Early Events of Photosensitized Oxidation of Sulfur-Containing Amino Acids Studied by Laser Flash Photolysis and Mass Spectrometry.

ABSTRACT: The mechanism of photooxidation of methionine (N-Ac-Met-NH-CH₃, 1) and methyl-cysteine (N-Ac-MeCys-NH-CH₃, 2) analogues by 3-carboxybenzophenone triplet (3CB*) in neutral aqueous solution was studied using techniques of nanosecond laser flash photolysis and steady-state photolysis. The short-lived transients derived from 3CB and sulfur-containing amino acids were identified, and their quantum yields and kinetics of formation and decay were determined. The stable photoproducts were analyzed using liquid chromatography coupled with high-resolution mass spectrometry. Substantial differences in the mechanisms were found for methionine and S-methyl-cysteine analogues for both primary and secondary photoreactions. A new secondary reaction channel (back

SUBMITTER: Pedzinski T 

PROVIDER: S-EPMC7498160 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature