Properties of Deoxycytidine Kinase Partially Purified from L1210 Cells

A kinase that catalyzes the phosphorylation of deoxycytidine has been purified 150-fold from L1210 murine leukemia cells. The reaction requires a divalent cation (preferably Mg++ or Mn++) and a nucleoside triphosphate. Optimal activity was obtained with ATP. Phosphorylation of deoxycytidine was competitively inhibited by both proximal (dCMP) and distal (dCDP and dCTP) end products and by cytosine arabinoside. Phosphorylation of the latter compound was also shown. Deoxycytidine kinase was relatively insensitive to —SH inhibitors and to surface active agents. An approximate molecular weight of 60,000 was found.