原核生物钾离子通道的功能重建。

Heginbotham L, Kolmakova-Partensky L, Miller C

Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02254, USA.

J Gen Physiol. 1998 Jun;111(6):741-9. doi: 10.1085/jgp.111.6.741.

SliK, a K+ channel encoded by the Streptomyces KcsA gene, was expressed, purified, and reconstituted in liposomes. A concentrative 86Rb+ flux assay was used to assess the ion transport properties of SliK. SliK-mediated ionic flux shows strong selectivity for K+ over Na+ and is inhibited by micromolar concentrations of Ba2+, mirroring the basic permeation characteristic of eukaryotic K+ channels studied by electrophysiological methods. 86Rb+ uptake kinetics and equilibrium measurements also demonstrate that the purified protein is fully active.

SliK是一种由链霉菌KcsA基因编码的钾离子通道，已在脂质体中表达、纯化并重构。采用86Rb+浓缩通量测定法评估SliK的离子转运特性。SliK介导的离子通量对K+的选择性远高于Na+，并受到微摩尔浓度Ba2+的抑制，这反映了通过电生理方法研究的真核钾离子通道的基本渗透特性。86Rb+摄取动力学和平衡测量也表明纯化后的蛋白具有完全活性。