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Key Documents

G3153

Sigma-Aldrich

β-Galactosidase from Escherichia coli

lyophilized powder, ≥500 units/mg protein

Synonym(s):

β-D-Galactoside galactohydrolase, Lactase

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About This Item

CAS Number:
Enzyme Commission number:
EC Number:
MDL number:
UNSPSC Code:
12352204
NACRES:
NA.54

recombinant

expressed in E. coli

Quality Level

form

lyophilized powder

specific activity

≥500 units/mg protein

mol wt

465 kDa

storage temp.

−20°C

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General description

β-galactosidase is a 465 kDa tetrameric protein. It is coded by the LacZ gene.

Application

β-Galactosidase from Escherichia coli has been used to produce biocatalytic Ca-alginate beads on a B-390 encapsulator (BUCHI). It has been used to prepare the source droplet solution and also as the cargo for Pep-1 (KETWWETWWTEWSQPKKKRKV-cysteamide).
β-Galactosidase may be used for derivatization, such as an enzyme label for IgG, without prior dialysis or gel filtration.

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 is considered as a reporter enzyme in applications involving gene expression regulation, analysis of protein function/structure and target gene expression.

Packaging

Package size based on protein content

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-galactopyranoside to o-nitrophenol and D-galactose per min at pH 7.3 at 37 °C.

Physical form

Stabilized with phosphate buffer and sucrose

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

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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Structure of beta-galactosidase at 3.2-AA resolution obtained by cryo-electron microscopy
Bartesaghi A, et al.
Proceedings of the National Academy of Sciences of the USA, 111(32), 11709-11709 (2014)
M J O'Sullivan et al.
Annals of clinical biochemistry, 16(5), 221-240 (1979-09-01)
In the last few years, the use of enzyme labels in immunoassays has been investigated. The aim of this review is to evaluate critically the role of such labels in clinical biochemistry. Special attention has been given to the problems
Peptide-Mediated Membrane Transport of Macromolecular Cargo Driven by Membrane Asymmetry
Li X, et al.
Analytical Chemistry, 89(22), 12369-12374 (2017)
Samuel Berhanu et al.
Journal of basic microbiology, 62(6), 669-688 (2022-03-16)
pUC18 and pUC19 are well-known high copy-number plasmid vectors routinely used for DNA cloning purposes. We show here that, in Escherichia coli transformed by native pUC18, the α-complementation of β-galactosidase (i.e., mediated by the peptide LacZα18) is intrinsically weak and
Bi-Enzymatic Embolization Beads for Two-Armed Enzyme-Prodrug Therapy
Olesen MTJ, et al.
Advances in Therapy, 1(4), 1800023-1800023 (2018)

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