with designs aiming for efficient ionization of intact protein complexes, flexible manipulation of multiple reactant flows, and precise control of reaction times over a broad range of flow rates on the submicroliter per minute scale. The performance of the prototype device is demonstrated by measurements of systems including monoclonal antibodies, antibody-antigen complexes, and coexisting protein conformers. This strategy may benefit elaborate structural analysis of biomacromolecules and inspire method development using the microchip-MS approach.
Collapse
Affiliation(s)
- Wen Li
- Research Center for Biomedical Optics and Molecular Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Lingxiao Chaihu
- School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.,Institute of Cell Analysis, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Jialu Jiang
- School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China
| | - Bizhu Wu
- Research Center for Biomedical Optics and Molecular Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Xuan Zheng
- Research Center for Biomedical Optics and Molecular Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Rongrong Dai
- School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China
| | - Ye Tian
- Institute of Cell Analysis, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Yanyi Huang
- Institute of Cell Analysis, Shenzhen Bay Laboratory, Shenzhen 518132, China.,Biomedical Pioneering Innovation Centre, Peking University, Beijing 100871, China
| | - Guanbo Wang
- Institute of Cell Analysis, Shenzhen Bay Laboratory, Shenzhen 518132, China.,Biomedical Pioneering Innovation Centre, Peking University, Beijing 100871, China
| | - Yongfan Men
- Research Center for Biomedical Optics and Molecular Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| |
Collapse
|
17
|
Bianchi G, Mangiagalli M, Barbiroli A, Longhi S, Grandori R, Santambrogio C, Brocca S. Distribution of Charged Residues Affects the Average Size and Shape of Intrinsically Disordered Proteins. Biomolecules 2022; 12:biom12040561. [PMID: 35454150 PMCID: PMC9031945 DOI: 10.3390/biom12040561] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 12/29/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are ensembles of interconverting conformers whose conformational properties are governed by several physico-chemical factors, including their amino acid composition and the arrangement of oppositely charged residues within the primary structure. In this work, we investigate the effects of charge patterning on the average compactness and shape of three model IDPs with different proline content. We model IDP ensemble conformations as ellipsoids, whose size and shape are calculated by combining data from size-exclusion chromatography and native mass spectrometry. For each model IDP, we analyzed the wild-type protein and two synthetic variants with permuted positions of charged residues, where positive and negative amino acids are either evenly distributed or segregated. We found that charge clustering induces remodeling of the conformational ensemble, promoting compaction and/or increasing spherical shape. Our data illustrate that the average shape and volume of the ensembles depend on the charge distribution. The potential effect of other factors, such as chain length, number of proline residues, and secondary structure content, is also discussed. This methodological approach is a straightforward way to model IDP average conformation and decipher the salient sequence attributes influencing IDP structural properties.
Collapse
Affiliation(s)
- Greta Bianchi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy; (G.B.); (M.M.); (R.G.)
| | - Marco Mangiagalli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy; (G.B.); (M.M.); (R.G.)
| | - Alberto Barbiroli
- Departement of Food, Environmental and Nutritional Sciences, University of Milan, 20133 Milan, Italy;
| | - Sonia Longhi
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, 13288 Marseille, France;
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy; (G.B.); (M.M.); (R.G.)
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy; (G.B.); (M.M.); (R.G.)
- Correspondence: (C.S.); (S.B.); Tel.: +39-02-6448-3363 (C.S.); +39-02-6448-3518 (S.B.)
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy; (G.B.); (M.M.); (R.G.)
- Correspondence: (C.S.); (S.B.); Tel.: +39-02-6448-3363 (C.S.); +39-02-6448-3518 (S.B.)
| |
Collapse
|
18
|
Massai L, Ciambellotti S, Cosottini L, Messori L, Turano P, Pratesi A. Direct detection of iron clusters in L ferritins through ESI-MS experiments. Dalton Trans 2021; 50:16464-16467. [PMID: 34729572 DOI: 10.1039/d1dt03106f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Human cytoplasmic ferritins are heteropolymers of H and L subunits containing a catalytic ferroxidase center and a nucleation site for iron biomineralization, respectively. Here, ESI-MS successfully detected labile metal-protein interactions revealing the formation of tetra- and octa-iron clusters bound to L subunits, as previously underscored by X-ray crystallography.
Collapse
Affiliation(s)
- Lara Massai
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, FI, Italy.
| | - Silvia Ciambellotti
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, FI, Italy. .,Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, FI, Italy. .,Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (C.I.R.M.M.P.), Via Luigi Sacconi 6, 50019 Sesto Fiorentino, FI, Italy
| | - Lucrezia Cosottini
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, FI, Italy. .,Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, FI, Italy. .,Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (C.I.R.M.M.P.), Via Luigi Sacconi 6, 50019 Sesto Fiorentino, FI, Italy
| | - Luigi Messori
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, FI, Italy.
| | - Paola Turano
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, FI, Italy. .,Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, FI, Italy. .,Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (C.I.R.M.M.P.), Via Luigi Sacconi 6, 50019 Sesto Fiorentino, FI, Italy
| | - Alessandro Pratesi
- Department of Chemistry and Industrial Chemistry (DCCI), University of Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
| |
Collapse
|
19
|
Pandeswari PB, Chary RN, Kamalanathan AS, Prabhakar S, Sabareesh V. Mimicking LysC Proteolysis by 'Arginine-Modification-cum-Trypsin digestion': Comparison of Bottom-Up & Middle-Down Proteomic Approaches by ESI-QTOF-MS. Protein Pept Lett 2021; 28:1379-1390. [PMID: 34587878 DOI: 10.2174/0929866528666210929163307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/04/2021] [Accepted: 08/09/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Middle-down (MD) proteomics is an emerging approach for reliable identification of post- translational modifications and isoforms, as this approach focuses on proteolytic peptides containing > 25 - 30 amino acid residues (a.a.r.), which are longer than typical tryptic peptides. Such longer peptides can be obtained by AspN, GluC, LysC proteases. Additionally, some special proteases were developed specifically to effect MD approach, e.g., OmpT, Sap9, etc. However, these proteases are expensive. Herein we report a cost-effective strategy, 'arginine modification-cum trypsin digestion', which can produce longer tryptic peptides resembling LysC peptides derived from proteins. OBJECTIVE To obtain proteolytic peptides that resemble LysC peptides, by using 'trypsin', which is an less expensive protease. METHODS This strategy is based on the simple principle that trypsin cannot act at the C-termini of those arginines in proteins, whose sidechain guanidine groups are modified by 1,2-cyclohexanedione or phenylglyoxal. RESULTS As a proof of concept, we demonstrate this strategy on four models: β-casein (bovine), β- lactoglobulin (bovine), ovalbumin (chick) and transferrin (human), by electrospray ionization-mass spectrometry (ESI-MS) involving hybrid quadrupole time-of-flight. From the ESI-MS of these models, we obtained several arginine modified tryptic peptides, whose lengths are in the range, 30 - 60 a.a.r. The collision-induced dissociation MS/MS characteristics of some of the arginine modified longer tryptic peptides are compared with the unmodified standard tryptic peptides. CONCLUSION The strategy followed in this proof-of-concept study, not only helps in obtaining longer tryptic peptides that mimic LysC proteolytic peptides, but also facilitates in enhancing the probability of missed cleavages by the trypsin. Hence, this method aids in evading the possibility of obtaining very short peptides that are < 5 - 10 a.a.r. Therefore, this is indeed an cost-effective alternative/substitute for LysC proteolysis and in turn, for those MD proteomic studies that utilize LysC. Additionally, this methodology can be fruitful for mass spectrometry based de novo protein and peptide sequencing.
