NEUROTRANSMITTER TRANSPORT

描述（申请人摘要）： 生物胺转运蛋白负责终止突触 5-羟色胺（5-HT）、多巴胺（DA）和去甲肾上腺素（NE）的作用。 他们 是抗抑郁药如丙咪嗪和百忧解的分子靶点 以及可卡因和安非他明等精神兴奋剂。 努力 目前致力于设计可卡因拮抗剂， 可卡因和生物胺结合位点的接近， 传送器 本申请描述了设计用于映射 生物胺转运蛋白中氨基酸残基的位置 与底物和抑制剂结合有关。 这些实验将 提供证据来测试现在用于设计可卡因的假设 治疗药物。 生物胺转运蛋白利用跨膜离子 梯度来驱动神经递质摄取。 偶联化学计量 该过程是每个转运体的特征。 该提案概述了 计划确定DA运输的离子耦合化学计量， 将其与NE和5-HT转运的化学计量进行比较。 突变体 将测试转运蛋白以确定 单个转运蛋白依赖于单个氨基酸。 总之，本提案中概述的实验是针对 最终目标是理解初级阶段的每一部分 生物胺转运蛋白的序列参与结合 和底物的移位。

DESCRIPTION (Applicant's Abstract): Biogenic amine transporters are responsible for terminating the synaptic action of serotonin (5-HT), dopamine (DA), and norepinephrine (NE). They are the molecular targets for antidepressants such as imipramine and Prozac as well as for psychostimulants such as cocaine and amphetamines. Efforts currently directed at designing cocaine antagonists make assumptions about the proximity of cocaine and biogenic amine binding sites on the transporter. This application describes experiments designed to map the location of amino acid residues in biogenic amine transporters that are involved with substrate and inhibitor binding. These experiments will provide evidence to test the assumptions now being used to design cocaine treatment medications. Biogenic amine transporters use transmembrane ion gradients to drive neurotransmitter uptake. The coupling stoichiometry for this process is characteristic of each transporter. This proposal outlines plans to determine the ion coupling stoichiometry for DA transport and to compare it with the stoichiometry for NE and 5-HT transport. Mutant transporters will be tested to determine how the stoichiometry of an individual transporter depends on individual amino acids. Taken together, the experiments outlined in this proposal are directed toward the ultimate goal of understanding how each part of the primary sequence of a biogenic amine transport protein participates in the binding and the translocation of substrates.