Proteoglycans properties

Proteoglycans are widely distributed throughout the body, being most abundant in connective tissue, where they may contribute up to 30% of that tissue s dry weight. They consist of a polypeptide backbone to which heteropolysaccharide chains are attached. However, unlike glycoproteins, proteolycans consist of up to, or in excess of, 95% carbohydrate and their properties resemble those of polysaccharides more than those of proteins. 

The activities of the purple fluid of the sea hare Aplysia dactylomela, such as toxic, antimicrobial and hemagglutinating properties, have been attributed to a substance of protein nature [332], Proteoglycans and adhesive glycoproteins present in the extracellular matrix of vertebrates, have also been reported in sponges. These molecules are probably involved in the cell adhesion systems of sponges [333], Recently, novel marine proteins have been reported, such as silicatein from sponge biosilica [334], and a metallothionein protein from the marine alga Fuats vesiculosus [335], Metallothioneins have also been isolated from Arctic... 

K. Schwarz, B. Breuer, and H.Kresse, Biosynthesis and properties of a further member of the small chondroitin/dermatan sulfate proteoglycan family. J. Biol. Chem., 256 (1990) 22,023-22,028. 

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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