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G6008

Sigma-Aldrich

β-Galactosidase from Escherichia coli

Grade VI, lyophilized powder, ≥250 units/mg protein

Synonym(s):

β-D-Galactoside galactohydrolase, Lactase

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About This Item

CAS Number:
9031-11-2
Enzyme Commission number:
3.2.1.23 (BRENDA, IUBMB)
EC Number:
232-864-1
MDL number:
MFCD00130623
UNSPSC Code:
12352204
NACRES:
NA.54

biological source

Escherichia coli

Quality Level

200

type

Grade VI

form

lyophilized powder

specific activity

≥250 units/mg protein

mol wt

465 kDa

does not contain

BSA as extender

composition

Protein, ≥50% biuret

shipped in

wet ice

storage temp.

−20°C

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General description

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.

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 expression of a promoter.

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.
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 properties

Tetramer molecular weight 465 kDa (subunits 116.3 kDa each)

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.

Physical form

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

inhibitor

Product No.
Description
Pricing

substrate

Product No.
Description
Pricing

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Regulatory Listings

Regulatory Listings are mainly provided for chemical products. Only limited information can be provided here for non-chemical products. No entry means none of the components are listed. It is the user’s obligation to ensure the safe and legal use of the product.

JAN Code

G6008-5KU:
G6008-VAR:
G6008-1KU:
G6008-10KU:
G6008-1KU-PW:
G6008-BULK:
G6008-10KU-PW:
G6008-5KU-PW:

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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David P Klebl et al.
Frontiers in molecular biosciences, 9, 945772-945772 (2022-08-23)
Advances in single particle cryo-EM data collection and processing have seen a significant rise in its use. However, the influences of the environment generated through grid preparation, by for example interactions of proteins with the air-water interface are poorly understood
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
PURIFICATION, COMPOSITION, AND MOLECULAR WEIGHT OF THE BETA-GALACTOSIDASE OF ESCHERICHIA COLI K12.
G R CRAVEN et al.
The Journal of biological chemistry, 240, 2468-2477 (1965-06-01)
D C Young et al.
Analytical biochemistry, 215(1), 24-30 (1993-11-15)
Bacterial beta-galactosidase is one of several reporter enzymes used in studying the transcriptional activity of eukaryotic promoters. Although it is one of the easiest and least expensive enzymes to assay, its use has been limited because of its low sensitivity
Orit Redy-Keisar et al.
Nature protocols, 9(1), 27-36 (2013-12-07)
This protocol describes the synthesis of modular turn-ON QCy7-based probes for the detection of biologically relevant analytes, such as hydrogen peroxide, ubiquitous sulfhydryl and β-galactosidase. The probes presented herein are prepared through a simple procedure that involves the preliminary alkylation
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