Abstract
Bovine nasal cartilage slices, biosynthetically labelled in their proteoglycan with35SO4, were used as substrate for the attack of free radicals generated on exposure to a Co60 source (which allows study of single radical species), and by chemical and enzymatic means. Systems generating hydroxyl (OH⋅) and superoxide (02 ⋅-) radicals degraded the proteoglycan efficiently, while the hydroperoxy radical (HO2 ⋅) was less efficient ; addition of appropriate radical scavengers inhibited degradation. The radioactive products were heterogeneous in molecular size, but with doses up to 3600 Gy were the same size range as intact chondroitin sulphate. They contained free amino groups, and more were liberated by aminopeptidase M digestion, implying that at least a small peptide was present. Thus a major site of radical attack may be the polypeptide chain. We suggest that free-radical fragmentation of polypeptides may be important both in extracellular catabolism and in intracellular proteolysis.
Similar content being viewed by others
References
Pryor WA, ed (1975–1983) Free Radicals in Biology vols 1–5, Academic Press.
Sutanthiran M, Solomon SD, Williams PS, Rubin AL, Novbyrodsky A & Stenzel KH (1984) Nature (London)307, 276–278.
Badwey JA, Robinson JM, Lazdins JK, Briggs RT, Karnovsky MJ & Karnovsky ML (1983) J. Cell. Physiol.115, 208–216.
Steinberg J, Sledge CB, Noble J & Stirrat CR (1979) Biochem. J.180, 403–412.
Willson RL (1978) in: Biochemical Mechanisms of Liver Injury (Slater TF, ed), Academic Press, pp. 123–224.
Walling C (1975) Acc. Chem. Res.8, 125–131.
Gutteridge, JMC, Richmond R & Halliwell B (1979) Biochem. J.184, 469–472.
Bray RC (1975) in: The Enzymes vol 12 (Boyer PD, ed), pp 303–388, Academic Press.
Barrett AJ, ed (1977) Proteinases in Mammalian Cells and Tissues, Elsevier.
Morrison RIGM, Barret AJ, Dingle JT & Prior D (1973) Biochim. Biophys. Acta302, 411–419.
Hardingham T (1981) Biochem. Soc. Trans.9, 489–497.
Udenfriend S, Stein S, Bohlen P, Dairman W, Leingruber W & Weigele M (1972) Science178, 871–872.
Ross F ¤ Ross AB (1977) Selected Specific Rates of Reactions of Transients from Water in Aqueous Solution, U.S. Dept. of Commerce.
Dean RT, Jessup W & Roberts CR (1984) in: Intracellular Protein Breakdown (Khairallah E, ed), Liss, in press.
Jooyandeh F, Moore JS, Morgan RE & Phillips GO (1971) Radiation Res.45, 455–461.
McCord JM (1974) Science185, 529–531.
Dean RT (1980) in: Degradative Processes in Heart and Skeletal Muscle (Wildenthal K, ed), pp 3–30, Elsevier.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dean, R.T., Roberts, C.R. & Forni, L.G. Oxygen-centred free radicals can efficiently degrade the polypeptide of proteoglycans in whole cartilage. Biosci Rep 4, 1017–1026 (1984). https://doi.org/10.1007/BF01116694
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01116694