Kaneka Corporation

Kanegafuchi Kagaku Kogyo Kabushiki Kaisha

Akira Iwasaki

Junzo Hasegawa

Yukio Yamada

Yasuhiro Ikenaka

Noriyuki Kizaki

Masahiro Ogura

Naoaki Taoka

Shinichi Yoshida

Tozo Nishiyama

Daisuke Moriyama

Motohisa Washida

Yoshihiko Yasohara

Keiji Matsumoto

Shunich Maemoto

Water-forming NADH oxidase derived fromshould be further improved in terms of stability for practical use in industrial production. An object of the present invention is to provide an enzyme that is obtained through modification of a water-forming NADH oxidase, which is useful as an NAD+ regeneration system for stereoselective oxidation catalyzed by an oxidoreductase, by protein engineering techniques so that the enzyme can withstand long-term use without exhibiting a reduction of its activity for the regeneration of NAD+, that is, an enzyme having improved stability, and to provide a method for efficiently producing a useful substance such as an optically active alcohol or amino acid. The present invention relates to an enzyme modification method that can improve the stability of water-forming NADH oxidase derived fromby appropriately introducing mutation.

Protein having NADH and/or NADPH oxidase activity

Isolated DNA encoding protein having improved stability

To provide a method for preparing optically active compounds, which mainly contain (R)-amino compounds, by microbial enzymes efficiently and inexpensively; a polypeptide having stereoselective transaminase activity which can be suitably used for the above preparation method; and a DNA encoding the polypeptide. A method for preparing an optically active amino compound, characterized in stereoselectively transaminating by acting a transaminase on an amino group acceptor, a ketone compound in the presence of an amino group donor, a primary amine; a DNA comprising a nucleotide sequence encoding a polypeptide having stereoselective transaminase activity; and a polypeptide having stereoselective transaminase activity obtainable from a culture of a microorganism belonging to the genus Arthrobacter.

Producing optically active amino compounds

Relating to an enzyme capable of efficiently converting a ketone compound to an optically active amino compound by transamination, and a process for preparing an optically active amino compound using the enzyme. An (S)-&agr;-phenethylamine:pyruvate transaminase, which acts on (S)-&agr;-phenethylamine and a ketone compound, thereby catalyzing transamination for forming acetophenone and an amino compound corresponding to the ketone compound; a process for preparing an optically active amino compound using the transaminase; and a method for culturing a microorganism for producing the above transaminase, comprising adding to a medium one or more compounds selected from the group consisting of propylamine, 1-butylamine, 2-butylamine, 2-pentylamine, isopropylamine and isobutylamine as an inducer for the enzyme when a microorganism for producing (S)-&agr;-phenethylamine:pyruvate transaminase is cultured.

(S)-&agr;-phenethylamine: pyruvate transaminase

The method for preparing an optically active (R)-amino compound characterized by the method comprising stereoselectively carrying out amino group transfer by action of an (R)-form-specific transaminase in the co-presence of a ketone compound (amino acceptor), and an amino compound (amino donor) of a racemic form or an (R)-form, to give an optically active (R)-amino compound. According to the present invention, it is made possible to easily prepare at a high yield the optically active (R)-amino compounds and the like having an aryl group and the like at their 1-position, which have been conventionally difficult to prepare.

(R)-transaminase from arthrobacter

Process for producing optically active amino compounds

The present invention discloses a separating and purifying (4R, 6R)-4-hydroxy-2,2,6-trimethyl cyclohexanone comprising the steps of:

Chemical modification method of diastereomer and separation method

Growing community of inventors

Akashi, Japan

Akira Iwasaki