Ketoester reductase for conversion of keto acid esters to optically active hydroxy acid esters

US5523223A · kind A · utility

Assignee

• Forschungszentrum Jülich GmbH · DE

Inventors

• Maria-Regina Kula · Jülich, DE
• Jorg Peters · Düsseldorf, DE

Key dates

• Filing date: Aug 11, 1994
• Grant date: Jun 4, 1996
• Expiry date: Aug 11, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S435/921
• WIPO field: Biotechnology
• WIPO sector: Chemistry

Abstract

A keto ester reductase capable of being used in an NADH-dependent enzymatic reaction for converting .beta., .gamma. and .delta. ketonic acid esters into the corresponding optically active .beta., .gamma. and .delta. hydroxycarboxylic acid esters can be isolated from strains of Candida parapsilosis, Yarrowinia cellobiosa, Rhodococcus erythropolis or Pseudomonas acidovorans, preferably cultivated on a long -chain alkane and/or alkane acid-containing culture medium, approximately in the presence of an inductor. The microorganism is preferrably, Candida parapsilosis DSM 70125. A usable enzyme preparation can be recovered by fractionated PEG-precipitation from the cell raw extract: high specific activities (for example 1855 U/mg) may then be obtained by chromatographic purification. The keto ester reductase is characterized as having a molecular weight of 136 kDa+11 kDa as determined by gel permeation chromatography on Sephadex G-200, a pH optimum for conversion of the keto ester to the hydroxy acid esters between pH 7.8 and 8.0 and for the reverse reaction of converting the acid esters to the keto esters at a pH optimum of 9.5, and a temperature optimum between 36.degree. and 40.degree…