Interactions of proteins with uniform colloidal hematite and chromium hydroxide particles. II. Stability and mobility

Stability of hematite and chromium hydroxide particles covered by ovalbumin, -globulin, and lysozyme, respectively, and mobilities of the same coated particles in aqueous media were investigated as a function of the pH, ionic strenght [NaNO₃, Mg(NO₃)₂], and the amount of added proteins. It was found that ovalbumin causes electrosteric stabilization of dispersions at pH values other than 5, while flocculation occurred at pH 5 (which was the i.e.p. of the coated particles). Mobility curves of ovalbumin covered particles resembled those of the pure protein. Dispersions with -globulin flocculated at and around the i.e.p. of the macromolecule (pH7). The mobility curves of -gobulin-coated sols were intermediate between those of the protein and of the cores, and were dependent upon the amount of adsorbed -globulin. Heterocoagulation was observed for both hematite and chromium hydroxide dispersions with lysozyme. Mobilities of lysozyme covered particles were between those of the cores and of the protein, but were not dependent upon the quantity of adsorbed polymer.Supported by the NSF Grant CHE-9108420Part of a Ph.D. Thesis     

源于大肠杆菌蛋白的表达、液相色谱复性与纯化新进展

对近两年来源于大肠杆菌（Escherichia coli,E．coli）的蛋白表达和用蛋白折叠液相色谱（protein folding liquid chromatography,PFLC）法对所形成的包涵体目标蛋白的复性并同时纯化的新近发展做了简要的介绍和评述．PFLC法用于包涵体蛋白分离、纯化很广,其特点是除了在色谱柱上将目标蛋白与其他组分分开,还同时要在色谱柱上进行包涵体蛋白折叠．可以说,现代生物技术中所用的大多数有价值蛋白产品的制备仍然有赖于不同机理的液相色谱（Lc）法．而用PFLC法对源于E．coli的蛋白的制备方法更具可塑性和容易达到规模化,其生成本可以成倍地降低．该文主要内容包括了E．coli蛋白的表达及样品前处理、PFLC的实用范围、PFLC的优化、PFLC中的新技术、新设备和新方法、PFLC的分子学机理、应用事例及对未来的展望．