Abstract
Liposidomycin C (C42H67N5O21S, M.W. 1009) is a novel nucleoside antibiotic containing uracil, a sulfated aminosugar, and a fatty acid. It is a specific inhibitor of peptidoglycan synthesis of bacteria, inhibiting the formation of the lipid intermediates from uridine 5'-diphospho-N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelyI-D-[14C]alanyl-D-[14C] alanine and uridine 5'-diphospho-N-acetylglucosamine with a particulate enzyme from Escherichia coli Y-10. It also inhibited the formation of MurNAc(-pentapeptide)-P-P-lipid in the absence of UDP-GlcNAc. On the other hand, it inhibited the activity of N-acetylglucosamine transglycosylase and peptidoglycan transglycosylase only weakly using the same system from E. coli. Thus, it is concluded that the site of action of liposidomycin C is phospho-N-acetylmuramyl-pentapeptide transferase in peptidoglycan synthesis.
