Klauser R, Cechová D, Tschesche H
Hoppe Seylers Z Physiol Chem. 1978 Feb;359(2):173-80. doi: 10.1515/bchm.1978.359.1.173.
Cow colostrum trypsin inhibitor (chromatographic form AIV[7])was subjected to basic conditions that favour beta-elimination of carbohydrates from O-glycosidic linkages. The unchanged carbohydrate composition and the unchanged values for serine and threonine indicate the presence of an alkali-stable N-glycosidic bond to asparagine. From a tryptic digest of S-aminoethylated inhibitor the glyco-decapeptide (residues 24 through 33) was isolated. The carbohydrate composition was identical with that of the S-aminoethylated inhibitor. Further degradation of this peptide by carboxypeptidase C (and aminopeptidase) produced the glycopeptide Asn(CHO)-Ser-(Thr) with the same carbohydrate composition. Thus, a single carbohydrate moiety is bound by a N-glycosidic linkage to asparagine-27 of the colostrum inhibitor. It is located opposite to the reactive site at the base of a pear-shaped molecule.
牛初乳胰蛋白酶抑制剂（色谱形式AIV[7]）在有利于从O-糖苷键中β-消除碳水化合物的碱性条件下进行处理。碳水化合物组成未变以及丝氨酸和苏氨酸的值未变，表明存在与天冬酰胺的碱稳定N-糖苷键。从S-氨乙基化抑制剂的胰蛋白酶消化物中分离出糖十肽（残基24至33）。其碳水化合物组成与S-氨乙基化抑制剂相同。用羧肽酶C（和氨肽酶）对该肽进一步降解产生了具有相同碳水化合物组成的糖肽Asn(CHO)-Ser-(Thr)。因此，单个碳水化合物部分通过N-糖苷键与初乳抑制剂的天冬酰胺-27相连。它位于梨形分子底部的活性位点对面。
