Li, Yinan and Martens, Jonathan and Tang, Wai Kit and Berden, Giel and Oomens, Jos and Chu, Ivan K. (2024) Characterization of glycylglycyltyrosine radical cations: Insights into R-radical formation and N-Cα peptide bond dissociation at the tyrosine residue. International Journal of Mass Spectrometry, 506. ISSN 1387-3806, DOI https://doi.org/10.1016/j.ijms.2024.117351.
Full text not available from this repository.Abstract
We investigated the dissociation and characterization of radical cations of glycylglycyltyrosine GGY](center dot+), focusing on R- radical-induced N-C alpha alpha peptide bond cleavage reactions at the tyrosyl residue. By combining density functional theory (DFT) calculations with experimental studies utilizing low-energy collision-induced dissociation (CID) mass spectrometry and deuterium labeling on the two R- hydrogen atoms of the tyrosyl residue in GGY](center dot+) we elucidated the intricacies of the R- radical structure and its origin. Unlike tryptophan-containing GGW](center dot+), which forms canonical it-radical precursors, infrared multiphoton dissociation (IRMPD) spectroscopy results reveal that the R- radical GGY(R)(center dot)](+) isomerizes from the phenoxy-radical GGY(o)(center dot)](+), with the radical localized on the R- carbon of the tyrosyl residue and the phenolic oxygen atom, respectively. The isomerization barriers from GGY(o)(center dot)](+) to GGYR(center dot)](+) are <109 kJ mol(-1) .
| Item Type: | Article |
|---|---|
| Funders: | Hong Kong Research Grants Council [Grant No: HKU 17303821 ; HKU 17304919], HKU Research Computing Facilities (HPC/HTC/AI platform) , the University of Hong Kong, Netherlands Organization for Scientific Research (NWO), Universiti Malaya, Shandong Science and Technology Department, Shandong Public Health Clinical Center Affiliated to Shandong University |
| Uncontrolled Keywords: | Gas-phase; Multiphoton ionization; Electron transfer |
| Subjects: | Q Science > QC Physics |
| Divisions: | Faculty of Science > Department of Chemistry |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 03 Nov 2025 07:48 |
| Last Modified: | 03 Nov 2025 07:48 |
| URI: | http://eprints.um.edu.my/id/eprint/46334 |
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