The purification and characterization of a third storage protein (convicilin) from the seeds of pea (Pisum sativum L.)

Abstract

A 3rd storage protein, distinct from legumin and vicilin, was purified from the seeds of pea (P. sativum L. cv. Feltham First). This protein was named convicilin and is present in protein bodies isolated from pea seeds. Convicilin has a subunit MW of 71,000 and 1 MW in its native form of 290,000. Convicilin is antigenically dissimilar to legumin, but gives a reaction of identity with vicilin when tested against antibodies raised against both proteins. However, convicilin contains no vicilin subunits and may be clearly separated from vicilin by non-dissociating techniques. Unlike vicilin, convicilin does not interact with concanavalin A, and contains insignificant amounts of carbohydrates. Limited heterogeneity, as shown by isoelectric focusing, N-terminal analysis and CNBr cleavage, is present in convicilin isolated from a single pea variety; genetic variation of the protein between pea lines was observed.