CTP: CMP phosphotransferase activity in L1210 cells.
Substrate converting enzymes interfering with the measurement of ribonucleotide reductase were assessed in cell-free extracts prepared from L1210 cells. Data show the presence of a myokinase-type enzyme activity (CTP:CMP phosphotransferase) which catalyzes the reaction: 2CDP in equilibrium CMP + CTP. This enzyme is not removed by passage of cell extracts over ATP-agarose columns. Monitoring of nucleoside diphosphate substrate level is, therefore, mandatory for obtaining accurate measurements of CDP reductase activity in crude cell extracts.
Chiba
P
P
Department of Internal Medicine, University of South Florida College of Medicine, Tampa 33612.
Cory
J G
JG
D000818:Animals; D002457:Cell Extracts; D002847:Chromatography, Agarose; D002851:Chromatography, High Pressure Liquid; D003565:Cytidine Diphosphate / Q000378:metabolism*; D003570:Cytidine Triphosphate / Q000378:metabolism*; D003597:Cytosine Nucleotides / Q000378:metabolism*; D007939:Leukemia L1210 / Q000201:enzymology*; D051379:Mice; D010770:Phosphotransferases / Q000378:metabolism*
D002457:Cell Extracts; D003597:Cytosine Nucleotides; D003565:Cytidine Diphosphate; D003570:Cytidine Triphosphate; D010770:Phosphotransferases