State-of-the-art review of snake venom phosphodiesterases (svPDEs).

Phosphodiesterases (PDEs) constitute an enzyme group able to hydrolyze nucleic acids as well as some second messengers. Due to this ability and their expression in several human tissues and organs, PDEs can control a gamut of physiological processes. They are also involved in some pathological conditions, such as Alzheimer's disease and erectile dysfunction. PDEs are also expressed in snake venom glands, being called snake venoms phosphodiesterases, or simply svPDEs. The occurrence of these enzymes has already been reported in crotalid, elapid and viperid venoms, such as Crotalus, Naja and Trimeresurus, respectively, but not all of them have been characterized concerning their structure, activity and function. In this review, we are addressing general characteristics of svPDEs, in addition to their structural, biochemical and functional characteristics, and we also report some potential applications of svPDEs.