Collapse
Affiliation(s)
- P Boomathi Pandeswari
- Centre for Bio-Separation Technology (CBST), Vellore Institute of Technology (VIT), Vellore, Tamil Nadu - 632014. India
| | - R Nagarjuna Chary
- Centre for Mass Spectrometry, Department of Analytical & Structural Chemistry, CSIR - Indian Institute of Chemical Technology (IICT), Hyderabad, Telangana - 500007. India
| | - A S Kamalanathan
- Centre for Bio-Separation Technology (CBST), Vellore Institute of Technology (VIT), Vellore, Tamil Nadu - 632014. India
| | - Sripadi Prabhakar
- Centre for Mass Spectrometry, Department of Analytical & Structural Chemistry, CSIR - Indian Institute of Chemical Technology (IICT), Hyderabad, Telangana - 500007. India
| | - Varatharajan Sabareesh
- Centre for Bio-Separation Technology (CBST), Vellore Institute of Technology (VIT), Vellore, Tamil Nadu - 632014. India
| |
Collapse
|
20
|
Cai CX, Schneck NA, Cozine T, Ivleva VB, Ragheb D, Gollapudi D, Patel A, Barefoot N, Gowetski DB, Lei QP. Investigation of Cysteine Modifications in Recombinant Protein Tetanus Toxoid Heavy Chain Fragment C. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1837-1840. [PMID: 34167299 PMCID: PMC9241332 DOI: 10.1021/jasms.1c00075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
For conjugated HIV-1 fusion peptide vaccine development, recombinant Tetanus toxoid heavy chain fragment C (rTTHC) was applied as a carrier protein to boost peptide immunogenicity. Understanding the characteristics of rTTHC is the first step prior to the peptide conjugation. A comprehensive mass spectrometry (MS) characterization was performed on E. coli expressed rTTHC during its purification process. Intact mass along with peptide mapping analysis discovered the existence of three cysteine modification forms: glutathionylation, trisulfide bond modification, and disulfide bond shuffling, in correlation to a three-peak profile during a hydrophobic interaction chromatography (HIC) purification step. Coexistence of these multiple oxidative forms indicated that the active thiols underwent redox reaction in the rTTHC material. Identity confirmation of the rTTHC carrier protein by MS analysis provided pivotal guidance to assess the purification step and helped ensure that vaccine development could proceed.
Collapse
Affiliation(s)
- Cindy X Cai
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Nicole A Schneck
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Taryn Cozine
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Vera B Ivleva
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Daniel Ragheb
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Deepika Gollapudi
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Aakash Patel
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Nathan Barefoot
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Daniel B Gowetski
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| | - Q Paula Lei
- Vaccine Production Program Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, Maryland 20878, United States
| |
Collapse
|
21
|
Brandis JEP, Zalesak SM, Kane MA, Michel SLJ. Cadmium Exchange with Zinc in the Non-Classical Zinc Finger Protein Tristetraprolin. Inorg Chem 2021; 60:7697-7707. [PMID: 33999622 PMCID: PMC8501473 DOI: 10.1021/acs.inorgchem.0c03808] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Tristetraprolin (TTP) is a nonclassical CCCH zinc finger protein that regulates inflammation. TTP targets AU-rich RNA sequences of cytokine mRNAs forming a TTP/mRNA complex. This complex is then degraded, switching off the inflammatory response. Cadmium, a known carcinogen, triggers proinflammatory effects, and there is evidence that Cd increases TTP expression in cells, suggesting that Zn-TTP may be a target for cadmium toxicity. We sought to determine whether Cd exchanges with Zn in the TTP active site and measure the effect of RNA binding on this exchange. A construct of TTP that contains the two CCCH domains (TTP-2D) was employed to investigate these interactions. A spin-filter ICP-MS experiment to quantify the metal that is bound to the ZF after metal exchange was performed, and it was determined that Cd exchanges with Zn in Zn2-TTP-2D and that Zn exchanges with Cd in Cd2-TTP-2D. A native ESI-MS experiment to identify the metal-ZF complexes formed after metal exchange was performed, and M-TTP-2D complexes with singular and double metal exchange were observed. Metal exchange was measured in both the absence and presence of TTP's partner RNA, with retention of RNA binding. These data show that Cd can exchange with Zn in TTP without affecting function.
Collapse
Affiliation(s)
- Joel E P Brandis
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Stephanie M Zalesak
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Sarah L J Michel
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| |
Collapse
|
22
|
Giampà M, Sgobba E. Insight to Functional Conformation and Noncovalent Interactions of Protein-Protein Assembly Using MALDI Mass Spectrometry. Molecules 2020; 25:E4979. [PMID: 33126406 PMCID: PMC7662314 DOI: 10.3390/molecules25214979] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 10/22/2020] [Accepted: 10/24/2020] [Indexed: 11/16/2022] Open
Abstract
Noncovalent interactions are the keys to the structural organization of biomolecule e.g., proteins, glycans, lipids in the process of molecular recognition processes e.g., enzyme-substrate, antigen-antibody. Protein interactions lead to conformational changes, which dictate the functionality of that protein-protein complex. Besides biophysics techniques, noncovalent interaction and conformational dynamics, can be studied via mass spectrometry (MS), which represents a powerful tool, due to its low sample consumption, high sensitivity, and label-free sample. In this review, the focus will be placed on Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS) and its role in the analysis of protein-protein noncovalent assemblies exploring the relationship within noncovalent interaction, conformation, and biological function.
