Disulphide structure of a sunflower seed albumin: Conserved and variant disulphide bonds in the cereal prolamin superfamily

Disulphide mapping of a methionine-rich 2S albumin from sunflower seeds showed four intra-chain disulphide bonds which are homologous with those in a related heterodimeric albumin from lupin seeds (conglutin δ). Similar conserved disulphide bonds are also present in α-gliadin and γ-gliadin storage proteins of wheat, but a lower level of conservation is present in a further related group of proteins, the cereal inhibitors of α-amylese and trypsin. These differences may relate to the different functions of the proteins.