Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.6.4 (chondroitinase)
 2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sulfation of dermatan sulfate by SO3-trimethylamine in N,N-dimethylformamide led to substitution initially at HO-6 of residues of 2-acetamido-2-deoxy-beta-D-galactopyranosyl 4-sulfate (1), to produce the 4,6-disulfate (6). When this step reached a level of greater than 50%, sulfation occurred with equal facility at HO-2 and HO-3 of residues of alpha-L-idopyranosyluronic acid (2), giving rise to a mixture of 2-,3-, and 2,3-disulfates. An analogous substitution pattern was observed for HO-2 and -3 of a simpler idopyranose unit, in the sulfation of methyl 4,6-O-benzylidene-alpha-D-idopyranoside (12). This lack of regioselectivity in the reaction of 2 (and 12) contrasts markedly with the high affinity of the reagent for HO-3 of residues of alpha-L-idopyranosyluronic acid present in a modified form of heparin. It is attributed to a difference between the two polymers in the relative orientation of their neighboring amino sugar residues, whereby there is an unobstructed access of the reagent in one instance, and hindrance of HO-2 selectively in the other. Enzymolysis by chondroitinase ABC was found to yield unsaturated disaccharide containing residues of 4,6-disulfate, as well as larger fragments containing unsaturated glycosyl groups derived from L-idopyranosyluronic acid 2-sulfate, evidence of a relatively broad enzyme specificity. The presence of extra sulfate groups in dermatan sulfate did not enhance its weak antithrombotic activity, as measured by anti Xa assay, in disagreement with earlier reports.
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PMID:Regioselectivity in the sulfation of dermatan sulfate and methyl 4,6-O-benzylidene-alpha-D-idopyranoside. 181 Mar 5

The level of sulfo-Lea (SO3-3Gal beta 1-3(Fuc alpha 1-4)GlcNAc) epitope recognized by monoclonal antibody (mAb) 91.9H in hepatic metastasis of colon carcinoma is known to be lower than at the primary sites. We examined 19 human colon carcinoma cell lines for their production of this epitope. Sixteen cell lines were found to produce high M(r) components that metabolically incorporated [35S]sulfate and were resistant to heparitinase I and chondroitinase ABC, and 8 of them were reactive with mAb 91.9H as shown by western blotting analysis. These were all of the 4 cell lines derived from well differentiated primary tumors (HCCP-2998, LS174T, GEO, and CBS), 2 of 10 cell lines (DLD-1 and HCT116) from moderately to poorly differentiated primary tumors, and 2 of 5 cell lines (SW480 and HCC-M1544) from metastases. Incubation of LS174T cells with benzyl-N-acetyl-alpha-D-galactosaminide abrogated the incorporation of [35S]sulfate and the reactivity of mAb 91.9H with high M(r) components in the cell lysates. Sodium chlorate, which inhibits the formation of 3'-phosphoadenosine 5'-phosphosulfate, also inhibited the [35S]sulfate incorporation and reactivity with mAb 91.9H. These treatments did not change the incorporation of [14C]threonine into high M(r) components. These results indicated that sulfo-Lea epitopes were expressed on O-linked carbohydrate chains in sulfomucins. Immunohistochemical studies of tumor tissues in nude mice indicated that sulfo-Lea was expressed at the site of orthotopic transplantation in the cecum. The expression appeared to be suppressed in liver metastatic foci in nude mice.
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PMID:Expression of mucin-associated sulfo-Lea carbohydrate epitopes on human colon carcinoma cells. 1008 87