Taflia Adi, Holcman David
Department of Mathematics, Weizmann Institute of Science, Rehovot 76100, Israel.
J Chem Phys. 2007 Jun 21;126(23):234107. doi: 10.1063/1.2746840.
We calculate the mean time a Brownian particle spends in a domain with traps and the number of bonds it makes before escaping through a small hole in the boundary. This mean time, called the Dwell time, depends on the backward binding rate (with the trap, e.g., scaffolding molecules), the mean time to reach the trap (forward binding rate), and the size of the hole. We estimate the mean and variance of the number of bonds made prior to exit. In a biochemical context, a quantitative signal occurs when the mean number of bonds exceeds a certain threshold, which may initiate a cascade of chemical reactions that have physiological consequences. We apply the present results to obtain estimates of the mean time a Brownian receptor spends inside a synaptic domain, when it moves freely by lateral diffusion on the membrane of a neuron and interacts at a synapse with scaffolding molecules.
我们计算了布朗粒子在有陷阱的区域中停留的平均时间，以及它在通过边界上的一个小孔逃逸之前形成的键的数量。这个平均时间，称为驻留时间，取决于反向结合速率（与陷阱，例如支架分子）、到达陷阱的平均时间（正向结合速率）以及孔的大小。我们估计了出口前形成的键的数量的均值和方差。在生化背景下，当键的平均数量超过某个阈值时，就会出现定量信号，这可能会引发一系列具有生理后果的化学反应。我们应用当前结果来估计布朗受体在突触区域内停留的平均时间，当它通过横向扩散在神经元膜上自由移动并在突触处与支架分子相互作用时。
