Phosphodiesterases (PDEs) play an important role in dynamic regulation of cAMP and cGMP signaling. PDE1B is a calcium/calmodulin-dependent cyclic nucleotide phosphodiesterase that is highly expressed in the striatum. It plays a physiological role in the central nervous system, and PDE1B activity has been linked to impaired cognition and spatial learning.

The PDE1B TR-FRET Assay Kit is designed for identification of inhibitors of PDE1B using TR-FRET (Time Resolved Fluorescence Resonance Energy Transfer) technology. The assay is based on the generation of FAM-labeled nucleotide monophosphates by the PDE1B. These phosphate groups bind to terbium-labeled nanoparticles, resulting in energy transfer from the terbium to the FAM, which emits a fluorescent signal at 520 nm. The change in fluorescent intensity can be easily measured using a fluorescence plate reader.

Using this kit, only two simple steps on a microtiter plate are required for the PDE1B activity assay. First, the fluorescent-labeled cAMP is incubated with a sample containing PDE1B for 1 hour. Second, a binding agent and a terbium donor are added to the reaction mix and incubated for 30 minutes. Then, fluorescence intensity can be measured using a fluorescence reader.