Structure and affinity for antithrombin of heparan sulfate chains derived from basement membrane proteoglycans.
Metabolically 35S- or 3H-labeled heparan sulfate was isolated from murine Reichert's membrane, an extraembryonic basement membrane produced by parietal endoderm cells, and from the basement membrane-producing Engelbreth-Holm-Swarm mouse tumor. The polysaccharides were subjected to structural analysis involving identification of products formed on deamination of the polysaccharides with nitrous acid. The polysaccharide from Reichert's membrane contained N- and O-sulfate groups in approximately equal proportions. It bound almost quantitatively and with high affinity to antithrombin. A high proportion of antithrombin-binding sequence was also indicated by the finding that 3-O-sulfated glucosamine residues accounted for about 10% of the total O-sulfate groups. In contrast, at least 80% of the sulfate residues in the heparan sulfate isolated from the mouse tumor were N-substituents. Only a minor proportion of this polysaccharide bound with high affinity to antithrombin, and no 3-O-sulfated glucosamine residues were detected. These results are discussed in relation to the possible functional role of heparan sulfate in basement membranes.
D000818:Animals; D000991:Antithrombins / Q000378:metabolism*; D001485:Basement Membrane / Q000032:analysis; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D006025:Glycosaminoglycans / Q000378:metabolism*; D006493:Heparin / Q000378:metabolism; D006497:Heparan Sulfate / Q000378:metabolism*; D046911:Macromolecular Substances; D051379:Mice; D011509:Proteoglycans / Q000378:metabolism*; D012513:Sarcoma, Experimental / Q000032:analysis / Q000648:ultrastructure*; D013462:Sulfur Radioisotopes; D014316:Tritium
D000991:Antithrombins; D006025:Glycosaminoglycans; D006493:Heparin; D006497:Heparan Sulfate; D046911:Macromolecular Substances; D011509:Proteoglycans; D013462:Sulfur Radioisotopes; D014316:Tritium