Novel heparan sulfate structures revealed by monoclonal antibodies.
The sulfated glycosaminoglycan heparan sulfate (HS) is found ubiquitously on cell surfaces, in the extracellular matrix, and intracellularly as HS proteoglycans. Because of the structural heterogeneity of HS, tissue-derived HS preparations represent a mixture of HS chains originating from different cell types and tissue loci. Monoclonal anti-HS antibodies have been employed to detect the localization of specific HS epitopes in tissues, but limited information has been available on the saccharide structures recognized by the antibodies. We have studied the saccharide epitope structures of four anti-HS antibodies, HepSS1, JM13, JM403, and 10E4, which all recognize distinct HS species as demonstrated by different patterns of immunoreactivity upon staining of embryonic rat and adult human tissues. The epitopes recognized by JM13 and HepSS1 were found almost exclusively in basement membrane HS, whereas JM403 and 10E4 reacted also with cell-associated HS species. The binding of HepSS1, JM403, and 10E4 to HS was dependent on the GlcN N-substitution of the polysaccharide rather than O-sulfation. HepSS1 thus interacted with N-sulfated HS domains, JM403 binding was critically dependent on N-unsubstituted GlcN residues, and 10E4 bound to "mixed" HS domains containing both N-acetylated and N-sulfated disaccharide units. By contrast, JM13 binding seemed to require the presence of 2-O-sulfated glucuronic acid residues.
van den Born
Jacob
J
Department of Molecular Cell Biology and Immunology, Vrije Universiteit Medical Center, Amsterdam 1007 MB, The Netherlands.
Salmivirta
Katriina
K
Henttinen
Tiina
T
Ostman
Nina
N
Ishimaru
Takeshi
T
Miyaura
Shuichi
S
Yoshida
Keiichi
K
Salmivirta
Markku
M
D000107:Acetylation; D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001485:Basement Membrane / Q000737:chemistry; D002584:Cervix Uteri / Q000737:chemistry; D004622:Embryo, Mammalian; D004848:Epithelium / Q000737:chemistry; D000939:Epitopes / Q000032:analysis; D005260:Female; D020723:Glucuronic Acid / Q000737:chemistry; D006497:Heparan Sulfate / Q000032:analysis / Q000737:chemistry* / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D008648:Mesoderm / Q000737:chemistry; D009055:Mouth; D011134:Polysaccharides / Q000737:chemistry; D051381:Rats; D013431:Sulfates / Q000737:chemistry; D014018:Tissue Distribution; D014070:Tooth
D000911:Antibodies, Monoclonal; D000939:Epitopes; D020723:Glucuronic Acid; D006497:Heparan Sulfate; D011134:Polysaccharides; D013431:Sulfates