Collapse
Affiliation(s)
- Marco Giampà
- MR Cancer Group, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway
| | - Elvira Sgobba
- Genetics and Plant Physiology, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden;
| |
Collapse
|
23
|
Singh SK, Mishra A, Goel G, Chirmule N, Rathore AS. Modulation of granulocyte colony stimulating factor conformation and receptor binding by methionine oxidation. Proteins 2020; 89:68-80. [PMID: 32860270 DOI: 10.1002/prot.25995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/04/2020] [Accepted: 08/25/2020] [Indexed: 12/16/2022]
Abstract
Biosimilars offer an avenue for potential cost savings and enhanced patient access to various emerging therapies in a budget neutral way. Biosimilars of the granulocyte colony stimulating factor (GCSF) are an excellent example in this regard with as many as 18 versions of the drug being currently approved across globe for treatment of neutropenia. Here, we identified oxidation of the various methionine residues in GCSF as a key heterogeneity that adversely impact its efficacy. In agreement with earlier studies, it was found that oxidation of Met 122 and Met 127 significantly contributes toward reduction of GCSF efficacy, measured using binding affinity to the GCSF receptor. The combination of molecular dynamics simulation along with structural characterization studies established that oxidation of Met 127 and Met 122 brings about a small local conformational change around the B-C loop in GCSF structure due to slight displacement of Asp113 and Thr117 residues. The simulation studies were validated using fluorescence quenching experiments using acrylamide as quencher and site-directed mutagenesis by replacing Met 122 and Met 127 residues with alanine. The results of this study lead to an enhanced mechanistic understanding of the oxidation in GCSF and should be useful in protein engineering efforts to design stable, safe, and efficacious GCSF product. In addition, the structure-function information can provide targets for protein engineering during early drug development and setting specifications of allowable limits of product variants in biosimilar products.
Collapse
Affiliation(s)
- Sumit Kumar Singh
- Department of Chemical Engineering, DBT Center of Excellence for Biopharmaceutical Technology, Indian Institute of Technology Delhi, New Delhi, India
| | - Avinash Mishra
- Department of Chemical Engineering, DBT Center of Excellence for Biopharmaceutical Technology, Indian Institute of Technology Delhi, New Delhi, India
| | - Gaurav Goel
- Department of Chemical Engineering, DBT Center of Excellence for Biopharmaceutical Technology, Indian Institute of Technology Delhi, New Delhi, India
| | | | - Anurag S Rathore
- Department of Chemical Engineering, DBT Center of Excellence for Biopharmaceutical Technology, Indian Institute of Technology Delhi, New Delhi, India
| |
Collapse
|
24
|
Niu C, Zhao Y, Bobst CE, Savinov SN, Kaltashov IA. Identification of Protein Recognition Elements within Heparin Chains Using Enzymatic Foot-Printing in Solution and Online SEC/MS. Anal Chem 2020; 92:7565-7573. [PMID: 32347711 DOI: 10.1021/acs.analchem.0c00115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding molecular mechanisms governing interactions of glycosaminoglycans (such as heparin) with proteins remains challenging due to their enormous structural heterogeneity. Commonly accepted approaches seek to reduce the structural complexity by searching for "binding epitopes" within the limited subsets of short heparin oligomers produced either enzymatically or synthetically. A top-down approach presented in this work seeks to preserve the chemical diversity displayed by heparin by allowing the longer and structurally diverse chains to interact with the client protein. Enzymatic lysis of the protein-bound heparin chains followed by the product analysis using size exclusion chromatography with online mass spectrometry detection (SEC/MS) reveals the oligomers that are protected from lysis due to their tight association with the protein, and enables their characterization (both the oligomer length, and the number of incorporated sulfate and acetyl groups). When applied to a paradigmatic heparin/antithrombin system, the new method generates a series of oligomers with surprisingly distinct sulfation levels. The extent of sulfation of the minimal-length binder (hexamer) is relatively modest yet persistent, consistent with the notion of six sulfate groups being both essential and sufficient for antithrombin binding. However, the masses of longer surviving chains indicate complete sulfation of disaccharides beyond the hexasaccharide core. Molecular dynamics simulations confirm the existence of favorable electrostatic interactions between the high charge-density saccharide residues flanking the "canonical" antithrombin-binding hexasaccharide and the positive patch on the surface of the overall negatively charged protein. Furthermore, electrostatics may rescue the heparin/protein interaction in the absence of the canonical binding element.
Collapse
Affiliation(s)
- Chendi Niu
- Chemistry Department, University of Massachusetts-Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Yunlong Zhao
- Chemistry Department, University of Massachusetts-Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Cedric E Bobst
- Chemistry Department, University of Massachusetts-Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Sergey N Savinov
- Biochemistry and Molecular Biology Department, University of Massachusetts-Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Igor A Kaltashov
- Chemistry Department, University of Massachusetts-Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| |
Collapse
|
25
|
Niu C, Yang Y, Huynh A, Nazy I, Kaltashov IA. Platelet Factor 4 Interactions with Short Heparin Oligomers: Implications for Folding and Assembly. Biophys J 2020; 119:1371-1379. [PMID: 32348723 DOI: 10.1016/j.bpj.2020.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 12/11/2022] Open
Abstract
Association of platelet factor 4 (PF4) with heparin is a first step in formation of aggregates implicated in the development of heparin-induced thrombocytopenia (HIT), a potentially fatal immune disorder affecting 1-5% of patients receiving heparin. Despite being a critically important element in HIT etiology, relatively little is known about the specific molecular mechanism of PF4-heparin interactions. This work uses native mass spectrometry to investigate PF4 interactions with relatively short heparin chains (up to decasaccharides). The protein is shown to be remarkably unstable at physiological ionic strength in the absence of polyanions; only monomeric species are observed, and the extent of multiple charging of corresponding ions indicates a partial loss of conformational integrity. The tetramer signal remains at or below the detection threshold in the mass spectra until the solution's ionic strength is elevated well above the physiological level, highlighting the destabilizing role played by electrostatic interactions vis-à-vis quaternary structure of this high-pI protein. The tetramer assembly is dramatically facilitated by relatively short polyanions (synthetic heparin-mimetic pentasaccharide), with the majority of the protein molecules existing in the tetrameric state even at physiological ionic strength. Each tetramer accommodates up to six pentasaccharides, with at least three such ligands required to guarantee the higher-order structure integrity. Similar results are obtained for PF4 association with longer and structurally heterogeneous heparin oligomers (decamers). These longer polyanions can also induce PF4 dimer assembly when bound to the protein in relatively low numbers, lending support to a model of PF4/heparin interaction in which the latter wraps around the protein, making contacts with multiple subunits. Taken together, these results provide a more nuanced picture of PF4-glycosaminoglycan interactions leading to complex formation. This work also advocates for a greater utilization of native mass spectrometry in elucidating molecular mechanisms underlying HIT, as well as other physiological processes driven by electrostatic interactions.
Collapse
Affiliation(s)
- Chendi Niu
- Chemistry Department, University of Massachusetts-Amherst, Amherst, Massachusetts
| | - Yang Yang
- Chemistry Department, University of Massachusetts-Amherst, Amherst, Massachusetts
| | - Angela Huynh
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Ishac Nazy
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Igor A Kaltashov
- Chemistry Department, University of Massachusetts-Amherst, Amherst, Massachusetts.
| |
Collapse
|
26
|
Kaltashov IA, Bobst CE, Pawlowski J, Wang G. Mass spectrometry-based methods in characterization of the higher order structure of protein therapeutics. J Pharm Biomed Anal 2020; 184:113169. [PMID: 32092629 DOI: 10.1016/j.jpba.2020.113169] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/06/2020] [Accepted: 02/11/2020] [Indexed: 12/31/2022]
Abstract
Higher order structure of protein therapeutics is an important quality attribute, which dictates both potency and safety. While modern experimental biophysics offers an impressive arsenal of state-of-the-art tools that can be used for the characterization of higher order structure, many of them are poorly suited for the characterization of biopharmaceutical products. As a result, these analyses were traditionally carried out using classical techniques that provide relatively low information content. Over the past decade, mass spectrometry made a dramatic debut in this field, enabling the characterization of higher order structure of biopharmaceuticals as complex as monoclonal antibodies at a level of detail that was previously unattainable. At present, mass spectrometry is an integral part of the analytical toolbox across the industry, which is critical not only for quality control efforts, but also for discovery and development.
