Sung Bong June, Yethiraj Arun
Department of Chemistry, Sogang University, Seoul, Republic of Korea.
Biophys J. 2009 Jul 22;97(2):472-9. doi: 10.1016/j.bpj.2009.04.060.
The diffusion of proteins in the cell membrane is investigated using computer simulations of a two-dimensional model. The membrane is assumed to be divided into compartments, with adjacent compartments separated by a barrier of stationary obstacles. Each compartment contains traps represented by stationary attractive disks. Depending on their size, these traps are intended to model either smaller compartments or binding sites. The simulations are intended to model the double-compartment model, which has been used to interpret single molecule experiments in normal rat kidney cells, where five regimes of transport are observed. The simulations show, however, that five regimes are observed only when there is a large separation between the sizes of the traps and large compartments, casting doubt on the double compartment model for the membrane. The diffusive behavior is sensitive to the concentration and size of traps and the strength of the barrier between compartments suggesting that the diffusion of proteins can be effectively used to characterize the structure of the membrane.
使用二维模型的计算机模拟研究蛋白质在细胞膜中的扩散。假设膜被划分为多个隔室，相邻隔室由固定障碍物的屏障隔开。每个隔室包含由固定吸引盘表示的陷阱。根据其大小，这些陷阱旨在模拟较小的隔室或结合位点。这些模拟旨在模拟双隔室模型，该模型已被用于解释正常大鼠肾细胞中的单分子实验，在该实验中观察到了五种运输模式。然而，模拟结果表明，只有当陷阱和大隔室的大小之间存在很大差异时才会观察到五种模式，这对膜的双隔室模型提出了质疑。扩散行为对陷阱的浓度和大小以及隔室之间屏障的强度敏感，这表明蛋白质的扩散可以有效地用于表征膜的结构。
