1
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He Q, Wang C, Jain R, Byrnes J, Farquhar ER, Reed E, Berezovsky E, Chance MR, Lodowski D, An R. An engineered lactate oxidase based electrochemical sensor for continuous detection of biomarker lactic acid in human sweat and serum. Heliyon 2024; 10:e34301. [PMID: 39149041 PMCID: PMC11324829 DOI: 10.1016/j.heliyon.2024.e34301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Accepted: 07/08/2024] [Indexed: 08/17/2024] Open
Abstract
Lactate levels in humans reveal intensity and duration of exertion and provide a critical readout for the severity of life-threatening illnesses such as pediatric sepsis. Using the lactate oxidase enzyme (Lox) from Aerococcus viridians, we demonstrated its functionality for lactate electrochemical sensing in physiological fluids in a lab setting. The structure and dynamics of LOx were validated by crystallography, X-ray scattering, and hydroxyl radical protein footprinting. This provided a validated protein template for understanding and designing an enzyme-based electrochemical sensing elements. Using this template, LOx enzyme variants were generated and compared. Comparison of the variants demonstrates that one exhibits effective lactate sensing at significantly reduced operating voltages. Additionally, we demonstrate that the four hexahistidine-tags on each enzyme tetramer are sufficient for immobilization to create a durable, functional sensor, with no need for a covalent attachment, enabling self-immobilization and eliminating the need for additional immobilization steps. The functionality of the LOx enzyme variants was verified at physiological lactate concentrations in both human serum (0-4 mM) and artificial sweat (0-100 mM) using 3-electrode setups for analysis of the three variants in parallel. Accuracy of measurement in both artificial sweat and human serum were high. Employing a microfluidic flow cell, we successfully monitored varying lactate levels in physiological fluids continuously over a 2h period. Overall, this optimized LOx enzyme, which self-immobilizes onto gold sensing electrodes, facilitates efficient and reliable lactate detection and continuous monitoring at reduced operating voltages suitable for further development towards commercial use.
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Affiliation(s)
- Qingrong He
- Department of Biomedical Engineering, University of Houston, United States
| | - Cheng Wang
- Department of Biomedical Engineering, University of Houston, United States
| | - Rohit Jain
- Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States
- Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, United States
- Center for Synchrotron Biosciences, School of Medicine, Case Western Reserve University, United States
| | - James Byrnes
- National Synchrotron Light Source II, Brookhaven National Laboratory, United States
| | - Erik R. Farquhar
- Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States
- Center for Synchrotron Biosciences, School of Medicine, Case Western Reserve University, United States
| | - Elliot Reed
- Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States
- Sensate Biosystems LLC, Cleveland, OH, United States
| | - Elizabeth Berezovsky
- Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States
- Sensate Biosystems LLC, Cleveland, OH, United States
| | - Mark R. Chance
- Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States
- Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, United States
- Center for Synchrotron Biosciences, School of Medicine, Case Western Reserve University, United States
- Sensate Biosystems LLC, Cleveland, OH, United States
| | - David Lodowski
- Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States
- Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, United States
- Sensate Biosystems LLC, Cleveland, OH, United States
| | - Ran An
- Department of Biomedical Engineering, University of Houston, United States
- Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States
- Department of Biomedical Sciences, University of Houston, United States
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2
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Otteson L, Nagy G, Kunkel J, Kodis G, Zheng W, Bignon C, Longhi S, Grubmüller H, Vaiana AC, Vaiana SM. Transient Non-local Interactions Dominate the Dynamics of Measles Virus N TAIL. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.22.604679. [PMID: 39091801 PMCID: PMC11291014 DOI: 10.1101/2024.07.22.604679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
The RNA genome of measles virus is encapsidated by the nucleoprotein within a helical nucleocapsid that serves as template for both transcription and replication. The intrinsically disordered domain of the nucleoprotein (NTAIL), partly protruding outward from the nucleocapsid, is essential for binding the polymerase complex responsible for viral transcription and replication. As for many IDPs, binding of NTAIL occurs through a short molecular recognition element (MoRE) that folds upon binding, with the majority of NTAIL remaining disordered. Though NTAIL regions far from the MoRE influence the binding affinity, interactions between them and the MoRE have not been investigated in depth. Using an integrated approach, relying on photo-induced electron transfer (PET) experiments between tryptophan and cysteine pairs placed at different positions in the protein under varying salt and pH conditions, combined with simulations and analytical models, we identified transient interactions between two disordered regions distant in sequence, which dominate NTAIL dynamics, and regulate the conformational preferences of both the MoRE and the entire NTAIL domain. Co-evolutionary analysis corroborates our findings, and suggests an important functional role for the same intramolecular interactions. We propose mechanisms by which these non-local interactions may regulate binding to the phosphoprotein, polymerase recruitment, and ultimately viral transcription and replication. Our findings may be extended to other IDPs, where non-local intra-protein interactions affect the conformational preferences of intermolecular binding sites.
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Affiliation(s)
- Lillian Otteson
- Center for Biological Physics, Arizona State University, Tempe, AZ, USA
- Department of Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Gabor Nagy
- Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - John Kunkel
- Center for Biological Physics, Arizona State University, Tempe, AZ, USA
- Department of Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Gerdenis Kodis
- Center for Biological Physics, Arizona State University, Tempe, AZ, USA
- Department of Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Wenwei Zheng
- College of Integrative Sciences and Arts, Arizona State University, Mesa, AZ 85212, USA
| | | | - Sonia Longhi
- Aix Marseille Univ, CNRS, AFMB, UMR 7257, Marseille, France
| | - Helmut Grubmüller
- Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Andrea C Vaiana
- Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Present address: Nature's Toolbox, Inc. (NTx), Rio Rancho, NM 87144, USA
| | - Sara M Vaiana
- Center for Biological Physics, Arizona State University, Tempe, AZ, USA
- Department of Physics, Arizona State University, Tempe, AZ 85287, USA
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3
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Castel J, Delaux S, Hernandez-Alba O, Cianférani S. Recent advances in structural mass spectrometry methods in the context of biosimilarity assessment: from sequence heterogeneities to higher order structures. J Pharm Biomed Anal 2023; 236:115696. [PMID: 37713983 DOI: 10.1016/j.jpba.2023.115696] [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: 06/28/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/17/2023]
Abstract
Biotherapeutics and their biosimilar versions have been flourishing in the biopharmaceutical market for several years. Structural and functional characterization is needed to achieve analytical biosimilarity through the assessment of critical quality attributes as required by regulatory authorities. The role of analytical strategies, particularly mass spectrometry-based methods, is pivotal to gathering valuable information for the in-depth characterization of biotherapeutics and biosimilarity assessment. Structural mass spectrometry methods (native MS, HDX-MS, top-down MS, etc.) provide information ranging from primary sequence assessment to higher order structure evaluation. This review focuses on recent developments and applications in structural mass spectrometry for biotherapeutic and biosimilar characterization.
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Affiliation(s)
- Jérôme Castel
- Laboratoire de Spectrométrie de Masse Bio-Organique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg 67087, France; Infrastructure Nationale de Protéomique ProFI, FR2048 CNRS CEA, Strasbourg 67087, France
| | - Sarah Delaux
- Laboratoire de Spectrométrie de Masse Bio-Organique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg 67087, France; Infrastructure Nationale de Protéomique ProFI, FR2048 CNRS CEA, Strasbourg 67087, France
| | - Oscar Hernandez-Alba
- Laboratoire de Spectrométrie de Masse Bio-Organique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg 67087, France; Infrastructure Nationale de Protéomique ProFI, FR2048 CNRS CEA, Strasbourg 67087, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse Bio-Organique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg 67087, France; Infrastructure Nationale de Protéomique ProFI, FR2048 CNRS CEA, Strasbourg 67087, France.
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4
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Minkoff BB, Burch HL, Wolfer JD, Sussman MR. Radical-Mediated Covalent Azidylation of Hydrophobic Microdomains in Water-Soluble Proteins. ACS Chem Biol 2023; 18:1786-1796. [PMID: 37463134 DOI: 10.1021/acschembio.3c00224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Hydrophobic microdomains, also known as hydrophobic patches, are essential for many important biological functions of water-soluble proteins. These include ligand or substrate binding, protein-protein interactions, proper folding after translation, and aggregation during denaturation. Unlike transmembrane domains, which are easily recognized from stretches of contiguous hydrophobic sidechains in amino acids via primary protein sequence, these three-dimensional hydrophobic patches cannot be easily predicted. The lack of experimental strategies for directly determining their locations hinders further understanding of their structure and function. Here, we posit that the small triatomic anion N3- (azide) is attracted to these patches and, in the presence of an oxidant, forms a radical that covalently modifies C-H bonds of nearby amino acids. Using two model proteins (BSA and lysozyme) and a cell-free lysate from the model higher plant Arabidopsis thaliana, we find that radical-mediated covalent azidylation occurs within buried catalytic active sites and ligand binding sites and exhibits similar behavior to established hydrophobic probes. The results herein suggest a model in which the azido radical is acting as an "affinity reagent" for nonaqueous three-dimensional protein microenvironments and is consistent with both the nonlocalized electron density of the azide moiety and the known high reactivity of azido radicals widely used in organic chemistry syntheses. We propose that the azido radical is a facile means of identifying hydrophobic microenvironments in soluble proteins and, in addition, provides a simple new method for attaching chemical handles to proteins without the need for genetic manipulation or specialized reagents.
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Affiliation(s)
- Benjamin B Minkoff
- Center for Genomic Science Innovation, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Heather L Burch
- Center for Genomic Science Innovation, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Jamison D Wolfer
- Center for Genomic Science Innovation, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Michael R Sussman
- Center for Genomic Science Innovation, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Department of Biochemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
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5
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Choi WJ, Haratipour Z, Blind RD. Full-length nuclear receptor allosteric regulation. J Lipid Res 2023; 64:100406. [PMID: 37356665 PMCID: PMC10388211 DOI: 10.1016/j.jlr.2023.100406] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/27/2023] Open
Abstract
Nuclear receptors are a superfamily of transcription factors regulated by a wide range of lipids that include phospholipids, fatty acids, heme-based metabolites, and cholesterol-based steroids. Encoded as classic two-domain modular transcription factors, nuclear receptors possess a DNA-binding domain (DBD) and a lipid ligand-binding domain (LBD) containing a transcriptional activation function. Decades of structural studies on the isolated LBDs of nuclear receptors established that lipid-ligand binding allosterically regulates the conformation of the LBD, regulating transcriptional coregulator recruitment and thus nuclear receptor function. These structural studies have aided the development of several FDA-approved drugs, highlighting the importance of understanding the structure-function relationships between lipids and nuclear receptors. However, there are few published descriptions of full-length nuclear receptor structure and even fewer descriptions of how lipids might allosterically regulate full-length structure. Here, we examine multidomain interactions based on the published full-length nuclear receptor structures, evaluating the potential of interdomain interfaces within these nuclear receptors to act as inducible sites of allosteric regulation by lipids.
