Patent ID: 6060290
Filing Date: 2000-05-09
Classification: C12N,C12P

Abstract:
An isolated and purified esterase which has the following physicochemical properties:(1) Enzyme action:the enzyme acts as a catalyst in the predominant hydrolysis of (R) forms of 6-aminochroman-3-acetic acid esters into (R) forms of 6-aminochroman-3-acetic acid and alcohol, and in an ester exchange reaction between an ester compound and alcohol;(2) Substrate specificity:for esters of straight-chain fatty acids and p-nitrophenol, the lesser the number of carbon atoms in the fatty acids, the stronger is the hydrolytic activity;(3) Molecular weight:the molecular weight of the enzyme is 50000.+-.2000 (SDS-PAGE);(4) Optimal pH:hydrolysis optimally take place at pH 7-10;(5) Optimal temperature:hydrolysis optimally takes place at 55.degree. C. to 60.degree. C.;(6) Temperature stability:90% of the hydrolyzing activity can be maintained for 30 minutes at pH 7.2 and at temperatures below 60.degree. C.;(7) pH stability:the enzyme is stable at a pH range of 5-10;(8) Inhibitors:upon treatment with various inhibitors in a 0.1 M phosphate buffer solution (pH 7.2) at 30.degree. C. for 30 minutes, the enzyme loses its activity by 30% with copper sulfate (1 mM), by 85% with phenylmethylsulfonyl fluoride (0.1 mM) and by 15% with diisopropyl flourophosphate (0.5 mM) and no reduction in the enzyme activity is observed with sodium lauryl sulfate (5 mM) or sodium deoxycholate (5 mM).