Spatial distribution of a depletion potential between a big solute of arbitrary geometry and a big sphere immersed in small spheres
Spatial distribution of a depletion potential between a big solute of arbitrary geometry and a big sphere immersed in small spheres
复制标题
DOI：
10.1063/1.1445106
复制
发表时间：
2002-02-22
影响因子：
4.4
通讯作者：
Kinoshita, M
中科院分区：
文献类型：
--
作者：
Kinoshita, M
在三维立方网格上求解超网链积分方程，计算了任意几何形状的大溶质和浸在形成溶剂的小球体中的大球体之间的耗尽势的空间分布。通过分析大球体沿特定轨迹的势，可以详细地考察由于大溶质的几何特征（台阶边缘、沟槽、角落、曲率变化等）而产生的影响。作为一个例子，分析了台阶边对沿壁面横向耗尽电位的影响。沿着所考虑的轨迹，大球体以恒定的高度移动，从壁面的中心开始，水平移动过边缘。大球体从边缘被排斥到壁面，为了逃逸到整体，它必须克服一个非常高的自由能垒。作为另一个例子，对大分子之间的锁和键的空间相互作用进行了简单的模型计算。正好适合锁的钥匙的接触电位（即稳定自由能）远远大于较小和较大的钥匙，并且大大超过Asakura-Oosawa理论预测的值。(C) 2002年美国物理研究所。
The hypernetted-chain integral equations are solved on a three-dimensional cubic grid to calculate the spatial distribution of the depletion potential between a big solute of arbitrary geometry and a big sphere immersed in small spheres forming the solvent. By analyzing the potential along a specific trajectory of the big sphere, effects due to the geometric feature of the big solute (step edges, trenches, corners, changing curvature, etc.) can be examined in detail. As an illustration, effects of the step edge on the lateral depletion potential along a wall surface are analyzed. Along the trajectory considered, the big sphere moves at constant height, starting on the center of the wall surface and moving horizontally past the edge. The big sphere is repelled from the edge into the wall surface, and to escape to the bulk it must overcome a significantly high free-energy barrier. As another illustration, simple model calculations are performed for the lock and key steric interaction between macromolecules. The potential at contact (i.e., the stabilization free energy) for the key that exactly fits the lock is far larger than for smaller and larger keys and considerably in excess of the value predicted by the Asakura-Oosawa theory. (C) 2002 American Institute of Physics.