Improved ketoreductase polypeptide and coding gene thereof, and cell for expressing polypeptide

Abstract

The invention relates to an improved ketoreductase polypeptide. The enzymatic activity of the improved ketoreductase polypeptide is higher than that of a wild type ketoreductase polypeptide; the enzymatic activity refers to the enzymatic activity for catalyzing a ketone compound to join in a reduction reaction to generate a chiral alcohol; the wild type ketoreductase polypeptide has an amino acidsequence shown in SEQ ID No. 2 and is from Lactobacillus kefiri DSM 20587; the improved ketoreductase polypeptide contains an amino acid sequence having at least 90% of sequence homology with the amino acid sequence shown in SEQ ID No. 2; and a residue in the amino acid sequence of the improved ketoreductase polypeptide in relation to the 94th residue in the amino acid sequence shown in SEQ ID No. 2 is a tyrosine residue.

Description

technical field [0001] The present invention relates to an improved ketoreductase polypeptide, its coding gene and cells expressing the polypeptide. Background technique [0002] Phenylephrine (phenylephrine), also known as phenylephrine, its chemical name is 3-(2-(N-methylamino)-1-hydroxy)phenol. It is often used clinically for paroxysmal supraventricular tachycardia, which can slow down the heart rate by constricting blood vessels and increasing blood pressure to excite the vagus nerve reflex. [0003] The synthesis method of phenylephrine includes chemical method and biological method, and its ketone substrate is stereoselectively reduced to a product with a chiral structure. [0004] Biological preparation of phenylephrine requires the use of stereoselective ketoreductase. [0005] However, the existing wild-type ketoreductase KRED has very low catalytic activity. For example, 10 g / l crude enzyme powder can only completely convert 1 g / l ketone substrate in 20 hours, wh...

AI Technical Summary

Problems solved by technology

[0005] However, the existing wild-type ketoreductase KRED has very low catalytic activity. For example, 10 g / l crude enzyme powder can only completely convert 1 g / l ketone substrate in 20 hours, which cannot meet the needs of industrial production

[0006] At present, for the biological preparation of phenylephrine, there is no ketoreductase with certain stereoselectivity and good catalytic activity.