Homology between legumin-like polypeptides from cereals and pea

Area of Science:

• Plant Biochemistry
• Protein Chemistry
• Food Science

Background:

• Globulins are major storage proteins in cereals like wheat, rye, and corn.
• Legumin is a key 11S globulin storage protein in legumes, known for its nutritional value.
• Understanding cereal globulin composition is vital for improving food quality and processing.

Purpose of the Study:

• To investigate the presence and characteristics of legumin-like proteins in wheat, rye, and corn globulins.
• To compare the structural and immunological properties of these cereal proteins with known legumin structures.
• To elucidate the subunit composition and assembly of these storage proteins.

Main Methods:

• Two-dimensional gel electrophoresis of wheat globulins to identify polypeptide components.
• Western blotting using antibodies against oat 12S globulin and pea legumin subunits.
• Immunological analysis to detect homologous proteins in wheat, rye, and corn globulin fractions.

Main Results:

• Legumin-like constituents were identified in the globulin fractions of wheat, rye, and corn.
• Wheat globulins contain reducible polypeptides of approximately 60 kDa, suggesting disulfide-linked dimers.
• Immunological analysis revealed homologous approximately 20 kDa and approximately 40 kDa subunits in wheat, rye, and corn, similar to pea legumin and oat 12S globulin.

Conclusions:

• Wheat, rye, and corn globulins contain legumin-like subunits, indicating conserved storage protein structures.
• These subunits associate via disulfide linkages to form larger protein complexes.
• The findings contribute to understanding cereal seed storage protein evolution and composition.