Abstract
1. Bean flavokinase has been highly purified to the specific activity of 80 mμmoles FMN formed per hour per mg protein at 30° by protamine treatment, fractionation with ammonium sulfate and chromatography on DEAE-cellulose. This preparation did not contain phosphatase activity and practically behaved as a homogeneous system in electrophoresis and ultracentrifugation.
2. The optimum pH was around 9.0 and the optimum temperature for the enzyme activity was abount 40°.
3. The metallic ions, especially Mg2+ was essential for full activity of the enzyme.
4. ATP was shown to be the specific phosphate donor. While ADP had a slight effect on the phosphorylation, GTP, CTP and ITP were entirely ineffective.
5. The enzyme was half saturated with riboflavin at the concentration of 1.3×10-5 M.
