多杀巴斯德菌皮肤坏死毒素形成的离子通道的特性

The characterization of ion channels formed by Pasteurella multocida dermonecrotic toxin.

作者信息

Krasilnikov O V, Ternovsky V I, Navasardyants D G, Kalmykova L I

机构信息

Institute of Physiology and Biophysics, Laboratory of Molecular Physiology, Tashkent, Uzbekistan.

出版信息

Med Microbiol Immunol. 1994 Nov;183(5):229-37. doi: 10.1007/BF00198457.

DOI:10.1007/BF00198457

PMID:7536293

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.

摘要

研究了多杀性巴氏杆菌血清型D产生的皮肤坏死致死毒素（约120 kDa）对平面磷脂双层的影响。发现该毒素能够通过形成低电导且阳离子选择性的离子通道来增加双层膜的电导[在4.0 M KCl、pH 7.5条件下为27 pS；在三倍跨膜梯度KCl（120 mM/40 mM）时零电流电位等于-14.5 +/- 0.5 mV]。在双离子条件下，这些通道对Na、K和Ca离子表现出较弱的选择性。电流-电压特性曲线的形状（在不同pH和盐浓度下测量）表明，离子通过的能量屏障位于离子通道水孔的中心附近。确定离子通道水孔的有效直径等于2.1 +/- 0.3 nm。