Michael L. Gross

Michael L. Gross

​Professor of Chemistry and of Immunology and Internal Medicine (School of Medicine)
PhD, University of Minnesota
BA, St. John's University
research interests:
  • Analytical Chemistry
  • Biological Chemistry
  • Biophysical Chemistry
  • Mass Spectrometry-Based Protein Biochemistry and Biophysics
  • Protein Footprinting
  • Proteomics

contact info:

mailing address:

  • Washington University
    CB 1134
    One Brookings Dr.
    St. Louis, MO 63130-4899

Our main research goals are to develop mass-spectrometry-based methods and apply them in collaborations to understand proteins, their solvent accessibility, aggregation, interfaces, affinities of binding, and their folding. We emphasize three general problems: (1) amyloid protein aggregation (e.g., Ab in Alzheimer’s disease), (2) membrane protein conformational changes accompanying interactions with drugs, for example, and (3) viral proteins and their interactions with other proteins and RNA (e.g., Covid, Ebola infections). Additionally, we are extending our methods to understand structural changes in mRNA, motivated by the new mRNA vaccines.

Figure 1. Proteomics provides primary structure.
Footprinting gives insight on higher order structure.

Our subject area is called “structural proteomics”, a new branch of protein science. It builds on proteomics methods, now the principal means of determining primary structure (amino-acid sequence) of proteins, to elucidate secondary, tertiary, and quaternary structure (Figure 1) by “decorating” the proteins with chemical reactions. Although our methods do not afford atomic coordinates, they are well suited to determine changes in structure and conformation that occur upon binding, changes in pH or heating, or mutation. Moreover, they are sensitive and have good throughput.  

Figure 2. FPOP schematic. Fast footprinting occurs at the junction of laser beam and protein flow where the native protein structure is modified by fast reactions.

FPOP:  One approach for footprinting is to map proteins with reactions of •OH radicals. We termed our version “fast photochemical oxidation of proteins” or FPOP whereby certain surface-accessible amino-acid residues are modified by chemical reactions conducted on the microsecond timescale in a flow tube. The reactive species are generated by pulsed photolysis of H2O2 by a pulsed KrF laser (248 nm). With appropriate scavengers, the reaction time is controlled. FPOP is useful for determining protein-protein interfaces, affinities for tiny amounts of proteins in biophysics, drug discovery, and epitope mapping.  FPOP is being adopted by biotechnology companies for quality control of protein therapeutics.

Figure 3. FPOP extended to footprinting membrane proteins where the reactive footprinters are producd by irradiation of a TiO2 nanoparticle attached to membrane. The membrane is kinked by a photochemical reaction open the membrane so that the radical can enter and react with the embedded protein.

Membrane Proteins:  We are extending FPOP to membrane proteins that are difficult to determine by X-ray, NMR, and CryoEM because they are not water soluble and are unstable outside the membrane. Instead of generating the radical from H2O2, we attach a nanoparticle to a liposome (or a living cell). By irradiating it with the FPOP laser, we produce OH radicals adjoining the liposome and admit them to the membrane by perturbing it by a chemical reaction initiated by the footprinting laser. Footprinting can use many other reactions, and we are developing new reactions and new methods and applying these reactions to difficult problems.  For example, for fast labeling, we are expanding to carbenes and carbocations. For specific amino-acid footprinting, we use labeling with NEM (N-ethylmaleimide) to follow changes in the local environment of Cys, GEE (glycyl ethyl ester) to monitor changes of Asp and Glu, for example.

Hydrogen/deuterium exchange (HDX):  HDX is another focus where we develop new methods and use them in problem solving.  Examples are pulsed HDX for following aggregation of Aβ, the plaque-forming protein in Alzheimer’s disease, and pH-dependent HDX for monitoring protein conformational changes as pH decreases.  We also developed an HDX titration platform to determine protein-ligand affinities, a method we call PLIMSTEX (Protein Ligand Interaction by Mass Spectrometry, Titration and H/D Exchange). We wish to apply this to determining affinities for specific regions of proteins, which is difficult by standard measurements. As an example, Figure 4 shows a convincing example of how the protein calmodulin binds Ca2+ to alternately tighten or protect some regions (purple), expose other regions (gold), and have no effect on others (gray).

