Description_x000D_ General description_x000D_ 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._x000D_ Application_x000D_ α-Lactalbumin from bovine milk has been used:_x000D_ • in indirect enzyme-linked immunosorbent assay (ELISA) and competitive ELISA methods_x000D_ • in binding of Hsp90 and HSJ1b analysis_x000D_ • to inhibit the lysozyme CAP-RAST assay_x000D_ Packaging_x000D_ 1 g in poly bottle_x000D_ 100, 500 mg in poly bottle_x000D_ Biochem/physiol Actions_x000D_ Alters the substrate specificity of galactosyltransferase to increase the rate of lactose formation; the complex of galactosyltransferase and α-lactalbumin is called lactose synthase. Site-directed mutagenesis of Asp87 or Asp88 to Ala completely abolishes the strong calcium binding affinity and reduces the stimulation of lactose synthase to <3.5% of the maximal rate._x000D_ α-Lactalbumin is the cheif protein in human milk. It 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 kD), and it has a three-dimensional structure with 1.7 Angstrom resolution, demonstrating four α-helices and a triple stranded antiparallel β-sheet._x000D_ Quality_x000D_ May contain traces of (NH4)2SO4 and sodium phosphate.