Collapse
Affiliation(s)
- Igor A Kaltashov
- Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, USA.
| | - Cedric E Bobst
- Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, USA
| | - Jake Pawlowski
- Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, USA
| | - Guanbo Wang
- School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu Province, PR China
| |
Collapse
|
27
|
Marchand A, Czar MF, Eggel EN, Kaeslin J, Zenobi R. Studying biomolecular folding and binding using temperature-jump mass spectrometry. Nat Commun 2020; 11:566. [PMID: 31992698 PMCID: PMC6987177 DOI: 10.1038/s41467-019-14179-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 12/19/2019] [Indexed: 01/14/2023] Open
Abstract
Characterizing folding and complex formation of biomolecules provides a view into their thermodynamics, kinetics and folding pathways. Deciphering kinetic intermediates is particularly important because they can often be targeted by drugs. The key advantage of native mass spectrometry over conventional methods that monitor a single observable is its ability to identify and quantify coexisting species. Here, we show the design of a temperature-jump electrospray source for mass spectrometry that allows one to perform fast kinetics experiments (0.16-32 s) at different temperatures (10-90 °C). The setup allows recording of both folding and unfolding kinetics by using temperature jumps from high to low, and low to high, temperatures. Six biological systems, ranging from peptides to proteins to DNA complexes, exemplify the use of this device. Using temperature-dependent experiments, the folding and unfolding of a DNA triplex are studied, providing detailed information on its thermodynamics and kinetics.
Collapse
Affiliation(s)
- Adrien Marchand
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Martin F Czar
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Elija N Eggel
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Jérôme Kaeslin
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland.
| |
Collapse
|
28
|
Zheng SJ, Zheng J, Xiong CF, Xiao HM, Liu SJ, Feng YQ. Hydrogen–Deuterium Scrambling Based on Chemical Isotope Labeling Coupled with LC–MS: Application to Amine Metabolite Identification in Untargeted Metabolomics. Anal Chem 2020; 92:2043-2051. [DOI: 10.1021/acs.analchem.9b04512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Shu-Jian Zheng
- Frontier Science Center for Immunology and Metabolism, Department of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Jie Zheng
- Frontier Science Center for Immunology and Metabolism, Department of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Cai-Feng Xiong
- Frontier Science Center for Immunology and Metabolism, Department of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Hua-Ming Xiao
- Frontier Science Center for Immunology and Metabolism, Department of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Shi-Jie Liu
- Frontier Science Center for Immunology and Metabolism, Department of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Yu-Qi Feng
- Frontier Science Center for Immunology and Metabolism, Department of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| |
Collapse
|
29
|
Schramm A, Bignon C, Brocca S, Grandori R, Santambrogio C, Longhi S. An arsenal of methods for the experimental characterization of intrinsically disordered proteins - How to choose and combine them? Arch Biochem Biophys 2019; 676:108055. [PMID: 31356778 DOI: 10.1016/j.abb.2019.07.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/16/2019] [Accepted: 07/24/2019] [Indexed: 12/12/2022]
Abstract
In this review, we detail the most common experimental approaches to assess and characterize protein intrinsic structural disorder, with the notable exception of NMR and EPR spectroscopy, two ideally suited approaches that will be described in depth in two other reviews within this special issue. We discuss the advantages, the limitations, as well as the caveats of the various methods. We also describe less common and more demanding approaches that enable achieving further insights into the conformational properties of IDPs. Finally, we present recent developments that have enabled assessment of structural disorder in living cells, and discuss the currently available methods to model IDPs as conformational ensembles.
Collapse
Affiliation(s)
- Antoine Schramm
- CNRS and Aix-Marseille Univ, Laboratoire Architecture et Fonction des Macromolecules Biologiques (AFMB), UMR 7257, Marseille, France
| | - Christophe Bignon
- CNRS and Aix-Marseille Univ, Laboratoire Architecture et Fonction des Macromolecules Biologiques (AFMB), UMR 7257, Marseille, France
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Sonia Longhi
- CNRS and Aix-Marseille Univ, Laboratoire Architecture et Fonction des Macromolecules Biologiques (AFMB), UMR 7257, Marseille, France.
| |
Collapse
|
30
|
Santambrogio C, Natalello A, Brocca S, Ponzini E, Grandori R. Conformational Characterization and Classification of Intrinsically Disordered Proteins by Native Mass Spectrometry and Charge‐State Distribution Analysis. Proteomics 2018; 19:e1800060. [DOI: 10.1002/pmic.201800060] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/29/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Carlo Santambrogio
- Department of Biotechnology and BiosciencesUniversity of Milano‐Bicocca Piazza della Scienza 2 20126 Milan Italy
| | - Antonino Natalello
- Department of Biotechnology and BiosciencesUniversity of Milano‐Bicocca Piazza della Scienza 2 20126 Milan Italy
| | - Stefania Brocca
- Department of Biotechnology and BiosciencesUniversity of Milano‐Bicocca Piazza della Scienza 2 20126 Milan Italy
| | - Erika Ponzini
- Department of Biotechnology and BiosciencesUniversity of Milano‐Bicocca Piazza della Scienza 2 20126 Milan Italy
| | - Rita Grandori
- Department of Biotechnology and BiosciencesUniversity of Milano‐Bicocca Piazza della Scienza 2 20126 Milan Italy
| |
Collapse
|
31
|
Murcia Rios A, Vahidi S, Dunn SD, Konermann L. Evidence for a Partially Stalled γ Rotor in F 1-ATPase from Hydrogen-Deuterium Exchange Experiments and Molecular Dynamics Simulations. J Am Chem Soc 2018; 140:14860-14869. [PMID: 30339028 DOI: 10.1021/jacs.8b08692] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
F1-ATPase uses ATP hydrolysis to drive rotation of the γ subunit. The γ C-terminal helix constitutes the rotor tip that is seated in an apical bearing formed by α3β3. It remains uncertain to what extent the γ conformation during rotation differs from that seen in rigid crystal structures. Existing models assume that the entire γ subunit participates in every rotation. Here we interrogated E. coli F1-ATPase by hydrogen-deuterium exchange (HDX) mass spectrometry. Rotation of γ caused greatly enhanced deuteration in the γ C-terminal helix. The HDX kinetics implied that most F1 complexes operate with an intact rotor at any given time, but that the rotor tip is prone to occasional unfolding. A molecular dynamics (MD) strategy was developed to model the off-axis forces acting on γ. MD runs showed stalling of the rotor tip and unfolding of the γ C-terminal helix. MD-predicted H-bond opening events coincided with experimental HDX patterns. Our data suggest that in vitro operation of F1-ATPase is associated with significant rotational resistance in the apical bearing. These conditions cause the γ C-terminal helix to get "stuck" (and unfold) sporadically while the remainder of γ continues to rotate. This scenario contrasts the traditional "greasy bearing" model that envisions smooth rotation of the γ C-terminal helix. The fragility of the apical rotor tip in F1-ATPase is attributed to the absence of a c10 ring that stabilizes the rotation axis in intact FoF1. Overall, the MD/HDX strategy introduced here appears well suited for interrogating the inner workings of molecular motors.
