Please select the most similar patent number from A, B, C and D. Which number is?
Disclosed is a new bifunctional lipase mutant and uses thereof in flour product processing. An amino acid sequence of the mutant has mutations in the form of 1) or 2): 1) P298T; P298T/H317P; P298T/H317P/V326S; P298T/T218S/S234F; P298T/H317P/P168L/A129S; P298T/S234F/K161R/V326S; and 2) a nucleotide sequence with homology over 80% that is obtained through deletion, substitution, insertion or mutation of bases on the basis of a nucleotide sequence defined in 1). The mutant has good application effects in flour product processing. The mutant has a significant whitening effect in processing of flour products such as steamed bun and has an effect of significantly increasing the specific volume in bread baking processing, and therefore has a good application prospect.
A: Disclosed is a nitrilase mutant and an application thereof. The mutant is obtained by one or more substitutions of amino acids at position 201 or amino acid sequences at positions 324-381 of the amino acid sequence shown in SEQ ID No. 2. Following protein modification, the thermal stability of the pure enzyme of nitrilase LNIT5 at 45°C is increased by a maximum of 4.5 times. By hydrolyzing 1-cyanocyclohexane acetonitrile under a high temperature (45°C) using a recombinant Escherichia coli containing a nitrilase mutant, the product yield is increased. Therefore, the obtained mutant is favorably applicable for high-efficacy catalysis of 1-cyanocyclohexane acetonitrile to synthesize 1-cyanocyclohexane acetic acid, which is an intermediate of gabapentin.
B: A double-carbonyl reductase mutant and application thereof. An amino acid sequence of the double-carbonyl reductase mutant is the mutant amino acid sequence coded by SEQ ID NO:9, the mutant amino acid sequence has at least two mutation sites: NO:94, NO:151, NO:231, NO:236 and NO:251, and the I mutation of NO:94 is V, A or G; the V mutation of NO:151 is Q, N or S; the F mutation of NO:231 is W, Y or P; the I mutation of NO:236 is L, V or A; the Q mutation of NO:251 is H, R or K; or the amino acid sequence of the double-carbonyl reductase mutant has the mutation sites in the mutant amino acid sequence, and has greater than 90% homology with the mutant amino acid sequence. The enzymatic activity of the double-carbonyl reductase mutant having the mutation sites is improved substantially.
C: Provided is a transaminase mutant, having a sequence on which an amino acid mutation takes place on the basis of the sequence as represented by SEQ ID NO: 13. Provided is an enatioselective flipped ω-transaminase ATA-117 mutant. The amino acid sequence of the mutant is as represented by SEQ ID NO: 1; the nucleic acid sequence coding the mutant is as represented by SEQ ID NO: 2. Also provided is a plasmid carrying the nucleic acid sequence, genetically engineered bacteria expressing the ω-transaminase ATA-117 mutant, and a method for producing (1R,2R)-1,3-dihydroxy-2-amino-1-p-methylsulfonylphenylpropane with the ω-transaminase ATA-117 mutant.
D: Provided is a lipase mutant and an application thereof. The amino acid sequence of the lipase mutant has the sequence shown in SEQ ID NO: 1, that is, the amino acid mutation site comprises a V154L site. The protein structure and function of the lipase mutant are changed, the solubility of the expression of same in E. coli is improved, and the catalytic activity of the enzyme is improved. In practical applications, the dosage of the enzyme is reduced, the reaction volume is reduced, and the difficulty of post-processing is reduced, and same is suitable for industrial production.
Answer: D