It is well known that K-casein plays an important role in stabilizing casein micelles,1} and forms a heat-induced complex with /Mactoglobulin which is one of the main components of whey proteins.2)3) This jc-casein-/?lactoglobulin interaction is of considerable importance in determining the heat stability and rennin clottability of milk and some of its products.4'5) It has been suggested

Short glycopeptides were prepared from bovine colostral K-casein treated with cyanogen bromide and proteases (pronase P and thermolysin), followed by gel filtrations and ion exchange chromatography. It was confirmed by Edman degradation that glycopeptide I among short glycopeptides obtained was homogeneous. From the effect of alkali treatment, it was assumed that three polysaccharide chains of glycopeptide I were attached to the peptide chain through OH groups of threonines. By chemical procedures and carboxypeptidase P treatment, the amino acid sequence of glycopeptide [ was established to be Ser-Gly-Glu-Pro-Thr-Ser-Thr-Pro-Thr-Thr-Glu-Ala-Val. Threonine residues of No. 5, 7 and 9 were bound to the carbohydrate chains through galactosamine. The sugar chain bound to the threonine residue at No.7 contained glucosamine. Glycopeptide I corresponded to residues of No. 127 ~ 139 in K-casein A from normal milk.

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