Abbr
O-Glycanase, Recombinant (Streptococcus pneumoniae)
Species
Streptococcus pneumoniae
Product Overview
The enzyme is inactivated with sulfhydryl reagents such as p-chloro-mercuribenzene sulfonic acid and transition metals such as Mn2+ or Zn2+. The enzyme is also inhibited with 1 mM EDTA. In a highly purified form, O-Glycanase adsorbs to glass surfaces and is inactivated or gives variable activities. Assays with purified substrates should be carried out in polypropylene vessels, and transfer of the enzyme solutions with glass pipettes should be avoided. The purified enzyme, as formulated, is stable at 2-8°C but about 30% of its activity is lost with a single freeze-thaw cycle. The enzyme activity is not significantly affected if the material is stored at room temperature for 24 hours. The optimum buffer for enzyme activity with the standard substrate is 50 mM sodium phosphate (pH 5.0). If glycosidase treatment is performed at suboptimal pH because of glycoprotein solubility or activity requirements, expect some diminution in enzyme activity.
Form
A sterile-filtered solution in 20 mM Tris-HCl, 25 mM NaCl (pH 7.5)
Molecular Weight
~180 kDa daltons
Purity
O-Glycanase is free of contaminating endo-and exoglycosidase activity. No protease activity was detectable after incubation of the enzyme with 0.2 mg resorufin-labeled casein for ~18 hours at 37°C according to the method described by Twining. The production host strain has been extensively tested and does not produce any detectable glycosidases.
Specificity
O-Glycanase cleaves Gal β (1-3) GalNAc α-as an intact disaccharide unit from serine or threonine residues of glycoproteins or glycopeptides. This disaccharide is the defining structural component for Core 1 type O-linked glycans. Cleavage of the glycosidic bond is between the GalNAc residue, in the alpha configuration, and the hydroxyl moiety of the amino acid side chain of the polypeptide. Substitutions of the disaccharide core with sialic acid, or a lactosaminic repeating unit of galactose-N-acetyl glucosamine of fucose, will block hydrolysis and prevent the liberation of the oligosaccharide from the protein. In order to expose the Core I type structure so that it is susceptible to the O-Glycanase action, extended oligosaccharides must first be treated with glycosidases, such as Sialidase A/NANase III, or inaddition, treatment with a combination of β (1-4)-galactosidase and β-N-Acetylhexosaminidase/Hexase I. The enzyme has no activity on single α-GlcNAc linked either to protein or carbohydrate. With the synthetic substrate analog, Gal β (1-3) GalNAc-p-nitrophenyl glycosidase, a Km value of ~200 μM was obtained. Interestingly, the enzyme is similar to other glycohydrolases and has been reported to have‘trans’glycosidase activity. Cleavage of the disaccharide unit is mediated by the formation of a covalent enzyme intermediate. The enzyme-bound glycan can be transferred to a number of hydroxylated acceptor molecules instead of displacement with water.
Optimum pH
Optimum: pH 5.0 Range: pH 5.0-6.0
Storage
Shipped on cold pack for next day delivery. Store at 2-8°C. DO NOT FREEZE.
Buffer
5x Reaction Buffer 5.0 (250 mM sodium phosphate, pH 5.0)
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