Modified catalytic performance of Lactobacillus fermentum l-lactate dehydrogenase by rational design

l-Lactate dehydrogenases can reduce alpha-keto carboxylic acids asymmetrically and generally have a broad substrate spectrum. dehydrogenase gene (LF-l-LDH0845) with reducing activity towards 3,4-dihydroxyphenylpyruvate phenylpyruvate was obtained from Lactobacillus fermentum JN248. To change the specificity of LDH0845 improve its catalytic large substrates, site-directed mutation Tyr221 performed by analyzing amino in active center. Kinetic parameters show that kcat values Y221F mutant on 3,4-dihydroxyphenylpyruvate, 4-methyl-2-oxopentanoate, glyoxylate are 1.21 s−1, 1.35 0.72 respectively, which 420%, 150% 130% wild-type LDH0845. This study shows mutations Y221 significantly LDH0845, making it become potential tool enzyme for reduction functional groups.