a phosphatase (as from snake venom) that acts on diesters (like some nucleotides) to hydrolyze only one of the two ester groups

an enzyme that hydrolyzes cyclic AMP to adenosine 5'-monophosphate.

An enzyme that inactivates cyclic nucleotide molecules, such as cyclic AMP or cyclic GMP.

Phosphodiesterase (PDE) is a group of enzymes that degrade the second messenger molecules: cyclic nucleotides cAMP and cGMP. They regulate the localization, duration, and amplitude of cyclic nucleotide signaling within subcellular domains. PDEs are therefore important regulators of signal transduction mediated by these second messenger molecules.