嘌呤核苷磷酸化酶/嘧啶核苷磷酸化酶共表达及固定化催化合成阿糖核苷OACSTPCD

Biocatalysis has demonstrated great potential in the synthesis of nucleoside analogues due to its mild reaction conditions,environmental friendliness and sustainability.As frequently used enzymes in biocatalytic approaches,nucleoside phosphorylases attracted great attention in recent years.Herein,the co-expression of purine and pyrimidine nucleoside phosphorylases was achieved in an engineered Escherichia coli(E.coli),which could overcome the limitation and reversibility of substrates in the transformation catalyzed by single nucleoside phosphorylase.The engineered E.coli strain,which was constructed through overexpression of both endogenous genes deoD and udp,was used for biosynthesis of different nucleoside analogues.As a result,the co-expression engineered strain could effectively catalyze the conversion of different arabinosides,with excellent preference for purine over pyrimidine.In addition,the immobilized double enzymes could further improve the substrate conversion rate and prolong the service life of the enzyme,notably with the cumulative effective catalytic time up to 684 h.Our research provided valuable information for the biosynthesis of nucleoside analogues.