Zitserman Vladimir Yu, Berezhkovskii Alexander M, Pustovoit Mark A, Bezrukov Sergey M
Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 125412, Russia.
J Chem Phys. 2008 Sep 7;129(9):095101. doi: 10.1063/1.2972981.
We analyze the relaxation of the particle number fluctuations in a membrane channel at arbitrary particle-channel interaction and derive general expressions for the relaxation time and low-frequency limit of the power spectral density. These expressions simplify significantly when the channel is symmetric. For a square-well potential of mean force that occupies the entire channel, we verify the accuracy of the analytical predictions by Brownian dynamics simulations. For such a channel we show that as the depth of the well increases, the familiar scaling of the relaxation time with the channel length squared is transformed into a linear dependence on the length.
我们分析了在任意粒子-通道相互作用下膜通道中粒子数涨落的弛豫情况，并推导了弛豫时间和功率谱密度低频极限的一般表达式。当通道对称时，这些表达式会显著简化。对于占据整个通道的平均力方阱势，我们通过布朗动力学模拟验证了解析预测的准确性。对于这样的通道，我们表明随着阱深度的增加，弛豫时间与通道长度平方的常见标度关系转变为对长度的线性依赖。
