Morisseau C, Archelas A, Guitton C, Faucher D, Furstoss R, Baratti J C
Biocatalysis and Fine Chemistry Group, Université de la Méditerranée, ESA CNRS 6111, Faculté des Sciences de Luminy, Marseille, France.
Eur J Biochem. 1999 Jul;263(2):386-95. doi: 10.1046/j.1432-1327.1999.00519.x.
The epoxide hydrolase from Aspergillus niger was purified to homogeneity using a four-step procedure and p-nitrostyrene oxide (pNSO) as substrate. The enzyme was purified 246-fold with 4% activity yield. The protein is a tetramer composed of four identical subunits of molecular mass 45 kDa. Maximum activity was observed at 40 degrees C, pH 7.0, and with dimethylformamide as cosolvent to dissolve pNSO. Hydrolysis of pNSO was highly enantioselective, with an E value (i.e. enantiomeric ratio) of 40 and a high regioselectivity (97%) for the less hindered carbon atom of the epoxide. This enzyme may be a good biocatalyst for the preparation of enantiopure epoxides or diols.
采用四步纯化程序，以对硝基苯乙烯氧化物（pNSO）为底物，将黑曲霉的环氧化物水解酶纯化至同质。该酶纯化了246倍，活性回收率为4%。该蛋白质是一种四聚体，由四个分子量为45 kDa的相同亚基组成。在40℃、pH 7.0以及以二甲基甲酰胺作为助溶剂溶解pNSO的条件下观察到最大活性。pNSO的水解具有高度对映选择性，对映体比率（E值）为40，对环氧化物中空间位阻较小的碳原子具有较高的区域选择性（97%）。这种酶可能是制备对映体纯环氧化物或二醇的良好生物催化剂。
