Endo-Beta-Galactosidase

内切β-半乳糖苷酶

E489844-20μl

20μl

Specific Activity ＞140 U/mg;Activity ＞14 U/ml

Product Description Endo-Beta-Galactosidase cleaves internal β(1-4) galactose linkages in unbranched, repeating poly-N-acetyllactosamine structures. Sulfated structures such as keratan sulfate are also cleaved. Branching and/or fucosylation of the substrate may decrease or eliminate cleavage. Endo-Beta-Galactosidase is useful for identifying and removing poly-N-acetyllactosamine structures on many biologically important glycoconjugates. Contents 60 µl aliquot of enzyme (0.9 U) in 20 mM tris-HCl, pH 7.5 1 vial reaction buffer- 250mM Sodium phosphate, pH 5.8 pH Optimum: 5.8 Molecular Weight 32,000 daltons Formulation The enzyme is provided as a sterile-filtered solution in 20 mM Tris-HCl, pH 7.5 Stability Stable at least 12 months when stored properly. Several days exposure to ambient temperatures will not reduce activity. Active at least 5 days under reaction conditions. Specificity Internal β(1-4) galactose linkages in unbranched, repeating poly-N-acetyllactosamine [GlcNAcβ(1-3) Galβ(1-4)]n structures are the preferred substrate. Sulfated structures such as keratan sulfate are also cleaved. Branching and/or fucosylation of the substrate may decrease or eliminate cleavage. Sulfation of C-6 on galactose will block cleavage. Oligosaccharidesof the neo-lacto group are cleaved at greatly educed rates depending on the deviation from the preferred substrate. For example, Galβ(1-3)GlcNAcβ(1-3)Galβ(1-4)Glc is cleaved at 5x10-5 the rate of keratan sulfate(see ref.4). Specificity is similar to the Escherichia freundii enzyme. except that it is limited to cleaving N-acetyllactosamine extensions on tetraantennary structures of erythropoietin(see ref 5). Specific Activity One unit of endo-β-Galactosidase is defined as the amount that will liberate one μmole of reducing sugar per minute at 37℃and pH 5.8 from bovine corneal keratan sulfate. Purity Endo-β-Galactosidase is tested for contaminating protease as follows: 10 ug of denatured BSA is incubated for 24 hours at 37℃ with 2 μl of enzyme. SDS-PAGE analysis of the treated BSA shows no evidence of degradation. The production strain of E. coli has been extensively tested and does not produce any detectable glycosidases. Directions for use For glycoproteins: 1. Add up to 100 μg of glycoprotein to a tube. 2. Add 4 ul 5X buffer and water to 19 μl. 3. Add 1 μl enzyme. 4. Incubate at 37℃ for 2 hrs. Procedure for oligosaccharides: Same as above except incubate from several hours to several days depending on the substrate. Add bovine serum albumen to 2 mg/ml to stabilize the protein during extended incubations. Applications Endo-β-Galactosidase (EC 3.2.1.103) cleaves internal β(1-4) galactose linkages in unbranched, repeating polyN-acetyllactosamine structures. Sulfated structures such as keratan sulfate are also cleaved. Branching and/or fucosylation of the substrate may decrease or eliminate cleavage. Endo-β-Galactosidase is useful for identifying and removing poly-N-acetyllactosamine structures on many biologically important glycoconjugates.

>14 U/ml