title: Structural and biological properties of the carbohydrate units of nervous tissue glycoproteins.
abstract: We have identified structures in nervous tissue glycoproteins that are novel for glycoproteins in general or enriched in nervous tissue or cells of neural origin. These include: (alpha 2-8)-linked polysialic acid units, the linear form of poly-N-acetyllactosamine glycans, the sialylated X antigen determinant NeuAc(alpha 2-3)-Gal(beta 1-4) [Fuc(alpha 1-3)]GlcNAc, a series of Man-O-Ser(Thr)-linked glycans, and the O-glycosidically linked disaccharide unit Gal(alpha 1-3)GalNAc. The polysialic and poly-N-acetyllactosamine glycans are also developmentally regulated. The polysialic acid units in the cell adhesion molecule N-CAM. The poly-N-acetyllactosamine units occur in the adhesion molecule NILE (which is immunologically similar to Ng-CAM and L1) and in some other components revealed by a cell surface-labelling method specific for these glycans. The mannose-linked glycans occur in a chondroitin sulphate proteoglycan involved in neuron-glia interactions. Other biological interactions of the carbohydrates include their serving as bacterial receptors in meningitis, their serving as models for molecular mimicry by the capsules of meningitis-causing bacteria, and the role of some structures as antigens in autoimmune conditions. At the molecular level, two types of mechanisms are suggested for the glycans in molecular interactions: they may function either as mediators of interactions by serving as specific recognition ligands, or as modulators of the interactions determined by polypeptides or other molecules.
authors.affiliation: Department of Medical Biochemistry, University of Turku, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Finne
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D015816:Cell Adhesion Molecules, Neuronal; D006023:Glycoproteins / Q000502:physiology*; D009424:Nervous System Physiological Phenomena; D009844:Oligosaccharides / Q000502:physiology*; D011134:Polysaccharides / Q000502:physiology*
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D006023:Glycoproteins; D009844:Oligosaccharides; D011134:Polysaccharides