Sugawara Takeshi, Kaneko Kunihiko
Cell Architecture Laboratory, Center for Frontier Research, National Institute of Genetics, 1111, Yata, Mishima, Shizuoka 411-8540, Japan.
Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro, Tokyo 153-8902, Japan; Complex Systems Biology Project, ERATO, JST, Komaba, Meguro, Tokyo 153-8902, Japan.
Biophysics (Nagoya-shi). 2011 Sep 11;7:77-88. doi: 10.2142/biophysics.7.77. eCollection 2011.
Biological units such as macromolecules, organelles, and cells are directed to a proper location by gradients of chemicals. We consider a macroscopic element with surface binding sites where chemical adsorption reactions can occur and show that a thermodynamic force generated by chemical gradients acts on the element. By assuming local equilibrium and adopting the grand potential used in thermodynamics, we derive a formula for the "chemophoresis" force, which depends on chemical potential gradients and the Langmuir isotherm. The conditions under which the formula is applicable are shown to occur in intracellular reactions. Further, the role of the chemophoresis in the partitioning of bacterial chromosomal loci/plasmids during cell division is discussed. By performing numerical simulations, we demonstrate that the chemophoresis force can contribute to the regular positioning of plasmids observed in experiments.
诸如大分子、细胞器和细胞等生物单元会通过化学物质的梯度被引导至合适的位置。我们考虑一个具有表面结合位点的宏观元素，在该位点可发生化学吸附反应，并表明由化学梯度产生的热力学力作用于该元素。通过假设局部平衡并采用热力学中使用的巨势，我们推导出了一个“化学趋肤效应”力的公式，该公式取决于化学势梯度和朗缪尔等温线。结果表明，该公式适用的条件会出现在细胞内反应中。此外，还讨论了化学趋肤效应在细胞分裂过程中细菌染色体位点/质粒分配中的作用。通过进行数值模拟，我们证明了化学趋肤效应力有助于实现实验中观察到的质粒的规则定位。
