Cooperative Effect of Artificial Chaperones and Guanidinium Chloride on Lysozyme Renaturation at High Concentrations

It has been recognized that the artificial chaperone system, cetyltrimethylammonium bromide and beta-cyclodextrin, is effective for enhancing protein renaturation. In this work, we studied the effect of the artificial chaperone system and guanidinium chloride (GdmC1) on the oxidative renaturation of lysozyme at 0.21—1.05 mg/mL, and a kinetic model based on the competition between protein folding and aggregation was employed to express the renaturation process. The refolding rate constant increased, while the aggregation rate constant decreased, with increasing concentration of the artificial chaperones. With increasing GdmC1 concentration (0.28—2 M), both rate constants decreased, but there existed a specific GdmC1 concentration that maximized the ratio of the two rate constants and thus the renaturation yield. The results obviously indicated the cooperative effect of GdmC1 and the artificial chaperones on enhancing protein renaturation.