title: Occurrence of a unique fucose-branched chondroitin sulfate in the body wall of a sea cucumber.
abstract: The sulfated polysaccharides in the body wall of the sea cucumber occur as three fractions that differ markedly in molecular mass and chemical composition. The fraction containing a high molecular mass component has a high proportion of fucose and small amounts of galactose and amino sugars, whereas another fraction contains primarily a sulfated fucan. The third fraction (F-2), which represents the major portion of the sea cucumber-sulfated polysaccharides, contains approximately equimolar quantities of glucuronic acid, N-acetyl galactosamine, and fucose, and has a sulfate content higher than that in the other two fractions. The structure of fraction F-2 was examined in detail. This polysaccharide has an unusual structure composed of a chondroitin sulfate-like core, containing side chain disaccharide units of sulfated fucopyranosyl linked to approximately half of the glucuronic acid moieties through the O-3 position of the acid. These unusual fucose branches obstruct the access of chondroitinases to the chondroitin sulfate core of F-2. However, after partial acid hydrolysis, which removes the sulfated fucose residues from the polymer, fraction F-2 is degraded by chondroitinases into 6-sulfated and nonsulfated disaccharides.
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002807:Chondroitin / Q000031:analogs & derivatives*; D002809:Chondroitin Sulfates / Q000302:isolation & purification*; D004447:Echinodermata / Q000032:analysis*; D005643:Fucose / Q000032:analysis*; D006868:Hydrolysis; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D012616:Sea Cucumbers / Q000032:analysis*
chemical_list: D002241:Carbohydrates; D007202:Indicators and Reagents; D005643:Fucose; D002807:Chondroitin; D002809:Chondroitin Sulfates