Method for improving catalytic performance of trypsin through multi-strategy combined mutation

The invention discloses a method for improving the catalytic performance of trypsin through multi-strategy combined mutation. According to a mutant, trypsin with the amino acid sequence shown in SEQ ID NO.3 serves as a parent, the 30 < th > amino acid is mutated into proline, the 224 < th > amino acid is mutated into asparagine, and the trypsin with the amino acid sequence shown in SEQ ID NO.3 serves as the parent. And serine, lysine, leucine, leucine, proline and proline are inserted between the 13th amino acid and the 14th amino acid to obtain the amino acid sequence. According to the invention, a trypsin molecular structure is modified by a method of inserting a gene segment and combining point mutation, and a mutant strain with improved thermal stability is obtained after mutation verification. The thermal stability of the mutant is obviously improved, and the catalytic activity of the enzyme is not influenced or even improved. The mutant can be industrially produced at a relatively high temperature, meet