MOLECULAR STUDIES OF CA++ TRANSPORT IN NERVE AND RETINA

神经系统的电活动是由一类蛋白质产生的 嵌入在神经细胞膜中的分子，催化主动泵 以及特定离子的被动选通。我们的实验室已经参与了 某些关键神经元的鉴定、分离及体外鉴定 哺乳动物脑中的离子转运蛋白：依赖于ATP的钙离子转运 参与神经递质释放调节的系统 以及一个电压敏感的钠离子门，它负责 神经元的“动作电位”。近年来，我们实验室开发了一种 膜纯化的新方法--“传输比分馏” 运输系统。利用这一技术，我们已经获得了对 神经元钙离子转运蛋白质接近同质性(大约100倍)。 我们现在正在研究阿片类药物对其可能的调节作用。 和其他内源性机制，并正在净化其他终端内的钙离子 运输系统。 同时，我们第一次成功地重组了洗涤剂 溶解的，电压敏感的钠离子门，并通过 “运输特定分馏”。我们正在进行进一步的净化，如果 同质化的可能性。我们打算将含有 提纯的钠门成平面双层，在那里它的电学性质可以 更多的定量观察。我们正在生产针对Na的单抗 用于免疫细胞化学的门。我们一直在研究钠的调节 离子门受内生环境因素影响。

The electrical activity of the nervous system is produced by a class of protein molecules, imbedded in the nerve cell membrane, that catalyze the active pumping and passive gating of specific ions. Our laboratory has been involved in the identification, isolation, and in vitro characterization of certainkey neuronal ion transport proteins from mammalian brain: an ATP-dependent Ca ions transport system involved in the regulation of neurotransmitter release from nerve terminals, and a voltage-sensitive Na ion gate that is responsible for the neuronal "action potential." In recent years, our laboratory has developed a new approach, "transport specific fractionation," for purification of membrane transport systems. Using this technique, we have obtained purification of the neuronal Ca ions transport protein to near homogeneity (approximately 100-fold). We are now in the process of studying its possible regulation by the opiates and other endogenous mechanisms and are purifying other intraterminal Ca ions transport systems. In parallel, we have for the first time successfully reconstituted the detergent solubilized, voltage-sensitive Na ion gate and have partially purified it by "transport specific fractionation". We are proceeding to further purify it, if possible to homogeneity. We intend to incorporate vesicles containing the purified Na gate into plannar bilayers, where its electrical properties can be more quantitatively observed. We are producing monoclonal antibodies to the Na gate for immunocytochemistry. We have been studying the regulation of the Na ion gate by endogenous environmental factors.