title: Biochemical properties of glycoproteins involved in lymphocyte recognition of high endothelial venules in man.
abstract: Lymphocyte interactions with high endothelial venules (HEV) are important to the in vivo migration of normal and neoplastic lymphocyte populations. We have previously described an 85- to 95-kDa lymphocyte surface glycoprotein(s) defined by mAb Hermes-1, that is involved in the recognition of HEV by human lymphocytes: antibodies against distinct epitopes of the Hermes-1 Ag differentially inhibit lymphocyte binding to lymph node, mucosal, or synovial HEV. Here we characterize further the Hermes-1-defined glycoproteins. No well defined differences were observed between the Hermes-1 Ag immunoprecipitated from PBL and from mucosa- vs lymph HEV-specific cell lines. The Ag is an acidic (isoelectric point = 4.2) sulfated molecule bearing both O-linked and (3,4) N-linked oligosaccharide side chains. A subset of the Hermes-1-immunoprecipitated species is modified by covalent linkage to chondroitin sulfate, yielding a Mr of approximately 180 to 200 kDa. Pulse-chase labeling reveals a major precursor of 76 kDa that appears to be processed either to the 85- to 95-kDa form or, by addition of chondroitin sulfate, to a 180- to 200-kDa form. The potential role of these structural modifications, and particularly of chondroitin sulfate, in the function of the putative adhesion molecules is discussed.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002236:Carbohydrate Conformation; D002809:Chondroitin Sulfates / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004727:Endothelium / Q000378:metabolism*; D004729:Endothelium, Lymphatic / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D006023:Glycoproteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D006026:Glycoside Hydrolases; D006031:Glycosylation; D006801:Humans; D007525:Isoelectric Focusing; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D051379:Mice; D008970:Molecular Weight; D009439:Neuraminidase; D011498:Protein Precursors / Q000378:metabolism; D051381:Rats; D011971:Receptors, Immunologic / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D016201:Receptors, Lymphocyte Homing
chemical_list: D000911:Antibodies, Monoclonal; D006023:Glycoproteins; D011498:Protein Precursors; D011971:Receptors, Immunologic; D016201:Receptors, Lymphocyte Homing; D002809:Chondroitin Sulfates; D006026:Glycoside Hydrolases; C020668:glycanase; D009439:Neuraminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase