Relating microscopic charge movement to macroscopic currents: the Ramo-Shockley theorem applied to ion channels.
Relating microscopic charge movement to macroscopic currents: the Ramo-Shockley theorem applied to ion channels.
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DOI：
10.1529/biophysj.104.047548
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发表时间：
2004-12
影响因子：
3.4
通讯作者：
W. Nonner;A. Peyser;D. Gillespie;B. Eisenberg
中科院分区：
文献类型：
--
作者：
W. Nonner;A. Peyser;D. Gillespie;B. Eisenberg
自从门控电流被发现以来，电生理学家通过改变电位和测量产生的电容电流来研究通道蛋白内带电基团的运动。然而，带电基团的原子尺度运动与在外部电路中测量的门控电流的关系并不明显。我们在这里报告，这个问题的一般解决方案存在的形式的拉莫-肖克利定理。对于具有不同数量的原子细节的系统，我们使用该定理来计算由蛋白质电荷运动产生的门控电荷。即使没有计算或模拟，Ramo-Shockley定理也消除了对实验结果的一类解释。该定理也可以在模拟的每个时间步长处使用以计算外部电流。
Since the discovery of gating current, electrophysiologists have studied the movement of charged groups within channel proteins by changing potential and measuring the resulting capacitive current. The relation of atomic-scale movements of charged groups to the gating current measured in an external circuit, however, is not obvious. We report here that a general solution to this problem exists in the form of the Ramo-Shockley theorem. For systems with different amounts of atomic detail, we use the theorem to calculate the gating charge produced by movements of protein charges. Even without calculation or simulation, the Ramo-Shockley theorem eliminates a class of interpretations of experimental results. The theorem may also be used at each time step of simulations to compute external current.