Using Hydrogen/Deuterium exchange and native mass spectrometry to study peptide antibiotics biosynthesis


Macdonald-Stewart Building MS2-022, 21111 Lakeshore Road, St Anne de Bellevue, QC, H9X 3V9, CA

Applied Mass Spectrometry Workshops. This talk is opened to anyone interested in learning more about Mass Spectrometry and its applications will obtain a great deal from these monthly workshops.

Guest speaker: Dr. Christopher Thibodeaux, Department of Chemistry, McGill University.

This lecture will focus on the application of mass spectrometry to study the involvement of protein conformational changes in biosynthetic enzyme function. Specifically, I will discuss the use of hydrogen/deuterium exchange mass spectrometry (HDX-MS) and native mass spectrometry coupled to ion mobility separations. HDX-MS measures how perturbations (substrate binding, mutagenesis, etc.) alter the exchange rate of solvent deuterium into the backbone amide moiety of proteins. This exchange rate is largely a function of protein secondary structure and, thus, provides information on the location of substrate binding sites and other perturbation-induced structural changes in the protein. In native mass spectrometry, proteins (or non-covalently bound protein-substrate complexes) are transferred from solution into the gas phase in a natively folded state using nano-electrospray ionization. Once in the gas phase, the conformational distribution of the folded protein can be probed by ion mobility separations. The parameters derived from these measurements can then be correlated to structural parameters derived from other techniques in order to build mechanistic models for the involvement of protein conformational changes in enzyme function. Finally, I will discuss how my lab is applying HDX-MS and native MS approaches to study the multifunctional enzymes involved in peptide natural product biosynthesis.


Christopher J. Thibodeaux is a native of Louisiana, where he graduated valedictorian with bachelor's degrees in Biochemistry, Botany, and Chemistry from Louisiana State University. He then entered graduate school in the lab of Hung-wen Liu at the University of Texas, Austin, where his Ph.D. focused on elucidating the chemical and kinetic mechanisms of enzyme catalysis. Following graduation, he had postdoctoral stints in the labs of Taekjip Ha and Wilfred van der Donk at the University of Illinois, Urbana-Champaign, where he studied biomolecular single molecule fluorescence spectroscopy and peptide natural product biosynthesis, respectively. In 2016, he began his independent career in the Chemistry Department at McGill University, where he is currently an assistant professor. His research is broadly aimed at combatting the problem of antimicrobial resistance by understanding the detailed molecular mechanisms of enzymes that synthesize structurally complex antimicrobial compounds, discovering novel antimicrobial compounds by genome mining, and by investigating the mechanisms used by bacteria to establish biofilms.