Dissociation of the DNAse-I . actin complex by formamide

Rabbit skeletal muscle actin labeled with 125 iodine by an enzymic method is shown to be capable of polymerization and to bind to matrix-bound pancreatic DNAse I like unlabeled G-actin. It was used to demonstrate that actin can be released from DNAse-I-agarose by 35--40% formamide. Actin which was only shortly exposed to this solvent was able to bind again to DNAse I and to form filaments indicating that it has been recovered functionally intact from the affinity matrix.