title: Cross-linked enzyme aggregates of Mung bean epoxide hydrolases: a highly active, stable and recyclable biocatalyst for asymmetric hydrolysis of epoxides.
abstract: A highly active and stable cross-linked enzyme aggregates (CLEAs) of epoxide hydrolases (EHs) from Mung bean, which plays a crucial role in synthesis of valuable enantiopure diols, were successfully prepared and characterized. Under the optimum preparation conditions, the activity recovery of CLEAs recorded 92%. The CLEAs were more efficient than the free enzyme in catalyzing asymmetric hydrolysis of styrene oxide to (R)-1-phenyl-1,2-ethanediol in organic solvent-containing biphasic system. The biocatalytic reaction performed in n-hexane/buffer biphasic system had a clearly faster initial reaction rate, much higher product yield and product e.e. value than that in aqueous medium. Moreover, the optimal volume ratio of n-hexane to buffer, reaction temperature, buffer pH value and substrate concentration for the enzymatic hydrolysis were found to be 1:1, 40 °C, 7.5 and 30 mM, respectively, under which the initial reaction rate, product yield and product e.e. value were 13.26 mM/h, 46% and 93.5%, respectively. The CLEAs retained more than 50% of their initial activity after 8 batches of re-use in phosphate buffer and maintained 53% of their original activity after 8 reaction cycle in biphasic system. The efficient biocatalytic process with CLEAs proved to be feasible on a 250-mL preparative scale, exhibiting great potential for asymmetric synthesis of chiral diols.
authors: School of Bioscience & Bioengineering, South China University of Technology, Guangzhou 510600, China.
authors: Chun-Yang
authors: CY
authors: Yu
authors: Xiao-Feng
authors: XF
authors: Li
authors: Wen-Yong
authors: WY
authors: Lou
authors: Min-Hua
authors: MH
authors: Zong
mesh_terms: D055162:Biocatalysis; D003432:Cross-Linking Reagents / Q000737:chemistry; D004789:Enzyme Activation; D004795:Enzyme Stability; D004851:Epoxide Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D004852:Epoxy Compounds / Q000378:metabolism*; D007887:Fabaceae / Q000201:enzymology* / Q000378:metabolism; D006586:Hexanes / Q000378:metabolism; D006868:Hydrolysis; D059027:Recycling
chemical_list: D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; D006586:Hexanes; C026385:n-hexane; C013690:styrene oxide; D004851:Epoxide Hydrolases