Okadaic acid

Okadaic Acid is a potent inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A), making it a valuable tool for studying the roles of PP1 and PP2A in cellular processes. It is a polyether compound produced by several species of dinoflagellates and has been the cause of diarrhetic shellfish poisoning (DSP).

History

Okadaic acid was first isolated in 1981 from the black sponge Halichondria okadai by two Japanese researchers, Takeshi Yasumoto and Masayasu Murata. The compound was named after the sponge from which it was derived.

Structure and Properties

Okadaic acid is a large, complex molecule with a molecular weight of 805.5 g/mol. It is composed of a 38-membered lactone ring with seven hydroxyl groups and two side chains. The molecule is highly polar due to the presence of these hydroxyl groups.

Biological Effects

Okadaic acid exerts its toxic effects by inhibiting the activity of protein phosphatases, particularly PP1 and PP2A. This inhibition disrupts cellular processes, leading to cell death. In humans, ingestion of okadaic acid can cause diarrhetic shellfish poisoning, a condition characterized by gastrointestinal symptoms such as diarrhea, nausea, vomiting, and abdominal pain.

Diarrhetic Shellfish Poisoning

Diarrhetic shellfish poisoning (DSP) is a type of shellfish poisoning caused by the consumption of shellfish contaminated with okadaic acid. The condition is not life-threatening but can cause severe gastrointestinal symptoms. DSP has been reported in many parts of the world, including Europe, Asia, and North America.

Detection and Treatment

Methods for detecting okadaic acid in shellfish include mouse bioassay, high-performance liquid chromatography (HPLC), and enzyme-linked immunosorbent assay (ELISA). Treatment for DSP is primarily supportive, with hydration and symptom management.

See Also

• Protein phosphatase
• Diarrhetic shellfish poisoning
• Dinoflagellate