title: Inhibition of the respiratory-linked membrane potential in E. coli membrane vesicles by octapeptin.
abstract: Octapeptin is a peptide antibiotic which affects bacterial membrane structure and selective membrane permeability for protons and potassium. The influence of octapeptin on the formation of a membrane potential generated across bacterial vesicles was monitored using the Rb+-valinomycin transport system. Octapeptin inhibited the respiratory-linked generation of membrane potentials formed in the presence of succinate or Asc/PMS. In addition, the antibiotic inhibited [3H]-leucine transport driven either by succinate or Asc/PMS. These studies support the proposal that the antimicrobial activity of octapeptin is due to inhibition of the formation of a membrane potential generated in the presence of appropriate respiratory substrates.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000378:metabolism; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D003864:Depression, Chemical; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D009842:Oligopeptides / Q000494:pharmacology*; D011868:Radioisotopes; D012413:Rubidium / Q000378:metabolism; D013386:Succinates / Q000378:metabolism; D014634:Valinomycin / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D009842:Oligopeptides; D011868:Radioisotopes; D013386:Succinates; D014634:Valinomycin; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D007930:Leucine; D012413:Rubidium; D001205:Ascorbic Acid