Figure 4. HDX of calmodulin after binding 4 Ca2+ ions. The experiment reveals the binding sites (loops that change conformation to bind Ca2+ and those helices that open to allow binding to other ligands and serve as a messenger.

Crosslinking, Native MS, Ion Mobility:  We also utilize chemical cross linking and native electrospray with ion mobility, where near-native forms of a protein or a protein complex are introduced into a mass spectrometer. We discovered that activating the entire complex by electron-capture dissociation (ECD) causes flexible regions of the constituent proteins to fragment. We complement these measurements with native MS, to examine stoichiometry of protein complexes, collisionally induced unfolding, to observe conformational change, and chemical cross linking, to determine topology of the complex.

 

This research prepares graduate and postdoctoral student to enter academics or biopharma and biotechnology labs, where scores of former coworkers now work.

Examples of applications are ongoing collaborations with

  • Carl Frieden and Greg DeKoster (WU Biochemisty and Molecular Biophysics or BMB), Thomas Brett (WU Medicine), and Andrew Yoo (Developmental Biology) on amyloids.
  • Weikai Li (BMB) on membrane proteins,
  • Gaya Amarasinghe, Daisy Leung, and Daved Fremont (WU Immunology) on viral proteins,
  • Leah Wang and Brian Gau (Pfizer) on structural changes of mRNA

Selected Publications (of 710 articles and book chapters):

