Native E. coli beta Galactosidase protein

Product details

Beta Galactosidase was prepared chromatographically. This product has been sterile filtered. Beta Galactosidase is used as a control in beta-galactosidase based immunological assays.

Beta-galactosidase, also called beta-gal or Beta-gal, is a hydrolase enzyme that catalyzes the hydrolysis of Beta-galactosides into monosaccharides. Substrates of different Beta-galactosidases include ganglioside GM1, lactosylceramides, lactose, and various glycoproteins. Lactase is often confused as an alternative name for Beta-galactosidase, but it is simply a sub-class of Beta-galactosidase. Beta-galactosidase is an exoglycosidase which hydrolyzes the Beta-glycosidic bond formed between a galactose and its organic moiety. It may also cleave fucosides and arabinosides but with much lower efficiency. It is an essential enzyme in the human body, deficiencies in the protein can result in galactosialidosis or Morquio B syndrome. In E. coli, the gene of Beta-galactosidase, the lacZ gene, is present as part of the inducible system lac operon which is activated in the presence of lactose when glucose level is low.

It is commonly used in molecular biology as a reporter marker to monitor gene expression. It also exhibits a phenomenon called alpha-complementation which forms the basis for the blue/white screening of recombinant clones. This enzyme can be split in two peptides, LacZ-alpha and LacZ-omega neither of which is active by itself but when both are present together, spontaneously reassemble into a functional enzyme. This property is exploited in many cloning vectors where the presence of the lacZ-alpha gene in a plasmid can complement in trans another mutant gene encoding the LacZ-omega in specific laboratory strains of E. coli. However, when DNA fragments are inserted in the vector, the production of LacZ-alpha is disrupted, the cells therefore show no Beta-galactosidase activity. The presence or absence of an active Beta-galactosidase may be detected by X-gal, which produces a characteristic blue dye when cleaved by Beta-galactosidase, thereby providing an easy means of distinguishing the presence or absence of cloned product in a plasmid.