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Affiliation(s)
- Woong Jae Choi
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Zeinab Haratipour
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Center for Structural Biology, Nashville, TN, USA; Program in Precision Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Raymond D Blind
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Center for Structural Biology, Nashville, TN, USA; Program in Precision Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA; Diabetes Research and Training Center, Vanderbilt University Medical Center, Nashville, TN, USA.
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6
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Luo S, Wohl S, Zheng W, Yang S. Biophysical and Integrative Characterization of Protein Intrinsic Disorder as a Prime Target for Drug Discovery. Biomolecules 2023; 13:biom13030530. [PMID: 36979465 PMCID: PMC10046839 DOI: 10.3390/biom13030530] [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] [Received: 02/10/2023] [Revised: 03/07/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
Protein intrinsic disorder is increasingly recognized for its biological and disease-driven functions. However, it represents significant challenges for biophysical studies due to its high conformational flexibility. In addressing these challenges, we highlight the complementary and distinct capabilities of a range of experimental and computational methods and further describe integrative strategies available for combining these techniques. Integrative biophysics methods provide valuable insights into the sequence–structure–function relationship of disordered proteins, setting the stage for protein intrinsic disorder to become a promising target for drug discovery. Finally, we briefly summarize recent advances in the development of new small molecule inhibitors targeting the disordered N-terminal domains of three vital transcription factors.
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Affiliation(s)
- Shuqi Luo
- Center for Proteomics and Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Samuel Wohl
- Department of Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Wenwei Zheng
- College of Integrative Sciences and Arts, Arizona State University, Mesa, AZ 85212, USA
- Correspondence: (W.Z.); (S.Y.)
| | - Sichun Yang
- Center for Proteomics and Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Correspondence: (W.Z.); (S.Y.)
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7
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Huang W, Li H, Kiselar J, Fink SP, Regmi S, Day A, Yuan Y, Chance M, Ready JM, Markowitz SD, Taylor DJ. Small molecule inhibitors of 15-PGDH exploit a physiologic induced-fit closing system. Nat Commun 2023; 14:784. [PMID: 36774348 PMCID: PMC9922282 DOI: 10.1038/s41467-023-36463-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 02/01/2023] [Indexed: 02/13/2023] Open
Abstract
15-prostaglandin dehydrogenase (15-PGDH) is a negative regulator of tissue stem cells that acts via enzymatic activity of oxidizing and degrading PGE2, and related eicosanoids, that support stem cells during tissue repair. Indeed, inhibiting 15-PGDH markedly accelerates tissue repair in multiple organs. Here we have used cryo-electron microscopy to solve the solution structure of native 15-PGDH and of 15-PGDH individually complexed with two distinct chemical inhibitors. These structures identify key 15-PGDH residues that mediate binding to both classes of inhibitors. Moreover, we identify a dynamic 15-PGDH lid domain that closes around the inhibitors, and that is likely fundamental to the physiologic 15-PGDH enzymatic mechanism. We furthermore identify two key residues, F185 and Y217, that act as hinges to regulate lid closing, and which both inhibitors exploit to capture the lid in the closed conformation, thus explaining their sub-nanomolar binding affinities. These findings provide the basis for further development of 15-PGDH targeted drugs as therapeutics for regenerative medicine.
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Affiliation(s)
- Wei Huang
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hongyun Li
- Department of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Janna Kiselar
- Department of Nutrition, Case Western Reserve University, Cleveland, OH, 44106, USA
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Stephen P Fink
- Department of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Sagar Regmi
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Alexander Day
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Yiyuan Yuan
- Department of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Mark Chance
- Department of Nutrition, Case Western Reserve University, Cleveland, OH, 44106, USA
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Joseph M Ready
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Sanford D Markowitz
- Department of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.
- University Hospitals Seidman Cancer Center, Cleveland, OH, 44106, USA.
| | - Derek J Taylor
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, 44106, USA.
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA.
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8
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Dang X, Guelen L, Lutje Hulsik D, Ermakov G, Hsieh EJ, Kreijtz J, Stammen-Vogelzangs J, Lodewijks I, Bertens A, Bramer A, Guadagnoli M, Nazabal A, van Elsas A, Fischmann T, Juan V, Beebe A, Beaumont M, van Eenennaam H. Epitope mapping of monoclonal antibodies: a comprehensive comparison of different technologies. MAbs 2023; 15:2285285. [PMID: 38010385 PMCID: PMC10730160 DOI: 10.1080/19420862.2023.2285285] [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: 11/02/2022] [Accepted: 11/15/2023] [Indexed: 11/29/2023] Open
Abstract
Monoclonal antibodies have become an important class of therapeutics in the last 30 years. Because the mechanism of action of therapeutic antibodies is intimately linked to their binding epitopes, identification of the epitope of an antibody to the antigen plays a central role during antibody drug development. The gold standard of epitope mapping, X-ray crystallography, requires a high degree of proficiency with no guarantee of success. Here, we evaluated six widely used alternative methods for epitope identification (peptide array, alanine scan, domain exchange, hydrogen-deuterium exchange, chemical cross-linking, and hydroxyl radical footprinting) in five antibody-antigen combinations (pembrolizumab+PD1, nivolumab+PD1, ipilimumab+CTLA4, tremelimumab+CTLA4, and MK-5890+CD27). The advantages and disadvantages of each technique are demonstrated by our data and practical advice on when and how to apply specific epitope mapping techniques during the drug development process is provided. Our results suggest chemical cross-linking most accurately identifies the epitope as defined by crystallography.
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Affiliation(s)
- Xibei Dang
- Pharmacokinetics, Merck & Co. Inc, Kenilworth, NJ, USA
| | - Lars Guelen
- Research, Aduro Biotech Europe, Oss, The Netherlands
| | | | | | | | - Joost Kreijtz
- Research, Aduro Biotech Europe, Oss, The Netherlands
| | | | | | | | - Arne Bramer
- Research, Aduro Biotech Europe, Oss, The Netherlands
| | | | | | | | | | - Veronica Juan
- Pharmacokinetics, Merck & Co. Inc, Kenilworth, NJ, USA
| | - Amy Beebe
- Pharmacokinetics, Merck & Co. Inc, Kenilworth, NJ, USA
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9
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Cheng Z, Misra SK, Shami A, Sharp JS. Structural Analysis of Phosphorylation Proteoforms in a Dynamic Heterogeneous System Using Flash Oxidation Coupled In-Line with Ion Exchange Chromatography. Anal Chem 2022; 94:18017-18024. [PMID: 36512753 PMCID: PMC9912381 DOI: 10.1021/acs.analchem.2c04365] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein posttranslational modifications (PTMs) are key modulators of protein structure and function that often change in a dynamic fashion in response to cellular stimuli. Dynamic PTMs are very challenging to structurally characterize using modern techniques, including covalent labeling methods, due to the presence of multiple proteoforms and conformers together in solution. We have coupled an ion exchange high-performance liquid chromatography separation with a flash oxidation system [ion exchange chromatography liquid chromatography-flash oxidation (IEX LC-FOX)] to successfully elucidate structural changes among three phosphoproteoforms of ovalbumin (OVA) during dephosphorylation with alkaline phosphatase. Real-time dosimetry indicates no difference in the effective radical dose between peaks or across the peak, demonstrating both the lack of scavenging of the NaCl gradient and the lack of a concentration effect on radical dose between peaks of different intensities. The use of IEX LC-FOX allows us to structurally probe into each phosphoproteoform as it elutes from the column, capturing structural data before the dynamics of the system to reintroduce heterogeneity. We found significant differences in the residue-level oxidation between the hydroxyl radical footprint of nonphosphorylated, monophosphorylated, and diphosphorylated OVA. Not only were our data consistent with the previously reported stabilization of OVA structure by phosphorylation, but local structural changes were also consistent with the measured order of dephosphorylation of Ser344 being removed first. These results demonstrate the utility of IEX LC-FOX for measuring the structural effects of PTMs, even in dynamic systems.
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Affiliation(s)
- Zhi Cheng
- Department of BioMolecular Sciences, University of Mississippi, Oxford, MS 38677, United States
| | - Sandeep K. Misra
- Department of BioMolecular Sciences, University of Mississippi, Oxford, MS 38677, United States
| | - Anter Shami
- Department of BioMolecular Sciences, University of Mississippi, Oxford, MS 38677, United States
| | - Joshua S. Sharp
- Department of BioMolecular Sciences, University of Mississippi, Oxford, MS 38677, United States
- Department of Chemistry and Biochemistry, University of Mississippi, Oxford, MS 38677, United States
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10
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Zheng W, Du Z, Ko SB, Wickramasinghe N, Yang S. Incorporation of D 2O-Induced Fluorine Chemical Shift Perturbations into Ensemble-Structure Characterization of the ERalpha Disordered Region. J Phys Chem B 2022; 126:9176-9186. [PMID: 36331868 PMCID: PMC10066504 DOI: 10.1021/acs.jpcb.2c05456] [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] [Indexed: 11/06/2022]
Abstract
Structural characterization of intrinsically disordered proteins (IDPs) requires a concerted effort between experiments and computations by accounting for their conformational heterogeneity. Given the diversity of experimental tools providing local and global structural information, constructing an experimental restraint-satisfying structural ensemble remains challenging. Here, we use the disordered N-terminal domain (NTD) of the estrogen receptor alpha (ERalpha) as a model system to combine existing small-angle X-ray scattering (SAXS) and hydroxyl radical protein footprinting (HRPF) data and newly acquired solvent accessibility data via D2O-induced fluorine chemical shifting (DFCS) measurements. A new set of DFCS data for the solvent exposure of a set of 12 amino acid positions were added to complement previously acquired HRPF measurements for the solvent exposure of the other 16 nonoverlapping amino acids, thereby improving the NTD ensemble characterization considerably. We also found that while choosing an initial ensemble of structures generated from a different atomic-level force field or sampling/modeling method can lead to distinct contact maps even when the same sets of experimental measurements were used for ensemble-fitting, comparative analyses from these initial ensembles reveal commonly recurring structural features in their ensemble-averaged contact map. Specifically, nonlocal or long-range transient interactions were found consistently between the N-terminal segments and the central region, sufficient to mediate the conformational ensemble and regulate how the NTD interacts with its coactivator proteins.
