Glysiinin

Glysiinin, commonly referred to as glycinin, is a major storage protein of seeds in soybeans (Glycine max) and is also found in some other legumes. It belongs to the 11S globulin family and can make up a substantial portion of seed protein. Glysiinin occurs as a hexamer composed of acidic and basic subunits derived from a single precursor polypeptide that is proteolytically cleaved into two chains linked by a disulfide bond. Multiple gene variants encode different subunits, contributing to heterogeneity in the mature complex.

During seed development, glysiinin serves as a nutrient reservoir, supplying amino acids for germination and seedling growth. In food systems, it contributes to texture, water binding, and emulsification. Heating induces denaturation and gelation, which influences the rheological properties of soy-based products such as tofu, soy milk, and other formulations. Glysiinin is a prominent component of commercially produced soy proteins, including isolates and concentrates.

From a nutritional perspective, glysiinin provides high-quality plant protein but may be relatively low in methionine. Some individuals may experience soy protein allergenicity, with storage proteins like glysiinin implicated in allergic responses. Processing methods such as heat treatment, fermentation, and enzymatic modification can alter both the functional properties and allergenic potential of glysiinin-containing products.

Glysiinin is one of several major seed storage proteins in legumes; in soybeans it coexists with other families such as legumin (12S) and vicilin (7S). The term glycinin is widely used in biochemistry, while glysiinin is an alternate spelling found in some languages or transliterations.