Production and specificity of monoclonal antibodies against nodularin conjugated through N-methyldehydrobutyrine

Nodularin (Nod) is a cyclic pentapeptide hepatotoxin produced by the cyanob acterial genus Nodularia living in brackish waters and coastal lagoons. The toxicity of Nod is due to specific inhibition of the type-1 and type-2A in tracellular protein phosphatases (PP1 and PP2A, respectively). We have deve loped a monoclonal antibody against Nod using chemical modification (aminoe thylation) of one of its core amino acids, N-methyldehydrobutyrine. The dev eloped antibody is highly specific for Nod, with negligible reactivity to t he closely related cyanobacterial toxin microcystin (MC). The monoclonal an tibody was employed for quantitative competitive ELISA assay. The analytica l sensitivity of the assay was up to 0.2 ng/ml. Comparison of the developed ELISA test with HPLC-based measurements of Nod, with both laboratory and f ield samples, showed a good correspondence between the results yielded by t hese two methods. The antibodies developed by this technique provide means for developing extremely sensitive and specific analytical assays for direc t measurement of nodularin and related toxins in cyanobacterial or water sa mples. (C) 2001 Elsevier Science Ltd. All rights reserved.