71] Trypsin inhibitor from cow colostrum

Abstract

Colostrum of mammals contains various amounts of antitryptic activity. Laskowski and Laskowski, observed a trypsin inhibitor in cow, hog, and human colostrum. They isolated and crystallized a low-molecular-weight inhibitor from bovine colostrum and, later with their coworkers, one from hog colostrum. The protein obtained was electrophoretically heterogeneous. Several new methods of isolation of the inhibitor from cow and hog colostrum were developed. The new data showed that the trypsin inhibitors from both hog and cow colostrums were glycoproteins occurring in several forms. The presence of multiple forms seems to be due both to microheterogeneity in amino acid composition and to differences in sugar moiety. The latter could result from the use of improper isolation methods. The primary structure of the cow colostrum proteinase inhibitor has been determined and was found to be similar to the covalent structure of the basic pancreatic polyvalent inhibitor (Kunitz), the trypsin inhibitor from Helix pomatia, and the structures of other inhibitors and snake toxins. The inhibitor mentioned above is not the only one present in bovine colostrums there are two other inhibitors of higher molecular weights, which are both acid and heat labile. The article details the assay methods, purification procedure and properties of trypsin inhibitor from cow colostrum.