Tessier Peter M, Sandler Stanley I, Lenhoff Abraham M
Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716, USA.
Protein Sci. 2004 May;13(5):1379-90. doi: 10.1110/ps.03419204. Epub 2004 Apr 9.
The importance of weak protein interactions, such as protein self-association, is widely recognized in a variety of biological and technological processes. Although protein self-association has been studied extensively, much less attention has been devoted to weak protein cross-association, mainly due to the difficulties in measuring weak interactions between different proteins in solution. Here a framework is presented for quantifying the osmotic second virial cross coefficient directly using a modified form of self-interaction chromatography called cross-interaction chromatography. A theoretical relationship is developed between the virial cross coefficient and the chromatographic retention using statistical mechanics. Measurements of bovine serum albumin (BSA)/lysozyme cross-association using cross-interaction chromatography agree well with the few osmometry measurements available in the literature. Lysozyme/alpha-chymotrypsinogen interactions were also measured over a wide range of solution conditions, and some counterintuitive trends were observed that may provide new insight into the molecular origins of weak protein interactions. The virial cross coefficients presented in this work may also provide insight into separation processes that are influenced by protein cross-interactions, such as crystallization, precipitation, and ultrafiltration.
弱蛋白质相互作用的重要性，如蛋白质自缔合，在各种生物学和技术过程中已得到广泛认可。尽管蛋白质自缔合已得到广泛研究，但对弱蛋白质交叉缔合的关注却少得多，主要是因为难以测量溶液中不同蛋白质之间的弱相互作用。本文提出了一个框架，用于直接使用一种称为交叉相互作用色谱的自相互作用色谱的改进形式来量化渗透第二维里交叉系数。利用统计力学建立了维里交叉系数与色谱保留之间的理论关系。使用交叉相互作用色谱法对牛血清白蛋白（BSA）/溶菌酶交叉缔合的测量结果与文献中现有的少量渗透压测量结果吻合良好。还在广泛的溶液条件下测量了溶菌酶/α-胰凝乳蛋白酶原相互作用，并观察到一些与直觉相反的趋势，这些趋势可能为弱蛋白质相互作用的分子起源提供新的见解。本文给出的维里交叉系数也可能为受蛋白质交叉相互作用影响的分离过程提供见解，如结晶、沉淀和超滤。
