Structural study of the carbohydrate moiety of hen ovomucoid. Occurrence of a series of pentaantennary complex-type asparagine-linked sugar chains.

Abstract

Hen ovomucoid contains a series of novel pentaantennary complex-type asparagine-linked sugar chains which can be classified into three groups, N-1, N-2, and N-3b, N-3b, the structure of which is found as a common (formula, see text) structure in all pentaantennary sugar chains. N-2 is a mixture of three isomeric monogalactosyl derivatives of N-3b, and N-1 is a mixture of two isomeric digalactosyl derivatives of N-3b. Most of the galactoses are beta-linked at the C-4 position of beta-N-acetylglucosamine residues 2 and 4 in the N-3b structure shown above. Small amounts of the galactoses are also linked at the C-4 position of beta-N-acetylglucosamine residue 3.