Mucopolysaccharides

They are also called "glycosaminoglycans" (GAGs). They include e.g.




 * Hyaluronic acid
 * Chondroitin sulfate (CS)
 * Keratan sulfate I and II (KS I and KS II)
 * Heparan sulfate (HS)
 * Heparin
 * Dermatan sulfate (DS)


 * They are formed by alternating hexosamine with uronic acid
 * Exception: keratan sulfate, which contains galactose instead of uronic acid
 * Uronic acids contain carboxyl groups and can also be sulfated (acidic character)


 * They have numerous functions in the organism, especially structural ones as part of the extracellular matrix
 * They are bound to the protein skeleton (axis protein) by an O-glycosidic or N-glycosidic bond
 * Axial proteins bind to hyaluronic acid with the help of a connecting protein to form proteoglycan aggregates
 * The amount of carbohydrates in proteoglycans can be up to 95%
 * Degradation takes place partly extracellularly, shorter fragments bind to connective cell receptors, are pinocytosed and degraded by lysosomal'endoglycosidases'' (sulfatase, hyaluronidase) and exoglycosidases ' (β-glucuronidase, xylosidase, iduronidase, galactosidase, N-acetylglucosaminidase)

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 * Mucopolysaccharidoses