Depolarization of the Membrane Potential by β-Lactams as a Signal to Induce Autolysis

• Published in: Biochemical and biophysical research communications 2002-02, Vol.290 (4), p.1169-1175
• Main Authors: Penyige, András, Matkó, János, Deák, Eleonóra, Bodnár, Andrea, Barabás, György
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Autolysis; Carbocyanines; Cefotaxime - pharmacology; Coloring Agents; DiOC 6; Drug Interactions; effect of penicillin G, cephotaxime, gramicidin D; fluorescence assay of bacterial membrane potential; Gramicidin - pharmacology; gramicidin D; induction of cell wall autolysis; Ionophores - pharmacology; kanamycin; mechanism of action of β-lactam antibiotics; Membrane Potentials - drug effects; Penicillin G - pharmacology; penicilloic acid; protoplasts; Streptomyces griseus; Streptomyces griseus - drug effects; Streptomyces griseus - metabolism
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.2001.6317

The effect of β-lactam antibiotics that are known to inhibit cell wall biosynthesis and induce cell wall autolysis on the electrophysiological state of the plasma membrane in Streptomyces griseus was studied. Addition of various β-lactam antibiotics induced a dose- and growth-stage-dependent depolarization of the membrane potential of Streptomyces griseus. The hydrolyzed biologically inactive derivative penicilloic acid had no depolarizing effect on the membrane potential. The ionophore gramicidin D, while depolarizing the membrane potential, also induced a dose-dependent increase in cell wall lysis. These observations suggest that alteration of the transmembrane potential could be an important signal in triggering cell wall autolysis of S. griseus.