  1. Evaluating Chemical Footprinting-Induced Perturbation of Protein High Order Structure, Wesley Wagner, Austin Moyle, Nicole Wagner, Don Rempel, Michael L. Gross, Analytical Chemistry, 96, 9693-9703 (2024)
  2. Hydrogen/Deuterium Exchange Mass Spectrometry Provides Insights into the role of Drosophila testis-specific Myosin VI light chain AndroCaM, Jing Li, Prashant N. Jethva, Henry W. Rohrs, Saketh Chemuru, Kathryn Miller, Michael L. Gross, Kathleen M. Beckingham, Biochemistry, 63, 610-624 (2024).
  3. An exploration of Resveratrol as a potent modulator of α-synuclein fibril formation, Eva Illes-Toth, Don L Rempel, Michael L Gross, ACS Chemical Neuroscience, 15, 503-516 (2024).
  4. Using Mass Spectrometry-Based Methods to Understand the Amyloid Formation and Inhibition of Alpha-Synuclein and Amyloid Beta, Wesley J. Wagner and Michael L. Gross, Mass Spectrometry Reviews, 43: 782–825 (2024).
  5. Development of a High-throughput Mass Spectrometry-based Sars-Cov-2 Immunoassay, Jie Sun, Jong Hee Song, Mary Danielson, Nathan Colley, Alia Thomas, David Hambly, Jonathan Barnes, Michael L. Gross, Analytical Chemistry, 96, 12-17 (2024).
  6. A broadly reactive antibody targeting the N-terminal domain of SARS-CoV-2 spike confers Fc-mediated protection, Lucas J. Adams, Laura A. VanBlargan, Zhuoming Liu, Pavlo Gilchuk, Haiyan Zhao, Rita E. Chen, Saravanan Raju, Zhenlu Chong, Bradley M. Whitener, Swathi Shrihari, Prashant N. Jethva, Michael L. Gross, James E. Crowe, Jr., Sean P.J. Whelan, Michael S. Diamond, and Daved H. Fremont, Cell Reports Medicine, 4,101305 (2023).
  7. Antibody Binding Captures High Energy State of an Antigen: The Case of Nsp1 SARS-CoV-2 as Revealed by Hydrogen–Deuterium Exchange Mass Spectrometry, Ravi Kant, Nawneet Mishra, and Michael L Gross, Int. J. Mol. Sci., 24, 17342. Precursor Reagent Hydrophobicity Affects Membrane Protein Footprinting, Chunyang Guo, Ming Cheng, Weikai Li, Michael L. Gross, J. Am. Soc. Mass Spectrom., 34, 2700-2710 (2023).
  8. Characterization of Higher Order Structural Changes of a Thermally Stressed Monoclonal Antibody via Mass Spectrometry Footprinting and Other Biophysical Approaches, Yanchun Lin, Austin B. Moyle, Victor A. Beaumont, Lucy L. Liu, Sharon Polleck, Haijun Liu, Heliang Shi, Jason C. Rouse, Hai-Young Kim, Ying Zhang, Michael L. Gross, Anal. Chem., 95,16840-16849 (2023).
  9. The intricacies of Ebola NP0VP35 formation of inclusion body-like structures and their disruption reducing viral infection, Chao Wu, Nicole Wagner, Austin B. Moyle, Annie Feng, Nitin Sharma, Sarah H. Stubbs, Callie Donahue, Robert Davey, Michael L. Gross, Daisy W. Leung, and Gaya K. Amarasinghe, Journal of Molecular Biology, 435, 168241 (2023).
  10. A Workflow for Validating Specific Amino Acid Footprinting Reagents for Protein HOS Elucidation, Austin B. Moyle, Nicole D. Wagner, Wesley J. Wagner, Ming Cheng, Michael L. Gross, Anal. Chem., 95, 10119-10126 (2023).
  11. Biochemical and HDX mass spectral characterization of the SARS-CoV-2 Nsp1 protein, Nawneet Mishraa, Ravi Kant, Daisy W. Leung, Michael L. Gross, and Gaya K. Amarasinghe, Biochemistry, 62, 1744-1754 (2023).
  12. Hydrogen Deuterium Exchange and other Mass Spectrometry-based Approaches for Epitope Mapping, Prashant N. Jethva and Michael L Gross, (Invited Review) Frontiers Anal. Sci. Volume 3 (2023).
  13. Antigenic landscapes on Staphylococcus aureus pore-forming toxins reveal insights into specificity and cross-neutralization, Shweta Kailasan, Ravi Kant, Madeleine Noonan-Shueh, Tulasikumari Kanipakala, Grant Liao, Sergey Shulenin, Daisy W. Leung, Richard A. Alm, Rajan P. Adhikaria, Gaya K. Amarasinghe, Michael L. Gross, and M. Javad Aman, mAbs, 14, e2083467: 1-17, (2022).
  14. Advances in Mass Spectrometry-Based Footprinting of Membrane Proteins (invited review), Jie Sun, Weikai Li, and Michael L. Gross, Proteomics, 22, e2100222 (2022)
  15. Isolation of a potently neutralizing and protective human monoclonal antibody targeting yellow fever virus, Michael P. Doyle, Joseph R. Genualdi, Adam L. Bailey, Nurgun Kose, Christopher Gainza, Jessica Rodriguez, Kristen M. Reeder, Christopher A. Nelson, Prashant N. Jethva, Rachel E. Sutton, Robin G. Bombardi, Michael L. Gross, Justin G. Julander, Daved H. Fremont Michael S. Diamond, James E. Crowe Jr.  Mbio, e00512-22 (2022).
  16. Benzoyl Transfer for Footprinting Alcohol-Containing Residues in Higher Order Structural Applications of Mass-Spectrometry-Based Proteomics, Austin B. Moyle, Ming Cheng, Nicole D. Wagner, Michael L. Gross, Anal. Chem. 94, 1520-1524 (2022).
  17. Nipah Virus V Protein Binding Alters MDA5 Helicase Folding Dynamics, Nicole Wagner, Hejun Liu, Henry Rohrs, Gaya Amarasinghe, Michael L Gross, Daisy Leung, ACS Infectious Diseases, ACS Infect. Dis., 8, 118−128 (2022).
