Influence of basic residues on dissociation kinetics and dynamics of singly protonated peptides: time-resolved photodissociation study

✍ Scribed by So Hee Yoon; Jeong Hee Moon; Yeon Ji Chung; Myung Soo Kim

• Book ID: 102379120
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 194 KB
• Volume: 44
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.1670

✦ Synopsis

Abstract

Product ion yields in postsource decay and time‐resolved photodissociation at 193 and 266 nm were measured for some peptide ions with lysine ([KF~6~ + H]^+^, [F~6~K + H]^+^, and [F~3~KF~3~ + H]^+^) formed by matrix‐assisted laser desorption ionization. The critical energy (E~0~) and entropy (Δ__S__^‡^) were determined by RRKM fitting of the data. The results were similar to those found previously for peptide ions with histidine. To summarize, the presence of a basic residue, histidine or lysine, inside a peptide ion retarded its dissociation by lowering Δ__S__^‡^. On the basis of highly negative Δ__S__^‡^, presence of intramolecular interaction involving a basic group in the transition structure was proposed. Copyright © 2009 John Wiley & Sons, Ltd.