ATOMIC SCALE STRUCTURE AND FUNCTIONAL MODELS OF VOLTAGE-GATED POTASSIUM CHANNELS
ATOMIC SCALE STRUCTURE AND FUNCTIONAL MODELS OF VOLTAGE-GATED POTASSIUM CHANNELS
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DOI：
10.1016/s0006-3495(92)81809-x
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发表时间：
1992-04-01
影响因子：
3.4
通讯作者：
GUY, HR
中科院分区：
文献类型：
--
作者：
DURELL, SR;GUY, HR
最近的诱变实验证实了我们的假设，即S5和S6之间的一段形成电压门控离子通道的离子选择性部分。基于这些和其他新的数据，我们已经修订了以前的模型的一般折叠模式的电压门控通道蛋白质，并已开发出原子尺度的模型的整个跨膜区的振荡器A K+通道。在这些模型中，离子选择性区域是跨越膜的外半部的β桶。电压依赖性激活门控的构象变化被模拟为“螺旋”机制，其中四个S4段沿着移动并绕其轴旋转。这些变化之后是电压依赖性构象变化，其中连接S4至S5的片段从阻塞孔的细胞内入口移动到形成孔的大内部部分的衬里的一部分。蛋白质的NH 2-末端被建模为α-螺旋，其堵塞孔的细胞内一半以堵塞通道。
Recent mutagenesis experiments have confirmed our hypothesis that a segment between S5 and S6 forms the ion selective portion of voltage-gated ion channels. Based on these and other new data, we have revised previous models of the general folding pattern of voltage-gated channel proteins and have developed atomic scale models of the entire transmembrane region of the Shaker A K+ channel. In these models, the ion selective region is a beta-barrel that spans the outer half of the membrane. The inner half of the pore is larger, The voltage-dependent conformational changes of activation gating are modeled to occur by the "helical screw" mechanism, in which the four S4 segments move along and rotate about their axes. These changes are followed by a voltage-independent conformational change, in which the segments linking S4 to S5 move from blocking the intracellular entrance of the pore to forming part of the lining of the large inner portion of the pore. The NH2-terminal of the protein was modeled as an alpha-helix that plugs the intracellular half of the pore to inactivate the channel.