Casein

Casein is a **family of related phosphoproteins**—primarily αS1-, αS2-, β-, and κ-caseins—found abundantly in mammalian milk. It constitutes about 80% of the protein content in cow’s milk and between 20–60% in human milk[1][4]. These proteins aggregate into large colloidal particles called **casein micelles**, which are stabilized by calcium phosphate bridges and play a crucial role as emulsifiers within milk[3][5]. Caseins are characterized by their high proline content and lack of ordered secondary or tertiary structure; this makes them flexible molecules capable of forming stable complexes that resist heat denaturation[2][5]. Biologically, caseins serve as an important source of essential amino acids for growth and tissue repair. They also facilitate the intestinal absorption of minerals such as calcium and phosphorus through the release of phosphopeptides during digestion. The slow digestion rate leads to sustained amino acid release into circulation—a property exploited for satiety enhancement in nutrition supplements[3][7]. Enzymatic hydrolysis during cheese production releases bioactive peptides from caseins with potential antihypertensive or immunomodulatory activities[6]. Casein is not considered a therapeutic target such as an enzyme or receptor but rather a dietary protein source. It does not have known interacting drugs or mechanisms typical for pharmacological targets. However, it can act as an allergen for some individuals sensitive to dairy proteins.

Other names

Milk caseinCasein proteinSodium caseinateNutroseαS1-caseinαS2-caseinβ-caseinκ-casein