A calorimetric procedure was developed for assaying the enzyme activity of chondroitinase AC from Flavobacterium heparinum and of chondroitinase ABC from Proteus vulgaris when chondroitin 4-sulfate is used as a substrate. The enzymatic digestion product, 2-acetamido-2-deoxy-3-0-(/3-Dgluco-4-enepyranosyluronic acid)-4-0-s&o-D-galactose, is oxidized with periodic acid to yield, among other produc...

The yolk sac carcinoma cell line L2 secretes a chondroitin/dermatan sulfate proteoglycan that has an Mr 10,000 core protein and carries an average of 14 glycosaminoglycan chains. The amino acid sequence of the mature core protein has been determined from cloned cDNA (Bourdon, M. A., Oldberg, A., Pierschbacher, M., and Ruoslahti, E. (1985) Proc. Natl. Acad. Sci. U. S. A. 82, 1321-1325). From add...

Understanding the changes in collagen and proteoglycan content of cartilage due to physical forces is necessary for progress in treating joint disorders, including those due to overuse. Physical forces in the chondrocyte environment can affect the cellular processes involved in the biosynthesis of extracellular matrix. In turn, the biomechanical properties of cartilage depend on its collagen an...

The cell surface proteoglycan on normal murine mammary gland mouse mammary epithelial cells consists of an ectodomain bearing heparan and chondroitin sulfate chains and a lipophilic domain that is presumed to be intercalated into the plasma membrane. Because the ectodomain binds to matrix components produced by stromal cells with specificity and high affinity, we have proposed that the cell sur...

We have previously shown that treatment of neonatal human articular-cartilage proteoglycan aggregates with H2O2 results in loss of the ability of the proteoglycan subunits to interact with hyaluronic acid and in fragmentation of the link proteins [Roberts, Mort & Roughley (1987) Biochem. J. 247, 349-357]. We now show the following. (1) Hyaluronic acid in proteoglycan aggregates is also fragment...

The intracellular pathway of cartilage proteoglycan biosynthesis was investigated in isolated chondrocytes using a protein A-gold electron microscopy immunolocalization procedure. Proteoglycans contain a protein core to which chondroitin sulfate and keratan sulfate chains and oligosaccharides are added in posttranslational processing. Specific antibodies have been used in this study to determin...

The future of biochemistry lies in understanding how single gene products associate and function together. Interactions in connective tissues, including those between the proteoglycans and collagens are especially piquant, evolutionarily conserved and physiologically significant. Connective tissues (e.g. skin, tendon, blood vessels, etc.) are systems of insoluble fibrils and soluble polymers wh...