Homology between legumin-like polypeptides from cereals and pea

Abstract

The presence of legumin-like constituents within the globulin fractions of wheat (Triticum aestivum), rye (Secale cereale) and corn (maize, Zea mays) was demonstrated. Two-dimensional analysis of wheat globulins in the presence and absence of a reducing agent revealed the existence of reducible approximately 60 kDa polypeptides. Western-blot analysis with 125I-labelled antibodies raised against the oat (Avena sativa) 12S globulin holoprotein or its alpha-subunits demonstrated, firstly, the immunological homology between the alpha- and beta-subunits of pea (Pisum sativum) legumin and oat 12S globulin, and secondly, the similar occurrence in wheat of antigenically homologous approximately 20kDa and approximately 40 kDa polypeptides that associate via disulphide linkage to form approximately 60 kDa dimers. Western blotting also showed the presence of disulphide-linked approximately 20 kDa and approximately 40 kDa legumin-like subunits within the globulin fractions of rye and corn.