[Binding of F-protein (phosphofructokinase) to F-actin]

By the use of sedimentation method the interaction of F-protein (phosphofructokinase) with F-actin has been studied in 0.1 M KCl, 10 mM K-phosphate buffer, pH 6.5. The calculated value of the constant of F-protein binding to F-actin is (7.3 +/- 1.0) X 10(5) M-1. The number of the F-protein binding sites calculated per chain weight of 80,000 is 0.43. The binding of F-protein to F-actin was found to be affected by pH-value.