Carboxymethyl-selenopyruvic acid as the product of the oxidative deamination of carboxymethyl-selenocysteine.

CMSeC labeled with 14C in the carboxymethyl moiety was incubated with snake venom L-aminoacid oxidase. As the product of the reaction only one ketoacid was detected, which retained all the radioactivity of the oxidized substrate. This clearly shows that no breakdown of the C-Se bond of CMSeC occurs during its oxidation, and confirms previously reported data indicating that the ketoacid arising from CMSeC is CMSeP.