Seed storage protein. Denaturation starts at 45 degrees Celsius. At temperatures above 75 degrees Celsius, begins to precipitate, and eventually becomes irreversibly denatured. Cannot be resolubilized in aqueous solution after being heated up to 95 degrees Celsius and then cooled down to 25 degrees Celsius. Homotrimer. Expressed in seed (at protein level). N-glycosylated; paucimannose-type structures containing xylose. Non-glycosylated. Glycosylated. Causes an allergic reaction in human. Natural protein binds to IgE in 26% of the 77 walnut-allergic patients tested. IgE-binding is reduced by simulated gastric fluid and in vitro duodenal digestion, but not by heat treatment. Cross-reacts with its counterparts from hazelnut (Cor a 11), pistachio and sesame. Could be used as a marker of IgE cross-reactivity among the vicilins of tree nuts in component resolved diagnosis. Belongs to the 7S seed storage protein family.