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)

Involvement of covalently linked protein or peptide in the structure or synthesis of hyaluronate has not previously been convincingly demonstrated. We have developed conditions for double-labeling with [3H]leucine and [14C]acetate, then isolating and characterizing the cell-associated and secreted hyaluronate-protein complexes of Rous sarcoma virus-transformed chick embryo fibroblasts. The preparations were purified by Bio-Gel A-15m gel filtration and CsCl density gradient ultracentrifugation under dissociative conditions, followed by acid agarose gel electrophoresis in the presence of 0.1% Nonidet P-40. The purified hyaluronate preparations did not change their 3H:14C ratios after further sodium dodecyl sulfate or alkali treatment. The cell-derived hyaluronate-protein was resistant to pronase but susceptible to proteinase K in the presence of sodium dodecyl sulfate. After chondroitinase ABC digestion, the cell-derived 3H-labeled protein was separated from the 14C-labeled hyaluronate disaccharides, then shown to give a broad band corresponding to Mr approximately 12,000 on sodium dodecyl sulfate-urea polyacrylamide gel electrophoresis and to be susceptible to both pronase and proteinase K. The corresponding 3H-labeled peptide was prepared in the same manner from the medium hyaluronate and the [3H]leucine shown to be present in material smaller in amount and size than that from the cell. We propose from these and other published data that the cell-associated hyaluronate-protein may be bound to the cell surface and that the hyaluronate in the medium may be derived from it as a result of proteolytic scission.
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PMID:Hyaluronate-protein complex of rous sarcoma virus-transformed chick embryo fibroblasts. 626 45

Infection of embryonic chicken notochord-somite explants with Rous sarcoma virus inhibited the in vitro differentiation of somites into cartilage. Visual inspection of the explants revealed that viral infection reduced the size of cartilage nodule formation. Formation of the complex of sulfated proteoglycans with hyaluronic acid was inhibited by RSV infection, and sedimentation analysis of the sulfated proteoglycans showed that very little fast sedimenting proteoglycans were synthesized by RSV-infected explants. The infected explants primarily synthesize a slowly sedimenting sulfated proteoglycan which was chondroitinase resistant. These slow-sedimenting sulfated proteoglycans lack the ability to associate with hyaluronic acid and appear to be noncartilaginous. These effects of RSV are apparently due to the src gene of this virus since the mutant td108, which lacks part of the src gene, has no detectable influence on the chondrogenic differentiation of somite explants. Similarly, infection with RAV-2 as well as with uv-irradiated virus had no detectable effect. The inhibition of synthesis of fast sedimenting proteoglycans was observed at 41 degrees C with explants infected with tsNY68, suggesting that residual activity of transforming gene of this virus at the non-permissive temperature is sufficient for this inhibition in the explants.
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PMID:Inhibition of precartilaginous chick somites by oncogenic virus. 630 11