|
Your query returned 3 entries. Printable version
EC | 4.2.2.19 | ||||||||||||||||||||
Accepted name: | chondroitin B lyase | ||||||||||||||||||||
Reaction: | Eliminative cleavage of dermatan sulfate containing (1→4)-β-D-hexosaminyl and (1→3)-β-D-glucurosonyl or (1→3)-α-L-iduronosyl linkages to disaccharides containing 4-deoxy-β-D-gluc-4-enuronosyl groups to yield a 4,5-unsaturated dermatan-sulfate disaccharide (ΔUA-GalNAc-4S). | ||||||||||||||||||||
Glossary: | chondroitin sulfate B = dermatan sulfate For the nomenclature of glycoproteins, glycopeptides and peptidoglycans, click here |
||||||||||||||||||||
Other name(s): | chondroitinase B; ChonB; ChnB | ||||||||||||||||||||
Systematic name: | chondroitin B lyase | ||||||||||||||||||||
Comments: | 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 [2]. 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(β1-3)GalNAc(β1-]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(α1-3)GalNAc(β1-]n of DS. Both the concentrations and locations of sulfate-ester substituents vary with glucosaminoglycan source [5]. | ||||||||||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 52227-83-5 | ||||||||||||||||||||
References: |
| ||||||||||||||||||||
EC | 4.2.2.20 | ||||||||||||||||||||
Accepted name: | chondroitin-sulfate-ABC endolyase | ||||||||||||||||||||
Reaction: | Endolytic cleavage of (1→4)-β-galactosaminic bonds between N-acetylgalactosamine and either D-glucuronic acid or L-iduronic acid to produce a mixture of Δ4-unsaturated oligosaccharides of different sizes that are ultimately degraded to Δ4-unsaturated tetra- and disaccharides | ||||||||||||||||||||
For diagram of reaction click here | |||||||||||||||||||||
Glossary: | chondroitin sulfate A = chondroitin 4-sulfate chondroitin sulfate B = dermatan sulfate chondroitin sulfate C = chondroitin 6-sulfate For the nomenclature of glycoproteins, glycopeptides and peptidoglycans, click here |
||||||||||||||||||||
Other name(s): | chondroitinase (ambiguous); chondroitin ABC eliminase (ambiguous); chondroitinase ABC (ambiguous); chondroitin ABC lyase (ambiguous); chondroitin sulfate ABC lyase (ambiguous); ChS ABC lyase (ambiguous); chondroitin sulfate ABC endoeliminase; chondroitin sulfate ABC endolyase; ChS ABC lyase I | ||||||||||||||||||||
Systematic name: | chondroitin-sulfate-ABC endolyase | ||||||||||||||||||||
Comments: | This enzyme degrades a variety of glycosaminoglycans of the chondroitin-sulfate- and dermatan-sulfate type. Chondroitin sulfate, chondroitin-sulfate proteoglycan and dermatan sulfate are the best substrates but the enzyme can also act on hyaluronan at a much lower rate. Keratan sulfate, heparan sulfate and heparin are not substrates. 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(β1-3)GalNAc(β1-]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(α1-3)GalNAc(β1-]n of DS. Both the concentrations and locations of sulfate-ester substituents vary with glucosaminoglycan source [5]. The related enzyme EC 4.2.2.21, chondroitin-sulfate-ABC exolyase, has the same substrate specificity but removes disaccharide residues from the non-reducing ends of both polymeric chondroitin sulfates and their oligosaccharide fragments produced by EC 4.2.2.20 [4]. | ||||||||||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9024-13-9 | ||||||||||||||||||||
References: |
| ||||||||||||||||||||
EC | 4.2.2.21 | ||||||||||||||||||||
Accepted name: | chondroitin-sulfate-ABC exolyase | ||||||||||||||||||||
Reaction: | Exolytic removal of Δ4-unsaturated disaccharide residues from the non-reducing ends of both polymeric chondroitin/dermatan sulfates and their oligosaccharide fragments. | ||||||||||||||||||||
For diagram of reaction click here | |||||||||||||||||||||
Glossary: | chondroitin sulfate A = chondroitin 4-sulfate chondroitin sulfate B = dermatan sulfate chondroitin sulfate C = chondroitin 6-sulfate For the nomenclature of glycoproteins, glycopeptides and peptidoglycans, click here |
||||||||||||||||||||
Other name(s): | chondroitinase (ambiguous); chondroitin ABC eliminase (ambiguous); chondroitinase ABC (ambiguous); chondroitin ABC lyase (ambiguous); chondroitin sulfate ABC lyase (ambiguous); ChS ABC lyase (ambiguous); chondroitin sulfate ABC exoeliminase; chondroitin sulfate ABC exolyase; ChS ABC lyase II | ||||||||||||||||||||
Systematic name: | chondroitin-sulfate-ABC exolyase | ||||||||||||||||||||
Comments: | This enzyme degrades a variety of glycosaminoglycans of the chondroitin-sulfate- and dermatan-sulfate type. Chondroitin sulfate, chondroitin-sulfate proteoglycan and dermatan sulfate are the best substrates but the enzyme can also act on hyaluronan at a much lower rate. Keratan sulfate, heparan sulfate and heparin are not substrates. The related enzyme EC 4.2.2.20, chondroitin-sulfate-ABC endolyase, has the same substrate specificity but produces a mixture of oligosaccharides of different sizes that are ultimately degraded to tetra- and disaccharides [4]. Both enzymes act by the removal of a relatively acidic C-5 proton of the uronic acid followed by the elimination of a 4-linked hexosamine, resulting in the formation of an unsaturated C4—C5 bond on the hexuronic acid moiety of the products [4,6]. | ||||||||||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 1000607-06-6 | ||||||||||||||||||||
References: |
| ||||||||||||||||||||