Enzymes
| UniProtKB help_outline | 3 proteins |
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- Name help_outline a neolactoside IV3-α-NeuAc-nLc4Cer(d18:1(4E)) Identifier CHEBI:58665 Charge -1 Formula C56H95N3O31R SMILEShelp_outline [H][C@]1(O[C@@](C[C@H](O)[C@H]1NC(C)=O)(O[C@H]1[C@@H](O)[C@@H](CO)O[C@@H](O[C@H]2[C@H](O)[C@@H](NC(C)=O)[C@@H](O[C@@H]2CO)O[C@H]2[C@@H](O)[C@@H](CO)O[C@@H](O[C@H]3[C@H](O)[C@@H](O)[C@H](OC[C@H](NC([*])=O)[C@H](O)\C=C\CCCCCCCCCCCCC)O[C@@H]3CO)[C@@H]2O)[C@@H]1O)C([O-])=O)[C@H](O)[C@H](O)CO 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,048 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline a neolactoside nLc4Cer(d18:1(4E)) Identifier CHEBI:17006 Charge 0 Formula C45H79N2O23R SMILEShelp_outline CCCCCCCCCCCCC\C=C\[C@@H](O)[C@H](CO[C@@H]1O[C@H](CO)[C@@H](O[C@@H]2O[C@H](CO)[C@H](O)[C@H](O[C@@H]3O[C@H](CO)[C@@H](O[C@@H]4O[C@H](CO)[C@H](O)[C@H](O)[C@H]4O)[C@H](O)[C@H]3NC(C)=O)[C@H]2O)[C@H](O)[C@H]1O)NC([*])=O 2D coordinates Mol file for the small molecule Search links Involved in 7 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline N-acetylneuraminate Identifier CHEBI:35418 Charge -1 Formula C11H18NO9 InChIKeyhelp_outline SQVRNKJHWKZAKO-LUWBGTNYSA-M SMILEShelp_outline [H][C@]1(OC(O)(C[C@H](O)[C@H]1NC(C)=O)C([O-])=O)[C@H](O)[C@H](O)CO 2D coordinates Mol file for the small molecule Search links Involved in 38 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:47852 | RHEA:47853 | RHEA:47854 | RHEA:47855 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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Properties of recombinant human cytosolic sialidase HsNEU2. The enzyme hydrolyzes monomerically dispersed GM1 ganglioside molecules.
Tringali C., Papini N., Fusi P., Croci G., Borsani G., Preti A., Tortora P., Tettamanti G., Venerando B., Monti E.
Recombinant human cytosolic sialidase (HsNEU2), expressed in Escherichia coli, was purified to homogeneity, and its substrate specificity was studied. HsNEU2 hydrolyzed 4-methylumbelliferyl alpha-NeuAc, alpha 2-->3 sialyllactose, glycoproteins (fetuin, alpha-acid glycoprotein, transferrin, and bov ... >> More
Recombinant human cytosolic sialidase (HsNEU2), expressed in Escherichia coli, was purified to homogeneity, and its substrate specificity was studied. HsNEU2 hydrolyzed 4-methylumbelliferyl alpha-NeuAc, alpha 2-->3 sialyllactose, glycoproteins (fetuin, alpha-acid glycoprotein, transferrin, and bovine submaxillary gland mucin), micellar gangliosides GD1a, GD1b, GT1b, and alpha 2-->3 paragloboside, and vesicular GM3. alpha 2-->6 sialyllactose, colominic acid, GM1 oligosaccharide, whereas micellar GM2 and GM1 were resistant. The optimal pH was 5.6, kinetics Michaelis-Menten type, V(max) varying from 250 IU/mg protein (GD1a) to 0.7 IU/mg protein (alpha(1)-acid glycoprotein), and K(m) in the millimolar range. HsNEU2 was activated by detergents (Triton X-100) only with gangliosidic substrates; the change of GM3 from vesicular to mixed micellar aggregation led to a 8.5-fold V(max) increase. HsNEU2 acted on gangliosides (GD1a, GM1, and GM2) at nanomolar concentrations. With these dispersions (studied in detailed on GM1), where monomers are bound to the tube wall or dilutedly associated (1:2000, mol/mol) to Triton X-100 micelles, the V(max) values were 25 and 72 microIU/mg protein, and K(m) was 10 and 15 x 10(-9) m, respectively. Remarkably, GM1 and GM2 were recognized only as monomers. HsNEU2 worked at pH 7.0 with an efficiency (compared with that at pH 5.6) ranging from 4% (on GD1a) to 64% (on alpha(1)-acid glycoprotein), from 7% (on GD1a) to 45% (on GM3) in the presence of Triton X-100, and from 30 to 40% on GM1 monomeric dispersion. These results show that HsNEU2 differentially recognizes the type of sialosyl linkage, the aglycone part of the substrate, and the supramolecular organization (monomer/micelle/vesicle) of gangliosides. The last ability might be relevant in sialidase interactions with gangliosides under physiological conditions. << Less
J. Biol. Chem. 279:3169-3179(2004) [PubMed] [EuropePMC]
This publication is cited by 5 other entries.