Patent ID: 11001823

Abstract:
The present invention discloses a nitrilase mutant and application thereof. The mutant is obtained by mutating the amino acid at position 201 or replacing one or more amino acids at region 324-381 of the amino acid sequence shown in SEQ ID No. 2. In the present invention, by the protein molecular modification, thermostability of the purified nitrilase LNIT5 is increased by up to 4.5 folds; and by utilizing recombinant E. coli containing the nitrilase mutant to hydrolyze 1-cyanocyclohexylacetonitrile at a high temperature (45° C.), product tolerance is increased, activity of NIT5-L201F is increased by 20%, and the mutant NITLNIT5-AcN can completely hydrolyze 750 mM 1-cyanocyclohexylacetonitrile within 8 hours and achieve an doubled conversion rate. Therefore, the mutants obtained by the present invention have a good application prospect in efficiently catalyzing 1-cyanocyclohexylacetonitrile to synthesize gabapentin intermediate, 1-cyanocyclohexyl acetic acid. In the present invention, by protein molecular modification, thermal stability of pure nitrilase LNIT5 at 45° C. is increased up to 4.5 times, and while 1-cyanocyclohexylacetonitrile is hydrolyzed using recombinant Escherichia coli containing nitrilase mutant at high temperature (45° C.), the product yield is increased. Therefore, the mutants obtained in the present invention have a good application prospect in highly efficiently catalyzing 1-cyanocyclohexylacetonitrile to 1-cyanocyclohexyl acetic acid, the gabapentin intermediate.