1
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Hou J, Chen Y, Cai Z, Heo GS, Yuede CM, Wang Z, Lin K, Saadi F, Trsan T, Nguyen AT, Constantopoulos E, Larsen RA, Zhu Y, Wagner ND, McLaughlin N, Kuang XC, Barrow AD, Li D, Zhou Y, Wang S, Gilfillan S, Gross ML, Brioschi S, Liu Y, Holtzman DM, Colonna M. Antibody-mediated targeting of human microglial leukocyte Ig-like receptor B4 attenuates amyloid pathology in a mouse model. Sci Transl Med 2024; 16:eadj9052. [PMID: 38569016 DOI: 10.1126/scitranslmed.adj9052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 03/08/2024] [Indexed: 04/05/2024]
Abstract
Microglia help limit the progression of Alzheimer's disease (AD) by constraining amyloid-β (Aβ) pathology, effected through a balance of activating and inhibitory intracellular signals delivered by distinct cell surface receptors. Human leukocyte Ig-like receptor B4 (LILRB4) is an inhibitory receptor of the immunoglobulin (Ig) superfamily that is expressed on myeloid cells and recognizes apolipoprotein E (ApoE) among other ligands. Here, we find that LILRB4 is highly expressed in the microglia of patients with AD. Using mice that accumulate Aβ and carry a transgene encompassing a portion of the LILR region that includes LILRB4, we corroborated abundant LILRB4 expression in microglia wrapping around Aβ plaques. Systemic treatment of these mice with an anti-human LILRB4 monoclonal antibody (mAb) reduced Aβ load, mitigated some Aβ-related behavioral abnormalities, enhanced microglia activity, and attenuated expression of interferon-induced genes. In vitro binding experiments established that human LILRB4 binds both human and mouse ApoE and that anti-human LILRB4 mAb blocks such interaction. In silico modeling, biochemical, and mutagenesis analyses identified a loop between the two extracellular Ig domains of LILRB4 required for interaction with mouse ApoE and further indicated that anti-LILRB4 mAb may block LILRB4-mApoE by directly binding this loop. Thus, targeting LILRB4 may be a potential therapeutic avenue for AD.
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Affiliation(s)
- Jinchao Hou
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Yun Chen
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Zhangying Cai
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Gyu Seong Heo
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Carla M Yuede
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zuoxu Wang
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Kent Lin
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Fareeha Saadi
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Tihana Trsan
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Aivi T Nguyen
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
| | - Eleni Constantopoulos
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
| | - Rachel A Larsen
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
| | - Yiyang Zhu
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nolan McLaughlin
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Xinyi Cynthia Kuang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Alexander D Barrow
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC 3000, Australia
| | - Dian Li
- Division of Nephrology, Department of Medicine, Washington University, St. Louis, MO 63110, USA
| | - Yingyue Zhou
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Shoutang Wang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pok Fu Lam, Hong Kong, China
| | - Susan Gilfillan
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Simone Brioschi
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Yongjian Liu
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - David M Holtzman
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO 63110, USA
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2
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Li J, Jethva PN, Rohrs HW, Chemuru S, Miller K, Gross ML, Beckingham KM. Hydrogen/Deuterium Exchange Mass Spectrometry Provides Insights into the Role of Drosophila Testis-Specific Myosin VI Light Chain AndroCaM. Biochemistry 2024; 63:610-624. [PMID: 38357882 DOI: 10.1021/acs.biochem.3c00618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
In Drosophila testis, myosin VI plays a special role, distinct from its motor function, by anchoring components to the unusual actin-based structures (cones) that are required for spermatid individualization. For this, the two calmodulin (CaM) light-chain molecules of myosin VI are replaced by androcam (ACaM), a related protein with 67% identity to CaM. Although ACaM has a similar bi-lobed structure to CaM, with two EF hand-type Ca2+ binding sites per lobe, only one functional Ca2+ binding site operates in the amino-terminus. To understand this light chain substitution, we used hydrogen-deuterium exchange mass spectrometry (HDX-MS) to examine dynamic changes in ACaM and CaM upon Ca2+ binding and interaction with the two CaM binding motifs of myosin VI (insert2 and IQ motif). HDX-MS reveals that binding of Ca2+ to ACaM destabilizes its N-lobe but stabilizes the entire C-lobe, whereas for CaM, Ca2+ binding induces a pattern of alternating stabilization/destabilization throughout. The conformation of this stable holo-C-lobe of ACaM seems to be a "prefigured" version of the conformation adopted by the holo-C-lobe of CaM for binding to insert2 and the IQ motif of myosin VI. Strikingly, the interaction of holo-ACaM with either peptide converts the holo-N-lobe to its Ca2+-free, more stable, form. Thus, ACaM in vivo should bind the myosin VI light chain sites in an apo-N-lobe/holo-C-lobe state that cannot fulfill the Ca2+-related functions of holo-CaM required for myosin VI motor assembly and activity. These findings indicate that inhibition of myosin VI motor activity is a precondition for transition to an anchoring function.
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Affiliation(s)
- Jing Li
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Prashant N Jethva
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Henry W Rohrs
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Saketh Chemuru
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Kathryn Miller
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Kathleen M Beckingham
- Department of Biosciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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3
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Gross ML. Treating the innocent victims of trolleys and war. Bioethics 2024. [PMID: 38385575 DOI: 10.1111/bioe.13273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 12/04/2023] [Accepted: 01/17/2024] [Indexed: 02/23/2024]
Abstract
Both trolleys and war leave innocent victims to suffer death and injury. Trolley problems accounting for the injured, and not only the dead, tease out intuitions about liability that enhance our understanding of the obligation to provide compensation and medical care to civilian victims of war. Like many trolley victims, civilians in war may suffer justifiable, excusable, or negligent harms that demand compensation. Chief among these is collateral harm befalling civilians. Collateral harm is endemic to war and comprises permissible but unavoidable death or injury following necessary and proportionate military operations. Although state armies sometimes offer condolence payments for civilian death, injury, and property loss, they deny liability. Instead, they use compensation to enhance counterinsurgency efforts and assuage feelings of agent regret. As part of the medical rules of eligibility, Coalition forces in Iraq and Afghanistan also provided medical care to victims of collateral harm. However, they denied care to similarly sick or injured civilians. While compensation is often justified to cure the harm civilians suffer, the differential use of medical resources is not. Rather, medical care remains subject to the principle of beneficence and medical need. The duty to provide civilian healthcare in war, particularly in wars of humanitarian intervention, is far-reaching and imposes significant costs that military and medical ethics are yet to recognize.
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Affiliation(s)
- Michael L Gross
- School of Political Science, University of Haifa, Haifa, Israel
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4
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Gross ML. Medical Sanctions Against Russia: Arresting Aggression or Abrogating Healthcare Rights? Am J Bioeth 2024:1-14. [PMID: 38376507 DOI: 10.1080/15265161.2024.2308163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Since 2022, the EU, US, and other nations have imposed medical sanctions on Russia to block the export of pharmaceuticals and medical devices and curtail clinical trials to degrade Russia's military capabilities. While international law proscribes sanctions that cause a humanitarian crisis, an outcome averted in Russia, the military effects of medical sanctions have been lean. Strengthening medical sanctions risks violating noncombatant and combatant rights to healthcare. Each group's claim is different. Noncombatants and severely injured soldiers who cannot return to duty enjoy the right to adequate health care that sanctions cannot undermine. Combatants falling captive enjoy the same medical care that adversaries provide their own troops. Combatants yet to renounce hostilities, however, have no claim to medical attention and remain subject to sanctions. Nevertheless, medical sanctions prove unworkable in this complex environment of conflicting rights and command no place in a sustainable sanction regime.
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Illes-Toth E, Rempel DL, Gross ML. Exploration of Resveratrol as a Potent Modulator of α-Synuclein Fibril Formation. ACS Chem Neurosci 2024; 15:503-516. [PMID: 38194353 PMCID: PMC10922803 DOI: 10.1021/acschemneuro.3c00571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024] Open
Abstract
The molecular determinants of amyloid protein misfolding and aggregation are key for the development of therapeutic interventions in neurodegenerative disease. Although small synthetic molecules, bifunctional molecules, and natural products offer a potentially advantageous approach to therapeutics to remodel aggregation, their evaluation requires new platforms that are informed at the molecular level. To that end, we chose pulsed hydrogen/deuterium exchange mass spectrometry (HDX-MS) to discern the phenomena of aggregation modulation for a model system of alpha synuclein (αS) and resveratrol, an antiamyloid compound. We invoked, as a complement to HDX, advanced kinetic modeling described here to illuminate the details of aggregation and to determine the number of oligomeric populations by kinetically fitting the experimental data under conditions of limited proteolysis. The misfolding of αS is most evident within and nearby the nonamyloid-β component region, and resveratrol significantly remodels that aggregation. HDX distinguishes readily a less solvent-accessible, more structured oligomer that coexists with a solvent-accessible, more disordered oligomer during aggregation. A view of the misfolding emerges from time-dependent changes in the fractional species across the protein with or without resveratrol, while details were determined through kinetic modeling of the protected species. A detailed picture of the inhibitory action of resveratrol with time and regional specificity emerges, a picture that can be obtained for other inhibitors and amyloid proteins. Moreover, the model reveals that new states of aggregation are sampled, providing new insights on amyloid formation. The findings were corroborated by circular dichroism and transmission electron microscopy.
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Affiliation(s)
- Eva Illes-Toth
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
| | - Don L Rempel
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
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6
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Sun J, Song JH, Danielson MK, Colley ND, Thomas A, Hambly D, Barnes JC, Gross ML. Development of a High-Throughput Mass Spectrometry-Based SARS-CoV-2 Immunoassay. Anal Chem 2024; 96:12-17. [PMID: 38109790 PMCID: PMC10909588 DOI: 10.1021/acs.analchem.3c02421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
The serious impact of the Covid-19 pandemic underscores the need for rapid, reliable, and high-throughput diagnosis methods for infection. Current analytical methods, either point-of-care or centralized detection, are not able to satisfy the requirements of patient-friendly testing, high demand, and reliability of results. Here, we propose a two-point separation on-demand diagnostic strategy that uses laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) and adopts a stable yet cleavable ionic probe as a mass reporter. The use of this reporter enables ultrasensitive, interruptible, storable, restorable, and high-throughput on-demand detection. We describe a demonstration of the concept whereby we (i) design and synthesize a laser-cleavable reporter (DTPA), (ii) conjugate the reporter onto an antibody and verify the function of the conjugate, (iii) detect with good turnaround and high sensitivity the conjugated reporter, (iv) analyze quantitatively by using a laser-cleavable internal standard, and (v) identify negative and positive samples containing the spike protein. The protocol has excellent sensitivity (amol for the SARS-CoV-2 Spike S1 subunit antibody) without any amplification. This strategy is also applicable for the detection of other disease antigens besides SARS-CoV-2.
