THE CHEMISTRY AND CELL BIOLOGY OF THE VACUOLAR PROTEINS OF SEEDS

Abstract

ABSTRACT Ultrastructural, cytochemical and immunochemical evidence obtained using different plant families supports a suggested model for the biosynthesis of the storage proteins of seeds. Aleurins of the legumin type are proposed to be homologous. The proposed homologues are usually hexamers or tetramers of a disulfide bridged subunit of the A‐S‐S‐B type. The large observed variations in amino acid composition of the proposed homologues imply they are liberal proteins; i.e., large variations in the amino acid sequence of the subunits do not cause lethal effects nor change the function of the protein. The list of proposed legumiu homologues includes the legumins, glycinin, arachin, edestin and cocosin. Some unnamed cottonseed proteins also seem to qualify.