legumins

Legumins are a class of seed storage proteins found primarily in legume crops such as beans, peas, lentils, and soybeans. They belong to the 11S globulin family and are among the major protein reserves in seeds, supporting seedling growth after germination.

Biochemically, legumins are synthesized as larger precursor polypeptides that are processed into two chains, an acidic and a basic chain, linked by a disulfide bond. The mature subunits assemble into high-molecular-weight, hexameric complexes and are typically stored in specialized protein bodies within the seed.

They accumulate during seed development and are mobilized during germination when proteases degrade the complexes to provide amino acids and nitrogen for the growing seedling.

Legumins are nutritionally valuable, contributing essential amino acids to the human diet, particularly in vegetarian and vegan diets. However, some legume legumin proteins are among the major allergens in foods, notably in peanuts (Ara h 3) and soybeans, where sensitization can cause immune reactions in susceptible individuals.

Within the broader family of seed storage proteins, legumins are contrasted with vicilins (7S globulins). Together these globulins comprise a large portion of legume seed protein and influence allergenicity, digestibility, and processing properties.