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Affiliation(s)
- Jie Sun
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Jong Hee Song
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Mary K. Danielson
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Nathan D. Colley
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Alia Thomas
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - David Hambly
- Advanced Therapy Product Consulting, Inc., Oak Park, CA, 91377, USA
| | - Jonathan C. Barnes
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
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7
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Adams LJ, VanBlargan LA, Liu Z, Gilchuk P, Zhao H, Chen RE, Raju S, Chong Z, Whitener BM, Shrihari S, Jethva PN, Gross ML, Crowe JE, Whelan SPJ, Diamond MS, Fremont DH. A broadly reactive antibody targeting the N-terminal domain of SARS-CoV-2 spike confers Fc-mediated protection. Cell Rep Med 2023; 4:101305. [PMID: 38039973 PMCID: PMC10772349 DOI: 10.1016/j.xcrm.2023.101305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 08/21/2023] [Accepted: 11/06/2023] [Indexed: 12/03/2023]
Abstract
Most neutralizing anti-SARS-CoV-2 monoclonal antibodies (mAbs) target the receptor binding domain (RBD) of the spike (S) protein. Here, we characterize a panel of mAbs targeting the N-terminal domain (NTD) or other non-RBD epitopes of S. A subset of NTD mAbs inhibits SARS-CoV-2 entry at a post-attachment step and avidly binds the surface of infected cells. One neutralizing NTD mAb, SARS2-57, protects K18-hACE2 mice against SARS-CoV-2 infection in an Fc-dependent manner. Structural analysis demonstrates that SARS2-57 engages an antigenic supersite that is remodeled by deletions common to emerging variants. In neutralization escape studies with SARS2-57, this NTD site accumulates mutations, including a similar deletion, but the addition of an anti-RBD mAb prevents such escape. Thus, our study highlights a common strategy of immune evasion by SARS-CoV-2 variants and how targeting spatially distinct epitopes, including those in the NTD, may limit such escape.
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Affiliation(s)
- Lucas J Adams
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Laura A VanBlargan
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Zhuoming Liu
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Pavlo Gilchuk
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Haiyan Zhao
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Rita E Chen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Saravanan Raju
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhenlu Chong
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Bradley M Whitener
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Swathi Shrihari
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Prashant N Jethva
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - James E Crowe
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sean P J Whelan
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Michael S Diamond
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA; Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO, USA.
| | - Daved H Fremont
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO, USA.
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8
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Kant R, Mishra N, Gross ML. Antibody Binding Captures High Energy State of an Antigen: The Case of Nsp1 SARS-CoV-2 as Revealed by Hydrogen-Deuterium Exchange Mass Spectrometry. Int J Mol Sci 2023; 24:17342. [PMID: 38139170 PMCID: PMC10743928 DOI: 10.3390/ijms242417342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
We describe an investigation using structural mass spectrometry (MS) of the impact of two antibodies, 15497 and 15498, binding the highly flexible SARS-CoV-2 Nsp1 protein. We determined the epitopes and paratopes involved in the antibody-protein interactions by using hydrogen-deuterium exchange MS (HDX-MS). Notably, the Fab (Fragment antigen binding) for antibody 15498 captured a high energy form of the antigen exhibiting significant conformational changes that added flexibility over most of the Nsp1 protein. The Fab for antibody 15497, however, showed usual antigen binding behavior, revealing local changes presumably including the binding site. These findings illustrate an unusual antibody effect on an antigen and are consistent with the dynamic nature of the Nsp1 protein. Our studies suggest that this interaction capitalizes on the high flexibility of Nsp1 to undergo conformational change and be trapped in a higher energy state by binding with a specific antibody.
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Affiliation(s)
- Ravi Kant
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA;
| | - Nawneet Mishra
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA;
| | - Michael L. Gross
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA;
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9
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Guo C, Cheng M, Li W, Gross ML. Precursor Reagent Hydrophobicity Affects Membrane Protein Footprinting. J Am Soc Mass Spectrom 2023; 34:2700-2710. [PMID: 37967285 PMCID: PMC10924779 DOI: 10.1021/jasms.3c00272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
Membrane proteins (MPs) play a crucial role in cell signaling, molecular transport, and catalysis and thus are at the heart of designing pharmacological targets. Although structural characterization of MPs at the molecular level is essential to elucidate their biological function, it poses a significant challenge for structural biology. Although mass spectrometry-based protein footprinting may be developed into a powerful approach for studying MPs, the hydrophobic character of membrane regions makes structural characterization difficult using water-soluble footprinting reagents. Herein, we evaluated a small series of MS-based photoactivated iodine reagents with different hydrophobicities. We used tip sonication to facilitate diffusion into micelles, thus enhancing reagent access to the hydrophobic core of MPs. Quantification of the modification extent in hydrophilic extracellular and hydrophobic transmembrane domains provides structurally sensitive information at the residue-level as measured by proteolysis and LC-MS/MS for a model MP, vitamin K epoxide reductase (VKOR). It also reveals a relationship between the reagent hydrophobicity and its preferential labeling sites in the local environment. The outcome should guide the future development of chemical probes for MPs and promote a direction for relatively high-throughput information-rich characterization of MPs in biochemistry and drug discovery.
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10
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Lin Y, Moyle AB, Beaumont VA, Liu LL, Polleck S, Liu H, Shi H, Rouse JC, Kim HY, Zhang Y, Gross ML. Characterization of Higher Order Structural Changes of a Thermally Stressed Monoclonal Antibody via Mass Spectrometry Footprinting and Other Biophysical Approaches. Anal Chem 2023; 95:16840-16849. [PMID: 37933954 PMCID: PMC10909587 DOI: 10.1021/acs.analchem.3c02422] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Characterizing changes in the higher order structure (HOS) of monoclonal antibodies upon stressed conditions is critical to gaining a better understanding of the product and process. One single biophysical approach may not be best suited to assess HOS comprehensively; thus, the synergy from multiple, complementary approaches improves characterization accuracy and resolution. In this study, we employed two mass spectrometry (MS )-based footprinting techniques, namely, fast photochemical oxidation of proteins (FPOP)-MS and hydrogen-deuterium exchange (HDX)-MS, supported by dynamic light scattering (DLS), differential scanning calorimetry (DSC), circular dichroism (CD), and nuclear magnetic resonance (NMR) to study changes to the HOS of a mAb upon thermal stress. The biophysical techniques report a nuanced characterization of the HOS in which CD detects no changes to the secondary or tertiary structure, yet DLS measurements show an increase in the hydrodynamic radius. DSC indicates that the stability decreases, and chemical or conformational changes accumulate with incubation time according to NMR. Furthermore, whereas HDX-MS does not indicate HOS changes, FPOP-MS footprinting reveals conformational changes at residue resolution for some amino acids. The local phenomena observed with FPOP-MS indicate that several residues show various patterns of degradation during thermal stress: no change, an increase in solvent exposure, and a biphasic response to solvent exposure. All evidences show that FPOP-MS efficiently resolves subtle structural changes and novel degradation pathways upon thermal stress treatment at residue-level resolution.
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Affiliation(s)
- Yanchun Lin
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63105, United States
| | - Austin B Moyle
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63105, United States
| | - Victor A Beaumont
- Pharmaceutical Sciences Small Molecules, Analytical Research and Development, Pfizer, Inc., Sandwich CT13 9FF, U.K
| | - Lucy L Liu
- Biotherapeutics Pharmaceutical Sciences, Analytical Research and Development, Pfizer, Inc., Andover, Massachusetts 01810, United States
| | - Sharon Polleck
- Biotherapeutics Pharmaceutical Sciences, Analytical Research and Development, Pfizer, Inc., Andover, Massachusetts 01810, United States
| | - Haijun Liu
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63105, United States
| | - Heliang Shi
- Global Product Development, Rare Disease Statistics, Pfizer, Inc., New York, New York 10017, United States
| | - Jason C Rouse
- Biotherapeutics Pharmaceutical Sciences, Analytical Research and Development, Pfizer, Inc., Andover, Massachusetts 01810, United States
| | - Hai-Young Kim
- Biotherapeutics Pharmaceutical Sciences, Analytical Research and Development, Pfizer, Inc., Andover, Massachusetts 01810, United States
| | - Ying Zhang
- Biotherapeutics Pharmaceutical Sciences, Analytical Research and Development, Pfizer, Inc., Andover, Massachusetts 01810, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63105, United States
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11
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Wu C, Wagner ND, Moyle AB, Feng A, Sharma N, Stubbs SH, Donahue C, Davey RA, Gross ML, Leung DW, Amarasinghe GK. Disruption of Ebola NP 0VP35 Inclusion Body-like Structures reduce Viral Infection. J Mol Biol 2023; 435:168241. [PMID: 37598728 DOI: 10.1016/j.jmb.2023.168241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 08/04/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023]
Abstract
Viral inclusion bodies (IBs) are potential sites of viral replication and assembly. How viral IBs form remains poorly defined. Here we describe a combined biophysical and cellular approach to identify the components necessary for IB formation during Ebola virus (EBOV) infection. We find that the eNP0VP35 complex containing Ebola nucleoprotein (eNP) and viral protein 35 (eVP35), the functional equivalents of nucleoprotein (N) and phosphoprotein (P) in non-segmented negative strand viruses (NNSVs), phase separates to form inclusion bodies. Phase separation of eNP0VP35 is reversible and modulated by ionic strength. The multivalency of eVP35, and not eNP, is also critical for phase separation. Furthermore, overexpression of an eVP35 peptide disrupts eNP0VP35 complex formation, leading to reduced frequency of IB formation and limited viral infection. Together, our results show that upon EBOV infection, the eNP0VP35 complex forms the minimum unit to drive IB formation and viral replication.
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA; Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Austin B Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Annie Feng
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Nitin Sharma
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Sarah H Stubbs
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Callie Donahue
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Robert A Davey
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Daisy W Leung
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
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12
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Jiang R, Rempel DL, Gross ML. Toward a MALDI in-source decay (ISD) method for top-down analysis of protein footprinting. Eur J Mass Spectrom (Chichester) 2023; 29:292-302. [PMID: 37750197 DOI: 10.1177/14690667231202695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Irreversible protein footprinting is a mass spectrometry-based approach in which solvent-accessible sites of a protein are modified to assess high-order protein structure. Structural insights can be gained by determining the position and extents of modification. The usual approach to obtain the "footprint" is to analyze the protein through bottom-up LC-MS/MS. In this approach, the proteins are digested to yield a mixture of peptides that are then separated by LC before locating the modification sites by MS/MS. This process consumes substantial amounts of time and is difficult to accelerate for applications that require quick and high-throughput analysis. Here, we describe employing matrix-assisted laser desorption/ionization (MALDI) in-source decay (ISD) to analyze a footprinted small test protein (ubiquitin) via a top-down approach. Matrix-assisted laser desorption/ionization is easily adapted for high-throughput analysis, and top-down strategies can avoid lengthy proteolysis and LC separation. We optimized the method with model peptides and then demonstrated its feasibility on ubiquitin submitted to two types of footprinting. We found that MALDI ISD can produce a comprehensive set of fragment ions for small proteins, affording footprinting information in a fast manner and giving results that agree with the established methods, and serve as a rough measure of protein solvent accessibility. To assist in the implementation of the MALDI approach, we developed a method of processing top-down ISD data.
