Characterization of Buckwheat Seed Storage Proteins

The major storage protein of buckwheat seed is the 13S globulin. Separation of buckwheat seed proteins by sucrose density gradient revealed the existence of an additional new minor storage protein. Analysis of 13S and the new minor class storage proteins by two systems of two-dimensional gel electrophoresis showed that the 13S globulin resembles a structure of legumin-like seed storage proteins, but the new protein appears to be a vicilin-like storage protein. The 57−58 kDa polypeptides, previously described as the unusual subunits of the 13S storage protein, in fact are the subunits of the minor class of buckwheat seed storage proteins. The major and minor classes of storage protein represent about 33 and 6.5% of total seed proteins, respectively.