Collapse
Affiliation(s)
- Angela Murcia Rios
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
| | - Siavash Vahidi
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
| | - Stanley D Dunn
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
| | - Lars Konermann
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
| |
Collapse
|
32
|
Nguyen D, Mayne L, Phillips MC, Walter Englander S. Reference Parameters for Protein Hydrogen Exchange Rates. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1936-1939. [PMID: 30022340 PMCID: PMC6087487 DOI: 10.1007/s13361-018-2021-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 06/15/2018] [Accepted: 06/19/2018] [Indexed: 05/11/2023]
Abstract
The analysis of many hydrogen exchange (HX) experiments depends on knowledge of exchange rates expected for the unstructured protein under the same conditions. We present here some minor adjustments to previously calibrated values and a stringent test of their accuracy. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- David Nguyen
- Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Leland Mayne
- Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - S Walter Englander
- Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
33
|
Minsky BB, Abzalimov RR, Niu C, Zhao Y, Kirsch Z, Dubin PL, Savinov SN, Kaltashov IA. Mass Spectrometry Reveals a Multifaceted Role of Glycosaminoglycan Chains in Factor Xa Inactivation by Antithrombin. Biochemistry 2018; 57:4880-4890. [PMID: 29999301 DOI: 10.1021/acs.biochem.8b00199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Factor Xa (fXa) inhibition by antithrombin (AT) enabled by heparin or heparan sulfate is critical for controlling blood coagulation. AT activation by heparin has been investigated extensively, while interaction of heparin with trapped AT/fXa intermediates has received relatively little attention. We use native electrospray ionization mass spectrometry to study the role of heparin chains of varying length [hexa-, octa-, deca-, and eicosasaccharides (dp6, dp8, dp10, and dp20, respectively)] in AT/fXa complex assembly. Despite being critical promoters of AT/Xa binding, shorter heparin chains are excluded from the final products (trapped intermediates). However, replacement of short heparin segments with dp20 gives rise to a prominent ionic signal of ternary complexes. These species are also observed when the trapped intermediate is initially prepared in the presence of a short oligoheparin (dp6), followed by addition of a longer heparin chain (dp20), indicating that binding of heparin to AT/fXa complexes takes place after the inhibition event. The importance of the heparin chain length for its ability to associate with the trapped intermediate suggests that the binding likely occurs in a bidentate fashion (where two distinct segments of oligoheparin make contacts with the protein components, while the part of the chain separating these two segments is extended into solution to minimize electrostatic repulsion). This model is corroborated by both molecular dynamics simulations with an explicit solvent and ion mobility measurements in the gas phase. The observed post-inhibition binding of heparin to the trapped AT/fXa intermediates hints at the likely role played by heparan sulfate in their catabolism.
Collapse
|
34
|
How can native mass spectrometry contribute to characterization of biomacromolecular higher-order structure and interactions? Methods 2018; 144:3-13. [PMID: 29704661 DOI: 10.1016/j.ymeth.2018.04.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 04/03/2018] [Accepted: 04/21/2018] [Indexed: 01/16/2023] Open
Abstract
Native mass spectrometry (MS) is an emerging approach for characterizing biomacromolecular structure and interactions under physiologically relevant conditions. In native MS measurement, intact macromolecules or macromolecular complexes are directly ionized from a non-denaturing solvent, and key noncovalent interactions that hold the complexes together can be preserved for MS analysis in the gas phase. This technique provides unique multi-level structural information such as conformational changes, stoichiometry, topology and dynamics, complementing conventional biophysical techniques. Despite the maturation of native MS and greatly expanded range of applications in recent decades, further dissemination is needed to make the community aware of such a technique. In this review, we attempt to provide an overview of the current body of knowledge regarding major aspects of native MS and explain how such technique contributes to the characterization of biomacromolecular higher-order structure and interactions.
Collapse
|
35
|
Kaltashov IA, Pawlowski JW, Yang W, Muneeruddin K, Yao H, Bobst CE, Lipatnikov AN. LC/MS at the whole protein level: Studies of biomolecular structure and interactions using native LC/MS and cross-path reactive chromatography (XP-RC) MS. Methods 2018; 144:14-26. [PMID: 29702225 DOI: 10.1016/j.ymeth.2018.04.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/11/2018] [Accepted: 04/18/2018] [Indexed: 11/25/2022] Open
Abstract
Interfacing liquid chromatography (LC) with electrospray ionization (ESI) to enable on-line MS detection had been initially implemented using reversed phase LC, which in the past three decades remained the default type of chromatography used for LC/MS and LC/MS/MS studies of protein structure. In contrast, the advantages of other types of LC as front-ends for ESI MS, particularly those that allow biopolymer higher order structure to be preserved throughout the separation process, enjoyed relatively little appreciation until recently. However, the past few years witnessed a dramatic surge of interest in the so-called "native" (with "non-denaturing" being perhaps a more appropriate adjective) LC/MS and LC/MS/MS analyses within the bioanalytical and biophysical communities. This review focuses on recent advances in this field, with an emphasis on size exclusion and ion exchange chromatography as front-end platforms for protein characterization by LC/MS. Also discussed are the benefits provided by the integration of chemical reactions in the native LC/MS analyses, including both ion chemistry in the gas phase (e.g., limited charge reduction for characterization of highly heterogeneous biopolymers) and solution-phase reactions (using the recently introduced technique cross-path reactive chromatography).