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Affiliation(s)
- Ruidong Jiang
- Department of Chemistry, Washington University in St Louis, St Louis, MO, USA
| | - Don L Rempel
- Department of Chemistry, Washington University in St Louis, St Louis, MO, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St Louis, St Louis, MO, USA
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13
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Gutierrez-Bayona NE, Scruggs SS, Yang HC, Chai M, Gross ML, Taylor JS. Post- and Pre-Radiolabeling Assays for anti Thymidine Cyclobutane Dimers as Intrinsic Photoprobes of Various Types of G-Quadruplexes, Reverse Hoogsteen Hairpins, and Other Non-B DNA Structures. Biochemistry 2023; 62:2269-2279. [PMID: 37459251 PMCID: PMC10474795 DOI: 10.1021/acs.biochem.3c00155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
G-quadruplexes are thought to play an important role in gene regulation and telomere maintenance, but developing probes for their presence and location is challenging due to their transitory and highly dynamic nature. The majority of probes for G-quadruplexes have relied on antibody or small-molecule binding agents, many of which can also alter the dynamics and relative populations of G-quadruplexes. Recently, it was discovered that ultraviolet B (UVB) irradiation of human telomeric DNA and various G-quadruplex forming sequences found in human promoters, as well as reverse Hoogsteen hairpins, produces a unique class of non-adjacent anti cyclobutane pyrimidine dimers (CPDs). Therefore, one can envision using a pulse of UVB light to irreversibly trap these non-B DNA structures via anti CPD formation without perturbing their dynamics, after which the anti CPDs can be identified and mapped. As a first step toward this goal, we report radioactive post- and pre-labeling assays for the detection of non-adjacent CPDs and illustrate their use in detecting trans,anti T=(T) CPD formation in a human telomeric DNA sequence. Both assays make use of snake venom phosphodiesterase (SVP) to degrade the trans,anti T=(T) CPD-containing DNA to the tetranucleotide pTT=(pTT) corresponding to CPD formation between the underlined T's of two separate dinucleotides while degrading the adjacent syn TT CPDs to the trinucleotide pGT=T. In the post-labeling assay, calf intestinal phosphodiesterase is used to dephosphorylate the tetranucleotides, which are then rephosphorylated with kinase and [32P]-ATP to produce radiolabeled mono- and diphosphorylated tetranucleotides. The tetranucleotides are confirmed to be non-adjacent CPDs by 254 nm photoreversion to the dinucleotide p*TT. In the pre-labeling assay, radiolabeled phosphates are introduced into non-adjacent CPD-forming sites by ligation prior to irradiation, thereby eliminating the dephosphorylation and rephosphorylation steps. The assays are also demonstrated to detect the stereoisomeric cis,anti T=(T) CPD.
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Affiliation(s)
| | - Savannah S Scruggs
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, United States
| | - Hsin-Chieh Yang
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, United States
| | - Mengqi Chai
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, United States
| | - Michael L Gross
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, United States
| | - John-Stephen Taylor
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, United States
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14
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Abstract
Although protein footprinting results are commonly obtained by ESI-based LC-MS/MS, a more rapid-turnaround alternative approach is desirable to expand the scope of protein footprinting and facilitate routine analysis such as monitoring protein high order structure in quality control or checking epitope maps. Considering that MALDI is a faster procedure that can be easily adapted for high-throughput analysis, we explore here the feasibility of developing a MALDI-based analysis "portfolio" of bottom-up peptide mass mapping for footprinting. The approach was applied to several model proteins that were submitted to two footprinting strategies, FPOP and GEE labeling, and their performance was evaluated. We found adequate coverage that can be improved with automatic off-line separation and spotting, demonstrating the capability to footprint accurately protein conformational change, showing that MALDI may be useful for selected applications in protein footprinting.
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Affiliation(s)
- Ruidong Jiang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Don L Rempel
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
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15
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Wu C, Wagner N, Moyle AB, Feng A, Sharma N, Stubbs SH, Donahue C, Davey R, Gross ML, Leung DW, Amarasinghe GK. The Ebola NP0VP35 Complex Phase Separates into Inclusion Body-Like Structures. Microsc Microanal 2023; 29:941. [PMID: 37613387 DOI: 10.1093/micmic/ozad067.468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Nicole Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Austin B Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Annie Feng
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Nitin Sharma
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Sarah H Stubbs
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Callie Donahue
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Robert Davey
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Daisy W Leung
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
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16
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Moyle AB, Wagner ND, Wagner WJ, Cheng M, Gross ML. Workflow for Validating Specific Amino Acid Footprinting Reagents for Protein Higher Order Structure Elucidation. Anal Chem 2023; 95:10119-10126. [PMID: 37351860 PMCID: PMC10476636 DOI: 10.1021/acs.analchem.3c01919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Protein footprinting mass spectrometry probes protein higher order structure and dynamics by labeling amino acid side-chains or backbone amides as a function of solvent accessibility. One category of footprinting uses residue-specific, irreversible covalent modifications, affording flexibility of sample processing for bottom-up analysis. Although several specific amino acid footprinting technologies are becoming established in structural proteomics, there remains a need to assess fundamental properties of new reagents before their application. Often, footprinting reagents are applied to complex or novel protein systems soon after their discovery and sometimes without a thorough investigation of potential downsides of the reagent. In this work, we assemble and test a validation workflow that utilizes cyclic peptides and a model protein to characterize benzoyl fluoride, a recently published, next-generation nucleophile footprinter. The workflow includes the characterization of potential side-chain reactive groups, reaction "quench" efficacies, reagent considerations and caveats (e.g., buffer pH), residue-specific kinetics compared to those of established reagents, and protein-wide characterization of modification sites with considerations for proteolysis. The proposed workflow serves as a starting point for improved footprinting reagent discovery, validation, and introduction, the aspects of which we recommend before applying to unknown protein systems.
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Affiliation(s)
- Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Wesley J. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Ming Cheng
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
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17
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Mishra N, Kant R, Leung DW, Gross ML, Amarasinghe GK. Biochemical and HDX Mass Spectral Characterization of the SARS-CoV-2 Nsp1 Protein. Biochemistry 2023; 62:1744-1754. [PMID: 37205707 PMCID: PMC10228561 DOI: 10.1021/acs.biochem.3c00035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/29/2023] [Indexed: 05/21/2023]
Abstract
A major challenge in defining the pathophysiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is to better understand virally encoded multifunctional proteins and their interactions with host factors. Among the many proteins encoded by the positive-sense, single-stranded RNA genome, nonstructural protein 1 (Nsp1) stands out due to its impact on several stages of the viral replication cycle. Nsp1 is the major virulence factor that inhibits mRNA translation. Nsp1 also promotes host mRNA cleavage to modulate host and viral protein expression and to suppress host immune functions. To better define how this multifunctional protein can facilitate distinct functions, we characterize SARS-CoV-2 Nsp1 by using a combination of biophysical techniques, including light scattering, circular dichroism, hydrogen/deuterium exchange mass spectrometry (HDX-MS), and temperature-dependent HDX-MS. Our results reveal that the SARS-CoV-2 Nsp1 N- and C-terminus are unstructured in solution, and in the absence of other proteins, the C-terminus has an increased propensity to adopt a helical conformation. In addition, our data indicate that a short helix exists near the C-terminus and adjoins the region that binds the ribosome. Together, these findings provide insights into the dynamic nature of Nsp1 that impacts its functions during infection. Furthermore, our results will inform efforts to understand SARS-CoV-2 infection and antiviral development.
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Affiliation(s)
- Nawneet Mishra
- Department
of Pathology and Immunology, Washington
University School of Medicine in St. Louis, St. Louis, Missouri 63110, United States
| | - Ravi Kant
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Daisy W. Leung
- Department
of Pathology and Immunology, Washington
University School of Medicine in St. Louis, St. Louis, Missouri 63110, United States
- Department
of Medicine, Washington University School
of Medicine, St. Louis, Missouri 63110, United States
| | - Michael L. Gross
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Gaya K. Amarasinghe
- Department
of Pathology and Immunology, Washington
University School of Medicine in St. Louis, St. Louis, Missouri 63110, United States
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18
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Li S, Sun J, Liu S, Zhou F, Gross ML, Li W. Missense VKOR mutants exhibit severe warfarin resistance but lack VKCFD via shifting to an aberrantly reduced state. Blood Adv 2023; 7:2271-2282. [PMID: 36508285 PMCID: PMC10225482 DOI: 10.1182/bloodadvances.2021006876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 12/14/2022] Open
Abstract
Missense vitamin K epoxide reductase (VKOR) mutations in patients cause resistance to warfarin treatment but not abnormal bleeding due to defective VKOR activity. The underlying mechanism of these phenotypes remains unknown. Here we show that the redox state of these mutants is essential to their activity and warfarin resistance. Using a mass spectrometry-based footprinting method, we found that severe warfarin-resistant mutations change the VKOR active site to an aberrantly reduced state in cells. Molecular dynamics simulation based on our recent crystal structures of VKOR reveals that these mutations induce an artificial opening of the protein conformation that increases access of small molecules, enabling them to reduce the active site and generating constitutive activity uninhibited by warfarin. Increased activity also compensates for the weakened substrate binding caused by these mutations, thereby maintaining normal VKOR function. The uninhibited nature of severe resistance mutations suggests that patients showing signs of such mutations should be treated by alternative anticoagulation strategies.
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Affiliation(s)
- Shuang Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
| | - Jie Sun
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO
| | - Shixuan Liu
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
| | - Fengbo Zhou
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
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19
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Abstract
Antigen-antibody interactions are a fundamental subset of protein-protein interactions responsible for the "survival of the fittest". Determining the interacting interface of the antigen, called an epitope, and that on the antibody, called a paratope, is crucial to antibody development. Because each antigen presents multiple epitopes (unique footprints), sophisticated approaches are required to determine the target region for a given antibody. Although X-ray crystallography, Cryo-EM, and nuclear magnetic resonance can provide atomic details of an epitope, they are often laborious, poor in throughput, and insensitive. Mass spectrometry-based approaches offer rapid turnaround, intermediate structural resolution, and virtually no size limit for the antigen, making them a vital approach for epitope mapping. In this review, we describe in detail the principles of hydrogen deuterium exchange mass spectrometry in application to epitope mapping. We also show that a combination of MS-based approaches can assist or complement epitope mapping and push the limit of structural resolution to the residue level. We describe in detail the MS methods used in epitope mapping, provide our perspective about the approaches, and focus on elucidating the role that HDX-MS is playing now and in the future by organizing a discussion centered around several improvements in prototype instrument/applications used for epitope mapping. At the end, we provide a tabular summary of the current literature on HDX-MS-based epitope mapping.