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Affiliation(s)
- Wenwei Zheng
- College of Integrative Sciences and Arts, Arizona State University, Mesa, Arizona 85212, United States
| | - Zhanwen Du
- Center for Proteomics and Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, United States
| | - Soo Bin Ko
- Center for Proteomics and Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, United States
| | - Nalinda Wickramasinghe
- Chemistry-NMR Facility, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Sichun Yang
- Center for Proteomics and Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, United States
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11
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Structural Investigation of Therapeutic Antibodies Using Hydroxyl Radical Protein Footprinting Methods. Antibodies (Basel) 2022; 11:antib11040071. [PMID: 36412837 PMCID: PMC9680451 DOI: 10.3390/antib11040071] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022] Open
Abstract
Commercial monoclonal antibodies are growing and important components of modern therapies against a multitude of human diseases. Well-known high-resolution structural methods such as protein crystallography are often used to characterize antibody structures and to determine paratope and/or epitope binding regions in order to refine antibody design. However, many standard structural techniques require specialized sample preparation that may perturb antibody structure or require high concentrations or other conditions that are far from the conditions conducive to the accurate determination of antigen binding or kinetics. We describe here in this minireview the relatively new method of hydroxyl radical protein footprinting, a solution-state method that can provide structural and kinetic information on antibodies or antibody-antigen interactions useful for therapeutic antibody design. We provide a brief history of hydroxyl radical footprinting, examples of current implementations, and recent advances in throughput and accessibility.
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12
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Hamid M, Khalid MF, Chaudhary SU, Khan S. The Solvation of the E. coli CheY Phosphorylation Site Mapped by XFMS. Int J Mol Sci 2022; 23:ijms232112771. [PMID: 36361564 PMCID: PMC9659070 DOI: 10.3390/ijms232112771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022] Open
Abstract
The Escherichia coli CheY protein belongs to a large bacterial response regulator superfamily. X-ray hydroxy radical foot-printing with mass spectroscopy (XFMS) has shown that allosteric activation of CheY by its motor target triggers a concerted internalization of aromatic sidechains. We reanalyzed the XFMS data to compare polar versus non-polar CheY residue positions. The polar residues around and including the 57D phosphorylated site had an elevated hydroxy radical reactivity. Bioinformatic measures revealed that a water-mediated hydrogen bond network connected this ring of residues with the central 57D. These residues solvated 57D to energetically stabilize the apo-CheY fold. The abundance of these reactive residues was reduced upon activation. This result was supported by the bioinformatics and consistent with the previously reported activation-induced increase in core hydrophobicity. It further illustrated XFMS detection of structural waters. Direct contacts between the ring residues and the phosphorylation site would stabilize the aspartyl phosphate. In addition, we report that the ring residue, 18R, is a constant central node in the 57D solvation network and that 18R non-polar substitutions determine CheY diversity as assessed by its evolutionary trace in bacteria with well-studied chemotaxis. These results showcase the importance of structured water dynamics for phosphorylation-mediated signal transduction.
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Affiliation(s)
- Maham Hamid
- Biomedical Informatics and Engineering Research Laboratory (BIRL), Lahore University of Management Sciences (LUMS), Lahore 54792, Pakistan
| | - Muhammad Farhan Khalid
- Biomedical Informatics and Engineering Research Laboratory (BIRL), Lahore University of Management Sciences (LUMS), Lahore 54792, Pakistan
| | - Safee Ullah Chaudhary
- Biomedical Informatics and Engineering Research Laboratory (BIRL), Lahore University of Management Sciences (LUMS), Lahore 54792, Pakistan
- Correspondence: (S.U.C.); (S.K.)
| | - Shahid Khan
- Syed Babar Ali School of Science & Engineering, Lahore University of Management Sciences (LUMS), Lahore 54792, Pakistan
- Molecular Biology Consortium, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Correspondence: (S.U.C.); (S.K.)
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13
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Cornwell O, Ault JR. Fast photochemical oxidation of proteins coupled with mass spectrometry. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140829. [PMID: 35933084 DOI: 10.1016/j.bbapap.2022.140829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/17/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Fast photochemical oxidation of proteins (FPOP) is a hydroxyl radical footprinting approach whereby radicals, produced by UV laser photolysis of hydrogen peroxide, induce oxidation of amino acid side-chains. Mass Spectrometry (MS) is employed to locate and quantify the resulting irreversible, covalent oxidations to use as a surrogate for side-chain solvent accessibility. Modulation of oxidation levels under different conditions allows for the characterisation of protein conformation, dynamics and binding epitopes. FPOP has been applied to structurally diverse and biopharmaceutically relevant systems from small, monomeric aggregation-prone proteins to proteome-wide analysis of whole organisms. This review evaluates the current state of FPOP, the progress needed to address data analysis bottlenecks, particularly for residue-level analysis, and highlights significant developments of the FPOP platform that have enabled its versatility and complementarity to other structural biology techniques.
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Affiliation(s)
- Owen Cornwell
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, UK
| | - James R Ault
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
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14
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Lubbe L, Sewell BT, Woodward JD, Sturrock ED. Cryo-EM reveals mechanisms of angiotensin I-converting enzyme allostery and dimerization. EMBO J 2022; 41:e110550. [PMID: 35818993 PMCID: PMC9379546 DOI: 10.15252/embj.2021110550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 04/21/2022] [Accepted: 05/27/2022] [Indexed: 11/09/2022] Open
Abstract
Hypertension (high blood pressure) is a major risk factor for cardiovascular disease, which is the leading cause of death worldwide. The somatic isoform of angiotensin I‐converting enzyme (sACE) plays a critical role in blood pressure regulation, and ACE inhibitors are thus widely used to treat hypertension and cardiovascular disease. Our current understanding of sACE structure, dynamics, function, and inhibition has been limited because truncated, minimally glycosylated forms of sACE are typically used for X‐ray crystallography and molecular dynamics simulations. Here, we report the first cryo‐EM structures of full‐length, glycosylated, soluble sACE (sACES1211). Both monomeric and dimeric forms of the highly flexible apo enzyme were reconstructed from a single dataset. The N‐ and C‐terminal domains of monomeric sACES1211 were resolved at 3.7 and 4.1 Å, respectively, while the interacting N‐terminal domains responsible for dimer formation were resolved at 3.8 Å. Mechanisms are proposed for intradomain hinging, cooperativity, and homodimerization. Furthermore, the observation that both domains were in the open conformation has implications for the design of sACE modulators.
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Affiliation(s)
- Lizelle Lubbe
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Bryan Trevor Sewell
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.,Electron Microscope Unit, University of Cape Town, Cape Town, South Africa
| | - Jeremy D Woodward
- Electron Microscope Unit, University of Cape Town, Cape Town, South Africa
| | - Edward D Sturrock
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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15
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Khaje NA, Eletsky A, Biehn SE, Mobley CK, Rogals MJ, Kim Y, Mishra SK, Doerksen RJ, Lindert S, Prestegard JH, Sharp JS. Validated determination of NRG1 Ig-like domain structure by mass spectrometry coupled with computational modeling. Commun Biol 2022; 5:452. [PMID: 35551273 PMCID: PMC9098640 DOI: 10.1038/s42003-022-03411-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/25/2022] [Indexed: 01/03/2023] Open
Abstract
High resolution hydroxyl radical protein footprinting (HR-HRPF) is a mass spectrometry-based method that measures the solvent exposure of multiple amino acids in a single experiment, offering constraints for experimentally informed computational modeling. HR-HRPF-based modeling has previously been used to accurately model the structure of proteins of known structure, but the technique has never been used to determine the structure of a protein of unknown structure. Here, we present the use of HR-HRPF-based modeling to determine the structure of the Ig-like domain of NRG1, a protein with no close homolog of known structure. Independent determination of the protein structure by both HR-HRPF-based modeling and heteronuclear NMR was carried out, with results compared only after both processes were complete. The HR-HRPF-based model was highly similar to the lowest energy NMR model, with a backbone RMSD of 1.6 Å. To our knowledge, this is the first use of HR-HRPF-based modeling to determine a previously uncharacterized protein structure. A mass spectrometry-based method guides computational modeling for de novo protein structure prediction.
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Affiliation(s)
- Niloofar Abolhasani Khaje
- Department of BioMolecular Sciences, University of Mississippi, University, MS, USA.,Analytical Operations Department, Gilead Sciences, Foster City, CA, USA
| | - Alexander Eletsky
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Sarah E Biehn
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
| | - Charles K Mobley
- Department of BioMolecular Sciences, University of Mississippi, University, MS, USA.,Protein Discovery Department, Impossible Foods, Redwood City, CA, USA
| | - Monique J Rogals
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Yoonkyoo Kim
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Sushil K Mishra
- Department of BioMolecular Sciences, University of Mississippi, University, MS, USA.,Glycoscience Center of Research Excellence, University of Mississippi, University, MS, USA
| | - Robert J Doerksen
- Department of BioMolecular Sciences, University of Mississippi, University, MS, USA.,Glycoscience Center of Research Excellence, University of Mississippi, University, MS, USA
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
| | - James H Prestegard
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Joshua S Sharp
- Department of BioMolecular Sciences, University of Mississippi, University, MS, USA. .,Glycoscience Center of Research Excellence, University of Mississippi, University, MS, USA. .,Department of Chemistry and Biochemistry, University of Mississippi, University, MS, USA.
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16
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Rogawski R, Sharon M. Characterizing Endogenous Protein Complexes with Biological Mass Spectrometry. Chem Rev 2022; 122:7386-7414. [PMID: 34406752 PMCID: PMC9052418 DOI: 10.1021/acs.chemrev.1c00217] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Indexed: 01/11/2023]
Abstract
Biological mass spectrometry (MS) encompasses a range of methods for characterizing proteins and other biomolecules. MS is uniquely powerful for the structural analysis of endogenous protein complexes, which are often heterogeneous, poorly abundant, and refractive to characterization by other methods. Here, we focus on how biological MS can contribute to the study of endogenous protein complexes, which we define as complexes expressed in the physiological host and purified intact, as opposed to reconstituted complexes assembled from heterologously expressed components. Biological MS can yield information on complex stoichiometry, heterogeneity, topology, stability, activity, modes of regulation, and even structural dynamics. We begin with a review of methods for isolating endogenous complexes. We then describe the various biological MS approaches, focusing on the type of information that each method yields. We end with future directions and challenges for these MS-based methods.
