哺乳动物孔蛋白通道在开放和“关闭”状态下的直径：在平面脂质双分子层中对单通道水平的直接测量

Diameter of the mammalian porin channel in open and "closed" states: direct measurement at the single channel level in planar lipid bilayer.

作者信息

Krasilnikov O V, Carneiro C M, Yuldasheva L N, Campos-de-Carvalho A C, Nogueira R A

机构信息

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

出版信息

Braz J Med Biol Res. 1996 Dec;29(12):1691-7.

PMID:9222434

Abstract

Porin isolated from bovine skeletal muscle was reconstitute in planar lipid bilayers under voltage clamp conditions. A set of non-electrolytes were used as molecular probes for determining the pore diameter. The maximal diameter of the open channel was estimated to be 3.02 +/- 0.26 nm. As observed for other porin channels, a large transmembrane potential drove the channel into a "closed" state. The channel transition to the low conductance (closed) state was followed by a decrease in the maximal diameter of the channel to 2.4 +/- 0.08 nm.

摘要

从牛骨骼肌中分离出的孔蛋白在电压钳条件下重构于平面脂质双分子层中。使用一组非电解质作为分子探针来测定孔径。开放通道的最大直径估计为3.02±0.26纳米。正如在其他孔蛋白通道中观察到的那样，大的跨膜电位会使通道进入“关闭”状态。通道转变为低电导（关闭）状态后，通道的最大直径减小至2.4±0.08纳米。