[Initial kinetics of milk protein hydrolysis by chymotrypsin].

The kinetics of the initial stages of hydrolysis of alpha- and beta-caseins, alpha-lactalbumin, beta-lactoglobulin, and bovine serum albumin was studied quantitatively by electrophoresis. The hydrolysis rates of caseins (demasked polypeptide chains) exceeded the rates of the degradation of milk whey proteins limited by the protein globule demasking by more than two orders of magnitude. Even relatively accessible for hydrolysis globular proteins (beta-lactoglobulin and BSA) were hydrolyzed by the one-by-one mechanism. The maximum value of the ratio between the rates of the peptide chain demasking and the protein globule hydrolysis was 0.0035.