REFOLDING OF RIBOFLAVIN CARRIER PROTEIN AS PROBED BY BIOCHEMICAL AND IMMUNOLOGICAL PARAMETERS

The unfolding of the chicken egg white riboflavin carrier protein by d isulfide reduction with dithiothreitol led to aggregation with concomi tant loss of ligand binding characteristics and the capacity to intera ct with six monoclonal antibodies directed against surface-exposed dis continuous epitopes. The reduced protein could, however, bind to a mon oclonal antibody recognizing sequential epitope. Under optimal conditi ons of protein refolding, the vitamin carrier protein regained its fol ded structure with high efficiency with simultaneous complete restorat ion of hydrophobic flavin binding site as well as the epitopic conform ations exposed at the surface in a manner comparable to its native for m.