Abstract

Innovative Methods and Mass Spectrometry Instrumentation for the Characterization of Proteins and MHC Peptides

Donald Hunt, Professor, University of Virginia

This lecture will focus on data generated with a new ion source that facilitates simultaneous generation of positively charged sample ions by electrospray ionization and negatively charged reagent ions for both electron transfer dissociation (ETD) and ion-ion proton transfer (IIPT) reactions on Orbitrap mass spectrometers. Implementation of multiple C-trap fills for enhanced sensitivity will be discussed and both peak parking, and ion ejection strategies to facilitate protein separation and enhanced sequence coverage of intact proteins will be described. Use of IIPT/ETD facilitates near complete sequence coverage on many intact proteins and is ideally suited for locating multiple posttranslational modifications on the same protein molecule. Sequence analysis of antibodies with an enzyme that generates 10 KDa fragments will be presented. Since dysregulation of cell signaling pathways is a hallmark of cancer, we hypothesized that class I MHC phosphopeptides that result from these pathways should be excellent candidates for use in the immunotherapy of cancer.  Recent results will be discussed.