Merck, 495604, Okadaic Acid, Prorocentrum sp.

General description
An ionophore-like polyether derivative of a C₃₈ fatty acid compound isolated from the dinoflagellates that have fed on the marine sponge Halinchrondria okadai. It is a potent non-comepetitive, reversible inhibitor of serine/threonine-specific protein phosphatases 1 (PP1, IC₅₀ = 10-15 nM, rabbit skeletal muscle, catalytic subunit) and 2A (PP2A, IC₅₀ = 0.1 nM, rabbit skeletal muscle, catalytic subunit). It has only a trivial effect on protein phosphatase 2B (IC₅₀ = 5 µM), a Ca²⁺/calmodulin-dependent enzyme, while PP2C, a Mg²⁺ dependent enzyme, is unaffected. Okadaic acid has no significant effect on the activities of tyrosine phosphatases, alkaline phosphatase, acid phosphatase, and inositol trisphosphatase. It is also a non-phorbol ester-type tumor promoter on mouse skin. Useful for the study of protein phosphatases and of PP1/PP2A in cell extracts, as well as in intact cells. Induces apoptosis in human breast carcinoma (MB-231 and MCF-7) and in myeloid cells, but inhibits glucocorticoid-induced apoptosis in T-cell hybridomas. Has marked contractile effect on smooth muscles and heart muscles. Implicated as a causative agent of diarrhetic shellfish poisoning.
Biochem/physiol Actions
Cell permeable: no
Primary Target
Protein phosphatase
Product does not compete with ATP.
Reversible: no
Target IC₅₀: 10-15 nM and 0.1 nM against protein phosphatase 1 and protein phosphatase 2A, respectively
Packaging
Packaged under inert gas
Preparation Note
Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 1 month at -20°C.
Other Notes
Due to the nature of the Hazardous Materials in this shipment, additional shipping charges may be applied to your order. Certain sizes may be exempt from the additional hazardous materials shipping charges. Please contact your local sales office for more information regarding these charges.
Gjertsen, B.T., et al. 1994. J. Cell Sci.107, 3363.
Kiguchi, K., et al. 1994. Cell Growth Differentiation5, 995.
Ohaka, Y., et al. 1993. Biochem. Biophys. Res. Commun. 197, 916.
Gopalakrishna, R., et al. 1992. Biochem. Biophys. Res. Commun. 189, 950.
Kreienbuhl, P., et al. 1992. Blood80, 2911.
Nomura, M., et al. 1992. Biochemistry31, 11915.
Song, Q., et al. 1992. J. Cell Physiol.153, 550.
Tada, Y., et al. 1992. Immunopharmacol.24, 17.
Cohen, P., et al. 1990. Trends Biochem. Sci.15, 98.
Cohen, P. 1989. Annu. Rev. Biochem.58, 453.
Cohen, P., and Cohen, P.T. 1989. J. Biol. Chem.264, 21435.
Haystead, T.A., et al. 1989. Nature337, 78.
Legal Information
CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany
Disclaimer
Toxicity: Toxic (F)