特异性生成(S)-3-氯-1-苯基-1-丙醇的酮还原酶的异源表达及酶学性质OA

A ketoreductase(KRED1),isolated from Lentilactobacillus kefiri,can specifically catalyze the reduction of 3-chloro-1-phenylpropanone.Upon the heterologous expression in Escherichia coli BL21(DE3)and subsequent purification of the recombinant KRED1,its enzymatic properties were characterized.As a result,KRED1 proved to be a novel NADPH-preference ketoreductase,with an optimal temperature of 35 ℃ and an optimal pH of 7.0.The Michaelis constant(Km)of KRED1 for 3-chloro-1-phenylpropanone was determined to be 0.6 mmol/L.Additionally,metal ions including Mn2+,Cu2+,and Zn2+showed strong inhibitory effects on the enzymatic activity of KRED1.Preliminary exploration was also conducted for the KRED1-catalyzed synthesis of(S)-3-chloro-1-phenylpropanol through a glucose dehydrogenase(GDH)-based coenzyme regeneration system.When the reaction was carried out at 35 ℃ and pH 8.0,(SS)-3-chloro-1-phenylpropanol could be generated at significantly higher rate,along with 99％enantiomeric excess(e.e.)Overall,our research demonstrated the potential application of KRED1 in the enzymatic synthesis of(S)-3-chloro-1-phenylpropanol.