A New Method for Measurement of Cyclic AMP Phosphodiesterase Activity

Abstract

The extreme sensitivity of chicken muscle fructose 1, 6-bisphosphatase to inhibition by 5'-AMPhas been utilized to develop a new method for the assay of cAMP phosphodiesterase activity. In this method, the substrate (cAMP) is first incubated with phosphodiesterase and the amount of 5'-AMP formed is then determined by measuring the degree of inhibition of fructose 1, 6-bis-
phosphatase activity. The present method conveniently employs the spectrophotometric technique and is sensitive enough to detect the conversion of 50 pmol of cAMP to 5'-AMP in 1 ml of reaction mixture. This method is considered particularly valuable for those laboratories that are not equipped with facilities for measuring radioactivity.