AMINO-ACIDS OXIDATION: A COMBINED STUDY OF CYSTEINE OXO-FORMS BY MASS SPECTROMETRY, IRMPD SPECTROSCOPY AND SIMULATIONS

摘要

Cysteine residues in sulfenic (-SOH), sulfinic (-SO_2H) and sulfonic (-SO_3H) forms are key intermediates in the redox-switch chemistry of proteins [1]. Although sulfenic acids have been identified in several biochemical frameworks, they are transient and not isolable in small molecular systems. Low-energy collision-induced dissociation of L-Cysteine sulfate affords Lcysteine sulfenic acid.