Okadaic Acid, Ammonium salt, Ammonium Salt #O-800, Potent, Inhibitor of PP-1. Okadaic acid is a polyether compound, isolated from a black sponge, Halichondria okadai. It is previously demonstrated as a non-TPA-type tumor promoter and then as a cell-permeable, potent and specific inhibitor of serine/threonine protein phosphatases 1 and 2A. In higher concentrations Okadaic acid induced apoptosis (IC50 = 0.5 μM).
Okadaic acid down-regulated the TNF receptor, induces the release of Ca2+ from intracellular stores in ECV304 endothelial cells and inhibits GH4 cell proliferation in a concentration-dependent manner (IC50 = 5 nM). Cell Signaling Activators and Inhibitors, Apoptosis Inducers. Protein Phosphatase Inhibitors; Protein Phosphatase Inhibitors (PP-1 and PP-2A).