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Affiliation(s)
- Rivkah Rogawski
- Department of Biomolecular
Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michal Sharon
- Department of Biomolecular
Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
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17
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Abstract
Knowledge of protein structure is crucial to our understanding of biological function and is routinely used in drug discovery. High-resolution techniques to determine the three-dimensional atomic coordinates of proteins are available. However, such methods are frequently limited by experimental challenges such as sample quantity, target size, and efficiency. Structural mass spectrometry (MS) is a technique in which structural features of proteins are elucidated quickly and relatively easily. Computational techniques that convert sparse MS data into protein models that demonstrate agreement with the data are needed. This review features cutting-edge computational methods that predict protein structure from MS data such as chemical cross-linking, hydrogen-deuterium exchange, hydroxyl radical protein footprinting, limited proteolysis, ion mobility, and surface-induced dissociation. Additionally, we address future directions for protein structure prediction with sparse MS data. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 73 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Sarah E Biehn
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio 43210, USA;
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio 43210, USA;
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18
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McKenzie-Coe A, Montes NS, Jones LM. Hydroxyl Radical Protein Footprinting: A Mass Spectrometry-Based Structural Method for Studying the Higher Order Structure of Proteins. Chem Rev 2021; 122:7532-7561. [PMID: 34633178 DOI: 10.1021/acs.chemrev.1c00432] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hydroxyl radical protein footprinting (HRPF) coupled to mass spectrometry has been successfully used to investigate a plethora of protein-related questions. The method, which utilizes hydroxyl radicals to oxidatively modify solvent-accessible amino acids, can inform on protein interaction sites and regions of conformational change. Hydroxyl radical-based footprinting was originally developed to study nucleic acids, but coupling the method with mass spectrometry has enabled the study of proteins. The method has undergone several advancements since its inception that have increased its utility for more varied applications such as protein folding and the study of biotherapeutics. In addition, recent innovations have led to the study of increasingly complex systems including cell lysates and intact cells. Technological advances have also increased throughput and allowed for better control of experimental conditions. In this review, we provide a brief history of the field of HRPF and detail recent innovations and applications in the field.
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Affiliation(s)
- Alan McKenzie-Coe
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Nicholas S Montes
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Lisa M Jones
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
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19
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Britt HM, Cragnolini T, Thalassinos K. Integration of Mass Spectrometry Data for Structural Biology. Chem Rev 2021; 122:7952-7986. [PMID: 34506113 DOI: 10.1021/acs.chemrev.1c00356] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mass spectrometry (MS) is increasingly being used to probe the structure and dynamics of proteins and the complexes they form with other macromolecules. There are now several specialized MS methods, each with unique sample preparation, data acquisition, and data processing protocols. Collectively, these methods are referred to as structural MS and include cross-linking, hydrogen-deuterium exchange, hydroxyl radical footprinting, native, ion mobility, and top-down MS. Each of these provides a unique type of structural information, ranging from composition and stoichiometry through to residue level proximity and solvent accessibility. Structural MS has proved particularly beneficial in studying protein classes for which analysis by classic structural biology techniques proves challenging such as glycosylated or intrinsically disordered proteins. To capture the structural details for a particular system, especially larger multiprotein complexes, more than one structural MS method with other structural and biophysical techniques is often required. Key to integrating these diverse data are computational strategies and software solutions to facilitate this process. We provide a background to the structural MS methods and briefly summarize other structural methods and how these are combined with MS. We then describe current state of the art approaches for the integration of structural MS data for structural biology. We quantify how often these methods are used together and provide examples where such combinations have been fruitful. To illustrate the power of integrative approaches, we discuss progress in solving the structures of the proteasome and the nuclear pore complex. We also discuss how information from structural MS, particularly pertaining to protein dynamics, is not currently utilized in integrative workflows and how such information can provide a more accurate picture of the systems studied. We conclude by discussing new developments in the MS and computational fields that will further enable in-cell structural studies.
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Affiliation(s)
- Hannah M Britt
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
| | - Tristan Cragnolini
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom.,Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, United Kingdom
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom.,Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, United Kingdom
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20
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Sharp JS, Chea EE, Misra SK, Orlando R, Popov M, Egan RW, Holman D, Weinberger SR. Flash Oxidation (FOX) System: A Novel Laser-Free Fast Photochemical Oxidation Protein Footprinting Platform. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1601-1609. [PMID: 33872496 PMCID: PMC8812269 DOI: 10.1021/jasms.0c00471] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Hydroxyl radical protein footprinting (HRPF) is a powerful and flexible technique for probing changes in protein topography. With the development of the fast photochemical oxidation of proteins (FPOP), it became possible for researchers to perform HRPF in their laboratory on a very short time scale. While FPOP has grown significantly in popularity since its inception, adoption remains limited due to technical and safety issues involved in the operation of a hazardous Class IV UV laser and irreproducibility often caused by improper laser operation and/or differential radical scavenging by various sample components. Here, we present a new integrated FOX (Flash OXidation) Protein Footprinting System. This platform delivers sample via flow injection to a facile and safe-to-use high-pressure flash lamp with a flash duration of 10 μs fwhm. Integrated optics collect the radiant light and focus it into the lumen of a capillary flow cell. An inline radical dosimeter measures the hydroxyl radical dose delivered and allows for real-time compensation for differential radical scavenging. A programmable fraction collector collects and quenches only the sample that received the desired effective hydroxyl radical dose, diverting the carrier liquid and improperly oxidized sample to waste. We demonstrate the utility of the FOX Protein Footprinting System by determining the epitope of TNFα recognized by adalimumab. We successfully identify the surface of the protein that serves as the epitope for adalimumab, identifying four of the five regions previously noted by X-ray crystallography while seeing no changes in peptides not involved in the epitope interface. The FOX Protein Footprinting System allows for FPOP-like experiments with real-time dosimetry in a safe, compact, and integrated benchtop platform.
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Affiliation(s)
- Joshua S. Sharp
- GenNext Technologies, Inc., Half Moon Bay, CA 94019
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, Mississippi 38677
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677
- Correspondence to Joshua S. Sharp,
| | | | - Sandeep K. Misra
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, Mississippi 38677
| | - Ron Orlando
- GenNext Technologies, Inc., Half Moon Bay, CA 94019
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602
- GlycoScientific, Athens, GA 30602
| | | | | | - David Holman
- GenNext Technologies, Inc., Half Moon Bay, CA 94019
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21
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Beveridge R, Calabrese AN. Structural Proteomics Methods to Interrogate the Conformations and Dynamics of Intrinsically Disordered Proteins. Front Chem 2021; 9:603639. [PMID: 33791275 PMCID: PMC8006314 DOI: 10.3389/fchem.2021.603639] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/19/2021] [Indexed: 12/21/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) and regions of intrinsic disorder (IDRs) are abundant in proteomes and are essential for many biological processes. Thus, they are often implicated in disease mechanisms, including neurodegeneration and cancer. The flexible nature of IDPs and IDRs provides many advantages, including (but not limited to) overcoming steric restrictions in binding, facilitating posttranslational modifications, and achieving high binding specificity with low affinity. IDPs adopt a heterogeneous structural ensemble, in contrast to typical folded proteins, making it challenging to interrogate their structure using conventional tools. Structural mass spectrometry (MS) methods are playing an increasingly important role in characterizing the structure and function of IDPs and IDRs, enabled by advances in the design of instrumentation and the development of new workflows, including in native MS, ion mobility MS, top-down MS, hydrogen-deuterium exchange MS, crosslinking MS, and covalent labeling. Here, we describe the advantages of these methods that make them ideal to study IDPs and highlight recent applications where these tools have underpinned new insights into IDP structure and function that would be difficult to elucidate using other methods.
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Affiliation(s)
- Rebecca Beveridge
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Antonio N. Calabrese
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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22
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Tadi S, Misra SK, Sharp JS. Inline Liquid Chromatography-Fast Photochemical Oxidation of Proteins for Targeted Structural Analysis of Conformationally Heterogeneous Mixtures. Anal Chem 2021; 93:3510-3516. [PMID: 33560821 DOI: 10.1021/acs.analchem.0c04872] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Structural analysis of proteins in a conformationally heterogeneous mixture has long been a difficult problem in structural biology. In structural analysis by covalent labeling mass spectrometry, conformational heterogeneity results in data reflecting a weighted average of all conformers, complicating data analysis and potentially causing misinterpretation of results. Here, we describe a method coupling size-exclusion chromatography (SEC) with hydroxyl radical protein footprinting using inline fast photochemical oxidation of proteins (FPOP). Using a controlled synthetic mixture of holomyoglobin and apomyoglobin, we validate that we can achieve accurate footprints of each conformer using LC-FPOP when compared to offline FPOP of each pure conformer. We then applied LC-FPOP to analyze the adalimumab heat-shock aggregation process. We found that the LC-FPOP footprint of unaggregated adalimumab was consistent with a previously published footprint of the native IgG. The LC-FPOP footprint of the aggregation product indicated that heat-shock aggregation primarily protected the hinge region, suggesting that this region is involved with the heat-shock aggregation process of this molecule. LC-FPOP offers a new method to probe dynamic conformationally heterogeneous mixtures that can be separated by SEC such as biopharmaceutical aggregates and to obtain accurate information on the topography of each conformer.
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Affiliation(s)
| | | | - Joshua S Sharp
- GenNext Technologies, Inc., Half Moon Bay, California 94037, United States
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23
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Biehn SE, Lindert S. Accurate protein structure prediction with hydroxyl radical protein footprinting data. Nat Commun 2021; 12:341. [PMID: 33436604 PMCID: PMC7804018 DOI: 10.1038/s41467-020-20549-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/08/2020] [Indexed: 01/10/2023] Open
Abstract
Hydroxyl radical protein footprinting (HRPF) in combination with mass spectrometry reveals the relative solvent exposure of labeled residues within a protein, thereby providing insight into protein tertiary structure. HRPF labels nineteen residues with varying degrees of reliability and reactivity. Here, we are presenting a dynamics-driven HRPF-guided algorithm for protein structure prediction. In a benchmark test of our algorithm, usage of the dynamics data in a score term resulted in notable improvement of the root-mean-square deviations of the lowest-scoring ab initio models and improved the funnel-like metric Pnear for all benchmark proteins. We identified models with accurate atomic detail for three of the four benchmark proteins. This work suggests that HRPF data along with side chain dynamics sampled by a Rosetta mover ensemble can be used to accurately predict protein structure.
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Affiliation(s)
- Sarah E Biehn
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, 43210, USA
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, 43210, USA.
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24
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Ruan H, Kiselar J, Zhang W, Li S, Xiong R, Liu Y, Yang S, Lai L. Integrative structural modeling of a multidomain polo-like kinase. Phys Chem Chem Phys 2020; 22:27581-27589. [PMID: 33236741 DOI: 10.1039/d0cp05030j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polo-like kinase 1 (PLK1) is a key regulator and coordinator for mitotic signaling that contains two major functional units of a kinase domain (KD) and a polo-box domain (PBD). While individual domain structures of the KD and the PBD are known, how they interact and assemble into a functional complex remains an open question. The structural model from the KD-PBD-Map205PBM heterotrimeric crystal structure of zebrafish PLK1 represents a major step in understanding the KD and the PBD interactions. However, how these two domains interact when connected by a linker in the full length PLK1 needs further investigation. By integrating different sources of structural data from small-angle X-ray scattering, hydroxyl radical protein footprinting, and computational sampling, here we report an overall architecture for PLK1 multidomain assembly between the KD and the PBD. Our model revealed that the KD uses its C-lobe to interact with the PBD via the site near the phosphopeptide binding site in its auto-inhibitory state in solution. Disruption of this auto-inhibition via site-directed mutagenesis at the KD-PBD interface increases its kinase activity, supporting the functional role of KD-PBD interactions predicted for regulating the PLK1 kinase function. Our results indicate that the full length human PLK1 takes dynamic structures with a variety of domain-domain interfaces in solution.
