Kinetic description of proteolysis. Part 2. Substrate regulation of peptide bond demasking and hydrolysis. Liquid chromatography of hydrolyzates.

Lower peptides and amino acids in hydrolyzates of casein obtained with protosubtilin were determined using high pressure liquid chromatography (HPLC). The dependences of product concentrations in hydrolyzates produced at different substrate concentrations on the degree of hydrolysis were obtained. With an increase of the substrate concentration the real type of proteolysis changes from "zipper" to "one-by-one". This result supports the assumption that the substrate proteolysis regulation is realized through the change in the ratio of the rates of peptide bond demasking to those of peptide bond hydrolysis.