Characterization of 30-kDa fragments derived from beta-conglycinin degradation process during germination and seedling growth of soybean.

The degradation process of beta-conglycinin, a vicilin-type glycosylated storage protein of soybean seeds, during germination and seedling growth was examined by concanavalin A blotting combined with polyacrylamide gel electrophoresis. We detected and analyzed the structures of key intermediary fragments of 30 kDa derived from beta-conglycinin degradation, they were proved to be single-domain type subunits of beta-conglycinin. We show here a degradation process of beta-conglycinin: beta-conglycinin is subjected to limited proteolysis at exposed regions on the molecular surface, like domain junctions, generating 30-kDa single-domain fragments before non-specific proteolysis.