PRODUCTION AND CHARACTERIZATION OF POLYCLONAL ANTIBODIES AGAINST NORSOLORINIC ACID REDUCTASE INVOLVED IN AFLATOXIN BIOSYNTHESIS

Polyclonal antibodies against norsolorinic acid reductase (NSR), an en zyme responsible for the conversion of norsolorinic acid to averantin in the early stage of aflatoxin biosynthesis, were produced after immu nizing rabbits with a semi-purified NSR preparation. Immunochemical an alysis of the enzyme extracts fr om Aspergillus parasiticus revealed t hat the antibodies reacted with several protein species, including ban ds corresponding to NSR activity. The ammonium sulfate-cut IgG was fur ther purified by passing it through a column aimed with protein fracti ons containing immunoreactivity, but no enzyme activity, isolated from the A. parasiticus extracts that had been subjected to Sepharose gel filtration. After subtractive affinity chromatography, the purified an tiserum reacted primarily with two protein bands (of molecular weight 43 and 48 kDa) and was capable of neutralizing the NSR activity. Enzym e-linked immunosorbent assay (ELISA) analysis of various fungal extrac ts showed that the purified antiserum was highly specific for the enzy me.