Donaldson P, Kistler J
Department of Cellular and Molecular Biology, University of Auckland, New Zealand.
J Membr Biol. 1992 Aug;129(2):155-65. doi: 10.1007/BF00219511.
Detergent-solubilized ovine lens membrane proteins, enriched in the 70-kDa gap junction component (MP70), were reconstituted into planar lipid bilayers and analyzed for channel activities. Three distinct activities were found. Those showing conductance steps of 290 pS (symmetrical 150-mM KCl solutions) had properties similar to those reported earlier for MIP26 (Ehring, G.R., Zampighi, G., Horwitz, J., Bok, D., Hall, J.E. 1990. J. Gen. Physiol. 96:631-664.) of which minor amounts were normally present in the detergent-solubilized preparations. Two novel channel activities had unitary conductances of 90 and 45 pS, were halothane sensitive and did not discriminate between sodium and potassium ions. The 90-pS channel was asymmetrically voltage dependent, and its properties would be consistent with the expected properties of junctional hemichannels.
用去污剂溶解的羊晶状体膜蛋白富含70-kDa间隙连接成分（MP70），将其重组重构成平面脂双层，并分析其通道活性。发现了三种不同的活性。那些在对称150 mM KCl溶液中显示290 pS电导阶梯的活性，其特性与先前报道的MIP26（Ehring, G.R., Zampighi, G., Horwitz, J., Bok, D., Hall, J.E. 1990. J. Gen. Physiol. 96:631 - 664.）相似，去污剂溶解制剂中通常存在少量该蛋白。两种新的通道活性的单位电导分别为90和45 pS，对氟烷敏感，且对钠离子和钾离子无选择性。90-pS通道具有不对称电压依赖性，其特性与预期的连接半通道特性一致。
