Immunoreactive anionic trypsin and anionic elastase in human milk.

Immunoreactive anionic trypsin and anionic elastase have been demonstrated in human milk, by immunodiffusion and immunoelectrophoresis. Cationic trypsin and cationic elastase could not be detected by these methods. The anionic trypsin is probably present in complex with IgA. No benzoyl-DL-arginine-p-nitroanilide (BAPNA) splitting activity was found in human skim milk. Anionic trypsin was isolated by immunoadsorption chromatography. The purified enzyme had a BAPNA-splitting activity.