Phase Equilibrium Theory of Aqueous Two-Phase Extraction: International Collaboration

该项目的目的是发展基于统计力学的蛋白质在含有聚乙二醇和葡聚糖或聚乙二醇和盐的两相聚合物水溶液中的溶解度的一般、全面的理论。目的是预测模型聚合物水相两相体系的自由能、水相分离和蛋白质分配系数作为一系列重要参数的函数：蛋白质和聚合物浓度、蛋白质和聚合物相对分子质量、蛋白质电荷、pH、蛋白质类型、聚合物类型、盐类型、离子强度、温度和亲和配体的结合能。这一理论将得到与世界著名的双水相萃取专家、德国杜塞尔多夫酶技术研究所的M·R·库拉教授合作进行的一系列国际实验的支持。这些实验将在库拉博士的实验室和北卡罗来纳州立大学的实验室进行。尽管双水相萃取技术在未来的分离技术中具有重要意义，但目前还没有全面的理论框架来预测这些体系中的蛋白质分配。这种基于统计力学的方法将使人们能够研究排除的体积效应和电子相互作用的相对重要性，并预测蛋白质分配系数和离子分配系数的值。这项研究应该提供对蛋白质分配的分子基础的洞察，并产生有用的蛋白质分配系数的关联。

The aim of this project is the development of a general, comprehensive theory, based on statistical mechanics, of protein solubility in two- phase aqueous polymer solutions containing either polyethylene glycol and dextran or polyethylene glycol and salt. The objective is to predict free energies, aqueous phase separations and protein partition coefficients for a model aqueous polymer two-phase system as a function of a number of important parameters: protein and polymer concentrations, protein and polymer molecular weights, protein charge, pH, protein type, polymer type, salt type, ionic strength, temperature and the binding energy of affinity ligands. The theory will be supported by a series of experiments conducted in international collaboration with a world-renown expert in aqueous two phase extraction, Prof. Dr. M. R. Kula of the Institute for Enzyme Technology in Dusseldorf, Germany. The experiments will be performed both in Dr. Kula's laboratory and in the North Carolina State University laboratory. Despite the projected importance of aqueous two-phase extractive techniques for future separations technology, no comprehensive theoretical framework exists for predicting protein partitioning in these systems. This approach, which is based in statistical mechanics, will allow one to investigate the relative importance of excluded volume effects and electronic interactions and to predict values for both protein partition coefficients and ion partition coefficients. The research should provide insight into the molecular basis of protein partitioning and yield a useful correlation of protein partition coefficients.