CHARACTERIZATION OF N-LINKED CARBOHYDRATE CHAINS OF THE CRAYFISH, ASTACUS-LEPTODACTYLUS HEMOCYANIN

The primary structure of the carbohydrate chains of hemocyanin from th e crayfish Astacus leptodactylus were investigated. The carbohydrate c ontent is 0.2% (w/w) as referred to total hemocyanin content, resp, 1. 8% as referred only to the one subunit which is glycosylated. Mannose and N-acetylglucosamine are present in a molar ratio of 6:2, The carbo hydrate chains are N-glycosidically linked as revealed by dot blot ana lysis using various lectins and enzymatic deglycosylation. Furthermore , they are part of only one hemocyanin subunit of A. leptodactylus. Af ter enzymatic deglycosylation with PNGase F, the oligosaccharide pool was separated by FPLC on Mono Q and subsequent HPLC on Lichrosorb-NH2, the subfractions were characterized by H-1 NMR spectroscopy, A total of six oligosaccharides, ranging from Man(4)GlcNAc(2) to Man(9)GlcNAc( 2) is present, Man(6)GlcNAc(2) representing the most abundant one with 57% of all oligosaccharides.