Purification and characterization of a highly enantioselective epoxide hydrolase from Aspergillus niger.
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.
Biocatalysis and Fine Chemistry Group, Université de la Méditerranée, ESA CNRS 6111, Faculté des Sciences de Luminy, Marseille, France.
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Morisseau
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Archelas
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Guitton
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Faucher
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Furstoss
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Baratti
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D001234:Aspergillus niger / Q000201:enzymology*; D001483:Base Sequence; D004305:Dose-Response Relationship, Drug; D004851:Epoxide Hydrolases / Q000737:chemistry* / Q000302:isolation & purification*; D004852:Epoxy Compounds / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D008969:Molecular Sequence Data; D013696:Temperature; D013997:Time Factors
D000596:Amino Acids; D004852:Epoxy Compounds; C033332:4-nitrostyrene oxide; D004851:Epoxide Hydrolases