锌离子压抑鲫鱼视网膜水平细胞内向整流钾离子通道的模型和机理探究  

Possible Mechanism of Zn^(2+) Inhibition Effect on Inwardly Rectifying Potassium Channel

作　　者：陈经纬[1] 张雅婷[1] 梁培基[1] 邱意弘[1] 

机构地区：[1]上海交通大学生物医学工程学院,上海200240

出　　处：《生物物理学报》2012年第10期826-836,共11页Acta Biophysica Sinica

基　　金：国家自然科学基金面上项目(30870836)~~

摘　　要：内向整流钾离子通道(inwardly rectifying potassium channel,Kir)广泛存在于神经元和肌肉细胞中,在维持细胞膜静息电位和传导神经信号中起到了重要作用。有研究显示,Zn2+在特定的pH值条件下可以抑制Kir电流。本文使用NEURON软件对Kir通道介导的电流建模,模拟了Kir的电流-电压关系,提出一组动力学状态转换方程来描述Zn2+对Kir的压抑作用。模型可以较好地描述不同浓度Zn2+对Kir电流的调节情况,提示Zn2+通过结合在Kir上的特定位点产生压抑作用,并且此位点会被H+竞争性结合。Inwardly rectifying potassium channel （Kir） is widely expressed in neurons and muscle cells. It plays an important role in preserving the static membrane voltage and conducting nerve signals. Previous studies showed that Zn2＋ could inhibit the Kir current at specific pH acidity. In this paper, a model is built with NEURON to simulate Kir current-voltage relationship, and a set of kinetic transfer equations is put forward to describe the inhibition of Zn2＋ on Kir current. The model can describe the modulation of different concentrations of Zn2＋ on Kir current well, which reveals that Zn2＋ inhibits Kir by binding to specific site on Kir and H＋ also competes to bind to the same site.

关 键 词：内向整流钾离子通道 锌离子 动力学状态转换过程 

分 类 号：Q424[生物学—神经生物学]