电压依赖性离子通道门控的分子机制

５０年代Ｈｏｄｇｋｉｎ和Ｈｕｘｌｅｙ双通道模型及其激活与失活学说,正逐步被８０年代以来的分子生物学和电生理学研究所证实。Ｎａ＾＋、Ｋ＾＋离子通道的激活主要决定于高度保守的带正电荷氨基酸残基密集的Ｓ４段,由膜内向膜外方向的拧改锥样旋转。Ｎａ＾＋通道的失活主要与其Ⅲ－Ⅳ功能区之间的胞内连结襻的“铰链盖”样运动有关;Ｋ＾＋通的失活分Ｎ－、Ｃ－、Ｐ－三型,分别发生在Ｎ－、Ｃ－末端和Ｐ区,其Ｎ型失活与Ｎ－末

Molecular mechanisms underlying gating activity of voltage dependent ion channels

A model of two-channel and its activation and inactivation proposed by Hodgkin and Huxley in 1950s have been continuously confirmed by molecular biological and electrophysiological studies since 1980s. The activation of Na+ and K+ channels seems to be dependent on screw-like rotation outward of S4 segment which is highly conservative and very rich in positively charged amino acid residues. The inactivation of Na+ channels appears to be related to "hinged lids" like movement of intracellular linker between domain III and IV; type N-, C-, and P- of inactivation can be divided in K+ channels, which seems to occur mainly in terminal N-, C- and region P, respectively and the N-type inactivation seems to be related to "ball and chain" like movement of terminal N.