  18. Nanoparticles and Photochemistry for Native-like Transmembrane Protein Footprinting Nanoparticles and Photochemistry for Native-like Transmembrane Protein Footprinting, Jie Sun, Xiaoran Roger Liu, Shuang Li, Peng He, Weikai Li, and Michael L. Gross, Nature Commun, 12, 7270 (2021).
  19. Diethylpyrocarbonate Footprints a Membrane Protein in Micelles, Chunyang Guo, Ming Cheng, Weikai Li, Michael L. Gross, J. Amer. Soc. Mass Spectrom., 32, 2636-2643 (2021).
  20. Carbocation Footprinting of Soluble and Transmembrane Proteins, Jie Sun, Shuang Li, Weikai Li, and Michael L. Gross, Anal. Chem., 93,13101-13105 (2021).
  21. Footprinting Mass Spectrometry of Membrane Proteins: Ferroportin Reconstituted in Saposin A Picodiscs, Fengbo Zhou, Yihu Yang, Saketh Chemuru, Weidong Cui, Shixuan Liu, Michael Gross, and Weikai Li, Anal. Chem., 93, 11370–11378 (2021).
  22. Pan-protective anti-alphavirus human antibodiestarget a conserved E1 protein epitope, Arthur S. Kim, Natasha M. Kafai, Emma S. Winkler, Theron C. Gilliland, Jr., Emily L. Cottle, James T. Earnest, Prashant N. Jethva, Paulina Kaplonek, Aadit P. Shah, Rachel H. Fong, Edgar Davidson, Ryan J. Malonis, Jose A. Quiroz, Lauren E. Williamson, Lo Vang, Matthias Mack, James E. Crowe, Jr., Benjamin J. Doranz, Jonathan R. Lai, Galit Alter, Michael L. Gross, William B. Klimstra, Daved H. Fremont, Michael Diamond, Cell, 184, 414-4429 (2021).
  23. Characterization of SARS-CoV-2 N protein reveals multiple functional consequences of the C-terminal domain, Chao Wu, Abraham J Qavi, Asamaa Hachim, Niloufar Kavian, Aidan R Cole, Austin B Moyle, Nicole D Wagner, Joyce Sweeney-Gibbons, Henry W Rohrs, Michael L Gross, J S Malik Peiris, Christopher F Basler, Christopher W Farnsworth, Sophie A Valkenburg, Gaya K Amarasinghe, Daisy W Leung, iScience 24, 102681 (2021).
  24. Native Mass Spectrometry and Gas-phase Fragmentation Provide Rapid and In-depth Topological Characterization of a PROTAC Ternary Complex, Jong Hee Song, Nicole D. Wagner, Jing Yan, Jing Li, Richard Y.-C. Huang, Aaron J. Balog, John A. Newitt, Guodong Chen, and Michael L. Gross, Cell Chemical Biology, 28, 1528-1538 (2021).
  25. Pulsed Hydrogen−Deuterium Exchange Reveals Altered Structures and Mechanisms in the Aggregation of Familial Alzheimer’s Disease Mutants, Eva Illes-Toth, Georg Meisl, Don L. Rempel, Tuomas P. J. Knowles, and Michael L. Gross, ACS Chemical Neuroscience, 12, 1972-1982 (2021).
  26. Free-Radical Membrane Protein Footprinting by Photolysis of Perfluoroisopropyl Iodide Partitioned to Detergent Micelle by Sonication, Ming Cheng, Chunyang Guo, Weikai Li, and Michael L Gross, Angewandte Chemie, Int Ed Engl, 16, 8867-8873 (2021).
  27. Protein higher-order-structure determination by fast photochemical oxidation of proteins and mass spectrometry analysis. Xiaoran Roger Liu, Don L Rempel, and Michael L. Gross, Nature Protocols, 15, 3942-3970 (2020). 
  28. Uncovering a membrane-distal conformation of KRAS available to recruit RAF to the plasma membrane, Ben Niu (…),  Michael L. Gross (…), and Andrew G. Stephen, Proceedings of the National Academy of Sciences of the USA, 117, 24258-24268 (2020).
  29. Calcium Binding to the Innate Immune Protein Human Calprotectin Revealed by Integrated Mass Spectrometry, Jagat Adhikari, Jules R. Stephan, Don L. Rempel, Elizabeth M. Nolan, and Michael L. Gross, J. Am. Chem. Soc., 142, 31, 13372–13383 (2020).
  30. Fast Protein Footprinting by X-ray Mediated Radical Trifluoromethylation, Ming Cheng, Awuri Asuru, Janna Kiselar, George Mathai, Mark R. Chance, and Michael L. Gross, J. Amer. Soc. Mass Spectrom., 31,1019-1024 (2020).
  31. Site-Specific Siderocalin Binding to Ferric and Ferric-Free Enterobactin as Revealed by Mass Spectrometry, Chunyang Guo, Lindsey K. Steinberg, Ming Cheng, Jong Hee Song, Jeffrey P. Henderson, Michael L. Gross, ACS Chemical Biology, 15, 1154-1160 (2020).
  32. Mass Spectrometry-Based Protein Footprinting for Higher Order Structure Analysis: Fundamentals and Applications, Xiaoran Roger Liu, Mengru Mira Zhang, and Michael L. Gross, Chemical Reviews, 120, 10, 4355-4454 (2020).
  33. The Cap-Snatching SFTSV Endonuclease Domain is an Antiviral Target, Wenjie Wang, Woo Jin Shin, Bojie Zhang, Younho Choi, Ji Seung Yoo, Maxwell I. Zimmerman, Thomas E. Frederick, Gregory R. Bowman, Michael L. Gross, Daisy W. Leung, Jae U. Jung, Gaya K. Amarasinghe, Cell Reports, 30, 153-163.e5 (2020).
  34. The Application of FluorineContaining Reagents in Structural Proteomics, Ming Cheng, Chunyang Guo, and Michael L. Gross, Angewandte Chemie-International Edition, 59, 5880-5889 (2020).
  35. Protein Footprinting and X-ray Crystallography Reveal the Interaction of PD-L1 and a Macrocyclic Peptide, Ben Niu, Todd C. Appleby, Ruth Wang, Mariya Morar, Johannes Voight, Armando G. Villaseñor, Sheila Clancy, Sarah Wise, Jean-Philippe Belzile, Giuseppe Papalia, Melanie Wong, Katherine M. Brendza, Latesh Lad, and Michael L. Gross, Biochemistry, 59, 541-551 (2020).

