The Interaction of Bovine Pancreatic Deoxyribonuclease I and Skeletal Muscle Actin

Abstract
The rate of exchange of actin-bound nucleotide is decreased by a factor of about 20 when actin is complexed with DNAase I without affecting the binding constant of Ca for actin. Binding constants of DNAse I to monomeric and filamentous actin were determined to be 5 .times. 108 M-1 and 1.2 .times. 104 M-1 respectively. Depolymerisation of F-actin by DNAase I appears to be due to a shift in the G-F equilibrium of actin by DNAase I. Inhibition of the DNA-degrading activity of DNAase I by G-actin is of the partially competitive type.