精氨酸、精氨酸盐酸、半胱氨酸、胱氨酸对重组人tPA蛋白复性的影响

以重组人tPA蛋白为材料研究了精氨酸、精氨酸盐酸盐、半胱氨酸、胱氨酸对蛋白质复性效果的影响,重组tPA蛋白包涵体经尿素变性溶解后,在精氨酸、精氨酸盐酸盐、半胱氨酸、胱氨酸存在的条件下进行复性,结果表明,碱性的精氨酸在质量分数0.2%时可减少蛋白质凝聚,显著提高复性效果,tPA复性后的活性可提高50%以上,半胱氨酸单独使用具有类似β-巯基乙醇的作用,精氨酸盐酸盐和胱氨酸单独使用对复性无影响,而半胱氨酸和胱氨酸联合使用,有类似氧化-还原系统作用。可提高活性20%。

Effects of Arginine, Arginine Hydrochloride, Cysteine, Cystine on tPA Renaturation

The effects of arginine, arginine - cl, cysteine and cystine on the renaturation of human tPA were studied, tPA inclusion body protein was dissolved and denatured in 8M urea with 5mM 2 - ME at pH 9.5. After removed urea and 2 -ME by G -25 column chromatography, the tPA protein in the solution was renatured in the present of arginine, arginine - cl, cysteine and cysteine - cystine. At pH 8.0 and room temperature for 24hr, the efficiency of renaturation was evaluated according to the activity of tPA. The results demonstrated that the renaturation efficiency of tPA was increased over 50 % by arginine alone, but arginine hydrochloride and cystine had no effect on tPA renaturation, the cysteine alone or cysteine plus cystine could slightly increase tPA activity.