Characterizing modified peptides by high-resolution FAIMS followed by electron transfer dissociation
Baird, Matthew A.
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Baird, Matthew & Pang, Xueqin. 2016. Characterizing modified peptides by high-resolution FAIMS followed by electron transfer dissociation. --In Proceedings: 12th Annual Symposium on Graduate Research and Scholarly Projects. Wichita, KS: Wichita State University, p. 21
Full characterization of proteins in living organisms, which is crucial to understanding biomedical processes, remains a stupendous analytical challenge. That especially holds for posttranslational modifications, which influence the protein structure and thus function. The localization variants (isomers with identical PTMs on different residues) that commonly co-exist in vivo are particularly problematic. While electron transfer dissociation (ETD) has greatly advanced PTM analyses, only two variants in a mixture are detectable. Here we present a novel approach to resolve and identify variants: field asymmetric waveform ion mobility spectrometry (FAIMS) coupled to ETD. We implemented that on a Thermo LTQ XL ion trap mass spectrometer employing a custom high-definition FAIMS system using helium/nitrogen gas buffers. The resulting broad variant separations allow analyses of complex variant mixtures for small and medium-sized peptides. The method is demonstrated for the phosphopeptides from the tau-protein relevant to Alzheimer's and the D- and L- stereoisomers of neuropeptides.
Presented to the 12th Annual Symposium on Graduate Research and Scholarly Projects (GRASP) held at the Heskett Center, Wichita State University, April 29, 2016.
Research completed at Department of Chemistry, Fairmount College of Liberal Arts and Sciences and Department of Chemistry, School of Pharmacy, University of Wisconsin.