Phosphodiesterase 1A (PDE1A) is a calcium/calmodulin-dependent enzyme belonging to the PDE1 family, which hydrolyzes cyclic nucleotides (cAMP and cGMP) to regulate intracellular signaling. It plays a critical role in diverse physiological processes, including smooth muscle contraction, neuronal signaling, and cardiovascular function. PDE1A activity is tightly regulated by calcium influx, as calmodulin binding enhances its catalytic efficiency. Dysregulation of PDE1A has been implicated in diseases such as hypertension, neurodegeneration, and cancer. Due to its role in modulating cyclic nucleotide levels, PDE1A is a potential therapeutic target for cardiovascular and neurological disorders.
Besides,G Protein Beta 3 (GNb3) has been identified as an interactor of PDE1A, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human PDE1A and recombinant human GNb3. Briefly, PDE1A was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to GNb3-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-PDE1A pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 µL stop solution to the wells and read at 450/630nm immediately. The binding activity of recombinant rat PDE1A and recombinant human GNb3 was shown in Figure 1, the EC50 for this effect is 0.027µg/mL.