Nucleoside Kinase Enzymes for Research & Drug Discovery

NOVOCIB offers a comprehensive portfolio of active human recombinant nucleoside kinases and other enzymes involved in nucleotide metabolism. These high-quality enzymes are essential tools for drug discovery, antiviral and anticancer research, and the study of nucleoside and nucleotide metabolism pathways. Available in lyophilized form, NOVOCIB's enzymes support reliable and reproducible in vitro phosphorylation assays and biochemical screening.

Nucleoside analogues have proven to be a highly successful class of anti-cancer and anti-viral drugs. Their therapeutic efficacy depends on intracellular phosphorylation. Two cellular nucleoside kinases— deoxycytidine kinase (dCK) and UMP-CMP kinase (CMK)—are critical for the phosphorylation of cytidine analogues. These enzymes catalyze the first two steps in activating potent anti-cancer and anti-viral agents such as 1-β-D-arabinofuranosylcytosine (araC, aracytidine), 2',2'-difluorodeoxycytidine (dFdC, gemcitabine), and β-D-2',3'-dideoxycytidine (ddC).

Both kinases also phosphorylate unnatural L-nucleosides, including β-L-2',3'-dideoxy-3'-thiacytidine (L-SSdC, 3-TC or lamivudine). Kinetic constants for araC, dFdC, and 3TC phosphorylation by recombinant dCK and CMK have been published. Comparing the phosphorylation profiles of new nucleoside analogues with those of established drugs provides a rational basis for selecting analogues with superior therapeutic potential.

To characterize the phosphorylation properties of new nucleoside analogues, NOVOCIB has developed human recombinant dCK and CMK nucleoside phosphorylation assays. As shown in Table 1, the CMK assay must be performed using monophosphate forms of nucleoside analogues, which requires preliminary phosphorylation and purification—an often time-consuming step.

To streamline this process, NOVOCIB has introduced a coupled dCK-CMK nucleoside phosphorylation assay, which delivers in a single step critical insights into both dCK and CMK substrate properties of the nucleoside analogue.