BIOSYNTHESIS OF DOLICHYL DIPHOSPHATE N-ACETYLGLUCOSAMINE INTERMEDIATES IN ASCARIDIA-GALLI MICROSOMES

1. N-acetylglucosamine-1-phosphate transferase was demonstrated in the microsomal fraction of Ascaridia galli. 2. The transferase reaction depends on exogenous dolichyl phosphate as lipid acceptor and was found to be inhibited by tunicamycin. 3. The enzyme activity was optimal in the presence of sodium deoxycholate as detergent and Mg cations after 10 min of incubation. 4. The product of the transferase reaction-dolichyl diphosphate N-acetylglucosamine was converted into lipid-disaccharide-dolichyl diphosphate N,N'-diacetylchitobiose. 5. The maximum level of the conversion was achieved at 5 mM concentration of unlabelled UDP-N-acetylglucosamine, while this conversion was negligible at lower UDP-N-acetylglucosamine concentrations (0.1 and 0.5 mM).