The mode of action of nanaomycin A in Gram-positive bacteria.

The mode of action of nanaomycin A on Gram-positive such as Staphylococcus aureaus, Bacillus cereus and Streptococcus faecalis was investigated. Nanaomycin A inhibited the biosyntheses of protein, DNA, RNA and cell-well peptidoglycan to a similar extent. It increased the oxygenous respiration of S. aureus cells at the minimal inhibitory concentration. The cells preincubated with nanaomycin A showed stimulation of proton influx after addition of N,N'-dicyclo-hexylcazrbodiimide, an inhibitor of Ca++, Mg++-ATPase. Nanaomycin A seems to interfere with the cytoplasmic or to inhibit coupling of oxidative phosphorylation, followed by secondary inhibitory effect on protein, nucleic acids and cell-wall peptidoglycan biosyntheses.