Collapse
Affiliation(s)
- Igor A Kaltashov
- Institute for Applied Life Sciences and Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, United States.
| | - Jake W Pawlowski
- Institute for Applied Life Sciences and Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, United States
| | - Wenhua Yang
- Institute for Applied Life Sciences and Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, United States
| | - Khaja Muneeruddin
- Institute for Applied Life Sciences and Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, United States
| | - Honglin Yao
- Institute for Applied Life Sciences and Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, United States
| | - Cedric E Bobst
- Institute for Applied Life Sciences and Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, United States
| | - Andrei N Lipatnikov
- Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Göteborg, Sweden
| |
Collapse
|
36
|
Wang G, Bondarenko PV, Kaltashov IA. Multi-step conformational transitions in heat-treated protein therapeutics can be monitored in real time with temperature-controlled electrospray ionization mass spectrometry. Analyst 2018; 143:670-677. [PMID: 29303166 DOI: 10.1039/c7an01655g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heat-induced conformational transitions are frequently used to probe the free energy landscapes of proteins. However, the extraction of information from thermal denaturation profiles pertaining to non-native protein conformations remains challenging due to their transient nature and significant conformational heterogeneity. Previously we developed a temperature-controlled electrospray ionization (ESI) source that allowed unfolding and association of biopolymers to be monitored by mass spectrometry (MS) in real time as a function of temperature. The scope of this technique is now extended to systems that undergo multi-step denaturation upon heat stress, as well as relatively small-scale conformational changes that are precursors to protein aggregation. The behavior of two therapeutic proteins (human antithrombin and an IgG1 monoclonal antibody) under heat-stress conditions is monitored in real time, providing evidence that relatively small-scale conformational changes in each system lead to protein oligomerization, followed by aggregation. Temperature-controlled ESI MS is particularly useful for the studies of heat-stressed multi-domain proteins such as IgG, where it allows distinct transitions to be observed. The ability of native temperature-controlled ESI MS to monitor both the conformational changes and oligomerization/degradation with high selectivity complements the classic calorimetric methods, lending itself as a powerful experimental tool for the thermostability studies of protein therapeutics.
Collapse
Affiliation(s)
- Guanbo Wang
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, and School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, China.
| | - Pavel V Bondarenko
- Attribute Sciences, Process Development, Amgen, Inc., Thousand Oaks, CA, USA
| | - Igor A Kaltashov
- Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, USA
| |
Collapse
|
37
|
Troilo F, Bignon C, Gianni S, Fuxreiter M, Longhi S. Experimental Characterization of Fuzzy Protein Assemblies: Interactions of Paramyxoviral NTAIL Domains With Their Functional Partners. Methods Enzymol 2018; 611:137-192. [DOI: 10.1016/bs.mie.2018.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
38
|
Portz A, Gebhardt CR, Dürr M. Real-Time Investigation of the H/D Exchange Kinetics of Porphyrins and Oligopeptides by Means of Neutral Cluster-Induced Desorption/Ionization Mass Spectrometry. J Phys Chem B 2017; 121:11031-11036. [PMID: 29160071 DOI: 10.1021/acs.jpcb.7b06897] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The kinetics of the H/D exchange reaction in angiotensin II, hexaglycine (Gly6), Co(II)tetra(3-carboxyphenyl)porphyrin, and tetra(4-carboxyphenyl)porphyrin were followed in real time by mass spectrometry employing desorption/ionization induced by neutral SO2 clusters. The change of the isotope patterns with increasing degree of deuteration was recorded as a function of D2O exposure and the underlying H/D exchange kinetics, i.e., the dependence of the different degrees of deuteration on time, were deduced. The results were modeled by means of Monte Carlo simulations taking into account different reaction constants for the H/D exchange reaction at different functional groups. In the case of the investigated porphyrins, the rate constants were directly assigned to the functional groups involved; in the case of the peptides, reaction at the explicit functional groups and the backbone chain of the molecules could be discriminated.
Collapse
Affiliation(s)
- André Portz
- Institut für Angewandte Physik, Justus-Liebig-Universität Giessen , Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | | | - Michael Dürr
- Institut für Angewandte Physik, Justus-Liebig-Universität Giessen , Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| |
Collapse
|
39
|
Abstract
Conditionally disordered proteins are either ordered or disordered depending on the environmental context. The substrates of the mitochondrial intermembrane space (IMS) oxidoreductase Mia40 are synthesized on cytosolic ribosomes and diffuse as intrinsically disordered proteins to the IMS, where they fold into their functional conformations; behaving thus as conditionally disordered proteins. It is not clear how the sequences of these polypeptides encode at the same time for their ability to adopt a folded structure and to remain unfolded. Here we characterize the disorder-to-order transition of a Mia40 substrate, the human small copper chaperone Cox17. Using an integrated real-time approach, including chromatography, fluorescence, CD, FTIR, SAXS, NMR, and MS analysis, we demonstrate that in this mitochondrial protein, the conformational switch between disordered and folded states is controlled by the formation of a single disulfide bond, both in the presence and in the absence of Mia40. We provide molecular details on how the folding of a conditionally disordered protein is tightly regulated in time and space, in such a way that the same sequence is competent for protein translocation and activity.
Collapse
|
40
|
Fraga H, Pujols J, Gil-Garcia M, Roque A, Bernardo-Seisdedos G, Santambrogio C, Bech-Serra JJ, Canals F, Bernadó P, Grandori R, Millet O, Ventura S. Disulfide driven folding for a conditionally disordered protein. Sci Rep 2017; 7:16994. [PMID: 29208936 PMCID: PMC5717278 DOI: 10.1038/s41598-017-17259-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/23/2017] [Indexed: 11/09/2022] Open
Abstract
Conditionally disordered proteins are either ordered or disordered depending on the environmental context. The substrates of the mitochondrial intermembrane space (IMS) oxidoreductase Mia40 are synthesized on cytosolic ribosomes and diffuse as intrinsically disordered proteins to the IMS, where they fold into their functional conformations; behaving thus as conditionally disordered proteins. It is not clear how the sequences of these polypeptides encode at the same time for their ability to adopt a folded structure and to remain unfolded. Here we characterize the disorder-to-order transition of a Mia40 substrate, the human small copper chaperone Cox17. Using an integrated real-time approach, including chromatography, fluorescence, CD, FTIR, SAXS, NMR, and MS analysis, we demonstrate that in this mitochondrial protein, the conformational switch between disordered and folded states is controlled by the formation of a single disulfide bond, both in the presence and in the absence of Mia40. We provide molecular details on how the folding of a conditionally disordered protein is tightly regulated in time and space, in such a way that the same sequence is competent for protein translocation and activity.
