G5635
β-Galactosidase from Escherichia coli
Grade VIII, lyophilized powder, ≥500 units/mg protein
Synonym(s):
β-D-Galactoside galactohydrolase, Lactase
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About This Item
CAS Number:
UNSPSC Code:
12352204
NACRES:
NA.54
EC Number:
232-864-1
MDL number:
Specific activity:
≥500 units/mg protein
type
Grade VIII
Quality Level
form
lyophilized powder
specific activity
≥500 units/mg protein
mol wt
465 kDa
does not contain
BSA as extender
composition
Protein, ≥60% biuret
storage temp.
−20°C
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.
Tetramer molecular weight 465 kDa (subunits 116.3 kDa each)
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.
Physical form
Contains Tris buffer salts and magnesium chloride
Other Notes
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.
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Storage Class
11 - Combustible Solids
wgk
WGK 3
flash_point_f
Not applicable
flash_point_c
Not applicable
ppe
Eyeshields, Gloves, type N95 (US)
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Articles
For use as a marker in SDS-PAGE; Albumin from chicken egg white, For use as a marker in SDS-PAGE; L-Lactic Dehydrogenase from rabbit muscle, Type XI, lyophilized powder, 600-1,200 units/mg protein
Related Content
QC Methods
Product Information Sheet
Alan Merk et al.
IUCrJ, 7(Pt 4), 639-643 (2020-07-23)
We report the determination of the structure of Escherichia coli β-galactosidase at a resolution of ∼1.8 Å using data collected on a 200 kV CRYO ARM microscope equipped with a K3 direct electron detector. The data were collected in a single 24 h
K Kato et al.
Journal of immunology (Baltimore, Md. : 1950), 116(6), 1554-1560 (1976-06-01)
1. A method for the conjugation of the Fab' fragment of rabbit IgG with beta-D-galactosidase from Escherichia coli is described. The method consists of two main steps: treatment of the Fab' fragments containing sulfhydryl groups with excess N,N'-o-phenylenedimaleimide, to introduce
Raimond B G Ravelli et al.
Nature communications, 11(1), 2563-2563 (2020-05-24)
The increasing demand for cryo-electron microscopy (cryo-EM) reveals drawbacks in current sample preparation protocols, such as sample waste and lack of reproducibility. Here, we present several technical developments that provide efficient sample preparation for cryo-EM studies. Pin printing substantially reduces