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 amount of glycosaminoglycan (GAG) in dry costal cartilage tissue of rats decreased with aging, while the GAG content in mg DNA (unit cartilage cell) remained the same with aging. These results can be explained by the finding that the total number of cartilage cells decreased with aging. Electrophoretic analysis showed that chondroitin 4-sulfate was the major GAG in rat costal cartilage of various ages. Rat costal cartilage of different ages was incubated with radioactive precursors, and newly synthesized GAG was prepared and the radioactivity analyzed to determine the biosynthetic activity. As to changes in the radioactivity uptake with aging per mg dry cartilage tissue, aging influenced [35S]sulfate incorporation into GAG more significantly than [3H]glucosamine incorporation into GAG. There was a significant decrease in the specific radioactivity of [35S]sulfate per mg DNA (unit cartilage cell), whereas the specific radioactivity of [3H]glucosamine per mg DNA did not change significantly with aging. Both the total sulfotransferase activity and the specific activity per mg DNA decreased significantly with aging. Analysis of disaccharide units formed after chondroitinase ABC digestion of labeled GAG isolated from young and old cartilage showed that the percentage of incorporation of [3H]glucosamine into deltaDi-OS increased significantly with aging. These results suggested that the appearance of nonsulfated positions in the structure of the chondroitin sulfate chain increased with aging. On the basis of gel chromatography on Bio-Gel A-1.5 m no significant difference in the approximate molecular size of chondroitin sulfate was observed between the young and old GAG samples. The present study indicated that the sulfation of chondroitin sulfate chains from rat costal cartilage decreased with the process of aging.
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PMID:The effect of aging on the synthesis of hexosamine-containing substances from rat costal cartilage. A decrease in sulfation of chondroitin sulfate with aging. 42 44

35S-labelled heparins were recovered from adipose tissue, hearts, lungs, peritoneal cavities and skins of rats given H2(35)SO4. Their purification involved incubation with Pronase, precipitation with cetylpyridinium chloride in 1.0 M-NaCl, gradient elution from DEAE-Sephacel and incubation with chondroitinase ABC. Each product was divided into proteoglycan and "depolymerization products' fractions by gel filtration on Bio-Gel A-15m. Heparin chains were released from a portion of each proteoglycan fraction by beta-elimination with NaOH. Proteoglycans, chains and depolymerization products were separated by gradient elution from a column of antithrombin-agarose into fractions with no affinity, low affinity and high affinity for antithrombin. The relative sizes of the products were determined by gel filtration on columns of Bio-Gel A-50m, A-15m, A-1.5m and A-0.5m. Skin was the major source of heparin and contained the largest proteoglycans and the lowest proportion of depolymerization products. Lungs contained the smallest proteoglycans, the smallest depolymerization products and the highest proportion of depolymerization products. The highest proportions of proteoglycans, chains and depolymerization products with high affinity for antithrombin were found in adipose tissue. The lowest proportions of each of these fractions were found in the peritoneal cavity. The data suggest that there was relatively little biosynthesis of sites with high affinity for antithrombin in peritoneal-cavity mast cells and that heparin catabolism was most active in lungs. Each source of heparin was unique with respect to both biosynthesis and subsequent breakdown of its proteoglycans.
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PMID:Rat heparins. A study of the relative sizes and antithrombin-binding characteristics of heparin proteoglycans, chains and depolymerization products from rat adipose tissue, heart, lungs, peritoneal cavity and skin. 382 37