Blank M
Biochim Biophys Acta. 1987 Jun 24;906(2):277-94. doi: 10.1016/0304-4157(87)90014-1.
This paper is a review of the surface compartment model of ion flow across the channels of natural membranes. The model emphasizes the role of electrical double layers in ion transport and is derived from first principles. When the surface compartment model is applied to the membrane of an excitable cell, (e.g., the squid axon), one can calculate voltage clamp currents that are similar to those observed in the sodium and potassium channels of excitable membranes. The difference in the selectivity of the two types of ion channel appears to be determined by the difference in gating current, and is in line with measurements on the sodium and potassium channels of squid axon. These results indicate that there is a kinetic basis for the selectivity of voltage gated channels and suggest that other types of channels may operate by related mechanisms. The focus of the surface compartment model on charged surfaces has led to a description of the channel opening/closing process in terms of surface free energy, assuming an analogy to the aggregation/disaggregation reactions in oligomeric proteins. The opening of voltage gated oligomeric channels can be formulated in terms of variations in the surface free energy that are triggered by changes in the surface charge density. On this basis, it is possible to introduce gating phenomena into the surface compartment model and to couple the channel processes with charge movements.
本文是对离子跨天然膜通道流动的表面隔室模型的综述。该模型强调了双电层在离子运输中的作用，并且是从第一原理推导出来的。当将表面隔室模型应用于可兴奋细胞（例如鱿鱼轴突）的膜时，可以计算出与在可兴奋膜的钠通道和钾通道中观察到的电流相似的电压钳制电流。两种类型离子通道选择性的差异似乎由门控电流的差异决定，并且与对鱿鱼轴突钠通道和钾通道的测量结果一致。这些结果表明电压门控通道的选择性存在动力学基础，并表明其他类型的通道可能通过相关机制运作。表面隔室模型对带电表面的关注导致了根据表面自由能对通道开放/关闭过程的描述，假设类似于寡聚蛋白中的聚集/解聚反应。电压门控寡聚通道的开放可以根据由表面电荷密度变化触发的表面自由能变化来表述。在此基础上，有可能将门控现象引入表面隔室模型，并将通道过程与电荷运动耦合起来。
