Acylamino acid racemase, Production and use thereof
申请人:Takeda Chemical Industries, Ltd.
公开号:EP0304021A2
公开(公告)日:1989-02-22
The present invention relates to acylamino acid racemase, production and use thereof.
The acylamino acid racemase of the present invention racemizes optically active N-acyl-α-aminocarboxylic acid alone at pH values around the neutral level at a normal temperature under normal pressure in the presence of optically active amino acid; its use in combination with D- or L-aminoacylase enables the production of optically active D- or L-α-amino acid from DL-acyl-α-aminocarboxylic acid at a high level of efficiency.
The D-aminoacylase produced by Alcaligenes denitrificans DA181 was a new type of aminoacylase which had both high stereospecificity and specific activity. The molecular weight and isoelectric point of this enzyme were 58,000 and 4.4, respectively. The apparent Km and kcat values of this enzyme for N-acetyl-D-methionine were estimated to be 0.48 him and 6.24 × 104 min respectively. The optimum temperature was 45°C. The enzyme was stable up to 55°C for 1 hr in the presence of 0.2 mg/ml bovine serum albumin. The enzyme was stable in the pH range of 6.0 to 11.0 with an optimum pH of 7.5. This enzyme contained about 2.1 g atom of zinc per mole of enzyme. Enzyme activity was inhibited by incubation with EDTA. The inhibition by EDTA was fully reversed by Co2+ and partially by Zn2+.