Michael Marty

Associate Professor, Chemistry and Biochemistry-Sci

Assistant Professor, BIO5 Institute

Assistant Professor, Chemistry and Biochemistry - Med

Member of the Graduate Faculty

My research program focuses on the characterization of the structure, biophysics, and interactions of membrane proteins and peptides by mass spectrometry and builds upon my background in biochemistry and analytical chemistry. As a graduate student, I worked with Prof. Stephen Sligar at the University of Illinois Urbana-Champaign to interface nanodiscs, self-assembled nanoscale lipoprotein complexes, with various analytical techniques including photonic microring resonator biosensors and mass spectrometry (MS). I also developed new methods for forming and characterizing nanodiscs using heterogeneous populations of membrane proteins. Through a collaboration with Prof. Michael Gross (Washington University, St. Louis) to perform native MS on nanodiscs, I was the first to show that nanodiscs could be maintained intact in the gas phase for native MS. As a postdoc with Prof. Dame Carol Robinson at the University of Oxford, I continued this vein of research but shifted my focus to native MS of membrane protein oligomers in nanodiscs. Challenging data motivated me to develop new MS data analysis algorithms and software that have since been widely adopted in the field. Combining new data analysis approaches with advances in high-mass Orbitrap instrumentation, I discovered that membrane protein oligomers ejected from nanodiscs retain a large number of bound lipids. I found that the stoichiometry of lipids bound to the membrane protein agrees with simulations for various shells of lipid interactions, including the lipid annular belt. Building on these results, I led a study to characterize nanodiscs with heterogeneous lipid populations by native MS, which has been further expanded to a wide range of lipids by my independent research group. I began my independent research laboratory in the Department of Chemistry and Biochemistry at the University of Arizona in 2016. To advance nanodiscs as a platform for native MS, my research group engineered a series of mutant membrane scaffold proteins that facilitate the interpretation of mass spectra from membrane protein nanodiscs. I have also continued development of UniDec software, adding new features for high-throughput deconvolution of native MS data and improvements to the deconvolution algorithm to reduce artifacts. Combining these techniques, we discovered that charge manipulation reagents provide a powerful tool for manipulating the gas-phase stability of nanodiscs. We were the first to measure the mass of an intact nanodisc with a membrane protein inside, which revealed the oligomeric state of the membrane protein without disrupting the membrane. We then applied native MS of intact nanodiscs to characterize interactions of antimicrobial peptides with nanodiscs containing different lipids. Our novel approach revealed a wide range of different types of peptide-peptide and peptide-lipid interactions between different antimicrobial peptides.

Offering Research Opportunities?

Yes

Prerequisite Courses

None

Majors Considered

Chemistry Biochemistry Computer Science

Types of Opportunities

Description of Opportunity

No description given

Start Date

January 2017

Primary Department

Affiliated Departments

Research Location