Development of antibodies for N-(1-deoxy-D-fructos-1-yl) fumonisin B1 and cross-reaction with modified fumonisins

Fumonisins are a group of mycotoxins that are routinely found worldwide in commodities such as maize. The group, which has many members, is generally characterised by the presence of one or more tricarballylic acid groups esterified to a long carbon backbone. The diversity of this group of toxins is further augmented by their ability to interact with matrix components non-covalently and to form covalent products with matrix constituents, such as carbohydrates and proteins. Covalent modifications to the toxins make it more difficult to assess the total amounts that may be present in a commodity. We developed monoclonal antibodies (Mabs) against a known product of the reaction of fumonisin B1 (FB1) with glucose: N-(1-deoxy-D-fructos-1-yl) fumonisin B1 (NDFrc-FB1). Similar reactions were used to produce fructosyl-analogs of fumonisins B2 and B3, as well as galactose, maltose, and rhamnose analogs of FB1. These analogs were tested in a competitive indirect ELISA for cross-reactivity towards one of the developed antibodies (Mab 213221). All of the carbohydrate analogs cross-reacted with the Mab, at levels ranging from 75% (the FB3 analog derived from D-glucose) to 181% (the FB1 analog derived from maltose). These results suggested the assay was capable of binding to a wide variety of fumonisin-carbohydrate derivatives. The same antibody was incorporated into an immunoaffinity column that was used to isolate modified fumonisins from a sample of naturally contaminated maize. These results demonstrate the potential to isolate and detect modified fumonisins and will facilitate efforts to determine the frequency of the occurrence of these compounds in maize.