Mode of action of vibriocin.
The mechanism of action of vibriocin, a bacteriocin produced by Vibrio comma, was investigated. Its lethal action (as defined by the loss in colony-forming ability) was reversed by tryptic digestion within 7 to 10 min after adsorption. The bacteriocin had a pronounced inhibitory effect on deoxyribonucleic acid (DNA) synthesis, whereas ribonucleic acid (RNA) and protein synthesis continued, although at a reduced rate. Chloramphenicol protected sensitive bacteria from the lethal action. Degradation of bacterial DNA prelabeled with (3)H-thymidine, as measured by changes in acid-precipitable radioactivity, occurred 10 min after treatment with vibriocin. The bacteriocin per se had no detectable deoxyribonuclease activity. Observation of vibriocin-treated cells by phase-contrast microscopy, measurement of ultraviolet light-absorbing capacity of extracellular fluid, and (42)K-efflux studies indicated a damaged bacterial membrane. This impairment of membrane function occurred in the presence of chloramphenicol and thus, unlike the lethal effect of vibriocin, was independent of protein synthesis.
D000327:Adsorption; D001426:Bacterial Proteins / Q000096:biosynthesis; D001430:Bacteriocins / Q000494:pharmacology*; D002247:Carbon Isotopes; D002462:Cell Membrane / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D002701:Chloramphenicol / Q000494:pharmacology; D004269:DNA, Bacterial / Q000096:biosynthesis; D011188:Potassium / Q000378:metabolism; D011194:Potassium Isotopes; D012329:RNA, Bacterial / Q000096:biosynthesis; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014357:Trypsin / Q000494:pharmacology; D014466:Ultraviolet Rays; D014498:Uracil / Q000378:metabolism; D014733:Vibrio / Q000187:drug effects / Q000378:metabolism
D001426:Bacterial Proteins; D001430:Bacteriocins; D002247:Carbon Isotopes; D004269:DNA, Bacterial; D011194:Potassium Isotopes; D012329:RNA, Bacterial; D014316:Tritium; D014498:Uracil; D002701:Chloramphenicol; D014357:Trypsin; D011188:Potassium; D013936:Thymidine