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Influence of basic residues on dissociation kinetics and dynamics of singly protonated peptides: time‐resolved photodissociation study
Author(s) -
Yoon So Hee,
Moon Jeong Hee,
Chung Yeon Ji,
Kim Myung Soo
Publication year - 2009
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1670
Subject(s) - chemistry , photodissociation , protonation , dissociation (chemistry) , ion , ionization , peptide , intramolecular force , kinetics , photochemistry , histidine , computational chemistry , stereochemistry , organic chemistry , biochemistry , physics , quantum mechanics , enzyme
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.