title: Electroinsertion and activation of the C-terminal domain of colicin A, a voltage gated bacterial toxin, into mammalian cell membranes.
abstract: The C-terminal fragment of colicin, a protein that is highly soluble in aqueous solution, is spontaneously and irreversibly inserted into the membranes of mammalian cells, which are locally permeabilized by a transmembrane voltage increase. Insertion is detected by immunodetection. This is obtained by mixing the protein with electropermeabilized cells. The same result is observed by pulsing the colicin/cell mixture. Electroinsertion is therefore obtained for the first time with a multi-fragment spanning protein. The cell viability is not affected beyond the effect of electropermeabilization. A train of low voltage repetitive transmembrane modulation, which cannot trigger membrane permeabilization, is applied a day after the electroinsertion. This induces no effect on unmodified cells but triggers the lysis of cells in which colicin has been inserted by the first electropulsation. The low-level electrical treatment is high enough to trigger the voltage gated opening of colicin and to induce the associated toxicity. A transmembrane configuration of colicin is therefore obtained by electroinsertion. The toxic effect of their voltage gating is only obtained when a critical number of voltage gated channels are activated.
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale du CNRS (UMR 5089), 205 route de Narbonne, F-31077 Toulouse cedex 4, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Raffy
authors.forename: Claude
authors.initials: C
authors.lastname: Lazdunski
authors.forename: Justin
authors.initials: J
authors.lastname: Teissié
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D016466:CHO Cells; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D002463:Cell Membrane Permeability; D002470:Cell Survival / Q000187:drug effects; D003087:Colicins / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D006224:Cricetinae; D004563:Electrochemistry; D004583:Electrons; D015640:Ion Channel Gating; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D021381:Protein Transport
chemical_list: D001427:Bacterial Toxins; D003087:Colicins; D010446:Peptide Fragments