Structural and Mechanistic Characterization of Neurotransmitter Reuptake Inhibiti

描述（由申请人提供）：Na？突触前质膜依赖的神经递质转运体在突触间隙的神经递质再摄取中起作用。这些蛋白包括血清素转运蛋白（SERT）、去甲肾上腺素转运蛋白（NET）和多巴胺转运蛋白（DAT）。它们通过直接降低突触间隙的神经递质浓度来调节神经传递过程。这些转运蛋白可以被各种药物抑制，因此是主要目标：抗抑郁药如氟西汀（百忧解）、舍曲林（左洛复）、哌醋甲酯（利他林）——一种通常用于治疗注意力缺陷多动障碍（ADHD）的处方药，以及精神兴奋剂如可卡因。尽管这些药物具有明显的药理和临床意义，但它们在SERT、NET或DAT蛋白中的结合位点尚不清楚，从而阻碍了对其抑制机制的理解和基于结构的药物设计。我们的目标是利用结构、生化和药理学技术的结合，确定这些不同类型的药物和精神兴奋剂在人类神经递质转运体中的结合位点，并了解它们的抑制机制。具体而言，我们建议：(A)建议确定三种类型抗抑郁药的人类SERT和NET蛋白的结合位点；(B)识别DAT中可卡因的结合位点；(C)鉴定人DAT蛋白中哌醋甲酯的结合位点；(D)表征这些药物抑制神经递质转运的分子机制。我们的目的是了解抗抑郁药对血清素和去甲肾上腺素转运体的抑制机制，利他林和可卡因对多巴胺转运体的抑制机制，采用结构、生化和药理学的结合方法。这些信息将有助于设计治疗抑郁症和注意力缺陷多动障碍的更有效的药物，以及管理可卡因滥用的药剂。

DESCRIPTION (provided by applicant): Na?-dependent neurotransmitter transporters of the presynaptic plasma membrane function in the reuptake of neurotransmitters from the synaptic cleft. These proteins include the serotonin transporter (SERT), norepinephrine transporter (NET) and dopamine transporter (DAT). They regulate the neurotransmission process by directly reducing the neurotransmitter concentration at the synaptic cleft. These transporter proteins can be inhibited by various drugs and therefore are the primary targets for: antidepressants such as fluoxetine (Prozac), sertraline (Zoloft), methylphenidate (Ritalin) -a prescription drug commonly used to treat attention-deficit hyperactivity disorder (ADHD), and psychostimulants like cocaine. In spite of their obvious pharmacological and clinical importance, the binding site for these drugs in the SERT, NET or DAT proteins are unknown, thereby hindering both the understanding of their inhibition mechanism and structure-based drug design. We aim to identify the binding site in the human neurotransmitter transporters for these various types of drugs and psychostimulants, and to understand their inhibition mechanism, using a combination of structural, biochemical and pharmacological techniques. Specifically, we propose: (A) to propose to identify the binding site in the human SERT and NET proteins for three types of antidepressants; (B) to identify the binding site in DAT for cocaine; (C) to identify the binding sites in the human DAT protein for methylphenidate; (D) to characterize the molecular mechanism of inhibition of neurotransmitter transporters by these drugs. We aim to understand the inhibition mechanisms of the serotonin and norepinephrine transporters by antidepressants and of the dopamine transporters by Ritalin and cocaine, using a combination of structural, biochemical and pharmacological approaches. Such information will aid in the design of more effective drugs for depression and for attention-deficit hyperactivity disorder, and of agents for the management of cocaine abuse.