Analysis of steric partition behavior of molecules in membranes using statistical physics. Application to gel chromatography and electrophoresis.
Analysis of steric partition behavior of molecules in membranes using statistical physics. Application to gel chromatography and electrophoresis.
复制标题
使用统计物理学分析膜中分子的空间分配行为。
DOI：
10.1016/s0006-3495(88)83043-1
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发表时间：
1988
影响因子：
3.4
通讯作者：
Schnitzer,JE
中科院分区：
文献类型：
--
作者：
Schnitzer,JE
统计物理学的原理被用来制定一般表达式的空间分配行为的分子在随机和有序的膜结构，可以适用于任何形状的溶质和/或体积排除元素的膜。这些表达式完全定义了分区的体积排除点分子和有限大小的分子。分子的平均有效排阻体积计算为全局相互作用能的函数，其随分子的位置、构象和取向而变化。它允许考虑静电和其他非空间因素。为了测试模型，特定的配分函数推导出几个简单的几何形状描述的膜和溶质。经常，推导出的表达式同意过去的分析，但是，一个新的表达式描述分区内的随机网络的纤维推导。它只在低排阻体积的限制下与过去的结果一致。随着更大的体积排除，过去的结果大大高估了分配函数。它适用于凝胶电泳和色谱，并通过了可用实验数据的测试。与过去的分析不同，它预测琼脂糖凝胶电泳的非线性弗格森图。此外，一个解析表达式预测排除从随机纤维矩阵的球的最小半径的推导，测试，并发现与实验数据一致。
The principles of statistical physics are used to formulate general expressions for the steric partition behavior of molecules in both random and ordered membrane structures that may be applied to any shape of the solute and/or the volume-excluding element of the membrane. These expressions fully define partitioning in terms of the volume excluded to point molecules and to finite-sized molecules. The mean effective exclusion volume for a molecule is calculated as a function of a global interaction energy, which varies with position, conformation, and orientation of the molecule. It allows consideration of electrostatic and other nonsteric factors. To test the model, specific partition functions are derived for several simple geometries describing the membrane and solute. Frequently, the derived expressions agree with past analyses; however, a new expression describing partitioning within an random network of fibers is derived. It agrees with past results only in the limit of low exclusion volumes. With greater volume exclusions, past results greatly overestimate the partition function. It is applied to gel electrophoresis and chromatography and survives testing with available experimental data. Unlike past analyses, it predicts nonlinear Ferguson plots for agarose gel electrophoresis. In addition, an analytical expression predicting the minimum radius of a sphere excluded from a random fiber matrix is derived, tested, and found to agree with experimental data.