Rat pancreas actin: purification and characterization.

Isolation of rat pancreas actin was performed with three different technics: polymerization-depolymerization method, affinity chromatography on DNase I-Sepharose 4B or ion exchange chromatography on DEAE-cellulose. Inhibition of DNase I activity, localization by SDS polyacrylamide slab gel electrophoresis and presence of microfilaments allowed its identification. Affinity process led us to obtain actin which kept inhibitory activity (30,000 U per mg) on DNase I when using vacuum dialysis. Actin eluted from DEAE-cellulose associated reversibly in 50-70 A microfilaments in the presence of phalloidin, was pure at 95% and had a satisfactory inhibitor activity (77,000 U per mg).