INHIBITION OF LIPID-LINKED SACCHARIDE SYNTHESIS - COMPARISON OF TUNICAMYCIN, STREPTOVIRUDIN, AND ANTIBIOTIC-24010

The effect of two antibiotics, Streptovirudin and antibiotic 24010, on the formation of lipid-linked saccharides was studied in enzyme preparations from pig aorta. Both of these antibiotics were quite similar to tunicamycin in that they inhibited the formation of N-acetylglucosaminyl-pyrophosphoryl-dolichol but had no effect on synthesis of mannosyl-phosphoryl-dolichol. They also did not inhibit the addition of the second N-acetylglucosamine. In either the particulate or soluble enzyme, 50% inhibition of N-acetylglucosamine transfer was observed at 0.01-0.05 μg/ml. Inhibition was observed throughout a time course showing that the antibiotic blocked the synthesis of glycolipid. These antibiotics, as well as tunicamycin, also inhibited the incorporation of glucose into glucosyl-phosphoryl-dolichol and into lipid-linked oligosaccharides. But in these cases, 2-5 μg/ml of antibiotic was required for 50% inhibition. © 1979.