AMINO ACID TRANSPORTER

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 神经递质：钠同向转运蛋白（NSS）通过再摄取机制调节突触间隙的神经传递。在这个蛋白质家族中，单胺转运蛋白包括多巴胺转运蛋白（DAT）、血清素转运蛋白（SERT）和去甲肾上腺素转运蛋白（NET），是抗抑郁药和精神兴奋剂的主要靶标。尽管这些药物的药理作用已被广泛研究，但可用的结构信息很少，从而阻碍了对抑制机制的透彻理解，并阻碍了基于结构的药物设计。我目前的研究重点是使用细菌同系物研究神经递质转运蛋白中抗抑郁药结合位点的原子结构。通过应用称为闪烁邻近分析（SPA）的药物筛选策略，我们鉴定了一组与细菌转运蛋白具有结合亲和力的药物。第一个药物靶点地昔帕明（一种三环类抗抑郁药）已与一种细菌氨基酸转运蛋白 LeuT 共结晶。人类蛋白质的同源模型是通过将其序列连接到 LeuT-地昔帕明结构上来构建的。我进一步设计了人类 SERT 中的功能丧失突变和人类 DAT 中的功能获得突变，以提供强有力的证据支持药物结合袋可能在人类神经递质转运蛋白中保守。其他候选药物正在测试中。这项工作将揭示不同的抗抑郁药如何阻断神经递质转运蛋白，防止构象变化，从而抑制底物转运。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Neurotransmitter:sodium symporters (NSS) regulate neurotransmission at the synaptic cleft through a reuptake mechanism. In this protein family, monoamine transporters including dopamine transporter (DAT), serotonin transporter (SERT) and norepinephrine transporter (NET), are primary targets for antidepressants and psychostimulants. Although the pharmacological effects of these drugs have been studied extensively, little structural information is available, thereby hampering the thorough understanding of the inhibition mechanism and hindering structure based drug design.My current research is focused on studying atomic structures of antidepressants binding sites in neurotransmitter transporters using bacterial homologues. By applying a drug screening strategy called scintillation proximity assay (SPA), We identified a group of drugs that have binding affinity to bacterial transporters. The first drug target desipramine, a tricyclic antidepressant, has been cocrystallized with LeuT, a bacterial amino acid transporter. Homology models of human proteins were built by threading their sequences onto the LeuT-desipramine structure. I further designed both loss-of-function mutations in human SERT and gain-of-function mutations in human DAT to provide strong evidence supporting that the drug binding pockets are probably conserved in human neurotransmitter transporters. The other drug candidates are being test. This work will reveal how different antidepressants block neurotransmitter transporters, prevent conformational changes, and therefore inhibit substrate transport.