title: Immunological studies of sheep brain keratan sulphate proteoglycans.
abstract: Recently, we reported the isolation and partial characterization of keratan sulphate (KS) from sheep brain. In this study, a panel of monoclonal antibodies (Mab) recognizing epitopes within KS chains and core proteins of KS-containing proteoglycans were used to detect, by immunoblotting, antigenically related molecules extracted from cerebrum, cerebellum and brainstem, respectively. Although the intensity of labelling varied with each of the antibodies, the brain KSPGs were recognized by all the monoclonals used, confirming the presence of KS side chains, which react with the Mabs: 5-D-4, EFG-11, EFG-4, I22, as also the presence of KSPGs related to phosphacan-KS (3H1 proteoglycan). Extracts of all the three brain areas could bind both anti-KS and anti-core protein Mabs, as also anti-HNK-1 monoclonal antibody. Binding was sensitive to keratanases degradation in the cerebrum and brainstem except cerebellum where the presence of a large molecular size hybrid CS/KSPG bearing KS chains partially resistant to keratanases was identified. This population reacts only with 5-D-4, EFG-11 and EFG-4 antibodies. Furthermore, the presence of HNK-1 epitope in CSPGs was detected in the cerebellum and brainstem. In contrast, in the cerebrum the coexistence of HNK-1 epitope and KS in KSPGs was identified. These data suggest that the KSs of sheep brain are part of proteoglycans containing protein and KS antigenic sites related to those of corneal and cartilage KSPG, as also of the brain proteoglycan phosphacan-KS.
authors.affiliation: Department of Chemistry, University of Patras, Patras, 26500, Greece. papageorg.letta@chemistry.upatras.gr
authors.forename: Nickoletta
authors.initials: N
authors.lastname: Papageorgakopoulou
authors.forename: Achilleas D
authors.initials: AD
authors.lastname: Theocharis
authors.forename: Spyros S
authors.initials: SS
authors.lastname: Skandalis
authors.forename: Demitrios H
authors.initials: DH
authors.lastname: Vynios
authors.forename: Dimitrios A
authors.initials: DA
authors.lastname: Theocharis
authors.forename: Constantine P
authors.initials: CP
authors.lastname: Tsiganos
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D015153:Blotting, Western; D001923:Brain Chemistry; D001933:Brain Stem / Q000737:chemistry; D002531:Cerebellum / Q000737:chemistry; D019765:Chondroitin ABC Lyase / Q000378:metabolism; D011508:Chondroitin Sulfate Proteoglycans / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology; D006026:Glycoside Hydrolases / Q000378:metabolism; D007632:Keratan Sulfate / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D000071234:Lumican; D012756:Sheep; D013687:Telencephalon / Q000737:chemistry
chemical_list: D000911:Antibodies, Monoclonal; D011508:Chondroitin Sulfate Proteoglycans; D000939:Epitopes; D000071234:Lumican; D007632:Keratan Sulfate; D006026:Glycoside Hydrolases; C026093:keratan-sulfate endo-1,4-beta-galactosidase; D019765:Chondroitin ABC Lyase