Amphomycin inhibits the incorporation of mannose and GlcNAc into lipid-linked saccharides by aorta extracts

Amphomycin inhibits the incorporation of mannose from GDP-¹⁴C]mannose and GlcNac from UDP-³H]GlcNAc into lipid-linked saccharides by either a particulate or a solubilized enzyme fraction from pig aorta. The solubilized enzyme was much more sensitive to the antibiotic than was the particulate fraction with 50% inhibition being observed at 8–15 μg of amphomycin. Although the antibiotic inhibited mannose transfer from GDP-¹⁴C]mannose into mannosyl-phosphoryl-dolichol, lipid-linked oligosaccharides and glycoprotein, the synthesis of mannosyl-phosphoryl-dolichol was much more sensitive to amphomycin. Amphomycin also inhibited the incorporation of mannose from GDP-¹⁴C]mannose into mannosyl-phosphoryldecaprenol in particulate extracts of $\text{Mycobacterium smegmatis}$.