Localizing Isomerized Residue Sites in Peptides with Tandem Mass Spectrometry.

ABSTRACT: Isomerized amino acid residues have been identified in many peptides extracted from tissues or excretions of humans and animals. These isomerized residues can play key roles by affecting biological activity or by exerting an influence on the process of aging. Isomerization occurs spontaneously and does not result in a mass shift. Thus, identifying and localizing isomerized residues in biological samples is challenging. Herein, we introduce a fast and efficient method using tandem mass spectrometry (MS) to locate isomerized residues in peptides. Although MS² spectra are useful for identifying peptides that contain an isomerized residue, they cannot reliably localize isomerization sites. We show that this limitation can be overcome by utilizing MS³ experiments to furthe

SUBMITTER: Wu HT 

PROVIDER: S-EPMC10995990 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature