Partial hydrolysis of cow's milk proteins by human trypsins and elastases in vitro.

The hydrolysis of bovine alpha-lactalbumin, beta-lactoglobulin, and casein by human anodal and cathodal trypsins and elastases was studied with the aid of electroimmunoassay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The rate of hydrolysis of the various proteins by cathodal elastase exceeded that by anodal or cathodal trypsin and anodal elastase. Casein was hydrolyzed more efficiently than alpha-lactalbumin or beta-lactoglobulin. The hydrolysis of the three proteins occurred at a considerably slower rate when present in crude form, as in cow's milk, than when in purified form.