Biochemical Studies on neurotransm tter transporters in syhoptic vesica

突触囊泡在神经末梢的神经元传递中起着重要作用。它们积累了高浓度的神经递质，并在接收到适当的信号后，通过胞吐作用将其分泌出来。我们发现囊泡上的液泡atp酶在膜上形成质子的电化学梯度，递质通过与这种梯度相结合的特定转运体被吸收。然而，对转运蛋白的生化特性知之甚少。本研究的重点是阐明转运体和液泡atp酶的一些生化特性。在这两年中，我们取得了以下成果：(1)谷氨酸转运体的能量偶联，转运体由膜电位驱动，其他转运体由DELTApH驱动。(2)建立了用细菌f - atp酶重组转运体的程序。本方法可用于转运体纯化的测定系统。(3)二苄基谷氨酸是谷氨酸转运蛋白的有效抑制剂。(4)我们发现突触囊泡多巴胺转座子识别甲基苯基吡啶（MPP^+）作为底物。这些结果为进一步开展递质转运体的生化研究提供了基础资料。

Synaptic vesicles play an important role in neuronal transmission in nerve termini. They accumulate high concentrations of neurotransmitters and , upon receiving the proper signal, secrete them by exocytosis. We found that vacuolar ATPase on the vesicles forms an electrochemical gradient of protons across the membranes and transmitters are taken up through specific transporters coupled with this gradient. However, little is known about biochemical properties on the transporters. This study was focused to elucidate some biochemical properties on the transporter and vacuolar ATPase. During the two years, we obtained following results. (1) Energy coupling of glutamate transporter, the transporter is driven by membrane potential but other transporters are driven by DELTApH. (2) We established a procedure for reconstitution of transporter with bacterial F-ATPase. The procedure can be used for the assay system for purification of transporter. (3) We identified dibenzylglutamate as potent inhibitor for glutamate transporter. (4) We found that synaptic vesicle dopamine transpoter recognized methlphenylpyridinium (MPP^+), as a substrate. These results give basic information for the further biochemical study of transmitter transporters.