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Affiliation(s)
- Hao Ruan
- BNLMS, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
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25
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Wheatley P, Gupta S, Pandini A, Chen Y, Petzold CJ, Ralston CY, Blair DF, Khan S. Allosteric Priming of E. coli CheY by the Flagellar Motor Protein FliM. Biophys J 2020; 119:1108-1122. [PMID: 32891187 DOI: 10.1016/j.bpj.2020.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/22/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Phosphorylation of Escherichia coli CheY protein transduces chemoreceptor stimulation to a highly cooperative flagellar motor response. CheY binds to the N-terminal peptide of the FliM motor protein (FliMN). Constitutively active D13K-Y106W CheY has been an important tool for motor physiology. The crystal structures of CheY and CheY ⋅ FliMN with and without D13K-Y106W have shown FliMN-bound CheY contains features of both active and inactive states. We used molecular dynamics (MD) simulations to characterize the CheY conformational landscape accessed by FliMN and D13K-Y106W. Mutual information measures identified the central features of the long-range CheY allosteric network between D57 phosphorylation site and the FliMN interface, namely the closure of the α4-β4 hinge and inward rotation of Y- or W106 with W58. We used hydroxy-radical foot printing with mass spectroscopy (XFMS) to track the solvent accessibility of these and other side chains. The solution XFMS oxidation rate correlated with the solvent-accessible area of the crystal structures. The protection of allosteric relay side chains reported by XFMS confirmed the intermediate conformation of the native CheY ⋅ FliMN complex, the inactive state of free D13K-Y106W CheY, and the MD-based network architecture. We extended the MD analysis to determine temporal coupling and energetics during activation. Coupled aromatic residue rotation was a graded rather than a binary switch, with Y- or W106 side-chain burial correlated with increased FliMN affinity. Activation entrained CheY fold stabilization to FliMN affinity. The CheY network could be partitioned into four dynamically coordinated sectors. Residue substitutions mapped to sectors around D57 or the FliMN interface according to phenotype. FliMN increased sector size and interactions. These sectors fused between the substituted K13-W106 residues to organize a tightly packed core and novel surfaces that may bind additional sites to explain the cooperative motor response. The community maps provide a more complete description of CheY priming than proposed thus far.
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Affiliation(s)
- Paige Wheatley
- Department of Biology, University of Utah, Salt Lake City, Utah
| | - Sayan Gupta
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California
| | - Alessandro Pandini
- Department of Computer Science-Synthetic Biology Theme, Brunel University London, Uxbridge, United Kingdom; Computational Cell and Molecular Biology, the Francis Crick Institute, London, United Kingdom
| | - Yan Chen
- Biological Systems and Engineering, Lawrence, Lawrence Berkeley National Laboratory, Berkeley, California
| | - Christopher J Petzold
- Biological Systems and Engineering, Lawrence, Lawrence Berkeley National Laboratory, Berkeley, California
| | - Corie Y Ralston
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California
| | - David F Blair
- Department of Biology, University of Utah, Salt Lake City, Utah
| | - Shahid Khan
- Computational Cell and Molecular Biology, the Francis Crick Institute, London, United Kingdom; Molecular Biology Consortium, Lawrence Berkeley National Laboratory, Berkeley, California.
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26
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Misra SK, Sharp JS. Enabling Real-Time Compensation in Fast Photochemical Oxidations of Proteins for the Determination of Protein Topography Changes. J Vis Exp 2020. [PMID: 32955502 DOI: 10.3791/61580] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Fast photochemical oxidation of proteins (FPOP) is a mass spectrometry-based structural biology technique that probes the solvent-accessible surface area of proteins. This technique relies on the reaction of amino acid side chains with hydroxyl radicals freely diffusing in solution. FPOP generates these radicals in situ by laser photolysis of hydrogen peroxide, creating a burst of hydroxyl radicals that is depleted on the order of a microsecond. When these hydroxyl radicals react with a solvent-accessible amino acid side chain, the reaction products exhibit a mass shift that can be measured and quantified by mass spectrometry. Since the rate of reaction of an amino acid depends in part on the average solvent accessible surface of that amino acid, measured changes in the amount of oxidation of a given region of a protein can be directly correlated to changes in the solvent accessibility of that region between different conformations (e.g., ligand-bound versus ligand-free, monomer vs. aggregate, etc.) FPOP has been applied in a number of problems in biology, including protein-protein interactions, protein conformational changes, and protein-ligand binding. As the available concentration of hydroxyl radicals varies based on many experimental conditions in the FPOP experiment, it is important to monitor the effective radical dose to which the protein analyte is exposed. This monitoring is efficiently achieved by incorporating an inline dosimeter to measure the signal from the FPOP reaction, with laser fluence adjusted in real-time to achieve the desired amount of oxidation. With this compensation, changes in protein topography reflecting conformational changes, ligand-binding surfaces, and/or protein-protein interaction interfaces can be determined in heterogeneous samples using relatively low sample amounts.
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Affiliation(s)
- Sandeep K Misra
- Department of Biomolecular Sciences, University of Mississippi
| | - Joshua S Sharp
- Department of Biomolecular Sciences, University of Mississippi; Department of Chemistry and Biochemistry, University of Mississippi; GenNext Technologies, Inc.;
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Liu XR, Zhang MM, Gross ML. Mass Spectrometry-Based Protein Footprinting for Higher-Order Structure Analysis: Fundamentals and Applications. Chem Rev 2020; 120:4355-4454. [PMID: 32319757 PMCID: PMC7531764 DOI: 10.1021/acs.chemrev.9b00815] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Proteins adopt different higher-order structures (HOS) to enable their unique biological functions. Understanding the complexities of protein higher-order structures and dynamics requires integrated approaches, where mass spectrometry (MS) is now positioned to play a key role. One of those approaches is protein footprinting. Although the initial demonstration of footprinting was for the HOS determination of protein/nucleic acid binding, the concept was later adapted to MS-based protein HOS analysis, through which different covalent labeling approaches "mark" the solvent accessible surface area (SASA) of proteins to reflect protein HOS. Hydrogen-deuterium exchange (HDX), where deuterium in D2O replaces hydrogen of the backbone amides, is the most common example of footprinting. Its advantage is that the footprint reflects SASA and hydrogen bonding, whereas one drawback is the labeling is reversible. Another example of footprinting is slow irreversible labeling of functional groups on amino acid side chains by targeted reagents with high specificity, probing structural changes at selected sites. A third footprinting approach is by reactions with fast, irreversible labeling species that are highly reactive and footprint broadly several amino acid residue side chains on the time scale of submilliseconds. All of these covalent labeling approaches combine to constitute a problem-solving toolbox that enables mass spectrometry as a valuable tool for HOS elucidation. As there has been a growing need for MS-based protein footprinting in both academia and industry owing to its high throughput capability, prompt availability, and high spatial resolution, we present a summary of the history, descriptions, principles, mechanisms, and applications of these covalent labeling approaches. Moreover, their applications are highlighted according to the biological questions they can answer. This review is intended as a tutorial for MS-based protein HOS elucidation and as a reference for investigators seeking a MS-based tool to address structural questions in protein science.
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Affiliation(s)
| | | | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA, 63130
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28
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Espino JA, King CD, Jones LM, Robinson RAS. In Vivo Fast Photochemical Oxidation of Proteins Using Enhanced Multiplexing Proteomics. Anal Chem 2020; 92:7596-7603. [PMID: 32383586 PMCID: PMC7815197 DOI: 10.1021/acs.analchem.0c00174] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
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In vivo fast photochemical oxidation of proteins
(IV-FPOP) is a hydroxyl radical protein footprinting method used to
study protein structure and protein–protein interactions. Oxidatively
modified proteins by IV-FPOP are analyzed by mass spectrometry (MS),
and the extent of oxidation is quantified by label-free MS. Peptide
oxidation changes yield useful information about protein structure,
due to changes in solvent accessibility. However, the sample size
necessary for animal studies requires increased sample preparation
and instrument time. Here, we report the combined application of IV-FPOP
and the enhanced multiplexing strategy combined precursor isotopic
labeling and isobaric tagging (cPILOT) for higher-throughput analysis
of oxidative modifications in C. elegans. Key differences
in the performance of label-free MS and cPILOT were identified. The
addition of oxygen (+16) was the most abundant modification identified
among all known possible FPOP modifications. This study presents IV-FPOP
coupled with enhanced multiplexing strategies such as cPILOT to increase
throughput of studies seeking to examine oxidative protein modifications.
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Affiliation(s)
- Jessica A Espino
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Christina D King
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Lisa M Jones
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Renã A S Robinson
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
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29
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Mass spectrometry-based methods for structural biology on a proteome-wide scale. Biochem Soc Trans 2020; 48:945-954. [DOI: 10.1042/bst20190794] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 11/17/2022]
Abstract
Mass spectrometry (MS) has long been used to study proteins mainly via sequence identification and quantitation of expression abundance. In recent years, MS has emerged as a tool for structural biology. Intact protein structural analysis has been enabled by the development of methods such as native MS, top-down proteomics, and ion mobility MS. Other MS-based structural methods include affinity purification MS, chemical cross-linking, and protein footprinting. These methods have enabled the study of protein–protein and protein–ligand interactions and regions of conformational change. The coupling of MS with liquid chromatography has permitted the analysis of complex samples. This bottom-up proteomics workflow enables the study of protein structure in the native cellular environment and provides structural information across the proteome. It has been demonstrated that the crowded environment of the cell affects protein binding interactions and affinities. Performing studies in this complex environment is essential for understanding the functional roles of proteins. MS-based structural methods permit analysis of samples such as cell lysates, intact cells, and tissue to provide a more physiological view of protein structure. This mini-review discusses the various MS-based methods that can be used for proteome-wide structural studies and highlights some of their application.
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30
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Cheng M, Asuru A, Kiselar J, Mathai G, Chance MR, Gross ML. Fast Protein Footprinting by X-ray Mediated Radical Trifluoromethylation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1019-1024. [PMID: 32255631 PMCID: PMC7486011 DOI: 10.1021/jasms.0c00085] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Synchrotron radiolysis generates hydroxyl radicals (•OH) that are successful footprinting reagents. Here, we describe a new reagent for the synchrotron platform, the trifluoromethyl radical (•CF3). The radical is produced by •OH displacement of •CF3 from sodium triflinate (Langlois reagent). Upon X-ray beam exposure, the reagent labels proteins extensively without any additional chemicals on a millisecond or shorter time scale. The •CF3 is comparably reactive to •OH and produces footprinting information that complements that of •OH alone. This reagent in combination with •OH should enable novel chemistry for protein footprinting on the synchrotron platform.
