Synthesis of protein conjugates and development of immunoassays for AAL toxins

AAL toxins and fumonisins, produced by Alternaria alternata f. sp. lycopersici and Fusarium moniliforme, respectively, are sphinganine-analogue mycotoxins with important health implications. Highly sensitive, inexpensive, and rapid immunoassays are needed to quantify these natural toxins in food products and animal feeds. We developed novel methods for the synthesis of protein conjugates of the AAL toxin TA. Mice were immunized with the conjugates, and the resulting polyclonal antisera were used to devise class-selective ELISAs for AAL compounds. The most selective assays had detection limits for the AAL toxins in the low parts per billion range with no significant cross-reactivities for a number of structurally similar compounds, including fumonisin B₁ and sphinganine. Our selected conjugates are candidate immunogens to produce monoclonal antibodies and further polyclonal antisera for the detection of the AAL toxins.