Orlov S N, Kravtsov G M
Biokhimiia. 1983 Sep;48(9):1447-55.
The effect of Ca2+ on the electric potential and permeability of human erythrocyte membranes for K+ was investigated. An increase of K+ concentration in a medium containing a Ca-ionophore A 23187 causes hyperpolarization of the erythrocyte membrane (by 50-60 mV) due to a 70-fold increase of its permeability for K+ (K0.5 for Ca2+ in both cases is equal to 2-3 microM). Using calmodulin-deficient inside-out erythrocyte membrane vesicles, it was demonstrated that regulation of the transmembrane potentials by Ca2+ is mediated by its interaction with calmodulin (K0.5 for Ca2+ and calmodulin is equal to 2-3 microM and 100-150 nM, respectively). It was assumed that the Ca2+-calmodulin complex is involved in the functioning of the plasma membrane K+-channel.
研究了Ca2+对人红细胞膜电位及K+通透性的影响。在含有钙离子载体A 23187的介质中，K+浓度增加会导致红细胞膜超极化（50 - 60 mV），这是由于其对K+的通透性增加了70倍（两种情况下Ca2+的K0.5均等于2 - 3 microM）。使用钙调蛋白缺陷的外翻式红细胞膜囊泡，证明了Ca2+对跨膜电位的调节是通过其与钙调蛋白的相互作用介导的（Ca2+和钙调蛋白的K0.5分别等于2 - 3 microM和100 - 150 nM）。据推测，Ca2+ - 钙调蛋白复合物参与了质膜K+通道的功能。
