Product Name

β-Galactosidase from Escherichia coli

General deion

β-Galactosidase is a tetramer consisting of four equal subunits of 135,000 Da each. It is a sulfhydryl containing enzyme, with 19 cysteine residues per subunit.

Synonym

β-D-Galactoside galactohydrolase, Lactase

Assay

Grade VI, 250-600 units/mg protein; Protein, ≥50% biuret

CAS Number

9031-11-2

MDL number

MFCD00130623

Suitability

BioReagent

l Physical and Chemical Information

Appearance

lyophilized powder

Physical form

Partially purified; contains Tris buffer salts, magnesium chloride, DL-dithiothreitol and 2-mercaptoethanol

l Biological Information

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.

Application

β-Galactosidase is conjugated to an antibody that specifically recognizes a target molecule (enzyme immunoassay or EIA). β-Galactosidase is also used as a reporter enzyme to monitor the level of gene  of a promoter.

Unit Definition

One unit will hydrolyze 1.0 μmole of o-nitrophenyl β-D-galactoside to o-nitrophenol and D-galactose per min at pH 7.3 at 37 °C.

l Storage

Storage temp.

-20°C

l Precautions and Disclaimer

This product is for R&D use only, not for drug, household, or other uses.

l References

1. http://www.drugbank.ca

2. https://ncit.nci.nih.gov

3. https://www.ncbi.nlm.nih.gov