Vicilinlike

Vicilin-like proteins are a family of seed storage proteins that share sequence similarity with vicilin, the major 7S globulin found in legume seeds. They are part of the cupin superfamily, typically featuring a beta-barrel fold and, in many members, two cupin-like domains within a single polypeptide. In seeds, vicilin-like proteins accumulate as nutrient reservoirs that support seedling growth during germination.

These proteins are usually synthesized as preproproteins with an N-terminal signal peptide directing them to protein storage vacuoles and are subsequently processed to mature polypeptides, which may be cleaved into alpha and beta subunits. The prevailing oligomerization state is trimeric, with some species forming higher-order assemblies such as hexamers. Monomers commonly have molecular masses around 50–60 kDa, though sizes vary among species.

Vicilin-like proteins occur broadly in seeds of many dicotyledonous plants, especially legumes such as soybean, pea, chickpea, lentil, and mung bean, but related sequences have been reported in other angiosperms. In addition to storage roles, some vicilin-like proteins exhibit defensive activities, including protease inhibition or antifungal properties. Several members are important food allergens (for example, peanut vicilin Ara h 1) and can show cross-reactivity with related legume allergens.

In research, vicilin-like proteins are studied to understand seed biology, allergenicity, and potential crop improvement through modifying storage protein composition or reducing allergenicity.