Enzymatic synthesis of 2′-deoxyadenosine and 6-methylpurine-2′-deoxyriboside by Escherichia coli DH5α overexpressing nucleoside phosphorylases from Escherichia coli BL21

Genes encoding purine nucleoside phosphorylase (deo D), uridine phosphorylase (udp) and thimidine phosphorylase (deo A) from Escherichia coli BL21 were cloned and overexpressed in E. coli DH5α. The recombinant strains were employed to synthesize 2′-deoxyadenosine (dAR) and 6-methylpurine-2′-deoxyriboside (MePdR). Experimental parameters such as strains, temperature, pH, reagent concentration and cell mass were optimized. Under the optimal situation, 96% adenine was converted to dAR and 95% 6-methylpurine (MeP) was converted to MePdR in an hour, using 0.2‰ (dry wt./v) cell paste as biocatalyst.