Proteoglycans, in cartilage

Potter, K., Kidder, L. H., Levin, I. W., Lewis, E. N. and Spencer, R. G. (2001) Imaging of collagen and proteoglycan in cartilage sections using Fourier transform infrared spectral imaging. Arthritis Rheum. 44, 846-55. 

H9. Hardingham, T. E., and Muir, H., Biosynthesis of proteoglycans in cartilage slices. Fractionation by gel chromatography and equilibrium density-gradient centrifugation. Biochem. J. 126, 791-803 (1972). 

Fig. 10 Schematic illustration for the strategy of hydrogel-cartilage integration by tissue-initiated photopolymerization. Individual steps of the process are (1) clearance of the proteoglycans in cartilage by chondroitinase to expose the collagen network (2) in situ generation of tyrosyl radicals by photo-oxidation of tyrosine residues on collagen with H2O2 under low intensity UV irradiation and (3) introduction of a macromer solution and in situ photo-gelation via tyrosyl radical initiation and UV-excitation (Reprinted with permission Advanced Functional Materials [321])...

PAPS is synthesized within the cytosol of cells. Sulfate enters cells through an active transport process [4]. A sulfate transporter has been identified which is mutated in diastrophic dysplasia, a disease characterized by undersulfation of proteoglycans in cartilage [9]. For utilization by Golgi sulfotransferases, PAPS must cross a lipid bilayer. A PAPS translocase, which functions through an antiport mechanism has been characterized at the biochemical level [10]. 

Watanabe, H., Y. Yamada, and K. Kimata. 1998. Roles of aggrecan, a large chondroitin sulfate proteoglycan, in cartilage structure and function. J. Biochem. 124 687-693. 

FIGURE 9.34 Hyaluronate (see Figure 7.33) forms the backbone of proteoglycan structures, such as those found in cartilage. 

In various types of arthritis, proteoglycans may act as autoantigens, thus contributing to the pathologic feamres of these conditions. The amount of chondroitin sulfate in cartilage diminishes with age, whereas the amounts of keratan sulfate and hyaluronic acid increase. These changes may contribute to the development of osteoarthritis. Changes in the amounts of cer-... 

Endogenous glucosamine is used for the production of glycosaminoglycans and other proteoglycans in articular cartilage. 

Hascall, V. C. Heinegard, D. The structure of cartilage proteoglycans. In Extracellular matrix influences on gene expression, pp. 423. Slavkin, H. C., Greulich, R. C. (eds.). New York Academic Press 1975... 

Camacho, N. P., West, P., Torzilli, P. A. and Mendelsohn, R. (2001) FTIR microscopic imaging of collagen and proteoglycan in bovine cartilage. Biopolymers 62, 1-8. 

The remarkable mechanical properties of articular cartilage result from the structure of collagen and proteoglycans, and from the properties of the fibrous composite formed by the interactions of collagen and proteoglycans in intercellular matrix. 

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