大鼠肝脏过氧化物酶体中大电导通道的单通道分析。

Single-channel analysis of a large conductance channel in peroxisomes from rat liver.

作者信息

Lemmens M, Verheyden K, Van Veldhoven P, Vereecke J, Mannaerts G P, Carmeliet E

机构信息

Laboratorium voor Fysiologie, Katholieke Universiteit Leuven, Belgium.

出版信息

Biochim Biophys Acta. 1989 Sep 18;984(3):351-9. doi: 10.1016/0005-2736(89)90302-7.

DOI:10.1016/0005-2736(89)90302-7

PMID:2476185

Abstract

Native membranes and Triton X-100 solubilized integral membrane proteins of peroxisomes from rat liver were reconstituted in liposomes. With the patch clamp technique, a channel was detected with a conductance of 420 +/- 30 pS and a PK/PC1 of about 3. The channel in native membrane fractions was weakly voltage dependent, residing most of the time in an open state with the possibility to shift to different substates. Solubilization changed the kinetic properties. The channel became strongly voltage dependent and closed at voltages negative to -20 mV. The estimated diameter of the channel is about 1.7 nm and might explain, at least partially, the permeability properties of the peroxisomal membrane.

摘要

大鼠肝脏过氧化物酶体的天然膜和经Triton X-100增溶的整合膜蛋白被重构到脂质体中。采用膜片钳技术，检测到一种电导为420±30 pS、PK/PC1约为3的通道。天然膜组分中的通道对电压依赖性较弱，大部分时间处于开放状态，有可能转变为不同的亚状态。增溶改变了动力学特性。该通道对电压依赖性增强，在电压低于-20 mV时关闭。估计该通道的直径约为1.7 nm，这至少可以部分解释过氧化物酶体膜的通透性特性。