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Affiliation(s)
- Prashant N. Jethva
- Department of Chemistry, Washington University in St. Louis, St Louis, MO 63130, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St Louis, MO 63130, USA
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20
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Yang HC, Li W, Sun J, Gross ML. Advances in Mass Spectrometry on Membrane Proteins. Membranes (Basel) 2023; 13:457. [PMID: 37233518 PMCID: PMC10220746 DOI: 10.3390/membranes13050457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/15/2023] [Accepted: 04/21/2023] [Indexed: 05/27/2023]
Abstract
Understanding the higher-order structure of membrane proteins (MPs), which are vital for numerous biological processes, is crucial for comprehending their function. Although several biophysical approaches have been used to study the structure of MPs, limitations exist owing to the proteins' dynamic nature and heterogeneity. Mass spectrometry (MS) is emerging as a powerful tool for investigating membrane protein structure and dynamics. Studying MPs using MS, however, must meet several challenges including the lack of stability and solubility of MPs, the complexity of the protein-membrane system, and the difficulty of digestion and detection. To meet these challenges, recent advances in MS have engendered opportunities in resolving the dynamics and structures of MP. This article reviews achievements over the past few years that enable the study of MPs by MS. We first introduce recent advances in hydrogen deuterium exchange and native mass spectrometry for MPs and then focus on those footprinting methods that report on protein structure.
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Affiliation(s)
- Hsin-Chieh Yang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA;
| | - Jie Sun
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
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21
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Gross ML. When Medical Ethics and Military Ethics Collide. Narrat Inq Bioeth 2023; 13:199-204. [PMID: 38661993 DOI: 10.1353/nib.2023.a924191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
In 12 narratives, medical workers from Afghanistan, Darfur, Gaza, Iraq, Israel, Myanmar, and Ukraine describe the day-to-day challenges of providing quality medical care in austere conflict zones. Faced with severe shortages of supplies, overwhelmed by sick and injured civilians and soldiers, and subject to constant attacks on medical personnel and facilities, the contributors to this collection confront difficult dilemmas of justice, medical impartiality, neutrality, burnout, and moral injury as they struggle to fulfill their duties as medical professionals, military officers, and conscientious citizens.
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22
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Greven JA, Song JH, Kober DL, Alexander‐Brett JM, Gross ML, Brett TJ. Biophysical analysis of TREM2 interactions reveals a shared binding site for Alzheimer’s disease ligands apoE and oligomeric amyloid beta. Alzheimers Dement 2022. [DOI: 10.1002/alz.067634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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23
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Wagner WJ, Gross ML. Using mass spectrometry-based methods to understand amyloid formation and inhibition of alpha-synuclein and amyloid beta. Mass Spectrom Rev 2022:10.1002/mas.21814. [PMID: 36224716 PMCID: PMC10090239 DOI: 10.1002/mas.21814] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Amyloid fibrils, insoluble β-sheets structures that arise from protein misfolding, are associated with several neurodegenerative disorders. Many small molecules have been investigated to prevent amyloid fibrils from forming; however, there are currently no therapeutics to combat these diseases. Mass spectrometry (MS) is proving to be effective for studying the high order structure (HOS) of aggregating proteins and for determining structural changes accompanying protein-inhibitor interactions. When combined with native MS (nMS), gas-phase ion mobility, protein footprinting, and chemical cross-linking, MS can afford regional and sometimes amino acid spatial resolution of the aggregating protein. The spatial resolution is greater than typical low-resolution spectroscopic, calorimetric, and the traditional ThT fluorescence methods used in amyloid research today. High-resolution approaches can struggle when investigating protein aggregation, as the proteins exist as complex oligomeric mixtures of many sizes and several conformations or polymorphs. Thus, MS is positioned to complement both high- and low-resolution approaches to studying amyloid fibril formation and protein-inhibitor interactions. This review covers basics in MS paired with ion mobility, continuous hydrogen-deuterium exchange (continuous HDX), pulsed hydrogen-deuterium exchange (pulsed HDX), fast photochemical oxidation of proteins (FPOP) and other irreversible labeling methods, and chemical cross-linking. We then review the applications of these approaches to studying amyloid-prone proteins with a focus on amyloid beta and alpha-synuclein. Another focus is the determination of protein-inhibitor interactions. The expectation is that MS will bring new insights to amyloid formation and thereby play an important role to prevent their formation.
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Affiliation(s)
- Wesley J Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
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24
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Moreno J, Gross ML, Becker J, Hereth B, Shortland ND, Evans NG. The ethics of AI-assisted warfighter enhancement research and experimentation: Historical perspectives and ethical challenges. Front Big Data 2022; 5:978734. [PMID: 36156934 PMCID: PMC9500287 DOI: 10.3389/fdata.2022.978734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
The military applications of AI raise myriad ethical challenges. Critical among them is how AI integrates with human decision making to enhance cognitive performance on the battlefield. AI applications range from augmented reality devices to assist learning and improve training to implantable Brain-Computer Interfaces (BCI) to create bionic "super soldiers." As these technologies mature, AI-wired warfighters face potential affronts to cognitive liberty, psychological and physiological health risks and obstacles to integrating into military and civil society during their service and upon discharge. Before coming online and operational, however, AI-assisted technologies and neural interfaces require extensive research and human experimentation. Each endeavor raises additional ethical concerns that have been historically ignored thereby leaving military and medical scientists without a cogent ethics protocol for sustainable research. In this way, this paper is a "prequel" to the current debate over enhancement which largely considers neuro-technologies once they are already out the door and operational. To lay the ethics foundation for AI-assisted warfighter enhancement research, we present an historical overview of its technological development followed by a presentation of salient ethics research issues (ICRC, 2006). We begin with a historical survey of AI neuro-enhancement research highlighting the ethics lacunae of its development. We demonstrate the unique ethical problems posed by the convergence of several technologies in the military research setting. Then we address these deficiencies by emphasizing how AI-assisted warfighter enhancement research must pay particular attention to military necessity, and the medical and military cost-benefit tradeoffs of emerging technologies, all attending to the unique status of warfighters as experimental subjects. Finally, our focus is the enhancement of friendly or compatriot warfighters and not, as others have focused, enhancements intended to pacify enemy warfighters.
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Affiliation(s)
- Jonathan Moreno
- Department of Bioethics, School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | | | - Jack Becker
- Harvard Law School, Cambridge, MA, United States
| | - Blake Hereth
- Department of Philosophy, University of Massachusetts at Lowell, Lowell, MA, United States
| | - Neil D. Shortland
- School of Criminology and Justice Studies, University of Massachusetts at Lowell, Lowell, MA, United States
| | - Nicholas G. Evans
- Department of Philosophy, University of Massachusetts at Lowell, Lowell, MA, United States
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25
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Murray NH, Lewis A, Rincon Pabon JP, Gross ML, Henzler-Wildman K, Pagliarini DJ. 2-Propylphenol Allosterically Modulates COQ8A to Enhance ATPase Activity. ACS Chem Biol 2022; 17:2031-2038. [PMID: 35904798 PMCID: PMC9586199 DOI: 10.1021/acschembio.2c00434] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
COQ8A is an atypical kinase-like protein that aids the biosynthesis of coenzyme Q, an essential cellular cofactor and antioxidant. COQ8A's mode of action remains unclear, in part due to the lack of small molecule tools to probe its function. Here, we blend NMR and hydrogen-deuterium exchange mass spectrometry to help determine how a small CoQ precursor mimetic, 2-propylphenol, modulates COQ8A activity. We identify a likely 2-propylphenol binding site and reveal that this compound modulates a conserved COQ8A domain to increase nucleotide affinity and ATPase activity. Our findings promise to aid further investigations into COQ8A's precise enzymatic function and the design of compounds capable of boosting endogenous CoQ production for therapeutic gain.
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Affiliation(s)
- Nathan H. Murray
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53715, USA
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Adam Lewis
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Juan P. Rincon Pabon
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | | | - David J. Pagliarini
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53715, USA
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Correspondence and requests for materials should be addressed to D.J.P.,
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26
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Wagner ND, Moyle AB, Pabon JPR, Gross ML. Automated Specific Amino Acid Footprinting Mass Spectrometry: Repurposing an HDX Platform for Determining Reagent Feasibility. Anal Chem 2022; 94:10314-10319. [PMID: 35830607 PMCID: PMC10482561 DOI: 10.1021/acs.analchem.2c02073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein footprinting is a mass spectrometry (MS)-based approach to measure protein conformational changes. One approach, specific amino acid labeling, imparts often an irreversible modification to protein side chains but requires careful selection of the reactive reagent and often time-consuming optimization of experimental parameters prior to submission to bottom-up MS analysis. In this work, we repurpose a hydrogen-deuterium exchange MS (HDX-MS) LEAP HDX system for automated specific amino acid footprinting MS, demonstrating its efficacy in reaction optimization and monitoring applicability to specific ligand binding systems. We screened reagent conditions for two model ligand-binding systems and demonstrate the method's efficacy for measuring differences induced by ligand binding. Our proof-of-concept experiments provide a platform for rapidly screening specific amino acid reagents and reaction conditions for protein systems to be studied by footprinting.
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Affiliation(s)
- Nicole D. Wagner
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
| | - Austin B. Moyle
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
| | - Juan P. Rincon Pabon
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
| | - Michael L. Gross
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
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27
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Sun J, Li W, Gross ML. Advances in mass spectrometry-based footprinting of membrane proteins. Proteomics 2022; 22:e2100222. [PMID: 35290716 PMCID: PMC10493193 DOI: 10.1002/pmic.202100222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 11/09/2022]
Abstract
Structural biology is entering an exciting time where many new high-resolution structures of large complexes and membrane proteins (MPs) are determined regularly. These advances have been driven by over 15 years of technological improvements, first in macromolecular crystallography, and recently in cryo-electron microscopy. Obtaining information about MP higher order structure and interactions is also a frontier, important but challenging owing to their unique properties and the need to choose suitable detergents/lipids for their study. The development of mass spectrometry (MS), both instruments and methodology in the past 10 years, has also advanced it as a complementary method to study MP structure and interactions. In this review, we discuss advances in MS-based footprinting for MPs and highlight recent methodologies that offer new promise for MP study by chemical footprinting and mass spectrometry.
