Postdoctoral Fellowship: MPS-Ascend: Elucidation of Peptide Scrambling in Collision Induced Dissociation: Energetic and Mechanistic Analysis via Guided Ion Beam Mass Spectrometry

Evan H. Perez is awarded an NSF Mathematical and Physical Sciences Ascending Postdoctoral Research Fellowship (NSF MPS-Ascend) to conduct a program of research and activities related to broaden participation by groups underrepresented in STEM. This fellowship to Dr. Perez supports the research project entitled “MPS-Ascend: Elucidation of Peptide Scrambling in Collision Induced Dissociation: Energetic and Mechanistic Analysis via Guided Ion Beam Mass Spectrometry” under the mentorship of a sponsoring scientist. The host institution for the fellowship is the University of Utah, and the sponsoring scientist is Dr. Peter B. Armentrout. This proposal seeks to deepen the understanding of peptide fragmentation and rearrangement mechanisms by using Guided Ion Beam Mass Spectrometry to observe energy-resolved collision events and model these energies using electronic structure calculations. The proposal will use polyglycine polymer ions to perform competitive threshold analysis and electronic structure calculations to elucidate the key chemical pathways for the observed fragmentation events. The proposed research will investigate the role of the peptide length from tetraglycine up to hexaglycine in the formation of macrocyclic structures which precedes the intramolecular fragmentation events known as “scrambling.” The work will implement traveling wave ion mobility SLIM (Structures for Lossless Ion Manipulation) experiments to allow for conformation specific fragmentation analysis as well as conformer analysis of the fragment ions. The proposed studies will enable comparison of fragmentation methods (hard single collision versus soft collisional heating) and correlation of conformation with mechanism. Successful implementation of this work may lead to improved understanding of peptide sequencing by mass spectrometry which could have significant impacts on determining protein sequences and advancing the proteomics field. The PI plans to mentor undergraduate and graduate students from underrepresented minority groups in research projects involving training in mass spectrometric techniques and learning quantum chemical calculations. The PI intends to participate with the STEM Action Center of the University of Utah in potential recruiting activities and mentoring of students from underrepresented groups. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.