title: Determination of pyrimidine phosphoribosyltransferase and uridine kinase activities by an assay with DEAE-paper discs.
abstract: Rapid (6 min washing step) and reliable methods for determining uridine kinase and pyrimidine phosphoribosyltransferase activities were devised. These procedures, consisting of a spotting technique on DEAE-discs followed by washing and elution, permitted the consistent recovery of about 90% of the nucleoside 5'-phosphate esters formed from radioactive precursors, either uridine or 5-fluorouracil, respectively. Of these precursors, less than 2% were retained on the discs. Direct counting of the discs (without elution), filtration by either gravity or suction, and the use of so-called activation of discs have not proved advantageous.
mesh_terms: D000327:Adsorption; D002478:Cells, Cultured; D002482:Cellulose / Q000031:analogs & derivatives; D003636:DEAE-Cellulose; D006801:Humans; D008722:Methods; D009369:Neoplasms / Q000201:enzymology*; D010430:Pentosyltransferases / Q000032:analysis*; D010770:Phosphotransferases / Q000032:analysis*; D011743:Pyrimidines / Q000032:analysis; D014541:Uridine Kinase / Q000032:analysis*
chemical_list: D011743:Pyrimidines; D002482:Cellulose; D003636:DEAE-Cellulose; D010430:Pentosyltransferases; C022500:pyrimidine phosphoribosyltransferase; D010770:Phosphotransferases; D014541:Uridine Kinase