Lactalbumin

α-Lactalbumin is a small, globular, whey protein that has been found in all milk studied to date. It is a metalloprotein of approximately 14 kDa produced in the mammary glands.

α-Lactalbumin was used in a cytologic assay for diagnosis of food hypersensitivity in patients with irritable bowel syndrome.

Lactalbumin has also been used in rearing anopheline mosquitoes.

α-Lactalbumin consists of a single polypeptide chain with 8 cysteines which form disulfide bridges. α-Lactalbumin binds several metal ions, including calcium, which is thought to play a role in the regeneration of native α-lactalbumin from the reduced, denatured form. α-Lactalbumin also has a distinct zinc binding site that is thought to play a role in the binding of the lactose synthase complex. The mature protein consists of 123 amino acid residues (14 kDa), and it has a three-dimensional structure with 1.7 Angstrom resolution, demonstrating four a-helices and a triple stranded antiparallel β-sheet.