Effects of polymyxin B on the synthesis and degradation of lipid, ribonucleic acid (RNA) and protein in Pseudomonas aeruginosa were investigated. It was found that polymyxin B caused a marked degradation of the lipid fraction which was prelabeled with (3H-2)-glycerol. Thin-layer chromatographic analysis indicated that the main degraded lipids were phosphatidylethanolamine and phosphatidylglycerol, which constituted 80%, and 15% of the total phospholipids of this organism, respectively. Polymyxin B also inhibited synthesis of RNA and protein in vivo. The severe inhibition of the uptake of labeled amino acids by polymyxin B indicated that the observed inhibition of RNA and protein synthesis possibly occurred at the level of substrate transports. The degradation of phospholipid might account for the defective membrane activities.
ASJC Scopus subject areas
- Drug Discovery