Isolation and Characterization of Secretory Actin . DNAase I Complex from Rat Pancreatic Juice

Abstract

DNAase I isolated from rat pancreatic juice was always found in association with a protein of MW 43,000. This association leads to inhibition of the isolated rat pancreatic DNAase I activity by 66%. The MW of the complex was 74,000 by gel filtration indicating a 1 : 1 molar association of both proteins. Since the protein of MW 43,00 has number of properties similar to skeletal muscle actin such as filament formation, nucleotide binding, inhibition of the rat pancreatic DNAase I activity and comigration with skeletal muscle actin on polyacrylamide gels in the presence of dodecylsulfate, it is concluded that DNAase I is bound to actin in rat pancreatic juice in a 1 : 1 complex. A protein fraction from bile is able to activate the DNAase I enzymatic activity of the rat secretory actin.cntdot. DNAase I complex.