Production and specificity of mono and polyclonal antibodies against microcystins conjugated through N-methyldehydroalanine

Microcystins (MCs) are a group of closely related toxic cyclic heptapeptide s produced by common cyanobacteria (blue-green algae). Their toxicity is as sociated with specific inhibition of intracellular protein phosphatases typ e-1 and type-2A (PP1 and PP2A, respectively). We have developed a battery o f antibodies to microcystins using chemical modification (aminoethylation) of one of its core amino acids, N-methyl-dehydroalanine. The developed anti bodies displayed different reactivities to closely related MCs. Selected mo noclonal antibodies were used for quantitative competitive ELISA assays. Th e analytical sensitivity of these assays was up to 1 ng/ml. Comparison of t he developed ELISA tests with HPLC-based measurements of MCs in laboratory and field samples showed a good correspondence between the results yielded by these two methods. The antibodies developed by this technique provide th e means for developing extremely sensitive and specific analytical assays f or direct measurement of toxins in cyanobacterial or water samples. (C) 200 0 Elsevier Science Ltd. All rights reserved.