Immunological characterization of ferrodoxin and methyl viologen interacting domains of glutamate synthase using monoclonal antibodies

Three monoclonal hybridoma cell lines were selected by the epitope specificity for the electron donor (ferredoxin and methyl viologen) interacting domains of glutamate synthase (EC 1.4.7.1) from Nicotiana tabacum L. cv Xanthi. The monoclonal antibodies (McAbs) inhibited the glutamate synthase reaction dependent on either reduced ferredoxin (Fd) or methyl viologen, or both Fd and methyl viologen as electron carrier. The three McAbs cross-reacted with the glutamate synthase polypeptide by western immunodetection. Competitive ELISA assays using two of these McAbs as either the first or the second McAb indicated that the three McAbs share a common epitope specificity for the reductant interacting sites