Production of Value-Added Arabinofuranosyl Nucleotide Analogues from Nucleoside by an In Vitro Enzymatic Synthetic Biosystem

Arabinofuranosyl nucleotide analogue (arabinoside) and the derived compounds, a family of nucleoside analogues, exhibit diverse, typically biological activities and are widely used as antibacterial, antiviral, anti-inflammatory, and antitumor drugs in both clinical and preclinical trials. Despite their long and rich history in medicinal chemistry, the biosynthesis of arabinoside has only been sporadically designed and studied and has remained a challenging task. In this study, an in vitro synthetic enzymatic biosystem was designed and constructed for the production of arabinoside from low-cost nucleoside, based on a phosphorolysis -isomerization-dephosphorylation enzymatic cascade conversion routes. The enzymatic system achieves the biosynthesis of arabinoside by isomerizing the ribose part of nucleoside to arabinose. The reaction conditions affecting the yield of arabinoside were investigated and optimized, including meticulous enzyme selection, key enzyme dosage, the concentration of orthophosphate, and reaction time. Under the optimized conditions, we achieved the production of 0.12 mM of arabinofuranosylguanine from 0.5 mM of guanosine, representing 24% of the theoretical yield. Furthermore, this biosystem also demonstrated the capability to produce other arabinosides, such as vidarabine, spongouridine, and hypoxanthine arabinofuranoside from corresponding nucleosides. Overall, our biosynthesis approach provides a pathway for the biosynthesis of arabinoside.