α-Lactalbumin is the second most abundant whey protein in bovine milk, constituting approximately 20-25% of total whey proteins. It is a globular protein consisting of 123 amino acid residues with a molecular weight of about 14.2 kDa. The protein features four disulfide bonds that stabilize its structure and contains a single calcium ion binding site essential for its stability. α-Lactalbumin plays a critical role in lactose synthesis in the mammary gland by acting as a regulatory subunit of the lactose synthase complex. It is highly soluble in water at neutral pH and exhibits good emulsifying and foaming properties, making it valuable in food formulations. The protein is rich in essential amino acids, particularly tryptophan, and is used in infant formula, nutritional supplements, and functional foods due to its high nutritional quality and bioactive peptides released upon digestion.