Abstract

Poster Presentations

Day 2, June 23（Mon.）　

Room P (Maesato East, Foyer, Ocean Wing)

2P-PM-43
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Advanced De Novo Peptide Sequencing Using N-terminal Coumarin Derivatization Aided LC-MS/MS for Peptidomics Analysis

(Kyushu Univ.)
^oMitsuru Tanaka, Hui Luan, Fumiya Honda, Yizhi Xiao, Risa Katagihara, Ryosuke Kaneko, Toshiro Matsui

De novo peptide sequencing is an analytical technique that determines amino acid sequences directly from MS/MS spectrum without relying on sequence databases. This approach possesses significant potential for discovering novel peptides and their metabolic pathways through untargeted peptidomics. In this study, we aim to develop a novel peptide derivatization method that can generate adequate fragment ions to achieve accurate sequence determination using LC-MS/MS.
In this study, an N-terminal derivatization method, N-succinimidyl 7-methoxy-coumarin-3-carboxylate (Met-Cou), showed all b-ions of tetrapeptide (Gly)₄ including the derivatized tag (b_0-3) by LC-MS/MS, which allowed a successful peptide sequencing. The Met-Cou-aided LC-MS/MS analysis of (Gly)₁₀ also resulted in the generation of all series of b_1-9-ion fragments, which demonstrated the successful sequencing of peptides with the length at least 10 residues. Furthermore, a mixture of 65 standards, including 57 dipeptides, and 8 oligopeptides (3-5 residues) was also successfully determined by the present Met-Cou-aided LC-MS/MS analysis, but not by non-derivatized LC-MS/MS analysis.
In conclusion, the present study demonstrated that Met-Cou-aided LC-MS/MS analysis could generate a series of b-ion fragments of peptides, which facilitate de novo peptide sequence. The present de novo peptide sequencing method can be an innovative technique for peptidomics analysis.