title: Requirement of heat and metabolic energy for the expression of inhibitory action of colicin K.
abstract: Escherichia coli B, induced for beta-galactoside permease, can accumulate thio-methyl-beta-galactoside in the cell even at 0 degrees D. At this temperature, cells adsorb colicin K but the adsorbed colicin does not inhibit thiomethyl-beta-galactoside uptake. Inhibition by colicin K is, however, seen at 0 degrees C after exposure of the colicin K-cell complex to a high temperature: a greater degree of inhibition occurs with increasing temperature or duration or exposure. There is a transition point at around 21 degrees C in Arrhenius plots of this colicin K activation reaction. If inhibitors of energy yielding reactions are present during the heat treatment, the inhibitory action of colicin K (as measured by thiomethyl-beta-galactoside uptake after returning the colicin K-cell complex to 0 degrees C and removal of the inhibitors) is prevented. These results indicate that adsorbed colicin K is converted into the active state only in the presence of metabolic energy and that cell surface fluidity appears to be concerned in this process.
mesh_terms: D002731:4-Chloromercuribenzenesulfonate / Q000494:pharmacology; D001692:Biological Transport; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D003087:Colicins / Q000494:pharmacology*; D003486:Cyanides / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D005459:Fluorides / Q000494:pharmacology; D005697:Galactosides / Q000494:pharmacology; D006358:Hot Temperature; D007700:Kinetics; D026901:Membrane Transport Proteins / Q000096:biosynthesis*; D008756:Methylgalactosides / Q000378:metabolism*; D008759:Methylglycosides / Q000378:metabolism*; D009154:Mutation; D013816:Thermodynamics; D013862:Thiogalactosides / Q000378:metabolism; D013997:Time Factors
chemical_list: D003087:Colicins; D003486:Cyanides; D004140:Dinitrophenols; D005697:Galactosides; D026901:Membrane Transport Proteins; D008756:Methylgalactosides; D008759:Methylglycosides; D013862:Thiogalactosides; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D002731:4-Chloromercuribenzenesulfonate; D005459:Fluorides; D004229:Dithiothreitol