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Affiliation(s)
- Jie Sun
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
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Gross ML, Rempel DL. A PERSPECTIVE ON PERSONAL CONTRIBUTIONS TO FT-ICR MASS SPECTROMETRY. Mass Spectrom Rev 2022; 41:178-193. [PMID: 32960989 PMCID: PMC8888036 DOI: 10.1002/mas.21657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/31/2020] [Indexed: 06/11/2023]
Abstract
This is a personal perspective on our contributions to FT-ICR, many of early ones in a collaboration with Charles Wilkins and Michael Gross starting in the mid-1970s and then continuing for many years in collaboration of Don Rempel and Michael Gross. The perspective is to honor Alan Marshall, who with Melvin Comisarow, first demonstrated FT-ICR MS in 1974 (Comisarow & Marshall, 1974). Our intention is to review the contributions made together with Wilkins, Rempel, and a group of graduate and postdoctoral students, starting at the University of Nebraska-Lincoln and continuing here at Washington University in St. Louis. Besides offering a chance to reminisce about the early and exciting days of FT-ICR MS when academic laboratories were building and modifying mass spectrometers and other instruments, a nearly lost art, I am reminded of my editorship of this journal occurring over part of that time.
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Affiliation(s)
- Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130
| | - Don L Rempel
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130
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29
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Moyle AB, Cheng M, Wagner ND, Gross ML. Benzoyl Transfer for Footprinting Alcohol-Containing Residues in Higher Order Structural Applications of Mass-Spectrometry-Based Proteomics. Anal Chem 2022; 94:1520-1524. [PMID: 35019278 PMCID: PMC10483880 DOI: 10.1021/acs.analchem.1c04659] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein footprinting mass spectrometry (MS), an emerging approach to elucidate higher-order structure (HOS) and binding, benefits from the iterative development of reaction strategies to expand the covalent labeling toolbox. Herein, we introduce a footprinting reagent for nucleophiles and demonstrate its efficacy for differential covalent labeling MS analysis. Benzoyl fluoride (BF), although reactive with water, is more practical for modifying nucleophilic functional groups than other acid halides and serves as an acyl-transfer reagent for proteins. BF is 10 times more reactive with phenolic Tyr than the current generation nucleophile footprinter. BF modifies, in addition to Tyr, Lys, His, and the N-terminus, weak nucleophiles Ser and Thr, for which few footprinters exist, imparting broad applicability with a range of nucleophiles. We applied benzoylation to a model Ser- and Thr-rich protein-ligand binding system without perturbing the protein HOS. This efficacious footprinting method expands the toolbox of reagents and provides promise for future reaction strategies including possibly membrane proteins.
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Affiliation(s)
- Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Ming Cheng
- Corresponding Authors Michael L. Gross - Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Saint. Louis, MO, 63130 USA. ; Ming Cheng - Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Saint. Louis, MO, 63130 USA.
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
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30
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Lin Y, Gross ML. Mass Spectrometry-Based Structural Proteomics for Metal Ion/Protein Binding Studies. Biomolecules 2022; 12:135. [PMID: 35053283 PMCID: PMC8773722 DOI: 10.3390/biom12010135] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
Metal ions are critical for the biological and physiological functions of many proteins. Mass spectrometry (MS)-based structural proteomics is an ever-growing field that has been adopted to study protein and metal ion interactions. Native MS offers information on metal binding and its stoichiometry. Footprinting approaches coupled with MS, including hydrogen/deuterium exchange (HDX), "fast photochemical oxidation of proteins" (FPOP) and targeted amino-acid labeling, identify binding sites and regions undergoing conformational changes. MS-based titration methods, including "protein-ligand interactions by mass spectrometry, titration and HD exchange" (PLIMSTEX) and "ligand titration, fast photochemical oxidation of proteins and mass spectrometry" (LITPOMS), afford binding stoichiometry, binding affinity, and binding order. These MS-based structural proteomics approaches, their applications to answer questions regarding metal ion protein interactions, their limitations, and recent and potential improvements are discussed here. This review serves as a demonstration of the capabilities of these tools and as an introduction to wider applications to solve other questions.
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Affiliation(s)
- Yanchun Lin
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
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Abstract
Nipah virus (NiV) is an emerging and deadly zoonotic paramyxovirus that is responsible for periodic epidemics of acute respiratory illness and encephalitis in humans. Previous studies have shown that the NiV V protein antagonizes host antiviral immunity, but the molecular mechanism is incompletely understood. To address this gap, we biochemically characterized NiV V binding to the host pattern recognition receptor MDA5. We find that the C-terminal domain of NiV V (VCTD) is sufficient to bind the MDA5SF2 domain when recombinantly co-expressed in bacteria. Analysis by hydrogen-deuterium exchange mass spectrometry (HDX-MS) studies revealed that NiV VCTD is conformationally dynamic, and binding to MDA5 reduces the dynamics of VCTD. Our results also suggest that the β-sheet region in between the MDA5 Hel1, Hel2, and Hel2i domains exhibits rapid HDX. Upon VCTD binding, these β-sheet and adjacent residues show significant protection. Collectively, our findings suggest that NiV V binding disrupts the helicase fold and dynamics of MDA5 to antagonize host antiviral immunity.
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Affiliation(s)
- Nicole D. Wagner
- Division of Infectious Diseases, John T. Milliken Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Hejun Liu
- Division of Infectious Diseases, John T. Milliken Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Henry W. Rohrs
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Daisy W. Leung
- Division of Infectious Diseases, John T. Milliken Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
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32
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Hertz U, Snider KLG, Levy A, Canetti D, Gross ML. To shoot or not to shoot: experiments on moral injury in the context of West Bank checkpoints and COVID-19 restrictions enforcement. Eur J Psychotraumatol 2022; 13:2013651. [PMID: 35087644 PMCID: PMC8788350 DOI: 10.1080/20008198.2021.2013651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Does exposure to events that transgress accepted norms, such as killing innocent civilians, prompt the psychological and emotional consequences of moral injury among soldiers? Moral injury is associated with negative emotions such as guilt, shame and anger, and a sense of betrayal and is identified among veterans following exposure to potentially morally injurious events (PMIE). OBJECTIVE We experimentally investigate how PMIE characteristics affect the intensity of MI and related negative moral emotions in participants with varied military experience. METHOD We conducted three controlled, randomized experiments. Each exposed male respondents with active combat experience (Study 1) and varied military experience (Study 2) to four textual vignettes describing PMIE (child/adult and innocent/non-innocent suspect) that transpire at an Israeli checkpoint in the West Bank. In study 3, we exposed participants to two scenarios, where descriptions of police officers enforcing COVID 19 restrictions confronted lockdown violators. RESULTS Participants assigned to vignettes describing killing an innocent civilian exhibited more intense levels of shame and guilt than those assigned to vignettes describing killing a person carrying a bomb. Religiosity and political ideology were strong predictors of guilt and shame in response to descriptions of checkpoint shootings. These effects disappeared in Study 3, suggesting that political ideology drives MI in intergroup conflict. CONCLUSIONS Background and PMIE-related characteristics affect the development of moral injury. Additionally, lab experiments demonstrate the potential and limitations of controlled studies of moral injury and facilitate an understanding of the aetiology of moral injury in a way unavailable to clinicians. Finally, experimental findings and methodologies offer further insights into the genesis of moral injury and avenues for therapy and prophylaxis.
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Affiliation(s)
- Uri Hertz
- Department of Cognitive Sciences, University of Haifa, Haifa, Israel
| | | | - Adi Levy
- School of Political Science, University of Haifa, Haifa, Israel
| | - Daphna Canetti
- School of Political Science, University of Haifa, Haifa, Israel
| | - Michael L Gross
- School of Political Science, University of Haifa, Haifa, Israel
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Kailasan S, Kant R, Noonan-Shueh M, Kanipakala T, Liao G, Shulenin S, Leung DW, Alm RA, Adhikari RP, Amarasinghe GK, Gross ML, Aman MJ. Antigenic landscapes on Staphylococcus aureus pore-forming toxins reveal insights into specificity and cross-neutralization. MAbs 2022; 14:2083467. [PMID: 35730685 PMCID: PMC9225675 DOI: 10.1080/19420862.2022.2083467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus carries an exceptional repertoire of virulence factors that aid in immune evasion. Previous single-target approaches for S. aureus-specific vaccines and monoclonal antibodies (mAbs) have failed in clinical trials due to the multitude of virulence factors released during infection. Emergence of antibiotic-resistant strains demands a multi-target approach involving neutralization of different, non-overlapping pathogenic factors. Of the several pore-forming toxins that contribute to S. aureus pathogenesis, efforts have largely focused on mAbs that neutralize α-hemolysin (Hla) and target the receptor-binding site. Here, we isolated two anti-Hla and three anti-Panton-Valentine Leukocidin (LukSF-PV) mAbs, and used a combination of hydrogen deuterium exchange mass spectrometry (HDX-MS) and alanine scanning mutagenesis to delineate and validate the toxins’ epitope landscape. Our studies identified two novel, neutralizing epitopes targeted by 2B6 and CAN6 on Hla that provided protection from hemolytic activity in vitro and showed synergy in rodent pneumonia model against lethal challenge. Of the anti-LukF mAbs, SA02 and SA131 showed specific neutralization activity to LukSF-PV while SA185 showed cross-neutralization activity to LukSF-PV, γ-hemolysin HlgAB, and leukotoxin ED. We further compared these antigen-specific mAbs to two broadly neutralizing mAbs, H5 (targets Hla, LukSF-PV, HlgAB, HlgCB, and LukED) and SA185 (targeting LukSF-PV, HlgAB, and LukED), and identified molecular level markers for broad-spectrum reactivity among the pore-forming toxins by HDX-MS. To further underscore the need to target the cross-reactive epitopes on leukocidins for the development of broad-spectrum therapies, we annotated Hla sequences isolated from patients in multiple countries for genomic variations within the perspective of our defined epitopes.
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Affiliation(s)
| | - Ravi Kant
- Department of Chemistry, Washington University in St. Louis, St. Louis, USA
| | | | | | - Grant Liao
- Integrated BioTherapeutics, Rockville, USA
| | | | - Daisy W Leung
- Department of Medicine, Washington University in St. Louis, St. Louis, USA
| | - Richard A Alm
- Boston University School of Law, Boston University, Boston, USA
| | | | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, USA
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Wu C, Qavi AJ, Moyle AB, Wagner ND, Hachim A, Kavian N, Cole AR, Sweeney-Gibbons J, Rohrs HW, Peiris JM, Basler CF, Gross ML, Valkenburg SA, Farnsworth CW, Amarasinghe GK, Leung DW. Domain-specific biochemical and serological characterization of SARS-CoV-2 nucleocapsid protein. STAR Protoc 2021; 2:100906. [PMID: 34642671 PMCID: PMC8495048 DOI: 10.1016/j.xpro.2021.100906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Nucleocapsid proteins are essential for SARS-CoV-2 life cycle. Here, we describe protocols to gather domain-specific insights about essential properties of nucleocapsids. These assays include dynamic light scattering to characterize oligomerization, fluorescence polarization to quantify RNA binding, hydrogen-deuterium exchange mass spectrometry to map RNA binding regions, negative-stain electron microscopy to visualize oligomeric species, interferon reporter assay to evaluate interferon signaling modulation, and a serology assay to reveal insights for improved sensitivity and specificity. These assays are broadly applicable to RNA-encapsidated nucleocapsids. For complete details on the use and execution of this protocol, please refer to Wu et al. (2021).
