[Antiprotease and immunostimulating effect of peptide components isolated from cuticle of the chicken stomach].

Peptides with molecular weights of 0.8 to 16 kDa were isolated from the keratinous envelope of chicken muscular stomach cuticle. The peptide preparation had a immunostimulating activity whose qualitative and quantitative traits made it comparable with the activity of known drugs of similar composition. In addition, the peptide preparation reversibly inactivated trypsin and activated chymotrypsin. A low-molecular-weight protein (14.1 kDa) was isolated from the peptide preparation by affinity chromatography on trypsin-Sepharose 4B. This protein was found to be a reversible noncompetitive inhibitor of trypsin.