Defining a process operating window for the synthesis of 5-methyluridine by transglycosylation of guanosine and thymine.

This paper describes a high yielding coupled enzymatic reaction using Bacillus halodurans purine nucleoside phosphorylase (PNP) and E. coli uridine phosphorylase (UP) for synthesis of 5-methyluridine (5-MU) by transglycosylation. Key parameters such as reaction temperature, pH, reactant loading, reactor configuration and enzyme loading were investigated.

Cloning, purification and characterisation of a recombinant purine nucleoside phosphorylase from Bacillus halodurans Alk36.

A purine nucleoside phosphorylase from the alkaliphile Bacillus halodurans Alk36 was cloned and overexpressed in Escherichia coli. The enzyme was purified fivefold by membrane filtration and ion exchange. The purified enzyme had a V (max) of 2.