Endo-beta-galactosidase cleaves internal ß(1-4) galactose linkages in unbranched, repeating poly-N-acetyllactosamine structures.
Recombinant from Bacteroides fragili.
Part Number – Amount of Enzyme
E-XBG01 – 60 µLs¹
E-XBG01-20 – 20 µls¹
E-XBG01-200 – 200 µls²
¹ includes buffer
² includes enzyme only
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.
Source Recombinant from Bacteroides fragilis
Specificity Cleaves internal ß(1-4) galactose linkages in unbranched, repeating poly-N-acetyllactosamine [GlcNAc-ß(1-3)Gal-ß(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, Gal-ß(1-3)GlcNAc-ß(1-3)Gal-ß(1-4)Glc is cleaved at 5×10-5 the rate of keratan sulfate(see ref.4). Specificity is similar to the Escherichia freundii enzyme. 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).
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
Specific Activity >140 U/mg
Activity >14 U/ml
Molecular weight ~32,000 daltons
Optimum pH 5.8
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˚C 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.
One unit of Endo-Beta-Galactosidase is defined as the amount that will liberate one µmole of reducing sugar per minute at 37˚C and pH 5.8 from bovine corneal keratan sulfate.
Stability Stable at least 24 months when stored properly. Several days exposure to ambient temperature will not reduce activity. Active for at least 5 days under reaction conditions.
Purity Endo-Beta-Galactosidase is tested for contaminating protease as follows: 10 μg of denatured BSA is incubated for 24 hours at 37°C 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.
1. Scudder,P., Uemura, K., Doby, J., Fukuda, M.N. & Feizi, T.(1983) Isolation and characterization of an endo-b-galactosidase from Bacteroides fragilis Biochem. J. 213 , 485-494.
2. Scudder,P., Hanfland, Pl, Uemura, K. & Feizi, T. (1984) Endo-b-galactosidases of Bacteroides fragilis and Escherichia freundii hydrolyze linear but not branched oligosaccharide domains of glycolipids of the neolacto series. J. Biol. Chem . 259, 6586-6592.
3. Scudder, P. Tang, P.W., Hounsell, E.F., Lawson, A.M., Mehmet, H. & Feizi, T. (1986) Isolation and characterization of sulfated oligosaccharides released from bovine corneal keratan sulphate by the action of endo-b-galactosidase. Eur. J. Biochem. 157, 365-373.
4. Murata, T., Hattori, T. Amarume, S. Koicki, A. & Usui, T. (2003) Kinetic studies on endo-beta-galactosidase by a novel colorimetric assay and synthesis of N-acetyllactosamine-repeating oligosaccharide beta-glycosides using its transglycosylation activity.Eur. J. Biochem 270, 3709-3719.
5. Hokke, C.H., Bergwerff, A.A., Van Dedem, D.W., Kamerling, J.P, and Vliegenthart, J.F. (1995) Structural analysis of the N- and O-linked carbohydrate chains of recombinant human erythropoietin expressed in Chinese hamster overay cells. Sialylation patters and branch location of dimeric N-acetyllactosamine units. Eur. J. Biochem. 228, 981-1008.