[Deuterium exchange of the methyl group of pyruvate catalyzed by human serum albumin].

Human serum albumin catalyzes proton exchange of the methyl group of the pyruvate molecule in heavy water. The exchange process is mainly due to the formation of bonds of a Schiff base type between six deprotonated protein amino groups and pyruvate. Both hydrated and non-hydrated forms of pyruvate interact with positively charged side amino acid residues of the polypeptide chain (most probably, with arginine) located in the hydrophobic "pockets" of the protein globule. The value of equilibrium association constants with serum albumin exceeds that for the hydrated form of pyruvate.