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Affiliation(s)
- Ming Cheng
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Awuri Asuru
- Center for Proteomics & Bioinformatics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Janna Kiselar
- Center for Proteomics & Bioinformatics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - George Mathai
- Department of Chemistry, Sacred Heart College, Thevara, Kochi, Kerala 682013, India
| | - Mark R. Chance
- Center for Proteomics & Bioinformatics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
- Corresponding Authors: MLG: Tel: (314)935-4814. Fax: (314)935-7484. , MRC: Phone: (216) 368-4406. Fax: (216) 368-3812.
| | - Michael L. Gross
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
- Corresponding Authors: MLG: Tel: (314)935-4814. Fax: (314)935-7484. , MRC: Phone: (216) 368-4406. Fax: (216) 368-3812.
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31
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Chance MR, Farquhar ER, Yang S, Lodowski DT, Kiselar J. Protein Footprinting: Auxiliary Engine to Power the Structural Biology Revolution. J Mol Biol 2020; 432:2973-2984. [PMID: 32088185 PMCID: PMC7245549 DOI: 10.1016/j.jmb.2020.02.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 12/25/2022]
Abstract
Structural biology is entering an exciting time where many new high-resolution structures of large complexes and membrane proteins are determined regularly. These advances have been driven by over fifteen years of technology advancements, first in macromolecular crystallography, and recently in Cryo-electron microscopy. These structures are allowing detailed questions about functional mechanisms of the structures, and the biology enabled by these structures, to be addressed for the first time. At the same time, mass spectrometry technologies for protein structure analysis, "footprinting" studies, have improved their sensitivity and resolution dramatically and can provide detailed sub-peptide and residue level information for validating structures and interactions or understanding the dynamics of structures in the context of ligand binding or assembly. In this perspective, we review the use of protein footprinting to extend our understanding of macromolecular systems, particularly for systems challenging for analysis by other techniques, such as intrinsically disordered proteins, amyloidogenic proteins, and other proteins/complexes so far recalcitrant to existing methods. We also illustrate how the availability of high-resolution structural information can be a foundation for a suite of hybrid approaches to divine structure-function relationships beyond what individual techniques can deliver.
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Affiliation(s)
- Mark R Chance
- Case Center for Proteomics and Bioinformatics, USA; Case Center for Synchrotron Biosciences, USA; Department of Nutrition, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH, 44106, USA.
| | | | - Sichun Yang
- Case Center for Proteomics and Bioinformatics, USA; Department of Nutrition, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH, 44106, USA
| | - David T Lodowski
- Case Center for Proteomics and Bioinformatics, USA; Department of Nutrition, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH, 44106, USA
| | - Janna Kiselar
- Case Center for Proteomics and Bioinformatics, USA; Department of Nutrition, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH, 44106, USA
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32
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Espino JA, Jones LM. In Vivo Hydroxyl Radical Protein Footprinting for the Study of Protein Interactions in Caenorhabditis elegans. J Vis Exp 2020. [PMID: 32310230 DOI: 10.3791/60910] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Fast oxidation of proteins (FPOP) is a hydroxyl radical protein footprinting (HRPF) method used to study protein structure, protein-ligand interactions, and protein-protein interactions. FPOP utilizes a KrF excimer laser at 248 nm for photolysis of hydrogen peroxide to generate hydroxyl radicals which in turn oxidatively modify solvent-accessible amino acid side chains. Recently, we expanded the use of FPOP of in vivo oxidative labeling in Caenorhabditis elegans (C. elegans), entitled IV-FPOP. The transparent nematodes have been used as model systems for many human diseases. Structural studies in C. elegans by IV-FPOP is feasible because of the animal's ability to uptake hydrogen peroxide, their transparency to laser irradiation at 248 nm, and the irreversible nature of the modification. The assembly of a microfluidic flow system for IV-FPOP labeling, IV-FPOP parameters, protein extraction, and LC-MS/MS optimized parameters are described herein.
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Affiliation(s)
| | - Lisa M Jones
- Department of Pharmaceutical Sciences, University of Maryland;
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33
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Roush AE, Riaz M, Misra SK, Weinberger SR, Sharp JS. Intrinsic Buffer Hydroxyl Radical Dosimetry Using Tris(hydroxymethyl)aminomethane. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:169-172. [PMID: 32031409 PMCID: PMC7650270 DOI: 10.1021/jasms.9b00088] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fast photochemical oxidation of proteins (FPOP) is a powerful covalent labeling tool that uses hydroxyl radicals generated by laser flash photolysis of hydrogen peroxide to footprint protein surfaces. Because radical production varies with many experimental parameters, hydroxyl radical dosimeters have been introduced to track the effective radical dosage experienced by the protein analyte. FPOP experiments performed using adenine optical radical dosimetry containing protein in Tris buffer demonstrated unusual dosimetry behavior. We have investigated the behavior of Tris under oxidative conditions in detail. We find that Tris can act as a novel gain-of-signal optical hydroxyl radical dosimeter in FPOP experiments. This new dosimeter is also amenable to inline real-time monitoring, thereby allowing real-time adjustments to compensate for differences in samples for their quenching ability.
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Affiliation(s)
- Addison E Roush
- Department of BioMolecular Sciences , University of Mississippi , Oxford , Mississippi 38677 , United States
- Department of Chemistry and Biochemistry , University of Mississippi , Oxford , Mississippi 38677 , United States
| | - Mohammad Riaz
- Department of BioMolecular Sciences , University of Mississippi , Oxford , Mississippi 38677 , United States
| | - Sandeep K Misra
- Department of BioMolecular Sciences , University of Mississippi , Oxford , Mississippi 38677 , United States
| | - Scot R Weinberger
- GenNext Technologies, Inc. , Montara , California 94037 , United States
| | - Joshua S Sharp
- Department of BioMolecular Sciences , University of Mississippi , Oxford , Mississippi 38677 , United States
- Department of Chemistry and Biochemistry , University of Mississippi , Oxford , Mississippi 38677 , United States
- GenNext Technologies, Inc. , Montara , California 94037 , United States
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34
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Ziemianowicz DS, MacCallum JL, Schriemer DC. Correlation between Labeling Yield and Surface Accessibility in Covalent Labeling Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:207-216. [PMID: 32031402 DOI: 10.1021/jasms.9b00083] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The functional properties of a protein are strongly influenced by its topography, or the solvent-facing contour map of its surface. Together with crosslinking, covalent labeling mass spectrometry (CL-MS) has the potential to contribute topographical data through the measurement of surface accessibility. However, recent efforts to correlate measures of surface accessibility with labeling yield have been met with mixed success. Most applications of CL-MS involve differential analysis of protein interactions (i.e., footprinting experiments) where such inconsistencies have limited effect. Extending CL-MS into structural analysis requires an improved evaluation of the relationship between labeling and surface exposure. In this study, we applied recently developed diazirine reagents to obtain deep coverage of the large motor domain of Eg5 (a mitotic kinesin), and together with computational methods we correlated labeling yields with accessibility data in a number of ways. We observe that correlations can indeed be seen at a local structural level, but these correlations do not extend across the structure. The lack of correlation arises from the influence of protein dynamics and chemical composition on reagent partitioning and, thus, also on labeling yield. We conclude that our use of CL-MS data should be considered in light of "chemical accessibility" rather than "solvent accessibility" and suggest that CL-MS data would be a useful tool in the fundamental study of protein-solute interactions.
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Affiliation(s)
- Daniel S Ziemianowicz
- Department of Biochemistry and Molecular Biology , University of Calgary , Calgary , Alberta , Canada T2N 4N1
- Robson DNA Science Centre, Arnie Charbonneau Cancer Institute , University of Calgary , Calgary , Alberta , Canada T2N 4N1
| | - Justin L MacCallum
- Department of Chemistry , University of Calgary , Calgary , Alberta , Canada T2N 4N1
| | - David C Schriemer
- Department of Biochemistry and Molecular Biology , University of Calgary , Calgary , Alberta , Canada T2N 4N1
- Robson DNA Science Centre, Arnie Charbonneau Cancer Institute , University of Calgary , Calgary , Alberta , Canada T2N 4N1
- Department of Chemistry , University of Calgary , Calgary , Alberta , Canada T2N 4N1
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35
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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
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36
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Chea EE, Deredge DJ, Jones LM. Insights on the Conformational Ensemble of Cyt C Reveal a Compact State during Peroxidase Activity. Biophys J 2019; 118:128-137. [PMID: 31810655 DOI: 10.1016/j.bpj.2019.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/29/2019] [Accepted: 11/11/2019] [Indexed: 12/19/2022] Open
Abstract
Cytochrome c (cyt c) is known for its role in the electron transport chain but transitions to a peroxidase-active state upon exposure to oxidative species. The peroxidase activity ultimately results in the release of cyt c into the cytosol for the engagement of apoptosis. The accumulation of oxidative modifications that accompany the onset of the peroxidase function are well-characterized. However, the concurrent structural and conformational transitions of cyt c remain undercharacterized. Fast photochemical oxidation of proteins (FPOP) coupled with mass spectrometry is a protein footprinting technique used to structurally characterize proteins. FPOP coupled with native ion mobility separation shows that exposure to H2O2 results in the accumulation of a compact state of cyt c. Subsequent top-down fragmentation to localize FPOP modifications reveals changes in heme coordination between conformers. A time-resolved functional assay suggests that this compact conformer is peroxidase active. Altogether, combining FPOP, ion mobility separation, and top-down and bottom-up mass spectrometry allows us to discern individual conformations in solution and obtain a better understanding of the conformational ensemble and structural transitions of cyt c as it transitions from a respiratory role to a proapoptotic role.
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Affiliation(s)
- Emily E Chea
- Department of Pharmaceutical Sciences, University of Maryland Baltimore, Baltimore, Maryland
| | - Daniel J Deredge
- Department of Pharmaceutical Sciences, University of Maryland Baltimore, Baltimore, Maryland
| | - Lisa M Jones
- Department of Pharmaceutical Sciences, University of Maryland Baltimore, Baltimore, Maryland.
