S carboxymethylcysteine synthase

In enzymology, a S-carboxymethylcysteine synthase (EC 4.5.1.5) is an enzyme that catalyzes the chemical reaction

3-chloro-L-alanine + thioglycolate ⇌ S-carboxymethyl-L-cysteine + chloride

Thus, the two substrates of this enzyme are 3-chloro-L-alanine and thioglycolate, whereas its two products are S-carboxymethyl-L-cysteine and chloride.

This enzyme belongs to the family of lyases, specifically the class of carbon-halide lyases. The systematic name of this enzyme class is 3-chloro-L-alanine chloride-lyase (adding thioglycolate S-carboxymethyl-L-cysteine-forming). This enzyme is also called S-carboxymethyl-L-cysteine synthase. It employs one cofactor, pyridoxal phosphate.