β-Galactosidase from Escherichia coli
SIGMA/G5635 - Grade VIII, lyophilized powder, ≥500 units/mg protein
Synonym: β-D-Galactoside galactohydrolase; Lactase
CAS Number: 9031-11-2
EC Number: 232-864-1
MDL Number: MFCD00155434
Product Type: Chemical
Stoichiometry: Lactose + H2O → D-Glucose + beta-D-Galactose
| composition | Protein, ≥60% biuret |
| does not contain | BSA as extender |
| form | lyophilized powder |
| mol wt | 465 kDa |
| Quality Level | 300  |
| specific activity | ≥500 units/mg protein |
| storage temp. | −20°C |
| type | Grade VIII |
| Application: | β-Galactosidase is conjugated to an antibody which specifically recognizes a target molecule (enzyme immunoassay or EIA). β-Galactosidase is also used as a reporter enzyme to monitor the level of gene expression of a promoter. It may be used as a positive control protein with anti-β-galactosidase antibodies. |
| Biochem/physiol Actions: | β-galactosidase cleaves lactose into its monosaccharide components, glucose and galactose. It also catalyses the transglycosylation of glucose into allolactose, the inducer of β-galactosidase, in a feedback loop. |
| General description: | Tetramer molecular weight 465 kDa (subunits 116.3 kDa each) |
| General description: | β-Galactosidase is a tetramer consisting of four equal subunits of 135,000 each. It is a sulfhydryl containing enzyme, with 19 cysteine residues per subunit. |
| Other Notes: | One unit will hydrolyze 1.0 μmole of o-nitrophenyl β- |
| Packaging: | 1000, 3000, 5000, 15000 units in serum bottle |
| Physical form: | Contains Tris buffer salts and magnesium chloride |
| RIDADR | NONH for all modes of transport |
| WGK Germany | WGK 3 |
| Flash Point(F) | Not applicable |
| Flash Point(C) | Not applicable |
| activity | specific activity: ≥500 units/mg protein |
| Storage Temp. | −20°C |
| Enzyme Commission (EC) Number | 3.2.1.23 ( BRENDA  | IUBMB ) |
| UNSPSC | 12352204 |