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G4155

β-Galactosidase from Escherichia coli

aqueous glycerol suspension, ≥500 units/mg protein (biuret)

Synonym(s):

β-D-Galactoside galactohydrolase, Lactase

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About This Item

CAS Number:
UNSPSC Code:
12352204
NACRES:
NA.54
EC Number:
MDL number:
Specific activity:
≥500 units/mg protein (biuret)
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form

aqueous glycerol suspension

Quality Segment

specific activity

≥500 units/mg protein (biuret)

mol wt

465 kDa

storage temp.

−20°C

General description

Tetramer molecular weight 465 kDa (subunits 116.3 kDa each)

Application

β-Galactosidase is used in the enzymatic assays in the synthesis of imidazolo-pyrrolidinoses.

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

Suspension in 50% glycerol, 5 mM Tris buffer salts, 5 mM magnesium chloride, 0.5 mM DTT, 0.5 mM mercaptoethanol. pH 7.4

Other Notes

Loss of enzymatic activity can occur if this enzyme is frozen. This enzyme is provided in a 50% glycerol solution and will not freeze if stored at -20° Celsius. It is not recommended that this enzyme preparation be stored in an ultracold freezer (-60 to -100° Celsius).
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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This Item
48275G5635G6008
specific activity

≥500 units/mg protein (biuret)

specific activity

~140 U/mg

specific activity

≥500 units/mg protein

specific activity

≥250 units/mg protein

form

aqueous glycerol suspension

form

powder

form

lyophilized powder

form

lyophilized powder

storage temp.

−20°C

storage temp.

−20°C

storage temp.

−20°C

storage temp.

−20°C

mol wt

465 kDa

mol wt

Mr ~135000

mol wt

465 kDa

mol wt

465 kDa

Quality Level

200

Quality Level

100

Quality Level

300

Quality Level

200


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Storage Class

10 - Combustible liquids

flash_point_f

Not applicable

flash_point_c

Not applicable

pictograms

Health hazard

signalword

Danger

hcodes

Hazard Classifications

Resp. Sens. 1



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Questions

1–2 of 2 Questions  
  1. Could you please advise if the density of the aqueous suspension of beta galactosidase from Escherichia coli (G4155) can be assumed as 1 uL of solution is equal to 1 mg, given that the SDS and provided enzyme assay do not contain this information?

    1 answer
    1. A search of the website does not show a density for product G4155. For products supplied in small quantities, it is not common for the density to be measured. However, for solutions available in larger quantities, density information is often provided. Although the density for G4155 is not stated, there is some useful information available from the website. The physical form of the product is a suspension in 50% glycerol, 5 mM Tris buffer salts, 5 mM magnesium chloride, 0.5 mM DTT, and 0.5 mM mercaptoethanol at pH 7.4.

      Helpful?

  2. We recently purchased this enzyme. Information given regarding enzyme volume is only 1000 units. I want to know what would be units per uL. How much is the liquid volume in the given product to calculate the enzyme concentration? Provide proper informatio

    1 answer
    1. Units/ml can be calculated using the numbers reported in batch specific CofA. Below is an example.
      CofA of G4155, lot 0000303635
      https://www.sigmaaldrich.com/certificates/sapfs/PROD/sap/certificate_pdfs/COFA/Q14/G4155-3KU0000303635.pdf
      1.5 mgP/ml X 766 units/mg Protein = 1149 units/ml

      Helpful?

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