Sugimoto N, Takagi M, Ozutsumi K, Harada S, Matsuda M
Research Institute for Microbial Diseases, Osaka University, Japan.
Biochem Biophys Res Commun. 1988 Oct 14;156(1):551-6. doi: 10.1016/s0006-291x(88)80877-5.
The enterotoxin of Clostridium perfringens type A was found to form ion-permeable channels in a lipid bilayer. A patch clamp technique was used to detect channel activities in an asolectin bilayer with incorporated enterotoxin. About 20% of the lipid bilayer patches examined showed rectangular or stepwise shift of membrane current. The shifts indicated the gating of ion-permeable channels in the patches. The channels showed high conductance (40-450 pS), no rectification in current-voltage curves and occasional long-lasting events. The significance of these findings is discussed in relation to the mechanism of action of the toxin.
已发现A型产气荚膜梭菌的肠毒素可在脂质双分子层中形成离子通透通道。采用膜片钳技术检测掺入肠毒素的大豆卵磷脂双分子层中的通道活性。在所检测的脂质双分子层膜片中,约20%显示出膜电流呈矩形或阶梯状变化。这些变化表明膜片中离子通透通道的开闭。这些通道具有高电导(40 - 450皮安),电流 - 电压曲线无整流现象,且偶尔会出现持续时间较长的事件。结合毒素的作用机制对这些发现的意义进行了讨论。