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37
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POT1-TPP1 differentially regulates telomerase via POT1 His266 and as a function of single-stranded telomere DNA length. Proc Natl Acad Sci U S A 2019; 116:23527-23533. [PMID: 31685617 PMCID: PMC6876245 DOI: 10.1073/pnas.1905381116] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Telomeres cap the ends of linear chromosomes and terminate in a single-stranded DNA (ssDNA) overhang recognized by POT1-TPP1 heterodimers to help regulate telomere length homeostasis. Here hydroxyl radical footprinting coupled with mass spectrometry was employed to probe protein-protein interactions and conformational changes involved in the assembly of telomere ssDNA substrates of differing lengths bound by POT1-TPP1 heterodimers. Our data identified environmental changes surrounding residue histidine 266 of POT1 that were dependent on telomere ssDNA substrate length. We further determined that the chronic lymphocytic leukemia-associated H266L substitution significantly reduced POT1-TPP1 binding to short ssDNA substrates; however, it only moderately impaired the heterodimer binding to long ssDNA substrates containing multiple protein binding sites. Additionally, we identified a telomerase inhibitory role when several native POT1-TPP1 proteins coat physiologically relevant lengths of telomere ssDNA. This POT1-TPP1 complex-mediated inhibition of telomerase is abrogated in the context of the POT1 H266L mutation, which leads to telomere overextension in a malignant cellular environment.
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38
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Misra SK, Orlando R, Weinberger SR, Sharp JS. Compensated Hydroxyl Radical Protein Footprinting Measures Buffer and Excipient Effects on Conformation and Aggregation in an Adalimumab Biosimilar. AAPS JOURNAL 2019; 21:87. [PMID: 31297623 DOI: 10.1208/s12248-019-0358-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 06/25/2019] [Indexed: 01/02/2023]
Abstract
Unlike small molecule drugs, therapeutic proteins must maintain the proper higher-order structure (HOS) in order to maintain safety and efficacy. Due to the sensitivity of many protein systems, even small changes due to differences in protein expression or formulation can alter HOS. Previous work has demonstrated how hydroxyl radical protein footprinting (HRPF) can sensitively detect changes in protein HOS by measuring the average topography of the protein monomers, as well as identify specific regions of the therapeutic protein impacted by the conformational changes. However, HRPF is very sensitive to the radical scavenging capacity of the buffer; addition of organic buffers and/or excipients can dramatically alter the HRPF footprint without affecting protein HOS. By compensating for the radical scavenging effects of different adalimumab biosimilar formulations using real-time adenine dosimetry, we identify that sodium citrate buffer causes a modest decrease in average solvent accessibility compared to sodium phosphate buffer at the same pH. We find that the addition of polysorbate 80 does not alter the conformation of the biosimilar in either buffer, but it does provide substantial protection from protein conformational perturbation during short periods of exposure to high temperature. Compensated HRPF measurements are validated and contextualized by dynamic light scattering (DLS), which suggests that changes in adalimumab biosimilar aggregation are major drivers in measured changes in protein topography. Overall, compensated HRPF accurately measured conformational changes in adalimumab biosimilar that occurred during formulation changes and identified the effect of formulation changes on protection of HOS from temperature extremes.
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Affiliation(s)
- Sandeep K Misra
- Department of BioMolecular Sciences, University of Mississippi, P.O. Box 1848, University, Oxford, Mississippi, 38677-1848, USA
| | - Ron Orlando
- GenNext Technologies, Inc., Montara, California, 94037, USA.,Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, 30602, USA.,GlycoScientific, Athens, Georgia, 30602, USA
| | | | - Joshua S Sharp
- Department of BioMolecular Sciences, University of Mississippi, P.O. Box 1848, University, Oxford, Mississippi, 38677-1848, USA. .,GenNext Technologies, Inc., Montara, California, 94037, USA.
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39
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Johnson DT, Di Stefano LH, Jones LM. Fast photochemical oxidation of proteins (FPOP): A powerful mass spectrometry-based structural proteomics tool. J Biol Chem 2019; 294:11969-11979. [PMID: 31262727 DOI: 10.1074/jbc.rev119.006218] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fast photochemical oxidation of proteins (FPOP) is a MS-based method that has proved useful in studies of protein structures, interactions, conformations, and protein folding. The success of this method relies on the irreversible labeling of solvent-exposed amino acid side chains by hydroxyl radicals. FPOP generates these radicals through laser-induced photolysis of hydrogen peroxide. The data obtained provide residue-level resolution of protein structures and interactions on the microsecond timescale, enabling investigations of fast processes such as protein folding and weak protein-protein interactions. An extensive comparison between FPOP and other footprinting techniques gives insight on their complementarity as well as the robustness of FPOP to provide unique structural information once unattainable. The versatility of this method is evidenced by both the heterogeneity of samples that can be analyzed by FPOP and the myriad of applications for which the method has been successfully used: from proteins of varying size to intact cells. This review discusses the wide applications of this technique and highlights its high potential. Applications including, but not limited to, protein folding, membrane proteins, structure elucidation, and epitope mapping are showcased. Furthermore, the use of FPOP has been extended to probing proteins in cells and in vivo These promising developments are also presented herein.
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Affiliation(s)
- Danté T Johnson
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201
| | - Luciano H Di Stefano
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201
| | - Lisa M Jones
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201.
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40
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Asuru A, Farquhar ER, Sullivan M, Abel D, Toomey J, Chance MR, Bohon J. The XFP (17-BM) beamline for X-ray footprinting at NSLS-II. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1388-1399. [PMID: 31274468 PMCID: PMC6613119 DOI: 10.1107/s1600577519003576] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 03/13/2019] [Indexed: 05/26/2023]
Abstract
Hydroxyl-radical mediated synchrotron X-ray footprinting (XF) is a powerful solution-state technique in structural biology for the study of macromolecular structure and dynamics of proteins and nucleic acids, with several synchrotron resources available to serve the XF community worldwide. The XFP (Biological X-ray Footprinting) beamline at the NSLS-II was constructed on a three-pole wiggler source at 17-BM to serve as the premier beamline for performing this technique, providing an unparalleled combination of high flux density broadband beam, flexibility in beam morphology, and sample handling capabilities specifically designed for XF experiments. The details of beamline design, beam measurements, and science commissioning results for a standard protein using the two distinct XFP endstations are presented here. XFP took first light in 2016 and is now available for general user operations through peer-reviewed proposals. Currently, beam sizes from 450 µm × 120 µm to 2.7 mm × 2.7 mm (FWHM) are available, with a flux of 1.6 × 1016 photons s-1 (measured at 325 mA ring current) in a broadband (∼5-16 keV) beam. This flux is expected to rise to 2.5 × 1016 photons s-1 at the full NSLS-II design current of 500 mA, providing an incident power density of >500 W mm-2 at full focus.
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Affiliation(s)
- Awuri Asuru
- Center for Synchrotron Bioscience, Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Systems Biology Graduate Program, Medical Scientist Training Program, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Erik R. Farquhar
- Center for Synchrotron Bioscience, Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Michael Sullivan
- Center for Synchrotron Bioscience, Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Donald Abel
- Center for Synchrotron Bioscience, Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - John Toomey
- Center for Synchrotron Bioscience, Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Mark R. Chance
- Center for Synchrotron Bioscience, Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Jen Bohon
- Center for Synchrotron Bioscience, Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
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41
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Abstract
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Protein
footprinting coupled with mass spectrometry is being increasingly
used for the study of protein interactions and conformations. The
hydroxyl radical footprinting method, fast photochemical oxidation
of proteins (FPOP), utilizes hydroxyl radicals to oxidatively modify
solvent accessible amino acids. Here, we describe the further development
of FPOP for protein structural analysis in vivo (IV-FPOP) with Caenorhabditis elegans. C. elegans, part
of the nematode family, are used as model systems for many human diseases.
The ability to perform structural studies in these worms would provide
insight into the role of structure in disease pathogenesis. Many parameters
were optimized for labeling within the worms including the microfluidic
flow system and hydrogen peroxide concentration. IV-FPOP was able
to modify several hundred proteins in various organs within the worms.
The method successfully probed solvent accessibility similarily to
in vitro FPOP, demonstrating its potential for use as a structural
technique in a multiorgan system. The coupling of the method with
mass spectrometry allows for amino-acid-residue-level structural information,
a higher resolution than currently available in vivo methods.
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Affiliation(s)
- Jessica A Espino
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - Lisa M Jones
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
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42
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Aprahamian ML, Lindert S. Utility of Covalent Labeling Mass Spectrometry Data in Protein Structure Prediction with Rosetta. J Chem Theory Comput 2019; 15:3410-3424. [PMID: 30946594 DOI: 10.1021/acs.jctc.9b00101] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Covalent labeling mass spectrometry experiments are growing in popularity and provide important information regarding protein structure. Information obtained from these experiments correlates with residue solvent exposure within the protein in solution. However, it is impossible to determine protein structure from covalent labeling data alone. Incorporation of sparse covalent labeling data into the protein structure prediction software Rosetta has been shown to improve protein tertiary structure prediction. Here, covalent labeling techniques were analyzed computationally to provide insight into what labeling data is needed to optimize tertiary protein structure prediction in Rosetta. We have successfully implemented a new scoring functionality that provides improved predictions. We developed two new covalent labeling based score terms that use a "cone"-based neighbor count to quantify the relative solvent exposure of each amino acid. To test our method, we used a set of 20 proteins with structures deposited in the Protein Data Bank. Decoy model sets were generated for each of these 20 proteins, and the normalized covalent labeling score versus RMSD distributions were evaluated. On the basis of these distributions, we have determined an optimal subset of residues to use when performing covalent labeling experiments in order to maximize the structure prediction capabilities of the covalent labeling data. We also investigated how much false negative and false positive data can be tolerated without meaningfully impacting protein structure prediction. Using these new covalent labeling score terms, protein models were rescored and the resulting models improved by 3.9 Å RMSD on average. New models were also generated using Rosetta's AbinitioRelax program under the guidance of covalent labeling information, and improvement in model quality was observed.
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Affiliation(s)
- Melanie L Aprahamian
- Department of Chemistry and Biochemistry , Ohio State University , Columbus , Ohio 43210 , United States
| | - Steffen Lindert
- Department of Chemistry and Biochemistry , Ohio State University , Columbus , Ohio 43210 , United States
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43
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Limpikirati P, Hale JE, Hazelbaker M, Huang Y, Jia Z, Yazdani M, Graban EM, Vaughan RC, Vachet RW. Covalent labeling and mass spectrometry reveal subtle higher order structural changes for antibody therapeutics. MAbs 2019; 11:463-476. [PMID: 30636503 PMCID: PMC6512938 DOI: 10.1080/19420862.2019.1565748] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 12/24/2018] [Accepted: 01/03/2019] [Indexed: 01/26/2023] Open
Abstract
Monoclonal antibodies are among the fastest growing therapeutics in the pharmaceutical industry. Detecting higher-order structure changes of antibodies upon storage or mishandling, however, is a challenging problem. In this study, we describe the use of diethylpyrocarbonate (DEPC)-based covalent labeling (CL) - mass spectrometry (MS) to detect conformational changes caused by heat stress, using rituximab as a model system. The structural resolution obtained from DEPC CL-MS is high enough to probe subtle conformation changes that are not detectable by common biophysical techniques. Results demonstrate that DEPC CL-MS can detect and identify sites of conformational changes at the temperatures below the antibody melting temperature (e.g., 55 ᴼC). The observed labeling changes at lower temperatures are validated by activity assays that indicate changes in the Fab region. At higher temperatures (e.g., 65 ᴼC), conformational changes and aggregation sites are identified from changes in CL levels, and these results are confirmed by complementary biophysical and activity measurements. Given the sensitivity and simplicity of DEPC CL-MS, this method should be amenable to the structural investigations of other antibody therapeutics.
