Galactosidases are enzymes (glycoside hydrolases) that catalyze the hydrolysis of galactosides into monosaccharides.
Galactosides can be classified as either alpha or beta. If the galactoside is classified as an alpha-galactoside, the enzyme is called alpha-galactosidase, and is responsible for catalyzing the hydrolysis of substrates that contain α-galactosidic residues, such as glycosphingolipids or glycoproteins.[1] On the other hand, if it is a beta-galactoside, it is called beta-galactosidase, and is responsible for breaking down the disaccharide lactose into its monosaccharide components, glucose and galactose.[1] Both varieties of galactosidase are categorized under the EC number 3.2.1.
Two recombinant forms of alpha-galactosidase are called agalsidase alfa (INN) and agalsidase beta (INN). Lack of alpha-galactosidase activity in leukocytes has been linked to Fabry Disease.[2]
Galactosidases have a variety of uses, including the production of prebiotics, the biosynthesis of transgalactosylated products, and the removal of lactose.
B-galactosidase forms the basis of lac z operon in bacteria which can be used to control gene expression.