Collapse
Affiliation(s)
- Hugo Fraga
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departamento de Bioquimica, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Jordi Pujols
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Marcos Gil-Garcia
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Alicia Roque
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | | | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | | | - Francesc Canals
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Pau Bernadó
- Centre de Biochimie Structurale, INSERM-U1054, CNRS UMR-5048, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | - Oscar Millet
- Protein Stability and Inherited Diseases Laboratory, CIC bioGUNE, 48160, Derio, Spain
| | - Salvador Ventura
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain. .,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
| |
Collapse
|
41
|
Fast CS, Vahidi S, Konermann L. Changes in Enzyme Structural Dynamics Studied by Hydrogen Exchange-Mass Spectrometry: Ligand Binding Effects or Catalytically Relevant Motions? Anal Chem 2017; 89:13326-13333. [DOI: 10.1021/acs.analchem.7b03506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Courtney S. Fast
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - 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
|
42
|
Huang HT, Bobst CE, Iwig JS, Chivers PT, Kaltashov IA, Maroney MJ. Co(II) and Ni(II) binding of the Escherichia coli transcriptional repressor RcnR orders its N terminus, alters helix dynamics, and reduces DNA affinity. J Biol Chem 2017; 293:324-332. [PMID: 29150441 DOI: 10.1074/jbc.ra117.000398] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 11/13/2017] [Indexed: 12/22/2022] Open
Abstract
RcnR, a transcriptional regulator in Escherichia coli, derepresses the expression of the export proteins RcnAB upon binding Ni(II) or Co(II). Lack of structural information has precluded elucidation of the allosteric basis for the decreased DNA affinity in RcnR's metal-bound states. Here, using hydrogen-deuterium exchange coupled with MS (HDX-MS), we probed the RcnR structure in the presence of DNA, the cognate metal ions Ni(II) and Co(II), or the noncognate metal ion Zn(II). We found that cognate metal binding altered flexibility from the N terminus through helix 1 and modulated the RcnR-DNA interaction. Apo-RcnR and RcnR-DNA complexes and the Zn(II)-RcnR complex exhibited similar 2H uptake kinetics, with fast-exchanging segments located in the N terminus, in helix 1 (residues 14-24), and at the C terminus. The largest difference in 2H incorporation between apo- and Ni(II)- and Co(II)-bound RcnR was observed in helix 1, which contains the N terminus and His-3, and has been associated with cognate metal binding. 2H uptake in helix 1 was suppressed in the Ni(II)- and Co(II)-bound RcnR complexes, in particular in the peptide corresponding to residues 14-24, containing Arg-14 and Lys-17. Substitution of these two residues drastically affected DNA-binding affinity, resulting in rcnA expression in the absence of metal. Our results suggest that cognate metal binding to RcnR orders its N terminus, decreases helix 1 flexibility, and induces conformational changes that restrict DNA interactions with the positively charged residues Arg-14 and Lys-17. These metal-induced alterations decrease RcnR-DNA binding affinity, leading to rcnAB expression.
Collapse
Affiliation(s)
- Hsin-Ting Huang
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003
| | - Cedric E Bobst
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003
| | - Jeffrey S Iwig
- Carmot Therapeutics, Inc., San Francisco, California 94158
| | - Peter T Chivers
- Departments of Biosciences and Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Igor A Kaltashov
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003
| | - Michael J Maroney
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003.
| |
Collapse
|
43
|
Natalello A, Santambrogio C, Grandori R. Are Charge-State Distributions a Reliable Tool Describing Molecular Ensembles of Intrinsically Disordered Proteins by Native MS? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:21-28. [PMID: 27730522 DOI: 10.1007/s13361-016-1490-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/13/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
Native mass spectrometry (MS) has become a central tool of structural proteomics, but its applicability to the peculiar class of intrinsically disordered proteins (IDPs) is still object of debate. IDPs lack an ordered tridimensional structure and are characterized by high conformational plasticity. Since they represent valuable targets for cancer and neurodegeneration research, there is an urgent need of methodological advances for description of the conformational ensembles populated by these proteins in solution. However, structural rearrangements during electrospray-ionization (ESI) or after the transfer to the gas phase could affect data obtained by native ESI-MS. In particular, charge-state distributions (CSDs) are affected by protein conformation inside ESI droplets, while ion mobility (IM) reflects protein conformation in the gas phase. This review focuses on the available evidence relating IDP solution ensembles with CSDs, trying to summarize cases of apparent consistency or discrepancy. The protein-specificity of ionization patterns and their responses to ligands and buffer conditions suggests that CSDs are imprinted to protein structural features also in the case of IDPs. Nevertheless, it seems that these proteins are more easily affected by electrospray conditions, leading in some cases to rearrangements of the conformational ensembles. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy.
| |
Collapse
|
44
|
Piovesan D, Tabaro F, Mičetić I, Necci M, Quaglia F, Oldfield CJ, Aspromonte MC, Davey NE, Davidović R, Dosztányi Z, Elofsson A, Gasparini A, Hatos A, Kajava AV, Kalmar L, Leonardi E, Lazar T, Macedo-Ribeiro S, Macossay-Castillo M, Meszaros A, Minervini G, Murvai N, Pujols J, Roche DB, Salladini E, Schad E, Schramm A, Szabo B, Tantos A, Tonello F, Tsirigos KD, Veljković N, Ventura S, Vranken W, Warholm P, Uversky VN, Dunker AK, Longhi S, Tompa P, Tosatto SCE. DisProt 7.0: a major update of the database of disordered proteins. Nucleic Acids Res 2016; 45:D219-D227. [PMID: 27899601 PMCID: PMC5210544 DOI: 10.1093/nar/gkw1056] [Citation(s) in RCA: 201] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 10/19/2016] [Accepted: 10/21/2016] [Indexed: 01/16/2023] Open
Abstract
The Database of Protein Disorder (DisProt, URL: www.disprot.org) has been significantly updated and upgraded since its last major renewal in 2007. The current release holds information on more than 800 entries of IDPs/IDRs, i.e. intrinsically disordered proteins or regions that exist and function without a well-defined three-dimensional structure. We have re-curated previous entries to purge DisProt from conflicting cases, and also upgraded the functional classification scheme to reflect continuous advance in the field in the past 10 years or so. We define IDPs as proteins that are disordered along their entire sequence, i.e. entirely lack structural elements, and IDRs as regions that are at least five consecutive residues without well-defined structure. We base our assessment of disorder strictly on experimental evidence, such as X-ray crystallography and nuclear magnetic resonance (primary techniques) and a broad range of other experimental approaches (secondary techniques). Confident and ambiguous annotations are highlighted separately. DisProt 7.0 presents classified knowledge regarding the experimental characterization and functional annotations of IDPs/IDRs, and is intended to provide an invaluable resource for the research community for a better understanding structural disorder and for developing better computational tools for studying disordered proteins.