Selected Awards:

2021

A Special Issue Dedicated to the Outstanding Scientific Career of Michael L. Gross

Mass Spectrometry Reviews, 40(3), 159-305 (2021), edited by Yinsheng Wang and David Russell.

2020

John Fenn Award for a Distinguished Contribution

American Society for Mass Spectrometry

2018

ACS Award in Analytical Chemistry

American Chemical Society

2017

Election as Fellow to AAAS

American Association for the Advancement of Science

2013

EAS Award for Achievements in Mass Spectrometry

Eastern Analytical Symposium

2012

Wolfgang Paul Lectureship

Mass Spectrometry Societies of Germany and Poland, Poznan

2011

Honorary Lifetime Membership

Mass Spectrometry Society of Japan

2006

J.J. Thomson Medal for Service to Int’l MS

Foundation for International Mass Spectrometry

2004&5

Excellence in Mentoring Award

Washington Univ. Grad. Student Senate

2002

Midwest Award for Achievements in Chemistry

American Chemical Society

2001&2

Outstanding Mentor Award

Washington Univ. Grad. Student Senate

1999

Field and Franklin Award

American Chemical Society

1996

Guest Faculty

NATO School on Biol. Mass Spectrometry

1995

Pioneers in Chemistry Series

Texas A&M University

1993

Honorary Lifetime Member

Indian Society for Mass Spectrometry

1992

Recognized as 50 Most Cited Chemists, 1984-1991

“The World's 50 Most Cited Chemists" Ranked by Total Citations, 1984-1991", Science Watch, 3[4], May 1992.

1990

Van’t Hoff Visiting Professor

Int’l Graduate School, University of Amsterdam

1990

Guest Professor and Scientific Organizer

NATO Adv. Study Inst. in Biol. Mass Spectrometry

1988

Albright & Wilson Visiting Professor

University of Warwick

1987

Pioneer Award

Commonwealth of Mass “In Search for the Health Consequences of Dioxin in Our Environment.”

1978

Amoco Teaching Medal

University of Nebraska-Lincoln