title: The characterization of ion channels formed by Pasteurella multocida dermonecrotic toxin.
abstract: The influence of the dermonecrotic lethal toxin (approximately 120 kDa) produced by Pasteurella multocida serovarian D on planar phospholipid bilayers was studied. It was found that the toxin is able to increase the conductance of the bilayers by formation of low-conductive and cation-selective ion channels [27 pS at 4.0 M KCl, pH 7.5; zero current potential equals to -14.5 +/- 0.5 mV at threefold transmembrane gradient KCl (120 mM/40 mM)]. In biionic conditions the channels displayed weak selectivity between Na, K and Ca ions. The shapes of current-voltage characteristics (which were measured at different pH and salt concentrations) indicate that an energetic barrier for passing ions is situated near the center of the water pore of the ion channels. The effective diameter of the ion channel's water pore was established to be equal to 2.1 +/- 0.3 nm.
authors.affiliation: Institute of Physiology and Biophysics, Laboratory of Molecular Physiology, Tashkent, Uzbekistan.
authors.forename: O V
authors.initials: OV
authors.lastname: Krasilnikov
authors.forename: V I
authors.initials: VI
authors.lastname: Ternovsky
authors.forename: D G
authors.initials: DG
authors.lastname: Navasardyants
authors.forename: L I
authors.initials: LI
authors.lastname: Kalmykova
mesh_terms: D001427:Bacterial Toxins / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D003885:Dermotoxins / Q000494:pharmacology*; D004553:Electric Conductivity; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism; D008567:Membranes, Artificial; D010325:Pasteurella / Q000737:chemistry*; D010743:Phospholipids / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D003885:Dermotoxins; D007473:Ion Channels; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010743:Phospholipids; C052804:dermonecrotic toxin, Pasteurella multocida