Collapse
Affiliation(s)
- Damiano Piovesan
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
| | - Francesco Tabaro
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy.,Institute of Biosciences and Medical Technology, University of Tampere, Finland
| | - Ivan Mičetić
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
| | - Marco Necci
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
| | - Federica Quaglia
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
| | - Christopher J Oldfield
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, 46202 Indianapolis, IN, USA
| | | | - Norman E Davey
- Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.,Ireland UCD School of Medicine & Medical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Radoslav Davidović
- Centre for Multidisciplinary Research, Institute of Nuclear Sciences Vinca, University of Belgrade, 11001 Belgrade, Serbia
| | - Zsuzsanna Dosztányi
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, 1/c Pázmány Péter sétány, 1117 Budapest, Hungary.,Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary
| | - Arne Elofsson
- Department of Biochemistry and Biophysics and Science for Life Laboratory, Stockholm University, Box 1031, 17121 Solna, Sweden
| | - Alessandra Gasparini
- Department of Woman and Child Health, University of Padova, I-35128 Padova, Italy
| | - András Hatos
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy.,Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary
| | - Andrey V Kajava
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), UMR 5237 CNRS, Université Montpellier 1919 Route de Mende, Cedex 5, Montpellier 34293, France.,Institut de Biologie Computationnelle (IBC), Montpellier 34095, France.,University ITMO, Institute of Bioengineering, St. Petersburg 197101, Russia
| | - Lajos Kalmar
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary.,Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - Emanuela Leonardi
- Department of Woman and Child Health, University of Padova, I-35128 Padova, Italy
| | - Tamas Lazar
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels 1050, Belgium.,Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Brussels 1050, Belgium
| | - Sandra Macedo-Ribeiro
- Biomolecular Structure and Function Group, Instituto de Biologia Molecular e Celular (IBMC) and Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Mauricio Macossay-Castillo
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels 1050, Belgium.,Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Brussels 1050, Belgium
| | - Attila Meszaros
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary
| | - Giovanni Minervini
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
| | - Nikoletta Murvai
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary
| | - Jordi Pujols
- Departament de Bioquimica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Daniel B Roche
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), UMR 5237 CNRS, Université Montpellier 1919 Route de Mende, Cedex 5, Montpellier 34293, France.,Institut de Biologie Computationnelle (IBC), Montpellier 34095, France
| | | | - Eva Schad
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary
| | | | - Beata Szabo
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary
| | - Agnes Tantos
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary
| | - Fiorella Tonello
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy.,CNR Institute of Neurosceince, I-35121 Padova, Italy
| | - Konstantinos D Tsirigos
- Department of Biochemistry and Biophysics and Science for Life Laboratory, Stockholm University, Box 1031, 17121 Solna, Sweden
| | - Nevena Veljković
- Centre for Multidisciplinary Research, Institute of Nuclear Sciences Vinca, University of Belgrade, 11001 Belgrade, Serbia
| | - Salvador Ventura
- Departament de Bioquimica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Wim Vranken
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels 1050, Belgium.,Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Brussels 1050, Belgium.,Interuniversity Institute of Bioinformatics in Brussels (IB2), ULB-VUB, Brussels 1050, Belgium
| | - Per Warholm
- Department of Biochemistry and Biophysics and Science for Life Laboratory, Stockholm University, Box 1031, 17121 Solna, Sweden
| | - Vladimir N Uversky
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg, Russia.,Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - A Keith Dunker
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, 46202 Indianapolis, IN, USA
| | - Sonia Longhi
- Aix-Marseille Univ, CNRS, AFMB, UMR 7257, Marseille, France
| | - Peter Tompa
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, PO Box 7,H-1518 Budapest, Hungary .,Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels 1050, Belgium.,Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Brussels 1050, Belgium
| | - Silvio C E Tosatto
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy .,CNR Institute of Neurosceince, I-35121 Padova, Italy
| |
Collapse
|
45
|
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
|
46
|
Metwally H, McAllister RG, Popa V, Konermann L. Mechanism of Protein Supercharging by Sulfolane and m-Nitrobenzyl Alcohol: Molecular Dynamics Simulations of the Electrospray Process. Anal Chem 2016; 88:5345-54. [DOI: 10.1021/acs.analchem.6b00650] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Haidy Metwally
- Department
of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Robert G. McAllister
- Department
of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Vlad Popa
- Department
of Biochemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Lars Konermann
- Department
of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
- Department
of Biochemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| |
Collapse
|
47
|
Fatunmbi O, Abzalimov RR, Savinov SN, Gershenson A, Kaltashov IA. Interactions of Haptoglobin with Monomeric Globin Species: Insights from Molecular Modeling and Native Electrospray Ionization Mass Spectrometry. Biochemistry 2016; 55:1918-28. [DOI: 10.1021/acs.biochem.5b00807] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ololade Fatunmbi
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Rinat R. Abzalimov
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Sergey N. Savinov
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Anne Gershenson
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Igor A. Kaltashov
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| |
Collapse
|
48
|
Load-dependent destabilization of the γ-rotor shaft in FOF1 ATP synthase revealed by hydrogen/deuterium-exchange mass spectrometry. Proc Natl Acad Sci U S A 2016; 113:2412-7. [PMID: 26884184 DOI: 10.1073/pnas.1520464113] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
FoF1 is a membrane-bound molecular motor that uses proton-motive force (PMF) to drive the synthesis of ATP from ADP and Pi. Reverse operation generates PMF via ATP hydrolysis. Catalysis in either direction involves rotation of the γε shaft that connects the α3β3 head and the membrane-anchored cn ring. X-ray crystallography and other techniques have provided insights into the structure and function of FoF1 subcomplexes. However, interrogating the conformational dynamics of intact membrane-bound FoF1 during rotational catalysis has proven to be difficult. Here, we use hydrogen/deuterium exchange mass spectrometry to probe the inner workings of FoF1 in its natural membrane-bound state. A pronounced destabilization of the γ C-terminal helix during hydrolysis-driven rotation was observed. This behavior is attributed to torsional stress in γ, arising from γ⋅⋅⋅α3β3 interactions that cause resistance during γ rotation within the apical bearing. Intriguingly, we find that destabilization of γ occurs only when FoF1 operates against a PMF-induced torque; the effect disappears when PMF is eliminated by an uncoupler. This behavior resembles the properties of automotive engines, where bearings inflict greater forces on the crankshaft when operated under load than during idling.
Collapse
|
49
|
Li J, Santambrogio C, Brocca S, Rossetti G, Carloni P, Grandori R. Conformational effects in protein electrospray-ionization mass spectrometry. MASS SPECTROMETRY REVIEWS 2016; 35:111-22. [PMID: 25952139 DOI: 10.1002/mas.21465] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/14/2015] [Indexed: 05/11/2023]
Abstract
Electrospray-ionization mass spectrometry (ESI-MS) is a key tool of structural biology, complementing the information delivered by conventional biochemical and biophysical methods. Yet, the mechanism behind the conformational effects in protein ESI-MS is an object of debate. Two parameters-solvent-accessible surface area (As) and apparent gas-phase basicity (GBapp)-are thought to play a role in controlling the extent of protein ionization during ESI-MS experiments. This review focuses on recent experimental and theoretical investigations concerning the influence of these parameters on ESI-MS results and the structural information that can be derived. The available evidence supports a unified model for the ionization mechanism of folded and unfolded proteins. These data indicate that charge-state distribution (CSD) analysis can provide valuable structural information on normally folded, as well as disordered structures.
Collapse
Affiliation(s)
- Jinyu Li
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University, 52057 Aachen, Germany
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Giulia Rossetti
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Paolo Carloni
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| |
Collapse
|
50
|
Gallagher ES, Hudgens JW. Mapping Protein–Ligand Interactions with Proteolytic Fragmentation, Hydrogen/Deuterium Exchange-Mass Spectrometry. Methods Enzymol 2016; 566:357-404. [DOI: 10.1016/bs.mie.2015.08.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|