Nippon Shokubai Co., Ltd.

Hisashi Semba

Yukio Dobashi

Eita Ichige

Masaharu Mukouyama

Norimasa Okuda

Toshiaki Shijuku

Shigeaki Harayama

This invention relates to S-hydroxynitrile lyase having excellent tolerance to heat, organic solvents, and the like, which is obtained by modifying at least one amino acid in the helix D3, helix A, and &#x3b2;-sheet 2 domains in the amino acid sequence of wild-type S-hydroxynitrile lyase.

Modified S-hydroxynitrile lyase

A method for efficient production of an S-hydroxynitrile lyase by gene recombination usingis provided. A gene is formed by altering a codon in an S-hydroxyniitrylase gene originating in cassava (Crantz) without changing the amino acid sequence thereof till the frequency of codon usage wholly with an amino acid inreaches a level of not less than 5%. According to the method for the production of an S-hydroxynitrile lyase by the use of the gene, the S-hydroxynitrile lyase can be produced in a large amount with an unusually high yield.

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The present invention relates to an enzyme reaction method which comprises performing an enzyme reaction, using an immobilized enzyme having a water content of 10% by weight or more as an enzyme and using an organic solvent substantially immiscible with water as a reaction solvent, under such conditions that a liquid phase forms a homogeneous system without phase separation although it is saturated with water or an aqueous buffer; a method for performing an enzyme reaction using an aldehyde compound as a substrate, which comprises removing a carboxylic acid compound contained in an aldehyde compound by subjecting the aldehyde compound to an alkaline treatment before starting the enzyme reaction; a method for performing an enzyme reaction using an aldehyde compound as a substrate, which comprises reducing a carboxylic acid compound content in the aldehyde compound to 0.1 wt % or less by subjecting the aldehyde compound to an alkaline treatment before starting the enzyme reaction; a method for enzymatically producing an optically active cyanohydrin from a carbonyl compound and prussic acid containing an acidic substance as a stabilizer, which comprises subjecting the prussic acid to a treatment for reducing inhibitory effect of the stabilizer on an enzyme, and performing an enzyme reaction to synthesize the optically active cyanohydrin using the treated prussic acid; a method for enzymatically producing an optically active cyanohydrin, which comprises dissolving prussic acid in an organic solvent substantially immiscible with water to give an organic solution of prussic acid, adding a buffer to this solution in a saturation amount or more, mixing, collecting the organic phase, and performing an enzyme reaction to synthesize the optically active cyanohydrin using the organic phase as prussic acid; as well as a method for enzymatically producing an optically active cyanohydrin, which comprises performing distillation of a reaction solution after completion of an enzyme reaction to separate and collect unreacted prussic acid and organic solvent therefrom, and repeatedly using the collected prussic acid and organic solvent at least once.

Method for enzymatically producing an optically active cyanohydrin

Method for producing &#x3b1;-hydroxycarboxylic acid

The present invention relates to a method for synthesizing optically active cyanohydrin. An immobilized enzyme is used in the invention, in which (S)-hydroxynitrile lyase is immobilized in a carrier comprising a porous inorganic material.

Immobilized euphorbiaceae, poaceae or olacaeae s-hydroxynitrile lyase

The present invention provides a process for producing S-hydroxynitrile lyase, comprising the steps of culturing in a medium yeast cells transformed with recombinant DNA comprising an expression vector into which a S-hydroxynitrile lyase (EC 4.1.2.37) coding gene derived from cassava ( ) has been incorporated, and collecting S-hydroxynitrile lyase from the yeast cells. According to the present invention, a large amount of S-hydroxynitrile lyase can be efficiently produced by genetic engineering techniques.

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Ibaraki, Japan

Hisashi Semba