Vicilin is made up of one α subunit, a single
glycerol, and a phosphate ion. The addition of a copper ligand provides structural integrity. The
N-terminus and
C-terminus fold into cupin folds to produce conserved β-barrels. Cupin folds cluster in seed storage proteins, and the presence of a metal ligand influences the protein's catalytic action. The C-terminus and N-terminus generate a cupin fold that is symmetrically centered off the axis. This axis is responsible for all copper ligand incorporation. This copper center's structure has four main residues: Cys-338, Tyr-67, His-340, and His-379. The copper ligand is coupled by a
trigonal planar structure generated by cysteine's sulfur. The bond formed by a
hydroxyl group attached to Tyr-67 is longer than the previous three. The enzymatic activity is connected to copper binding via histidine residues. These copper ligands act catalytically on
proteins. ==Allergy==