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)

Confluent cultures of mouse aortic endothelial (END-D) were incubated with either [35S]methionine or 35SO4 2-, and the radiolabelled proteoglycans in media and cell layers were analysed for their hyaluronate-binding activity. The proteoglycan subfraction which bound to hyaluronate accounted for about 18% (media) and 10% (cell layers) of the total 35S radioactivity of each proteoglycan fraction. The bound proteoglycan molecules could be dissociated from the aggregates either by digestion with hyaluronate lyase or by treatment with hyaluronate decasaccharides. Digestion of [methionine-35S]proteoglycans with chondroitinase and/or heparitinase, followed by SDS/polyacrylamide-gel electrophoresis, indicated that the medium and cell layer contain at least three chondroitin sulphate proteoglycans, one dermatan sulphate proteoglycan, and two heparan sulphate proteoglycans which differ from one another in the size of core molecules. Among these, only the hydrodynamically large chondroitin sulphate species with an Mr 550,000 core molecule was shown to bind to hyaluronate. A very similar chondroitin sulphate proteoglycan capable of binding to hyaluronate was also found in cultures of calf pulmonary arterial endothelial cells (A.T.C.C. CCL 209). These observations, together with the known effects of hyaluronate on various cellular activities, suggest the existence of possible specialized functions of this proteoglycan subspecies in cellular processes characteristic of vascular development and diseases.
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PMID:Aortic endothelial cells synthesize a large chondroitin sulphate proteoglycan capable of binding to hyaluronate. 230 73

Sulfation of glycosaminoglycans (GAGs) secreted by baby hamster kidney (BHK) cells and the polyoma virus-transformants (PY-BHK) was investigated. It has been reported that chondroitin sulfate (CS) of cell membranes from PY-BHK cells is undersulfated compared to that from BHK cells (Cancer Res. 43, 2712-2717, 1983). In the first series of experiments of the present study, cells were incubated with [3H]glucosamine and [35S]sulfate, and GAGs isolated from the culture medium were examined. GAG composition was comparable between the BHK and PY-BHK cultures. Disaccharide analysis of the chondroitinase ACII digests of the hyaluronate lyase-resistant materials showed a high proportion (68% for BHK and 47% for PY-BHK) of delta Di-0S, with delta Di-4S (32% for BHK and 53% for PY-BHK) as the major sulfated disaccharide on the basis of 3H-radioactivities. The beta-D-xyloside treatment did not alter the degree of undersulfation of the CS of either culture. In the second series of experiments, disaccharide analysis of the chondroitinase ABC digests of unlabeled GAGs demonstrated similar disaccharide composition for the two cell types. The BHK and PY-BHK preparations showed 28 and 17% (mol percent) of delta Di-0S, 58 and 72% of delta Di-4S, and 14 and 11% of delta Di-6S, respectively. These results indicate a considerable degree of undersulfation of secretory CS from both cells, and a slightly higher degree, if any, of under-sulfation of secretory CS from BHK cells if compared between the two cell types, which is in contrast to the results reported for membrane CS.
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PMID:Sulfation of chondroitin sulfate secreted by baby hamster kidney cells and their polyoma virus-transformed counterparts. 300 Oct 40

Thirty-three strains of Vibrio vulnificus of clinical and environmental origin were examined for production of 12 extracellular enzymes of potential importance to the virulence of this bacterium. Strains of Vibrio vulnificus were consistent in their production of protease, mucinase, lipase, chondroitinase, hyaluronidase, DNase, sulfatase, and hemolysin. No differences between clinical and environmental isolates were noted. Although none of the enzymes appeared to correlate with the ability of these strains to produce lethality in mice, the production of hemolysin and of a protease with activity against native serum albumin may be significant in the pathogenesis of the potentially fatal infections produced by this organism. The production of several of these exoenzymes also appeared to correlate with pathogenicity in the seven other Vibrio species examined. Culture filtrates of all virulent strains of Vibrio vulnificus were cytotoxic for Chinese hamster ovary cells, whereas those of the strains of Vibrio parahaemolyticus and Vibrio alginolyticus examined lacked this activity.
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PMID:Production of extracellular enzymes and cytotoxicity by Vibrio vulnificus. 352 90

In high performance liquid chromatographic procedures hitherto described, SiO2, NH2 and RP columns have been used for the analysis of disaccharides produced by the digestion of glycosaminoglycans with the chondroitin sulphate lyases AC and ABC. The use of a potent anion exchanger offers the following advantages over these columns: superior separation characteristics for non-sulphated disaccharides, and improved column performance, coupled with more stable analytical conditions. Elution with dilute saline solutions permits separation of the two non-sulphated disaccharides from chondroitin and hyaluronate. The sequential application of chondroitinase AC and ABC permits the determination of hyaluronate, the chondroitin sulphate isomers and the dermatan sulphate isomers by high performance liquid chromatographic separation of the products of enzymatic hydrolysis. In a previously described method, hyaluronate lyase was used for the determination of hyaluronate. It has been found, however, that omission of the hyaluronate lyase step results in superior accuracy in the high performance liquid chromatographic separation of the non-sulphated disaccharides. The enzymatic analysis of human articular cartilage glycosaminoglycans has repeatedly yielded a fraction which is not digestable by chondroitinase AC, but is completely digestable by chondroitinase ABC. More extensive characterization has disclosed that this fraction differs structurally from chondroitin sulphate. Enzymatic characterization indicates that it should presumably be assigned to dermatan sulphate.
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PMID:High performance liquid chromatographic assay of disaccharides and oligosaccharides produced by the digestion of glycosaminoglycans with chondroitin sulphate lyases. 398 79

Galactose mutarotase plays a key role in normal galactose metabolism by catalyzing the interconversion of beta-D-galactose and alpha-D-galactose. Here we describe the three-dimensional architecture of galactose mutarotase from Lactococcus lactis determined to 1.9-A resolution. Each subunit of the dimeric enzyme displays a distinctive beta-sandwich motif. This tertiary structural element was first identified in beta-galactosidase and subsequently observed in copper amine oxidase, hyaluronate lyase, chondroitinase, and maltose phosphorylase. Two cis-peptides are found in each subunit, namely Pro(67) and Lys(136). The active site is positioned in a rather open cleft, and the electron density corresponding to the bound galactose unequivocally demonstrates that both anomers of the substrate are present in the crystalline enzyme. Those residues responsible for anchoring the sugar to the protein include Arg(71), His(96), His(170), Asp(243), and Glu(304). Both His(96) and His(170) are strictly conserved among mutarotase amino acid sequences determined thus far. The imidazole nitrogens of these residues are located within hydrogen bonding distance to the C-5 oxygen of galactose. Strikingly, the carboxylate group of Glu(304) is situated at approximately 2.7 A from the 1'-hydroxyl group of galactose, thereby suggesting its possible role as a general acid/base group.
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PMID:High resolution X-ray structure of galactose mutarotase from Lactococcus lactis. 1190 40