Enzymatic synthesis and phosphorolysis of 4(2)-thioxo- and 6(5)-azapyrimidine nucleosides by E. coli nucleoside phosphorylases.

ABSTRACT: The trans-2-deoxyribosylation of 4-thiouracil (^4SUra) and 2-thiouracil (^2SUra), as well as 6-azauracil, 6-azathymine and 6-aza-2-thiothymine was studied using dG and E. coli purine nucleoside phosphorylase (PNP) for the in situ generation of 2-deoxy-α-D-ribofuranose-1-phosphate (dRib-1P) followed by its coupling with the bases catalyzed by either E. coli thymidine (TP) or uridine (UP) phosphorylases. ^4SUra revealed satisfactory substrate activity for UP and, unexpectedly, complete inertness for TP; no formation of 2'-deoxy-2-thiouridine (^2SUd) was observed under analogous reaction conditions in the presence of UP and TP. On the contrary, ^2SU, ^2SUd, ^4STd and ^2STd are good substrates

SUBMITTER: Stepchenko VA 

PROVIDER: S-EPMC5238616 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature