Anticoagulant sulfated glycosaminoglycans in the tissues of the primitive chordate Styela plicata (Tunicata).
We performed a biochemical and histochemical study of sulfated glycosaminoglycans in the tissues of the ascidian Styela plicata. A highly sulfated dermatan sulfate and a heparin-like polymer, identified by incubation with specific lyases, occur at different concentrations in intestine, heart, pharynx, and cloak. Dermatan sulfate prevails in the pharynx, whereas the heparin-like polymer abounds in the intestine. Staining of tissues sections with the cationic dye 1,9-dimethylmethylene blue before and after incubation with specific lyases revealed that the dermatan sulfate occurs in the extracellular matrix, while the heparin-like polymer is located within cytoplasmic granules of cells in the lumen of intestine and pharynx. The dermatan sulfate has a similar disaccharide composition in all tissues studied, whereas the heparin-like polymer differs in sulfate content. A direct relationship between sulfate content of the heparin-like polymer and antithrombin activity was observed. Analysis of the repeating disaccharide units of the heparin-like polymer indicates the presence of relatively high amounts of the disulfated disaccharide namely DeltaUA-1-->4-GlcN(SO(4))-(6SO(4)), which may suggest the occurrence in ascidians of regulatory biosynthetic mechanisms different from those observed for heparin in mammals.
Gandra
M
M
Departamento de Bioquímica Médica, Instituto de Ciências Biomédicas and Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Caixa Postal 68041, Rio de Janeiro, RJ 21941-590, Brazil.
Cavalcante
M
M
Pavão
M
M
D000818:Animals; D000991:Antithrombins / Q000378:metabolism*; D002240:Carbohydrate Sequence; D006025:Glycosaminoglycans / Q000737:chemistry / Q000378:metabolism*; D013431:Sulfates / Q000737:chemistry; D014561:Urochordata / Q000378:metabolism*
D000991:Antithrombins; D006025:Glycosaminoglycans; D013431:Sulfates