direct enzymatic phosphorylation does not seem to be essential to the mechanism of action of the nucleoside insofar as competitive inhibition of deoxycytidine kinase ( an enzyme that directly phosphorylates purines as well as pyrimidines ) or of deoxyguanosine kinase fails to inhibit 8brguo stimulation selectively .
C0031715
phosphorylation
C0011486
deoxycytidine