非还原脲变性蛋白溶菌酶稀释复性过程中集聚现象的研究

用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、阴极聚丙烯酰胺凝胶电泳和高效凝胶排阻色谱法, 研究了非还原脲变性蛋白溶菌酶在稀释复性过程中的集聚现象. 实验发现, 在整个稀释复性过程中, 没有蛋白溶菌酶集聚体沉淀产生. 当最终复性液中蛋白溶菌酶浓度小于4.0 mg/mL时, 复性过程中不会形成蛋白溶菌酶分子集聚体; 当最终复性液中蛋白溶菌酶浓度介于4.0～8.0 mg/mL时, 复性过程中会形成由非共价相互作用所引起的蛋白溶菌酶二分子和三分子集聚体; 而当最终复性液中蛋白溶菌酶浓度大于8.0 mg/mL时, 复性过程中除了会形成二分子和三分子蛋白溶菌酶集聚体外, 还会形成四分子蛋白溶菌酶集聚体. 在此基础上, 结合文献, 对非还原脲变性蛋白溶菌酶的稀释复性过程进行了描述.

Aggregation Interaction among Non-Reducing Egg White Lysozymes Denatured by Urea during Their Refolding

The aggregation interaction between non-reducing-denatured egg white lysozyme during the refolding procedure in urea solution was studied by means of normal SDS-PAGE, cathode PAGE and size-exclusion chromatography. It was found that contrary to the refolding procedure of reduced-denatured egg white lysozyme in urea solution, no aggregate precipitate was formed in the refolding procedure of non-reducing-denatured egg white lysozyme in urea solution. When the final egg white lysozyme concentration in renaturation solution was lower than 4.0 mg/mL, no egg white lysozyme aggregate was formed during the refolding procedure of non-reducing-denatured egg white lysozyme in urea solution; when the final egg white lysozyme concentration was in the range of 4.0-8.0 mg/mL, the bi-molecular and tri-molecular egg white lysozyme aggregates could be formed through the non-covalent interaction among the egg white lysozyme intermediates formed in the refolding procedure of non-reducing-denatured egg white lysozyme; and when the final egg white lysozyme concentration was higher than 8.0 mg/mL, the tetra-molecular egg white lysozyme aggregate could also be formed besides the bi-molecular and tri-molecular egg white lysozyme aggregates. And finally, a suggested refolding procedure of non-reducing-denatured egg white lysozyme in urea solution was presented.