2P-01 PDF
Analysis of oxidation reactions of peptides using collision-induced dissociation of multiply-charged analytes [A+nH]n+
Collision-induced dissociation (CID) combined with ESI was used for the analysis of multiply-charged peptides [A+nH]n+ (n=3~6). The CID product ions originated from a peptide ACTH1-17 (SYSMEHFRWGKPVGKKR, Mm 2092.1) were assigned on the basis of CID characteristics such as the proline effect, the charge-mediated selective cleavages at Asp/Glu/Cys-Xxx residues, and the ”mobile proton”. Oxidation sites of ACTH1-17 were assigned by CID product ions. Low-energy CID spectra of peptide obtained with and without oxidation treatments showed multiply-charged analyte ions [A+nH]n+ and [A+mO+nH]n+ (n=3~6, m=3~6). The sites of oxidation were histidine, phenylalanine and methionine residues of analytes.