蛋白酶K的突变及其性质研究

Study on the mutation of proteinase K and its properties

首先获得了野生型的蛋白酶K表达菌株,然后通过软件预测得到了对其热稳定性具有潜在影响的3个氨基酸残基位点,对其进行了点突变,分别在毕赤酵母(Pichia pastoris)GS115中进行了分泌表达,通过筛选获得了1个热稳定性提高了30%,比活性提高约50%的蛋白酶K突变体pPicZαA-PK108。这对蛋白酶K在工业上的应用起到了一定的促进作用,可以减少蛋白酶K在洗涤剂、食品加工中的用量,降低生产成本;此外,也可提高污水中病毒的灭活效率,减少环境污染。

A wild-type proteinase K expression strain was obtained.Then three amino acid residue positions that had potential effects on its thermal stability were obtained through software prediction,and point mutations were performed on them in Pichia pastoris GS115,respectively.Secreted expression was carried out,a proteinase K mutant pPicZαA-PK108 with a 30%increase in thermal sta⁃bility and an approximately 50%increase in specific activity was obtained.This study had played a certain role in promoting the appli⁃cation of proteinase K in industry.It can reduce the amount of proteinase K used in detergent and food industry,and reduce production costs.In addition,it can also improve the efficiency of virus inactivation in sewage and reduce the environment pollution.