title: Manipulation of intracellular magnesium content in polymyxin B nonapeptide-sensitized Escherichia coli by ionophore A23187.
abstract: Escherichia coli B cells were sensitized to ionophore A23187 by polymyxin B nonapeptide, and the induced magnesium and potassium ion fluxes were studied. Combined ionophore treatment permeabilized the cytoplasmic membrane of E. coli in an ion-specific manner and allowed the manipulation of intracellular Mg2+ content from the outside. A23187-induced Mg2+ efflux or influx was dependent on the free Mg2+ concentration gradient between the outside and inside of the cytoplasmic membrane and on the pH gradient. Most of the intracellular Mg2+ was bound, whereas only 1 to 2 mM was free in solution in the cellular sap.
authors.forename: T
authors.initials: T
authors.lastname: Alatossava
authors.forename: H
authors.initials: H
authors.lastname: Jütte
authors.forename: A
authors.initials: A
authors.lastname: Kuhn
authors.forename: E
authors.initials: E
authors.lastname: Kellenberger
mesh_terms: D001692:Biological Transport; D000001:Calcimycin / Q000494:pharmacology*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D003470:Culture Media; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000378:metabolism*; D011112:Polymyxin B / Q000031:analogs & derivatives / Q000494:pharmacology*; D011113:Polymyxins / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism
chemical_list: D003470:Culture Media; D011113:Polymyxins; D000001:Calcimycin; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C038934:polymyxin B nonapeptide; D008274:Magnesium; D011112:Polymyxin B; D011188:Potassium