Läuger P
Biochim Biophys Acta. 1976 Dec 2;455(2):493-509. doi: 10.1016/0005-2736(76)90320-5.
If the permeability of an ion channel is high, the overall transport becomes ultimately limited by the rate with which ions from the aqueous phase arrive at the mouth of the channel. In this study a theoretical treatment of diffusion-limited ion transport through pores is given which takes both concentration and electric potential gradients into account as driving forces for the flow of ions. The current-voltage characteristic of a diffusion-limited channel is found to be strongly saturating. Addition of an impermeable elesults from a reduction in the electric field strength near the mouth of the channel. At low voltages the permeability P of the pore is obtaines as 1/P =(1/Pi)+(1/P'c)+(1/P''c) where Pi is the intrinsic permeability and P'c, P''c are the left-hand and right-hand convergence permeabilities, respectivelyl which are proportional to the aqueous diffusion coefficient of the permeable ion and to the effective capture radius of the pore.
如果离子通道的通透性很高，那么整体的运输最终会受到离子从水相到达通道口的速率的限制。在本研究中，给出了对通过孔的扩散限制离子运输的理论处理方法，该方法将浓度梯度和电势梯度都视为离子流动的驱动力。发现扩散限制通道的电流 - 电压特性具有很强的饱和性。添加不可渗透物质会导致通道口附近电场强度降低。在低电压下，孔的通透性P可表示为1/P =(1/Pi)+(1/P'c)+(1/P''c)，其中Pi是固有通透性，P'c和P''c分别是左手侧和右手侧的汇聚通透性，它们分别与可渗透离子的水相扩散系数以及孔的有效捕获半径成正比。