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Affiliation(s)
| | | | - Mark Hazelbaker
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - Yongbo Huang
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - Zhiguang Jia
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, USA
| | - Mahdieh Yazdani
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, USA
| | | | - Robert C. Vaughan
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - Richard W. Vachet
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, USA
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44
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Garcia NK, Deperalta G, Wecksler AT. Current Trends in Biotherapeutic Higher Order Structure Characterization by Irreversible Covalent Footprinting Mass Spectrometry. Protein Pept Lett 2019; 26:35-43. [PMID: 30484396 DOI: 10.2174/0929866526666181128141953] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/01/2018] [Accepted: 10/29/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND Biotherapeutics, particularly monoclonal antibodies (mAbs), are a maturing class of drugs capable of treating a wide range of diseases. Therapeutic function and solutionstability are linked to the proper three-dimensional organization of the primary sequence into Higher Order Structure (HOS) as well as the timescales of protein motions (dynamics). Methods that directly monitor protein HOS and dynamics are important for mapping therapeutically relevant protein-protein interactions and assessing properly folded structures. Irreversible covalent protein footprinting Mass Spectrometry (MS) tools, such as site-specific amino acid labeling and hydroxyl radical footprinting are analytical techniques capable of monitoring the side chain solvent accessibility influenced by tertiary and quaternary structure. Here we discuss the methodology, examples of biotherapeutic applications, and the future directions of irreversible covalent protein footprinting MS in biotherapeutic research and development. CONCLUSION Bottom-up mass spectrometry using irreversible labeling techniques provide valuable information for characterizing solution-phase protein structure. Examples range from epitope mapping and protein-ligand interactions, to probing challenging structures of membrane proteins. By paring these techniques with hydrogen-deuterium exchange, spectroscopic analysis, or static-phase structural data such as crystallography or electron microscopy, a comprehensive understanding of protein structure can be obtained.
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Affiliation(s)
- Natalie K Garcia
- Department of Protein Analytical Chemistry, Genentech Inc., South San Francisco, CA 94080, United States
| | - Galahad Deperalta
- Department of Protein Analytical Chemistry, Genentech Inc., South San Francisco, CA 94080, United States
| | - Aaron T Wecksler
- Department of Protein Analytical Chemistry, Genentech Inc., South San Francisco, CA 94080, United States
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45
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Bohon J. Development of Synchrotron Footprinting at NSLS and NSLS-II. Protein Pept Lett 2019; 26:55-60. [PMID: 30484397 DOI: 10.2174/0929866526666181128125125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/30/2018] [Accepted: 11/06/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND First developed in the 1990's at the National Synchrotron Light Source, xray synchrotron footprinting is an ideal technique for the analysis of solution-state structure and dynamics of macromolecules. Hydroxyl radicals generated in aqueous samples by intense x-ray beams serve as fine probes of solvent accessibility, rapidly and irreversibly reacting with solvent exposed residues to provide a "snapshot" of the sample state at the time of exposure. Over the last few decades, improvements in instrumentation to expand the technology have continuously pushed the boundaries of biological systems that can be studied using the technique. CONCLUSION Dedicated synchrotron beamlines provide important resources for examining fundamental biological mechanisms of folding, ligand binding, catalysis, transcription, translation, and macromolecular assembly. The legacy of synchrotron footprinting at NSLS has led to significant improvement in our understanding of many biological systems, from identifying key structural components in enzymes and transporters to in vivo studies of ribosome assembly. This work continues at the XFP (17-BM) beamline at NSLS-II and facilities at ALS, which are currently accepting proposals for use.
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Affiliation(s)
- Jen Bohon
- Center for Synchrotron Biosciences, Department of Nutrition, Case Western Reserve University, Cleveland, OH, United States
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46
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Sheng Y, Capri J, Waring A, Valentine JS, Whitelegge J. Exposure of Solvent-Inaccessible Regions in the Amyloidogenic Protein Human SOD1 Determined by Hydroxyl Radical Footprinting. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:218-226. [PMID: 30328005 PMCID: PMC6347482 DOI: 10.1007/s13361-018-2075-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/18/2018] [Accepted: 09/22/2018] [Indexed: 06/08/2023]
Abstract
Solvent-accessibility change plays a critical role in protein misfolding and aggregation, the culprit for several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Mass spectrometry-based hydroxyl radical (·OH) protein footprinting has evolved as a powerful and fast tool in elucidating protein solvent accessibility. In this work, we used fast photochemical oxidation of protein (FPOP) hydroxyl radical (·OH) footprinting to investigate solvent accessibility in human copper-zinc superoxide dismutase (SOD1), misfolded or aggregated forms of which underlie a portion of ALS cases. ·OH-mediated modifications to 56 residues were detected with locations largely as predicted based on X-ray crystallography data, while the interior of SOD1 β-barrel is hydrophobic and solvent-inaccessible and thus protected from modification. There were, however, two notable exceptions-two closely located residues inside the β-barrel, predicted to have minimal or no solvent accessibility, that were found modified by FPOP (Phe20 and Ile112). Molecular dynamics (MD) simulations were consistent with differential access of peroxide versus quencher to SOD1's interior complicating surface accessibility considerations. Modification of these two residues could potentially be explained either by local motions of the β-barrel that increased peroxide/solvent accessibility to the interior or by oxidative events within the interior that might include long-distance radical transfer to buried sites. Overall, comparison of modification patterns for the metal-free apoprotein versus zinc-bound forms demonstrated that binding of zinc protected the electrostatic loop and organized the copper-binding site. Our study highlights SOD1 hydrophobic groups that may contribute to early events in aggregation and discusses caveats to surface accessibility conclusions. Graphical Abstract.
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Affiliation(s)
- Yuewei Sheng
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Joseph Capri
- The Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, CA, USA
| | - Alan Waring
- Department of Medicine, University of California, Los Angeles, CA, USA
| | | | - Julian Whitelegge
- The Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, CA, USA.
- The Brain Research Institute, University of California, Los Angeles, CA, USA.
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47
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Kaur U, Johnson DT, Chea EE, Deredge DJ, Espino JA, Jones LM. Evolution of Structural Biology through the Lens of Mass Spectrometry. Anal Chem 2019; 91:142-155. [PMID: 30457831 PMCID: PMC6472977 DOI: 10.1021/acs.analchem.8b05014] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Upneet Kaur
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Danté T. Johnson
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Emily E. Chea
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Daniel J. Deredge
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Jessica A. Espino
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
| | - Lisa M. Jones
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21201, United States
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48
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Kaur U, Johnson DT, Chea EE, Deredge DJ, Espino JA, Jones LM. Evolution of Structural Biology through the Lens of Mass Spectrometry. Anal Chem 2019; 91:142-155. [PMID: 30457831 DOI: 10.1021/acs.analchem.1028b05014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Upneet Kaur
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - Danté T Johnson
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - Emily E Chea
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - Daniel J Deredge
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - Jessica A Espino
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - Lisa M Jones
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
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49
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A Metastable Contact and Structural Disorder in the Estrogen Receptor Transactivation Domain. Structure 2018; 27:229-240.e4. [PMID: 30581045 DOI: 10.1016/j.str.2018.10.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/06/2018] [Accepted: 10/25/2018] [Indexed: 11/23/2022]
Abstract
The N-terminal transactivation domain (NTD) of estrogen receptor alpha, a well-known member of the family of intrinsically disordered proteins, mediates the receptor's transactivation function. However, an accurate molecular dissection of NTD's structure-function relationships remains elusive. Here, we show that the NTD adopts a mostly disordered, unexpectedly compact conformation that undergoes structural expansion on chemical denaturation. By combining small-angle X-ray scattering, hydroxyl radical protein footprinting, and computational modeling, we derive the ensemble-structures of the NTD and determine its ensemble-contact map revealing metastable long-range contacts, e.g., between residues I33 and S118. We show that mutation at S118, a known phosphorylation site, promotes conformational changes and increases coactivator binding. We further demonstrate via fluorine-19 (19F) nuclear magnetic resonance that mutations near I33 alter 19F chemical shifts at S118, confirming the proposed I33-S118 contact in the ensemble of structural disorder. These findings extend our understanding of how specific contact metastability mediates critical functions of disordered proteins.
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50
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Pouget JP, Georgakilas AG, Ravanat JL. Targeted and Off-Target (Bystander and Abscopal) Effects of Radiation Therapy: Redox Mechanisms and Risk/Benefit Analysis. Antioxid Redox Signal 2018; 29:1447-1487. [PMID: 29350049 PMCID: PMC6199630 DOI: 10.1089/ars.2017.7267] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE Radiation therapy (from external beams to unsealed and sealed radionuclide sources) takes advantage of the detrimental effects of the clustered production of radicals and reactive oxygen species (ROS). Research has mainly focused on the interaction of radiation with water, which is the major constituent of living beings, and with nuclear DNA, which contains the genetic information. This led to the so-called target theory according to which cells have to be hit by ionizing particles to elicit an important biological response, including cell death. In cancer therapy, the Poisson law and linear quadratic mathematical models have been used to describe the probability of hits per cell as a function of the radiation dose. Recent Advances: However, in the last 20 years, many studies have shown that radiation generates "danger" signals that propagate from irradiated to nonirradiated cells, leading to bystander and other off-target effects. CRITICAL ISSUES Like for targeted effects, redox mechanisms play a key role also in off-target effects through transmission of ROS and reactive nitrogen species (RNS), and also of cytokines, ATP, and extracellular DNA. Particularly, nuclear factor kappa B is essential for triggering self-sustained production of ROS and RNS, thus making the bystander response similar to inflammation. In some therapeutic cases, this phenomenon is associated with recruitment of immune cells that are involved in distant irradiation effects (called "away-from-target" i.e., abscopal effects). FUTURE DIRECTIONS Determining the contribution of targeted and off-target effects in the clinic is still challenging. This has important consequences not only in radiotherapy but also possibly in diagnostic procedures and in radiation protection.
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Affiliation(s)
- Jean-Pierre Pouget
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), Montpellier, France
| | - Alexandros G Georgakilas
- 2 DNA Damage Laboratory, Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens , Athens, Greece
| | - Jean-Luc Ravanat
- 3 Univ. Grenoble Alpes , CEA, CNRS INAC SyMMES UMR 5819, Grenoble, France
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