[Radiometric method of determining ATP: D-pantothenate-4'-phosphotransferase activity]

A radiometric procedure is developed for estimation of pantothenate kinase (EC 2.7.1.33) activity in various preparations of rat liver tissue; sodium 14C-D-pantothenate was used as a substrate and the reaction end product 4'-phosphopantothenic acid was measured. Optimal separation of the substrate and the end product was achieved by means of chromatography on DEAE-Sephadex A-25. 4'-phosphopantothenic acid was eluted from the column by 0.4 N HCl thus avoiding the label dilution and possible quenching of scintillation.