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Abraham J. Qavi
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Asmaa Hachim
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Niloufar Kavian
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Assistance Publique–Hôpitaux de Paris, Hôpital Universitaire Paris Centre, Centre Hospitalier Universitaire Cochin, Service d’Immunologie Biologique, Paris, France
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Aidan R. Cole
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Joyce Sweeney-Gibbons
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Henry W. Rohrs
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - J.S. Malik Peiris
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Division of Public Health Laboratory Sciences, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Christopher F. Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Sophie A. Valkenburg
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Christopher W. Farnsworth
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Daisy W. Leung
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
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35
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Sun J, Liu XR, Li S, He P, Li W, Gross ML. Nanoparticles and photochemistry for native-like transmembrane protein footprinting. Nat Commun 2021; 12:7270. [PMID: 34907205 PMCID: PMC8671412 DOI: 10.1038/s41467-021-27588-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 10/05/2021] [Indexed: 11/29/2022] Open
Abstract
Mass spectrometry-based footprinting can probe higher order structure of soluble proteins in their native states and serve as a complement to high-resolution approaches. Traditional footprinting approaches, however, are hampered for integral membrane proteins because their transmembrane regions are not accessible to solvent, and they contain hydrophobic residues that are generally unreactive with most chemical reagents. To address this limitation, we bond photocatalytic titanium dioxide (TiO2) nanoparticles to a lipid bilayer. Upon laser irradiation, the nanoparticles produce local concentrations of radicals that penetrate the lipid layer, which is made permeable by a simultaneous laser-initiated Paternò-Büchi reaction. This approach achieves footprinting for integral membrane proteins in liposomes, helps locate both ligand-binding residues in a transporter and ligand-induced conformational changes, and reveals structural aspects of proteins at the flexible unbound state. Overall, this approach proves effective in intramembrane footprinting and forges a connection between material science and biology.
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Affiliation(s)
- Jie Sun
- grid.4367.60000 0001 2355 7002Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Box 1134, Saint Louis, MO 63130 USA
| | - Xiaoran Roger Liu
- grid.4367.60000 0001 2355 7002Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Box 1134, Saint Louis, MO 63130 USA
| | - Shuang Li
- grid.4367.60000 0001 2355 7002Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave, Box 8231, St. Louis, MO 63110 USA
| | - Peng He
- grid.4367.60000 0001 2355 7002Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave, Box 8231, St. Louis, MO 63110 USA
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave, Box 8231, St. Louis, MO, 63110, USA.
| | - Michael L. Gross
- grid.4367.60000 0001 2355 7002Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Box 1134, Saint Louis, MO 63130 USA
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Abstract
Membrane proteins play crucial roles in cell signaling and transport and, thus, are the targets of many small molecule drugs. The characterization of membrane protein structures poses challenges for the high-resolution biophysical tools because the transmembrane (TM) domain is hydrophobic, opening an opportunity for mass spectrometry (MS)-based footprinting. The hydrophobic reagent diethylpyrocarbonate (DEPC), a heavily studied footprinter for water-soluble proteins, can label up to 30% of surface residues via a straightforward protocol, streamlining the MS-based footprinting workflow. To test its applicability to membrane proteins, we footprinted vitamin K epoxide reductase (VKOR) membrane protein with DEPC. The results demonstrate that besides labeling the hydrophilic extracellular (extramembrane (EM)) domain, DEPC can also diffuse into the hydrophobic TM domain and subsequently label that region. The labeling process was facilitated by tip sonication to enhance reagent diffusion into micelles. We then analyzed the correlation between the residue modification extent and the theoretical accessible surface area percentage (%ASA); the data generally show good correlation with the residue location. Compared with conventional hydrophilic footprinters, the relatively hydrophobic DEPC can map a membrane protein's TM domain, suggesting that the reagent's hydrophobicity can be exploited to obtain structural information on the membrane-spanning region. This encouraging result should assist in the development of more efficient footprinters for membrane protein TM domain footprinting, enabled by further understanding the relationship between a reagent's hydrophobicity and its preferred labeling sites.
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Affiliation(s)
- Chunyang Guo
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Ming Cheng
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Michael L Gross
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
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37
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Abstract
Here, we introduce carbocations (R3C+) as laser-initiated footprinting reagents for proteins. We screened seven candidates and selected trifluomethoxy benzyl bromide (TFBB) as an effective precursor for the electrophilic trifluomethoxy benzyl carbocation (TFB+) under laser (248 nm) irradiation on the fast photochemical oxidation of proteins (FPOP) platform. Initial results demonstrate that this electrophilic cation reagent affords residue coverage of nucleophilic amino acids including H, W, M, and S. Further, the addition of TFB+ increases the hydrophobicity of the peptides so that separation of isomeric peptide products by reversed-phase LC is improved, suggesting opportunities for subresidue footprinting. Comparison of apo- and holo-myoglobin footprints shows that the TFB+ footprinting is sensitive to protein conformational change and solvent accessibility. Interestingly, because the TFB+ is amphiphilic, the reagent can potentially footprint membrane proteins as demonstrated for vitamin K epoxide reductase (VKOR) stabilized in a micelle. Not only does footprinting of the extra-membrane domain occur, but also some footprinting of the hydrophobic transmembrane domain is achieved owing to the interaction of TFB+ with the micelle. Carbocation precursors are stable and amenable for tailoring their properties and those of the incipient carbocation, enabling targeting their soluble or membrane-associated or embedded regions and distinguishing between the extra- and trans-membrane domains of membrane proteins.
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Affiliation(s)
- Jie Sun
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Shuang Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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38
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Ganaie SS, Schwarz MM, McMillen CM, Price DA, Feng AX, Albe JR, Wang W, Miersch S, Orvedahl A, Cole AR, Sentmanat MF, Mishra N, Boyles DA, Koenig ZT, Kujawa MR, Demers MA, Hoehl RM, Moyle AB, Wagner ND, Stubbs SH, Cardarelli L, Teyra J, McElroy A, Gross ML, Whelan SPJ, Doench J, Cui X, Brett TJ, Sidhu SS, Virgin HW, Egawa T, Leung DW, Amarasinghe GK, Hartman AL. Lrp1 is a host entry factor for Rift Valley fever virus. Cell 2021; 184:5163-5178.e24. [PMID: 34559985 DOI: 10.1016/j.cell.2021.09.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/29/2021] [Accepted: 09/01/2021] [Indexed: 12/26/2022]
Abstract
Rift Valley fever virus (RVFV) is a zoonotic pathogen with pandemic potential. RVFV entry is mediated by the viral glycoprotein (Gn), but host entry factors remain poorly defined. Our genome-wide CRISPR screen identified low-density lipoprotein receptor-related protein 1 (mouse Lrp1/human LRP1), heat shock protein (Grp94), and receptor-associated protein (RAP) as critical host factors for RVFV infection. RVFV Gn directly binds to specific Lrp1 clusters and is glycosylation independent. Exogenous addition of murine RAP domain 3 (mRAPD3) and anti-Lrp1 antibodies neutralizes RVFV infection in taxonomically diverse cell lines. Mice treated with mRAPD3 and infected with pathogenic RVFV are protected from disease and death. A mutant mRAPD3 that binds Lrp1 weakly failed to protect from RVFV infection. Together, these data support Lrp1 as a host entry factor for RVFV infection and define a new target to limit RVFV infections.
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Affiliation(s)
- Safder S Ganaie
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Madeline M Schwarz
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Cynthia M McMillen
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - David A Price
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Annie X Feng
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Joseph R Albe
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Wenjie Wang
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Shane Miersch
- The Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Anthony Orvedahl
- Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Aidan R Cole
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Monica F Sentmanat
- Genome Engineering and iPSC Center (GEiC), Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Nawneet Mishra
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Devin A Boyles
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zachary T Koenig
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael R Kujawa
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Matthew A Demers
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ryan M Hoehl
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Austin B Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Sarah H Stubbs
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Lia Cardarelli
- The Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Joan Teyra
- The Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Anita McElroy
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Pediatrics, Division of Pediatric Infectious Disease, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Sean P J Whelan
- Department of Molecular Microbiology, Washington University in St. Louis, St. Louis, MO, USA
| | - John Doench
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Xiaoxia Cui
- Genome Engineering and iPSC Center (GEiC), Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Tom J Brett
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Sachdev S Sidhu
- The Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Herbert W Virgin
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; Current address: Vir Biotechnology, San Francisco, CA, USA
| | - Takeshi Egawa
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
| | - Amy L Hartman
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
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39
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Khubaib MU, Stark BE, Gross B, Gross ML, Vazquez O. A Rare Case of Septic Knee Arthritis Caused by Clostridium perfringens in a Patient With Colostomy. Cureus 2021; 13:e16823. [PMID: 34522480 PMCID: PMC8425027 DOI: 10.7759/cureus.16823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2021] [Indexed: 11/30/2022] Open
Abstract
Septic arthritis of the knee is commonly caused by aerobic organisms. Rarely, it can be caused by Clostridium perfringens, usually due to penetrating trauma. This is a rare case of C. perfringens septic arthritis in a patient with colostomy due to hematogenous spread. The patient was treated successfully with a synovectomy and a prolonged intravenous antibiotic course. The case report summarizes the existing literature on the topic and discusses the diagnosis, management, and prognosis of such cases as well.
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Affiliation(s)
| | - Brett E Stark
- Orthopaedic Surgery, Active Orthopedics & Sports Medicine, Hackensack, USA
| | - Benjamin Gross
- Sports Medicine, Active Orthopedics & Sports Medicine, Hackensack, USA
| | - Michael L Gross
- Sports Medicine, Active Orthopedics & Sports Medicine, Hackensack, USA
| | - Oscar Vazquez
- Sports Medicine, Active Orthopedics & Sports Medicine, Hackensack, USA
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40
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Kim AS, Kafai NM, Winkler ES, Gilliland TC, Cottle EL, Earnest JT, Jethva PN, Kaplonek P, Shah AP, Fong RH, Davidson E, Malonis RJ, Quiroz JA, Williamson LE, Vang L, Mack M, Crowe JE, Doranz BJ, Lai JR, Alter G, Gross ML, Klimstra WB, Fremont DH, Diamond MS. Pan-protective anti-alphavirus human antibodies target a conserved E1 protein epitope. Cell 2021; 184:4414-4429.e19. [PMID: 34416146 PMCID: PMC8382027 DOI: 10.1016/j.cell.2021.07.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/01/2021] [Accepted: 07/02/2021] [Indexed: 12/13/2022]
Abstract
Alphaviruses are emerging, mosquito-transmitted pathogens that cause musculoskeletal and neurological disease in humans. Although neutralizing antibodies that inhibit individual alphaviruses have been described, broadly reactive antibodies that protect against both arthritogenic and encephalitic alphaviruses have not been reported. Here, we identify DC2.112 and DC2.315, two pan-protective yet poorly neutralizing human monoclonal antibodies (mAbs) that avidly bind to viral antigen on the surface of cells infected with arthritogenic and encephalitic alphaviruses. These mAbs engage a conserved epitope in domain II of the E1 protein proximal to and within the fusion peptide. Treatment with DC2.112 or DC2.315 protects mice against infection by both arthritogenic (chikungunya and Mayaro) and encephalitic (Venezuelan, Eastern, and Western equine encephalitis) alphaviruses through multiple mechanisms, including inhibition of viral egress and monocyte-dependent Fc effector functions. These findings define a conserved epitope recognized by weakly neutralizing yet protective antibodies that could be targeted for pan-alphavirus immunotherapy and vaccine design.
