ID   4.2.2.20
DE   chondroitin-sulfate-ABC endolyase.
AN   chondroitin ABC eliminase.
AN   chondroitin ABC lyase.
AN   chondroitinase.
AN   chondroitinase ABC.
AN   chondroitin sulfate ABC endoeliminase.
AN   chondroitin sulfate ABC endolyase.
AN   chondroitin sulfate ABC lyase.
AN   ChS ABC lyase.
AN   ChS ABC lyase I.
CA   Endolytic cleavage of (1->4)-beta-galactosaminic bonds between
CA   N-acetylgalactosamine and either D-glucuronic acid or L-iduronic acid to
CA   produce a mixture of Delta(4)-unsaturated oligosaccharides of different
CA   sizes that are ultimately degraded to Delta(4)-unsaturated tetra- and
CA   disaccharides.
CC   -!- Degrades a variety of glycosaminoglycans of the chondroitin-sulfate-
CC       and dermatan-sulfate type.
CC   -!- Chondroitin sulfate, chondroitin-sulfate proteoglycan and dermatan
CC       sulfate are the best substrates but the enzyme can also act on
CC       hyaluronan at a much lower rate.
CC   -!- Keratan sulfate, heparan sulfate and heparin are not substrates.
CC   -!- In general, chondroitin sulfate (CS) and dermatan sulfate (DS) chains
CC       comprise a linkage region, a chain cap and a repeat region.
CC   -!- The repeat region of CS is a repeating disaccharide of glucuronic
CC       acid (GlcA) and N-acetylgalactosamine (GalNAc) [-4)GlcA(beta1-
CC       3)GalNAc(beta1-]n, which may be O-sulfated on the C-4 and/or C-6 of
CC       GalNAc and C-2 of GlcA.
CC   -!- GlcA residues of CS may be epimerized to iduronic acid (IdoA) forming
CC       the repeating disaccharide [-4)IdoA(alpha1-3)GalNAc(beta1-]n of DS.
CC   -!- Both the concentrations and locations of sulfate-ester substituents
CC       vary with glucosaminoglycan source.
CC   -!- The related enzyme EC 4.2.2.21 has the same substrate specificity but
CC       removes disaccharide residues from the non-reducing ends of both
CC       polymeric chondroitin sulfates and their oligosaccharide fragments
CC       produced by EC 4.2.2.20.
CC   -!- Formerly EC 4.2.2.4 and EC 4.2.99.6.
DR   P59807, CABC1_PROVU;  T2KMH5, PLH29_FORAG;
//