α-Lactalbumin

Abstract

The whey protein, α-lactalbumin, has a key role in the biosynthesis of lactose and in the formation and secretion of the aqueous phase of milk. Mechanistically, α-lactalbumin interacts with β-1,4-galactosyltransferase-I to modify its specificity so that it can catalyze the transfer of galactose to glucose (lactose synthesis) rather than to glycoconjugates. α-Lactalbumin is a member of the type-c lysozyme superfamily. It has a 3D structure similar to those of the lysozymes that contains a tightly bound stabilizing calcium ion. Complexes of partially folded α-lactalbumin with lipids are cytotoxic to tumor cells but the specificity of this is uncertain.