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Affiliation(s)
- Arthur S Kim
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Natasha M Kafai
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Emma S Winkler
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Theron C Gilliland
- Center for Vaccine Research and Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Emily L Cottle
- Center for Vaccine Research and Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - James T Earnest
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Prashant N Jethva
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Paulina Kaplonek
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Aadit P Shah
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Rachel H Fong
- Integral Molecular, Inc., Philadelphia, PA 19104, USA
| | | | - Ryan J Malonis
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jose A Quiroz
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Lauren E Williamson
- Vanderbilt Vaccine Center and Departments of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Lo Vang
- Emergent BioSolutions, Gaithersburg, MD 20879, USA
| | - Matthias Mack
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - James E Crowe
- Vanderbilt Vaccine Center and Departments of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Jonathan R Lai
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Galit Alter
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - William B Klimstra
- Center for Vaccine Research and Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Daved H Fremont
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63110, USA; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Michael S Diamond
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO 63110, USA.
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41
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Batra J, Mori H, Small GI, Anantpadma M, Shtanko O, Mishra N, Zhang M, Liu D, Williams CG, Biedenkopf N, Becker S, Gross ML, Leung DW, Davey RA, Amarasinghe GK, Krogan NJ, Basler CF. Non-canonical proline-tyrosine interactions with multiple host proteins regulate Ebola virus infection. EMBO J 2021; 40:e105658. [PMID: 34260076 DOI: 10.15252/embj.2020105658] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/23/2021] [Accepted: 07/09/2021] [Indexed: 01/08/2023] Open
Abstract
The Ebola virus VP30 protein interacts with the viral nucleoprotein and with host protein RBBP6 via PPxPxY motifs that adopt non-canonical orientations, as compared to other proline-rich motifs. An affinity tag-purification mass spectrometry approach identified additional PPxPxY-containing host proteins hnRNP L, hnRNPUL1, and PEG10, as VP30 interactors. hnRNP L and PEG10, like RBBP6, inhibit viral RNA synthesis and EBOV infection, whereas hnRNPUL1 enhances. RBBP6 and hnRNP L modulate VP30 phosphorylation, increase viral transcription, and exert additive effects on viral RNA synthesis. PEG10 has more modest inhibitory effects on EBOV replication. hnRNPUL1 positively affects viral RNA synthesis but in a VP30-independent manner. Binding studies demonstrate variable capacity of the PPxPxY motifs from these proteins to bind VP30, define PxPPPPxY as an optimal binding motif, and identify the fifth proline and the tyrosine as most critical for interaction. Competition binding and hydrogen-deuterium exchange mass spectrometry studies demonstrate that each protein binds a similar interface on VP30. VP30 therefore presents a novel proline recognition domain that is targeted by multiple host proteins to modulate viral transcription.
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Affiliation(s)
- Jyoti Batra
- J. David Gladstone Institutes, San Francisco, CA, USA.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.,Quantitative Biosciences Institute, University of California, San Francisco, CA, USA
| | - Hiroyuki Mori
- Department of Microbiology, NEIDL, Boston University School of Medicine, Boston, MA, USA
| | - Gabriel I Small
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Manu Anantpadma
- Department of Microbiology, NEIDL, Boston University School of Medicine, Boston, MA, USA
| | - Olena Shtanko
- Host-Pathogen Interactions, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Nawneet Mishra
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Mengru Zhang
- Department of Chemistry, Washington University School of Medicine, St. Louis, MO, USA
| | - Dandan Liu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Caroline G Williams
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Nadine Biedenkopf
- Institute of Virology, Philipps University of Marburg, Marburg, Germany
| | - Stephan Becker
- Institute of Virology, Philipps University of Marburg, Marburg, Germany
| | - Michael L Gross
- Department of Chemistry, Washington University School of Medicine, St. Louis, MO, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Robert A Davey
- Department of Microbiology, NEIDL, Boston University School of Medicine, Boston, MA, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Nevan J Krogan
- J. David Gladstone Institutes, San Francisco, CA, USA.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.,Quantitative Biosciences Institute, University of California, San Francisco, CA, USA
| | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
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42
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Wagner ND, Huang Y, Liu T, Gross ML. Post-HDX Deglycosylation of Fc Gamma Receptor IIIa Glycoprotein Enables HDX Characterization of Its Binding Interface with IgG. J Am Soc Mass Spectrom 2021; 32:1638-1643. [PMID: 33625217 PMCID: PMC8906513 DOI: 10.1021/jasms.1c00003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Protein glycosylation is a common and highly heterogeneous post-translational modification that challenges biophysical characterization technologies. The heterogeneity of glycoproteins makes their structural analysis difficult; in particular, hydrogen-deuterium exchange mass spectrometry (HDX-MS) often suffers from poor sequence coverage near the glycosylation site. A pertinent example is the Fc gamma receptor RIIIa (FcγRIIIa, CD16a), a glycoprotein expressed on the surface of natural killer cells (NK) that binds the Fc domain of IgG antibodies as a trigger for antibody-dependent cell-mediated cytotoxicity (ADCC). Here, we describe an adaptation of a previously reported method using PNGase A for post-HDX deglycosylation to characterize the binding between the highly glycosylated CD16a and IgG1. Upon optimization of the method to improve sequence coverage while minimizing back-exchange, we achieved coverage of four of the five glycosylation sites of CD16a. Despite some back-exchange, trends in HDX are consistent with previously reported CD16a/IgG-Fc complex structures; furthermore, binding of peptides covering the glycosylated asparagine-164 can be interrogated when using this protocol, previously not seen using standard HDX-MS.
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Affiliation(s)
- Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Yining Huang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285 United States
- Corresponding Authors: ,
| | - Tun Liu
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285 United States
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
- Corresponding Authors: ,
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43
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Wu C, Qavi AJ, Hachim A, Kavian N, Cole AR, Moyle AB, Wagner ND, Sweeney-Gibbons J, Rohrs HW, Gross ML, Peiris JSM, Basler CF, Farnsworth CW, Valkenburg SA, Amarasinghe GK, Leung DW. Characterization of SARS-CoV-2 nucleocapsid protein reveals multiple functional consequences of the C-terminal domain. iScience 2021; 24:102681. [PMID: 34095780 PMCID: PMC8168301 DOI: 10.1016/j.isci.2021.102681] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 05/13/2021] [Accepted: 05/28/2021] [Indexed: 12/13/2022] Open
Abstract
Nucleocapsid (N) encoded by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays key roles in the replication cycle and is a critical serological marker. Here, we characterize essential biochemical properties of N and describe the utility of these insights in serological studies. We define N domains important for oligomerization and RNA binding and show that N oligomerization provides a high-affinity RNA-binding platform. We also map the RNA-binding interface, showing protection in the N-terminal domain and linker region. In addition, phosphorylation causes reduction of RNA binding and redistribution of N from liquid droplets to loose coils, showing how N-RNA accessibility and assembly may be regulated by phosphorylation. Finally, we find that the C-terminal domain of N is the most immunogenic, based on antibody binding to patient samples. Together, we provide a biochemical description of SARS-CoV-2 N and highlight the value of using N domains as highly specific and sensitive diagnostic markers.
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Abraham J. Qavi
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Asmaa Hachim
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Niloufar Kavian
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Assistance Publique–Hôpitaux de Paris, Hôpital Universitaire Paris Centre, Centre Hospitalier Universitaire Cochin, Service d’Immunologie Biologique, Paris, France
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Aidan R. Cole
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Joyce Sweeney-Gibbons
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Henry W. Rohrs
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - J. S. Malik Peiris
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Division of Public Health Laboratory Sciences, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Christopher F. Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Christopher W. Farnsworth
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Sophie A. Valkenburg
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Daisy W. Leung
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
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44
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Illes-Toth E, Meisl G, Rempel DL, Knowles TPJ, Gross ML. Pulsed Hydrogen-Deuterium Exchange Reveals Altered Structures and Mechanisms in the Aggregation of Familial Alzheimer's Disease Mutants. ACS Chem Neurosci 2021; 12:1972-1982. [PMID: 33988976 DOI: 10.1021/acschemneuro.1c00072] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Mutations of the Amyloid Precursor Protein, from which the amyloid β peptide Aβ42 is cleaved, are associated with familial Alzheimer's disease. The disease-relevant familial mutations include the Arctic (E22G), Iowa (D23N), Italian (E22K), Dutch (E22Q), Japanese (D7N), English (D6R), and Flemish (A21G) variants. A detailed mechanistic understanding of the aggregation behavior of the mutant peptides at the residue level is, however, still lacking. We report here a study of the aggregation kinetics of these mutants in vitro by pulsed hydrogen-deuterium exchange mass spectrometry (HDX-MS) to obtain a temporally and sequence resolved picture of their self-assembly. For all variants, HDX occurs to give a bimodal distribution representing two soluble classes of aggregates, one protected and one solvent-exposed. There is no evidence of other classes of structural intermediates within the detection limits of the HDX approach. The fractional changes in the bimodal exchange profiles for several regions of Aβ42 reveal that the central and C-terminal peptides gain protection upon fibril formation, whereas the N-terminal regions remain largely solvent-accessible. For these mutants, all peptide fragments follow the same kinetics, acquiring solvent protection at the same time, further supporting that there are no significant populations of intermediate species under our experimental conditions. The results demonstrate the potential of pulsed HDX-MS for resolving the region-specific aggregation behavior of Aβ42 isoforms in solution where X-ray crystallography and solid-state NMR (ssNMR) are challenged.
