NEUROBIOLOGY OF SULFATED GLUCURONYL GLYCOCONJUGATES

本项目的主要长期目标是了解 磺基葡萄糖醛酸基糖脂（SGGL）和其他新乳糖系列的功能 阶段特异性和发育调节的糖脂 中枢神经系统皮质中的抗原，在重要的 细胞分化和细胞迁移期。 碳水化合物部分 SGGL的免疫原性高，单克隆抗体如HNK-1， 与碳水化合物结合的蛋白质也与相同或相似的 表位的几个重要的糖蛋白参与细胞 相互作用，如神经细胞粘附分子，N_CAM，L1，J1， 腱生蛋白、细胞增殖素、整合素、NILE、髓鞘相关糖蛋白和PO 蛋白 神经系统的正常发育取决于这些 分子。 尽管SGGL在胚胎发育期和胚胎发育期在皮质中表达， 仅在新生儿发育时，它们与浦肯野细胞相关， 周围神经系统，即使是成年人。 目前的具体目标 是为了了解他们的差异化的生物化学调节 通过研究这些酶， 参与这些脂质的代谢。 酶包括几种 糖基转移酶和糖苷酶。 除SGGL外，其他新乳糖系列 具有相同主链的糖脂，如岩藻新乳四糖苷和 神经节苷脂LD 1也是发育调节的抗原， 在发育过程中的位置。 表达特异性 碳水化合物将在体外进行研究，以评估这些 抗原的成熟和分化。 SGGL和硫苷脂作为 配体细胞-细胞间、细胞-基质间粘附及结合 细胞外基质蛋白层粘连蛋白。 计划进行研究， 来自发育皮质的30 kD SGGL/硫苷脂结合蛋白， 小脑 该蛋白质和针对该蛋白质的抗体将被用作 研究SGGL和HNK-1反应蛋白作用的探针 在细胞相互作用中。 开发了新的固定方法， HNK-1反应性脂质的免疫细胞化学鉴别定位 与神经组织中的蛋白质相比。 这种方法将用于精确地 在光照下定位脂质与蛋白质抗原的表达， 电镜水平观察皮层和小脑发育过程中， 在某些突变体中 细胞和亚细胞定位这些 分子可能会提供新的线索，他们的功能作用。

The major long term goal of this project is to understand the role and function of sulfoglucuronyl glycolipids (SGGLs) and other neolacto series of glycolipids which are stage specific and developmentally regulated antigens in the cortex in the central nervous system, during the important period of cell differentiation and cell migration. The carbohydrate moiety of SGGLs is highly immunogenic and monoclonal antibodies such as HNK-1, which bind to the carbohydrate also react with either the same or similar epitope on several important glycoproteins involved in cellular interaction, such as neural cell adhesion molecules, N_CAMs, L1, J1, tenascin, cytotactin, integrin, NILE, myelin associated glycoprotein and PO protein. The proper development of the nervous system depends upon these molecules. Although SGGLs are expressed in the cortex during embryonic and neonatal development only, they are associated with Purkinje cells and in peripheral nervous system, even in the adult. The present specific aims are to understand the biochemical regulation of their differential expression in these areas of the nervous system by studying the enzymes involved in the metabolism of these lipids. Enzymes include several glycosyltransferases and glycosidases. Besides SGGLs other neolactoseries of glycolipids having the same backbone, such as fuconeolactotetraoside and ganglioside LD1 are also developmentally regulated antigens to their proper location in the cortex during development. Cells expressing specific carbohydrates will be studied in vitro to evaluate the role of these antigens in maturation and differentiation. SGGLs and sulfatide act as ligand cell-adhesion between cell-cell, cell-substratum and bind extracellular matrix protein laminin. Studies are planned to characterize a 30 kD SGGL/sulfatide binding protein from developing cortex and cerebellum. The protein and antibodies to this protein will be used as probes to investigate the role of SGGLs and of the HNK-1 reactive proteins in cellular interactions. New fixation method has been developed to differentiate immunocytochemical localization of HNK-1 reactive lipids versus proteins in neural tissues. This method will be used to precisely localize the expression of lipid versus protein antigens, at light and electron microscopic level during development of the cortex and cerebellum, and in certain mutants. Cellular and subcellular localization of these molecules may provide new clues as to their functional role.