4results about How to "Increased specific enzyme activity" patented technology

This invention discloses a method with NMN + A preferred glucose-6-phosphate dehydrogenase mutant and its preparation method were investigated. Using the TmG6PDH-R7 mutant as the starting protein, random mutations were performed using error-prone PCR to construct a random mutant library. A high-throughput screening method for positive clones on plates was used to obtain the clones with the most obvious color development. Recombinant bacteria were cultured and purified to obtain the mutants. After three rounds of screening, NMN with amino acid sequences as shown in SEQ ID NO.6, SEQ ID NO.8, or SEQ ID NO.10 was obtained. + A glucose-6-phosphate dehydrogenase mutant with enhanced preference, achieving NMN + The specific enzyme activity of TmG6PDH coenzyme is increased. The mutant with the amino acid sequence shown in SEQ ID NO.10 has more than 5 times higher specific enzyme activity at 37 degrees compared with the R7 mutant with the highest specific enzyme activity, and has good application prospects in industrial production.

The application discloses a sulfonylurea herbicide hydrolytic enzyme TsmE mutant, a coding gene thereof and application. The sulfonylurea herbicide hydrolytic enzyme TsmE mutant has an amino acid sequence shown in SEQ ID NO. 4. The application also discloses a gene coding the mutant. The application further discloses application of the mutant in degrading sulfonylurea herbicides. The application takes wild-type TsmE as a starting template, and obtains a mutant M7 (S179A) with significantly improved enzyme activity through a directional evolution technology. Compared with the wild type, the specific enzyme activity of the mutant M7 to metsulfuron methyl, mesosulfuron methyl, tribenuron, bensulfuron methyl, sulfometuron methyl and chlorimuron ethyl is respectively increased by 1.7, 1.6, 2.5, 1.3, 1.4 and 1.2 times. The mutant and the coding gene thereof can be used for constructing a sulfonylurea herbicide-resistant transgenic crop, and can also be used for removing sulfonylurea herbicides in soil and water, and has very important theoretical and application values.

The application discloses an acyl-CoA synthetase mutant, a coding gene thereof, an expression strain and application thereof. The application is based on an acyl-CoA synthetase from a marine uncultured microbial source, a mutation site is designed by using Funclib, and then a whole gene is synthesized to obtain a mutant gene. After expression of an engineering bacterium containing the mutant plasmid, an acyl-CoA synthetase with improved specific enzyme activity and stability is obtained. When palmitic acid is used as a substrate, the specific enzyme activity of the mutant is improved by 7.0 times, and the mutant has potential application value in an enzyme method for detecting free fatty acids in vitro.

The invention relates to a dicamba monooxygenase mutant DicX4M2 and application of the dicamba monooxygenase mutant DicX4M2. In particular to a dicamba monooxygenase mutant DicX4M2, a gene for coding the dicamba monooxygenase mutant DicX4M2, a recombinant vector inserted with the gene, a transformant transformed with the gene, a method for improving the activity of the dicamba monooxygenase, a method for preparing the dicamba monooxygenase mutant DicX4M2 and application of the dicamba monooxygenase mutant DicX4M2 and the dicamba monooxygenase mutant DicX4M2. Compared with the wild type dicamba monooxygenase, the dicamba monooxygenase mutant DicX4M2 obtained after the 82nd histidine of the wild type dicamba monooxygenase is replaced with isoleucine and the 190th phenylalanine of the wild type dicamba monooxygenase is replaced with leucine has the advantages that the enzyme activity is obviously improved, and the dicamba monooxygenase mutant DicX4M2 has a better dicamba degradation effect; the dicamba-resistant crops can be prepared, and the dicamba resistance of the crops is improved.