MOLECULAR STUDY ON MYELIN-ASSOCIATED NEURAMINIDASE

描述：(改编自申请者摘要)尽管 大量证据表明，唾液酸偶联物可能对 在髓鞘的形成和维持中起重要作用， 关于它们在髓鞘中的代谢和调节的信息 少突胶质细胞仍然稀少。调查人员已经 研究了中枢神经系统中的神经氨酸酶活性和 证明存在神经氨酸酶的固有活性 髓鞘和少突胶质细胞。为了阐明功能角色 神经氨酸酶在髓鞘和少突胶质细胞中的表达 提出了具体的目标：(1)纯化和表征 髓鞘相关神经氨酸酶，(2)酶的定位，(3) 酶的发育表达调控机制 髓鞘和少突胶质细胞的活动，以及(4)功能 髓鞘相关神经氨酸酶的作用。为了实现这些目标， 调查人员将首先提纯髓鞘相关神经氨酸酶以 来自大鼠大脑的同质性。生物化学和动力学性质 将检测酶的活性并与 微粒体中神经氨酸酶活性。特异性抗体 将制备酶以检测酶的定位。 使用免疫细胞化学和免疫印迹技术。为了 检测髓鞘神经氨酸酶活性和 少突胶质细胞在mRNA水平上受到调控， 髓鞘相关基因编码基因的发育表达 神经氨酸酶将使用制备的特定cdna探针进行检测。 与大鼠少突胶质细胞的mRNA结合，探讨其作用机制 髓鞘酶活性的发育变化也会 通过分析数量、完整性和微观 酶在发育过程中的环境。要检查 髓鞘相关神经氨酸酶在发育中的代谢作用 髓鞘唾液酸糖结合物组成的变化 少突胶质细胞将被检查与 神经氨酸酶活性指向内源性 唾液酸糖结合物以及外源底物。 髓鞘相关神经氨酸酶可能起粘连作用 将使用不同类型的结合来研究分子 实验和细胞培养系统。这些成就的实现 具体目标应提供有关 髓鞘相关神经氨酸酶在骨髓瘤的形成和维持中的作用 髓鞘。

DESCRIPTION: (adapted from Applicant's Abstract) Although a growing body of evidence has suggested that sialoglycoconjugates may play an important role in the formation and maintenance of the myelin sheath, information about their metabolism and regulation in myelin and oligodendroglial cells is still scanty. The investigators have studied neuraminidase activities in the central nervous system and demonstrated the presence of neuraminidase activities intrinsic to myelin and oligodendroglial cells. To elucidate the functional roles of neuraminidase in myelin and oligodendroglial cells, the following specific aims are proposed: (1) purification and characterization of myelin-associated neuraminidase, (2) localization of the enzyme, (3) regulatory mechanisms for developmental expression of the enzyme activities in myelin and oligodendroglial cells, and (4) functional roles of myelin-associated neuraminidase. To achieve these goals, the investigators will first purify myelin-associated neuraminidase to homogeneity from rat brain. The biochemical and kinetic properties of the enzyme will be examined and compared with those of neuraminidase activities in microsomes. Specific antibodies against the enzyme will be prepared to examine the localization of the enzyme using immunocytochemical and immunoblotting techniques. In order to examine whether the neuraminidase activities in myelin and oligodendroglial cells are regulated at the mRNA level, the developmental expression of mRNA coding for myelin-associated neuraminidase will be examined using a specific cDNA probe prepared with mRNA of rat oligodendroglial cells.The mechanism of the developmental changes in the activity of the myelin enzyme will also be investigated by analyzing the amounts, integrity, and micro- environment of the enzyme during development. To examine the metabolic role of myelin-associated neuraminidase, developmental changes in the composition of sialoglycoconjugates in myelin and oligodendroglial cells will be examined in relation to the neuraminidase activities directed toward endogenous sialoglycoconjugates as well as exogenous substrates.The possibility that myelin-associated neuraminidase may function as an adhesion molecule will be investigated using different types of binding experiments and cell culture systems. The achievement of these specific aims should provide vital information concerning the role of myelin-associated neuraminidase in the formation and maintenance of the myelin sheath.