人工伴侣和盐酸胍促进溶菌酶复性的协同效应

COOPERATIVE EFFECT OF ARTIFICIAL CHAPERONE AND GUANIDINE HYDROCHLORIDE ON FACILITATING LYSOZYME REFOLDING

研究了表面活性剂十六烷基三甲基溴化铵 (CTAB)加 β -环糊精 (β -CD) (人工伴侣系统 )和盐酸胍对高浓度变性 -还原溶菌酶氧化复性的影响 ,利用基于二态复性模型的表观动力学模型分析了溶菌酶的复性过程 .结果表明 ,存在最佳盐酸胍浓度 ,使酶的复性率最大 ;当盐酸胍浓度一定时 ,提高人工伴侣系统的浓度使复性反应速率常数增大、逆反应速率常数降低 ,从而提高复性收率 ,证明人工伴侣和盐酸胍对促进变性溶菌酶复性具有协同效应 .在最佳盐酸胍浓度和较高浓度的人工伴侣存在下 ,6 0min内可使浓度为 1.0 5mg·ml-1的变性酶复性收率达到81% ,而相同条件下的自发复性收率仅为 49% .

The effect of guanidine hydrocloride (GuHCl) concentration on the oxidative refolding of denatured-reduced lysozyme of high concentration in the presence of artificial chaperone, that is, cetyl trimethyl ammonium bromide (CTAB) and β-cyclodextrin (β-CD), was studied. A two-state refolding model was used to analyze the refolding kinetics. It was shown that there existed an optimum GuHCl concentration that gave maximum refolding yield of lysozyme. At this GuHCl concentration, the refolding rate constant increased, while the reverse refolding-rate constant decreased, with the increase of artificial chaperone concentration, which led to the increase of refolding yield. The results indicated that the effect of artificial chaperone and GuHCl was cooperative in facilitating the refolding of denatured-reduced lysozyme. At the optimum GuHCl concentration, the spontaneous refolding yield of 1.05 mg &middot ml-1 lysozyme in 60 min was only 49%. In contrast, cooperated with artificial chaperone-facilitated refolding the recovery yield reached as high as 81%.