PP2A Inhibition Assay Using Recombinant Enzyme for Rapid Detection of Okadaic Acid and Its Analogs in Shellfish

Toxins

Tsuyoshi Ikehara¹  Shihoko Imamura¹  Atsushi Yoshino¹ 

[1] Tropical Technology Center Ltd., 5-1 Suzaki, Uruma, Okinawa 904-2234, Japan;

关键词: diarrhetic shellfish poisoning (DSP);    okadaic acid (OA);    protein phosphatase 2A (PP2A) inhibition assay;    digestive gland (DG);   

DOI  :  10.3390/toxins2010195

来源: mdpi

【 摘 要 】

Okadaic acid and its analogs (OAs) responsible for diarrhetic shellfish poisoning (DSP) strongly inhibit protein phosphatase 2A (PP2A) and thus are quantifiable by measuring the extent of the enzyme inhibition. In this study, we evaluated the suitability of the catalytic subunit of recombinant human PP2A (rhPP2Ac) for use in a microplate OA assay. OA, dinophysistoxin-1(DTX1), and hydrolyzate of 7-O-palmitoyl-OA strongly inhibited rhPP2Ac activity with IC₅₀ values of 0.095, 0.104, and 0.135 nM, respectively. The limits of detection and quantitation for OA in the digestive gland of scallops and mussels were 0.0348 μg/g and 0.0611 μg/g respectively, and, when converted to the whole meat basis, are well below the regulation level proposed by EU (0.16 μg/g whole meat). A good correlation with LC-MS data was demonstrated, the correlation coefficient being 0.996 with the regression slope of 1.097.

【 授权许可】

CC BY   
© 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland