Artificially modified enzyme of pepsin with high enzyme activity and molecular modification method and expression application of artificially modified enzyme

The invention discloses an artificially modified enzyme of pepsin with high enzyme activity and a molecular modification method and expression application of the artificially modified enzyme. Rational design is performed on the basis of the distance between an O atom of water at a catalytic active site and an amide C atom of a peptide bond to improve the activity of the pepsin, and the pepsin is subjected to artificial molecular modification; and screening to obtain a mutant of which the enzyme activity is remarkably improved. The sequence, the structure and the function of the pepsin are deeply researched, and the pepsin is mutated from two aspects of stabilizing a catalytic structure and promoting a catalytic reaction, so that the high-activity enzyme with higher application value in industrial production is obtained. 本申请公开了一种高酶活胃蛋白酶的人工改造酶及其分子改造方法和表达应用，以催化活性位点处水的O原子与肽键的酰胺C原子间距离为基础进行理性设计提高胃蛋白酶活性，对胃蛋白酶进行人工分子改造，筛选得到酶活显著提高的突变体。本发明通过对胃蛋白酶的序列、结构和功能进行深入研究，从稳定催化结构和促进催化反应两方面对胃蛋白酶进行突变，获取在工业生产中更具备应用价值的高活力酶。