Asymmetric reduction of the conjugated C=C bonds by the old yellow enzymes(OYEs)presents a promising field in the synthesis of chiral chemicals.Nevertheless,few natural OYEs have been applied in large-scale applicatio...Asymmetric reduction of the conjugated C=C bonds by the old yellow enzymes(OYEs)presents a promising field in the synthesis of chiral chemicals.Nevertheless,few natural OYEs have been applied in large-scale applications due to the requirement of costly NADPH and low operational stability.Herein,a stable and efficient fusion of YqjM from Bacillus subtilis and glucose dehydrogenase(GDH)from Bacillus megaterium was constructed to stereoselectively reduce the conjugated C=C bonds in a self-sufficient continuous process.The effects of the enzyme order and different linkers on the fusions were investigated by structural analysis and all-atom molecular dynamics simulation.The best fusion YqjM_G_GDH gave 98% conversion of 100 mmol/L 2-methylcyclopentenone with an excellent ee value(>99%)in 3 h,while the mixture of individual enzymes only obtained 68% conversion after more than 8 h.The improved substrate conversion of YqjM_G_GDH fusion was probably attributed to the increased flexibility of each fused enzyme and the shortening of the diffusion distance of NADPH regenerated.A one-pot process was designed to purify and immobilize the fusion on the Ni2t-nitrilotriacetic acid functionalized magnetic mesoporous silica nanoflowers.The resulting immobilized biocatalyst not only catalyzed the asymmetric reduction of various α,β-unsaturated ketones(20 mmol/L)continuously with only 50μmol/L NADPt to initiate the whole process,but also retained more than 82%of the initial activity after seven cycles,serving as a good candidate for the industrial applications.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2021YFC2104100)the National Natural Science Foundation of China(Nos.21901058,22178083 and 22078081)+3 种基金the Hebei Key Research and Development Project(Nos.21372805D,21372804D and 20372802D)the Science and Technology Research Project of Hebei Higher Education(No.ZD2019045)the Natural Science Foundation of Hebei province(Nos.B2019202216,B2017202056 and C2019208174)the Natural Science Foundation of Tianjin City(No.20JCYBJC00530).
文摘Asymmetric reduction of the conjugated C=C bonds by the old yellow enzymes(OYEs)presents a promising field in the synthesis of chiral chemicals.Nevertheless,few natural OYEs have been applied in large-scale applications due to the requirement of costly NADPH and low operational stability.Herein,a stable and efficient fusion of YqjM from Bacillus subtilis and glucose dehydrogenase(GDH)from Bacillus megaterium was constructed to stereoselectively reduce the conjugated C=C bonds in a self-sufficient continuous process.The effects of the enzyme order and different linkers on the fusions were investigated by structural analysis and all-atom molecular dynamics simulation.The best fusion YqjM_G_GDH gave 98% conversion of 100 mmol/L 2-methylcyclopentenone with an excellent ee value(>99%)in 3 h,while the mixture of individual enzymes only obtained 68% conversion after more than 8 h.The improved substrate conversion of YqjM_G_GDH fusion was probably attributed to the increased flexibility of each fused enzyme and the shortening of the diffusion distance of NADPH regenerated.A one-pot process was designed to purify and immobilize the fusion on the Ni2t-nitrilotriacetic acid functionalized magnetic mesoporous silica nanoflowers.The resulting immobilized biocatalyst not only catalyzed the asymmetric reduction of various α,β-unsaturated ketones(20 mmol/L)continuously with only 50μmol/L NADPt to initiate the whole process,but also retained more than 82%of the initial activity after seven cycles,serving as a good candidate for the industrial applications.
