ENZYME entry: EC 4.2.2.19
Accepted Name |
chondroitin B lyase.
|
Alternative Name(s) |
ChonB. |
chondroitinase B. |
Reaction catalysed |
Eliminative cleavage of dermatan sulfate containing (1->4)-beta-D-hexosaminyl and (1->3)-beta-D-glucurosonyl or (1->3)-alpha-L-iduronosyl linkages to disaccharides containing 4-deoxy-beta-D-gluc-4-enuronosyl groups to yield a 4,5-unsaturated dermatan-sulfate disaccharide (DeltaUA-GalNAc-4S) |
Comment(s) |
- This is the only lyase that is known to be specific for dermatan
sulfate as substrate.
- The minimum substrate length required for catalysis is a
tetrasaccharide.
- In general, chondroitin sulfate (CS) and dermatan sulfate (DS) chains
comprise a linkage region, a chain cap and a repeat region.
- The repeat region of CS is a repeating disaccharide of glucuronic
acid (GlcA) and N-acetylgalactosamine (GalNAc) [-4)GlcA(beta1-
3)GalNAc(beta1-]n, which may be O-sulfated on the C-4 and/or C-6 of
GalNAc and C-2 of GlcA.
- GlcA residues of CS may be epimerized to iduronic acid (IdoA) forming
the repeating disaccharide [-4)IdoA(alpha1-3)GalNAc(beta1-]n of DS.
- Both the concentrations and locations of sulfate-ester substituents
vary with glucosaminoglycan source.
|
Cross-references |
BRENDA | 4.2.2.19 |
EC2PDB | 4.2.2.19 |
ExplorEnz | 4.2.2.19 |
PRIAM enzyme-specific profiles | 4.2.2.19 |
KEGG Ligand Database for Enzyme Nomenclature | 4.2.2.19 |
IUBMB Enzyme Nomenclature | 4.2.2.19 |
IntEnz | 4.2.2.19 |
MEDLINE | Find literature relating to 4.2.2.19 |
MetaCyc | 4.2.2.19 |
Rhea expert-curated reactions | 4.2.2.19 |
UniProtKB/Swiss-Prot |
|
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