title: Membrane permeability changes associated with DNA gyrase inhibitors in Escherichia coli.
abstract: Inhibition of DNA synthesis in Escherichia coli B/r by a DNA gyrase inhibitor results in cell death after a 50-min lag period. Examination of the cells under phase-contrast and electron microscopes revealed that they appeared to undergo plasmolysis coincident with the onset of cell death. The inhibited cells were also found to become susceptible to low levels of detergent at this time. With a fluorescent membrane probe, the level of membrane permeability was assessed and found to increase concurrently with the decrease in culture viability. Analysis of the cell envelope constituents revealed that, other than a shift in the protein/lipid ratio, the compositions of the cell membranes were unperturbed.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D002463:Cell Membrane Permeability / Q000187:drug effects; D004926:Escherichia coli / Q000032:analysis / Q000187:drug effects*; D008563:Membrane Lipids / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D008970:Molecular Weight; D009268:Nalidixic Acid / Q000494:pharmacology*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D059005:Topoisomerase II Inhibitors
chemical_list: D001426:Bacterial Proteins; D008563:Membrane Lipids; D008565:Membrane Proteins; D059005:Topoisomerase II Inhibitors; D012967:Sodium Dodecyl Sulfate; D009268:Nalidixic Acid