Glycopeptides. III. Isolation and properties of glycopeptides from a bovine globulin of colostrum and from fraction II-3 of human globulin.

In the preceding paper (1)) the isolation, amino acid sequence, and carbohydrate composition of several glycopeptides obtained from rabbit y-globulin were described. In this communication we report the isolation and some properties of glycopeptides from a bovine y-globulin of colostrum and a human Fraction II-3 y-globulin. The amino acid sequence of a glycopeptide from bovine y-globulin has been determined and evidence for a covalent linkage of the carbohydrate to a carboxyl group of an aspartyl residue is presented. Present information indicates that glycopeptides isolated from Fraction II-3 of human yglobulin are probably identical with those previously obtained by Rosevear and Smith (2) from Fraction 11-l ,2 of human y-globulin.