Molecular origins of osmotic second virial coefficients of proteins
Molecular origins of osmotic second virial coefficients of proteins
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DOI：
10.1016/s0006-3495(98)77691-x
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发表时间：
1998-11-01
影响因子：
3.4
通讯作者：
Lenhoff, AM
中科院分区：
文献类型：
--
作者：
Neal, BL;Asthagiri, D;Lenhoff, AM
蛋白质溶液的热力学性质是由溶剂分子和溶质分子的相互作用决定的。对这种关系的定量理解将有助于更系统地操作过程环境中的属性。本文研究了渗透二次维里系数B-22的分子基础；渗透效应在膜运输中是至关重要的，B-22的值也被证明与蛋白质结晶行为有关。这里的计算考虑了空间、静电和短程相互作用，并明确考虑了蛋白质分子的结构和功能各向异性。蛋白质相互作用的方向依赖性被认为对计算有显著的影响；特别是，相对较少的蛋白质-蛋白质构型中，相对的表面显示几何互补性，对B-22的贡献不成比例。静电相互作用的重要性也在这些高互补性配置中被放大。分子识别在确定B-22中的重要性可以解释与结晶行为的相关性，并表明局部分子几何形状的改变有助于操纵蛋白质溶液行为。这些结果也暗示了蛋白质相互作用在生物自组织中的作用。
The thermodynamic properties of protein solutions are determined by the molecular interactions involving both solvent and solute molecules. A quantitative understanding of the relationship would facilitate more systematic procedures for manipulating the properties in a process environment. In this work the molecular basis for the osmotic second virial coefficient, B-22, is studied; osmotic effects are critical in membrane transport, and the value of B-22 has also been shown to correlate with protein crystallization behavior. The calculations here account for steric, electrostatic, and short-range interactions, with the structural and functional anisotropy of the protein molecules explicitly accounted for. The orientational dependence of the protein interactions is seen to have a pronounced effect on the calculations; in particular, the relatively few protein-protein configurations in which the apposing surfaces display geometric complementarity contribute disproportionately strongly to B-22. The importance of electrostatic interactions is also amplified in these high-complementarity configurations. The significance of molecular recognition in determining B-22 can explain the correlation with crystallization behavior, and it suggests that alteration of local molecular geometry can help in manipulating protein solution behavior. The results also have implications for the role of protein interactions in biological self-organization.