NEUROFIBROUS PROTEINS IN NORMAL AND AGING BRAIN

核苷酸和微管相关蛋白在 微管介导的细胞功能的调节。持续努力 将澄清核苷酸在脑微管中的作用 浊度测量、电子显微镜和31P原子核组装 使用纯化的微管相关微管蛋白的磁共振研究 鸟苷核苷酸的蛋白质和硫代类似物。二 核苷二磷酸激酶(NDPK)和微管蛋白刺激的酶 ATPase，存在于脑微管蛋白组分中，由 将详细研究组装-拆卸的几个循环。这些 将提纯酶并用于回答以下问题：1) NDPK和ATPase的体外作用机制是什么 微管聚合？2)NDPK能使GDP磷酸化吗？ 微管蛋白的可交换部位？3)NDPK或ATPase与 微管蛋白、微管和/或微管相关蛋白？ GTP、GDP、ATP和/或ADP的硫代磷酸类似物与 微管相关的NDPK或ATPase？5)NDPK或ATPase 微管蛋白对ATP结合位点的影响？此外，单克隆 和/或微管相关NDPK多克隆抗体和 ATPase将用于不同细胞的免疫细胞化学定位 类型，并确定组织特异性。这些研究应该有助于 阐明核苷酸和微管相关酶在血管内皮生长中的作用 细胞骨架和增加我们对微管功能的理解。他们 也应该有助于我们理解年龄相关的改变 脑内微管相关酶的活性。

Nucleotides and microtubule-associated proteins are important in the regulation of microtubule-mediated functions in cells. Continued effort will be made to clarify the role of nucleotides in brain microtubule assembly by turbidimetric measurements, electron microscopy and 31P nuclear magnetic resonance studies using purified tubulin, microtubule-associated proteins and phosphorothioate analogues of guanosine nucleotides. Two enzymes, nucleoside diphosphate kinase (NDPK) and tubulin-stimulated ATPase, which are found in brain microtubule protein fractions prepared by several cycles of assembly-disassembly will be studied in detail. These enzymes will be purified and used to answer the following questions: 1) What are the mechanisms by which NDPK and ATPase effect in vitro microtubule polymerization? 2) Does NDPK phosphorylate GDP bound to the exchangeable site of tubulin? 3) Does NDPK or ATPase interact with tubulin, microtubules and/or microtubule-associated proteins? 4) Do thiophosphate analogues of GTP, GDP, ATP and/or ADP interact with microtubule-associated NDPK or ATPase? 5) Does NDPK or ATPase have an effect on a proposed ATP binding site of tubulin? In addition, monoclonal and/or polyclonal antibodies raised to microtubule-associated NDPK and ATPase will be used for immunocytochemical localization in different cell types and to determine tissue specificity. These studies should help to elucidate the role of nucleotides and microtubule-associated enzymes on the cytoskeleton and increase our understanding of microtubule functions. They should also contribute to our understanding of age-dependent alterations of microtubule-associated enzyme activities in brain.