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Affiliation(s)
- Eva Illes-Toth
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
| | - Georg Meisl
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
| | - Don L. Rempel
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
| | - Tuomas P. J. Knowles
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
| | - Michael L. Gross
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
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45
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Song JH, Wagner ND, Yan J, Li J, Huang RYC, Balog AJ, Newitt JA, Chen G, Gross ML. Native mass spectrometry and gas-phase fragmentation provide rapid and in-depth topological characterization of a PROTAC ternary complex. Cell Chem Biol 2021; 28:1528-1538.e4. [PMID: 34081921 DOI: 10.1016/j.chembiol.2021.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/17/2021] [Accepted: 05/07/2021] [Indexed: 01/24/2023]
Abstract
Proteolysis-targeting chimeras (PROTACs) represent a new direction in small-molecule therapeutics whereby a heterobifunctional linker to a protein of interest (POI) induces its ubiquitination-based proteolysis by recruiting an E3 ligase. Here, we show that charge reduction, native mass spectrometry, and gas-phase activation methods combine for an in-depth analysis of a PROTAC-linked ternary complex. Electron capture dissociation (ECD) of the intact POI-PROTAC-VCB complex (a trimeric subunit of an E3 ubiquitin ligase) promotes POI dissociation. Collision-induced dissociation (CID) causes elimination of the nonperipheral PROTAC, producing an intact VCB-POI complex not seen in solution but consistent with PROTAC-induced protein-protein interactions. In addition, we used ion mobility spectrometry (IMS) and collisional activation to identify the source of this unexpected dissociation. Together, the evidence shows that this integrated approach can be used to screen for ternary complex formation and PROTAC-protein contacts and may report on PROTAC-induced protein-protein interactions, a characteristic correlated with PROTAC selectivity and efficacy.
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Affiliation(s)
- Jong Hee Song
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jing Yan
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jing Li
- Bristol Myers Squibb Company, Research and Early Development, Princeton, NJ 08543, USA
| | - Richard Y-C Huang
- Bristol Myers Squibb Company, Research and Early Development, Princeton, NJ 08543, USA
| | - Aaron J Balog
- Bristol Myers Squibb Company, Research and Early Development, Princeton, NJ 08543, USA
| | - John A Newitt
- Bristol Myers Squibb Company, Research and Early Development, Princeton, NJ 08543, USA
| | - Guodong Chen
- Bristol Myers Squibb Company, Research and Early Development, Princeton, NJ 08543, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA.
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VanBlargan LA, Errico JM, Kafai NM, Burgomaster KE, Jethva PN, Broeckel RM, Meade-White K, Nelson CA, Himansu S, Wang D, Handley SA, Gross ML, Best SM, Pierson TC, Fremont DH, Diamond MS. Broadly neutralizing monoclonal antibodies protect against multiple tick-borne flaviviruses. J Exp Med 2021; 218:e20210174. [PMID: 33831142 PMCID: PMC8040518 DOI: 10.1084/jem.20210174] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/26/2021] [Accepted: 03/03/2021] [Indexed: 12/30/2022] Open
Abstract
Although Powassan virus (POWV) is an emerging tick-transmitted flavivirus that causes severe or fatal neuroinvasive disease in humans, medical countermeasures have not yet been developed. Here, we developed a panel of neutralizing anti-POWV mAbs recognizing six distinct antigenic sites. The most potent of these mAbs bind sites within domain II or III of the envelope (E) protein and inhibit postattachment viral entry steps. A subset of these mAbs cross-react with other flaviviruses. Both POWV type-specific and cross-reactive neutralizing mAbs confer protection in mice against POWV infection when given as prophylaxis or postexposure therapy. Several cross-reactive mAbs mapping to either domain II or III also protect in vivo against heterologous tick-transmitted flaviviruses including Langat and tick-borne encephalitis virus. Our experiments define structural and functional correlates of antibody protection against POWV infection and identify epitopes targeted by broadly neutralizing antibodies with therapeutic potential against multiple tick-borne flaviviruses.
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MESH Headings
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/immunology
- Antibodies, Neutralizing/administration & dosage
- Antibodies, Neutralizing/immunology
- Cell Line
- Chlorocebus aethiops
- Cross Reactions/immunology
- Encephalitis Viruses, Tick-Borne/drug effects
- Encephalitis Viruses, Tick-Borne/genetics
- Encephalitis Viruses, Tick-Borne/immunology
- Encephalitis Viruses, Tick-Borne/physiology
- Encephalitis, Tick-Borne/immunology
- Encephalitis, Tick-Borne/prevention & control
- Encephalitis, Tick-Borne/virology
- Epitopes/immunology
- HEK293 Cells
- Humans
- Immunoglobulin G/administration & dosage
- Immunoglobulin G/immunology
- Mice, Inbred C57BL
- Mutation
- Vero Cells
- Viral Envelope Proteins/immunology
- Viral Vaccines/administration & dosage
- Viral Vaccines/immunology
- Mice
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Affiliation(s)
- Laura A. VanBlargan
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - John M. Errico
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Natasha M. Kafai
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Katherine E. Burgomaster
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | | | - Rebecca M. Broeckel
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT
| | - Kimberly Meade-White
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT
| | - Christopher A. Nelson
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | | | - David Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO
| | - Scott A. Handley
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | | | - Sonja M. Best
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT
| | - Theodore C. Pierson
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Daved H. Fremont
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
- Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO
| | - Michael S. Diamond
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO
- Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO
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47
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Cheng M, Guo C, Li W, Gross ML. Free‐Radical Membrane Protein Footprinting by Photolysis of Perfluoroisopropyl Iodide Partitioned to Detergent Micelle by Sonication. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ming Cheng
- Department of Chemistry Washington University in St. Louis One Brookings Drive Saint Louis MO 63130 USA
- Current address: Department of Molecular Medicine The Scripps Research Institute La Jolla CA 92037 USA
| | - Chunyang Guo
- Department of Chemistry Washington University in St. Louis One Brookings Drive Saint Louis MO 63130 USA
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics Washington University School of Medicine St. Louis MO 63130 USA
| | - Michael L. Gross
- Department of Chemistry Washington University in St. Louis One Brookings Drive Saint Louis MO 63130 USA
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48
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Cheng M, Guo C, Li W, Gross ML. Free-Radical Membrane Protein Footprinting by Photolysis of Perfluoroisopropyl Iodide Partitioned to Detergent Micelle by Sonication. Angew Chem Int Ed Engl 2021; 60:8867-8873. [PMID: 33751812 PMCID: PMC8083173 DOI: 10.1002/anie.202014096] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/29/2020] [Indexed: 12/14/2022]
Abstract
A free-radical footprinting approach is described for integral membrane protein (IMP) that extends, significantly, the "fast photochemical oxidation of proteins" (FPOP) platform. This new approach exploits highly hydrophobic perfluoroisopropyl iodide (PFIPI) together with tip sonication to ensure efficient transport into the micelle interior, allowing laser dissociation and footprinting of the transmembrane domains. In contrast to water soluble footprinters, PFIPI footprints both the hydrophobic intramembrane and the hydrophilic extramembrane domains of the IMP vitamin K epoxide reductase (VKOR). The footprinting is fast, giving high coverage for Tyr (100 %) and Trp. The incorporation of the reagent with sonication does not significantly affect VKOR's enzymatic function, and tyrosine iodination does not compromise protease digestion and the subsequent analysis. The locations for the modifications are largely consistent with the corresponding solvent accessibilities, recommending this approach for future membrane protein footprinting.
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Affiliation(s)
- Ming Cheng
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Saint Louis, MO, 63130, USA
- Current address: Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Chunyang Guo
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Saint Louis, MO, 63130, USA
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Saint Louis, MO, 63130, USA
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49
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Pei J, Wagner ND, Zou AJ, Chatterjee S, Borek D, Cole AR, Kim PJ, Basler CF, Otwinowski Z, Gross ML, Amarasinghe GK, Leung DW. Structural basis for IFN antagonism by human respiratory syncytial virus nonstructural protein 2. Proc Natl Acad Sci U S A 2021; 118:e2020587118. [PMID: 33649232 PMCID: PMC7958447 DOI: 10.1073/pnas.2020587118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Human respiratory syncytial virus (RSV) nonstructural protein 2 (NS2) inhibits host interferon (IFN) responses stimulated by RSV infection by targeting early steps in the IFN-signaling pathway. But the molecular mechanisms related to how NS2 regulates these processes remain incompletely understood. To address this gap, here we solved the X-ray crystal structure of NS2. This structure revealed a unique fold that is distinct from other known viral IFN antagonists, including RSV NS1. We also show that NS2 directly interacts with an inactive conformation of the RIG-I-like receptors (RLRs) RIG-I and MDA5. NS2 binding prevents RLR ubiquitination, a process critical for prolonged activation of downstream signaling. Structural analysis, including by hydrogen-deuterium exchange coupled to mass spectrometry, revealed that the N terminus of NS2 is essential for binding to the RIG-I caspase activation and recruitment domains. N-terminal mutations significantly diminish RIG-I interactions and result in increased IFNβ messenger RNA levels. Collectively, our studies uncover a previously unappreciated regulatory mechanism by which NS2 further modulates host responses and define an approach for targeting host responses.
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Affiliation(s)
- Jingjing Pei
- John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO 63110
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110
| | - Angela J Zou
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Srirupa Chatterjee
- John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO 63110
| | - Dominika Borek
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Aidan R Cole
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Preston J Kim
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303
| | - Zbyszek Otwinowski
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Daisy W Leung
- John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO 63110;
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
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50
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Adhikari J, Zhao H, Fernandez E, Huang Y, Diamond MS, Fremont DH, Gross ML. Hydrogen-deuterium exchange mass spectrometry identifies spatially distinct antibody epitopes on domain III of the Zika virus envelope protein. J Mass Spectrom 2021; 56:e4685. [PMID: 36101787 PMCID: PMC9467453 DOI: 10.1002/jms.4685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/10/2020] [Indexed: 06/15/2023]
Abstract
Zika Virus (ZIKV) has become a global public health concern because it causes fetal microcephaly and other neurological complications in humans. Currently, there are no approved treatments or vaccines for ZIKV infection. We describe here the detailed epitopes for six monoclonal antibodies (mAbs) that bind to domain III of the envelope protein of ZIKV, some of which have therapeutic potential. We show that by using hydrogen-deuterium exchange mass spectrometry (HDX-MS), we can identify three spatially distinct epitopes for the six mAbs investigated. The HDX-MS approach identified epitopes for three mAbs that agreed well with recently reported X-ray crystallography data. The HDX-MS determined epitopes for the other three anti-ZIKV mAbs for which there were no crystal structures, and the epitopes were confirmed by structure-guided mutagenesis and biolayer interferometry (BLI) competition binding assay. Our results have implications for the design of vaccine and antibody therapeutics against ZIKV and demonstrate the use of HDX-MS as a rapid and valid approach for epitope mapping.
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Affiliation(s)
- Jagat Adhikari
- Department of Chemistry, Washington University in St. Louis, Saint Louis, Missouri, USA
| | - Haiyan Zhao
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Estefania Fernandez
- Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Yining Huang
- Department of Chemistry, Washington University in St. Louis, Saint Louis, Missouri, USA
- Present address: Eli Lilly and Company, Indianapolis, Indiana, USA
| | - Michael S Diamond
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
- Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
- Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, Missouri, USA
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Daved H Fremont
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
- Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, Missouri, USA
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, Saint Louis, Missouri, USA
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