Description_x000D_ General description_x000D_ Phosphodiesterase (PDE1) exists in two isoforms -PDE1A2 and PDE1B1. The enzyme has a role in the complex interaction between cyclic nucleotides and Ca2+ second-messenger systems._x000D_ Application_x000D_ Phosphodiesterase, 3′,5′-cyclic-nucleotide-specific from bovine brain has been used to assay the protein activator, calmodulin and in in vitro adenylate cyclase assay._x000D_ Biochem/physiol Actions_x000D_ Hydrolyzes the 3′,5′-phosphodiester in cyclic nucleotide monophosphates, such as cAMP and cGMP, to the corresponding nucleotide 5′-monophosphate._x000D_ Packaging_x000D_ Package size based on activated units_x000D_ Unit Definition_x000D_ One unit will hydrolyze 1.0 μmole of 3′,5′-cyclic-AMP to 5′-AMP per min at pH 7.5 at 30 °C._x000D_ Physical form_x000D_ Lyophilized powder containing Tris-HCl buffer salts and lactose_x000D_ Preparation Note_x000D_ Affinity purified preparation which has been depleted of calmodulin._x000D_ Reconstitution_x000D_ Reconstitute with 50% glycerol. The total activated units of enzyme will remain constant for at least 5 days when stored at −20 °C. However, the calmodulin-deficient activity may increase up to 200%. Both the activated and calmodulin-deficient activity may decrease approximately 30% in 24 hours if stored at 4 °C._x000D_ Analysis Note_x000D_ Protein determined by Warburg-Christian