Abstract
S-(N-Methylthiocarbamoyl)-D- and L-cysteine (MTCC)are new irreversible inhibitors of the amino acid racemase from Pseudomonas putida. Interactions between d- or l-MTCCand purified amino acid racemase were investigated.
The racemase catalyzes not only racemization reactions of d- and L-MTCCbut also their α, β-elimination reactions with concomitant inactivation. This inactivation exhibits the characteristics of suicide inhibition, i.e., pseudo-first order kinetics, irreversibility, stoichiometric labeling of active enzyme by the C3 chain derived from MTCC, and protection by substrate.
