Neurochemistry of Drug Abuse

描述（由申请人提供）： 了解多巴胺转运蛋白的结构和机制是了解多巴胺能神经传递中这种关键膜结合蛋白的重要一步。虽然多巴胺和相关的神经递质去甲肾上腺素和5-羟色胺与几种具有严重社会影响的精神障碍有关，但参与其信号传导的关键蛋白质的结构和机制仍然难以捉摸。应用这类知识的一个例子是开发治疗可卡因滥用的药物，这是解决全国药物滥用问题的一个重要目标。为了开发阻止可卡因与其靶点多巴胺转运蛋白结合的新药，了解可卡因和多巴胺在转运蛋白上的结合位置将非常有用。一种定位可卡因结合位点的方法是探索影响与转运蛋白结合的可卡因类似物的结构特征。这种方法的延伸是开发与转运蛋白不可逆结合的抑制剂。这类化合物与蛋白质反应，在抑制剂和蛋白质之间形成共价键。知道这个键在哪里形成，也就是说，序列中的哪个氨基酸参与，允许结合位点开始被定位。然后，突变研究可以进一步探测该区域。 使用一系列不可逆抑制剂，包括不可逆可卡因类似物，可以构建可卡因结合位点的图谱。为了鉴定底物结合区，将使用与转运蛋白发生不可逆反应的底物多巴胺的类似物。因此，将确定在抑制和转运中重要的区域。结合的结果将有助于构建一个图片的配体结合区域的关键人类多巴胺转运蛋白的功能和抑制。 如果没有足够的结构信息，就不可能理解这种重要的膜结合蛋白在正常发挥功能或对急性或慢性药物滥用作出反应时的机制。识别结构域，和结构域内的残基，参与底物和抑制剂的结合是重要的第一步，了解这一机制和相关的转运。

DESCRIPTION (provided by applicant): Knowledge of the structure and mechanism of the dopamine transporter is an important step in understanding this key membrane bound protein in dopaminergic neurotransmission. While dopamine and the related neurotransmitters norepinephrine and serotonin are implicated in several mental disorders with severe social impact, the structure and mechanism of the key proteins involved in their signaling remain elusive. One example for the application of such knowledge is the development of medications to treat cocaine abuse, an important goal in addressing the national problem of drug abuse. In order to develop new drugs which prevent the binding of cocaine to its target, the dopamine transporter, it would be very useful to know where both cocaine and dopamine bind on the transporter protein. One approach to localization of the binding site for cocaine has been to explore the structural features of cocaine analogs that affect binding to the transporter. An extension of this approach has been to develop inhibitors which bind irreversibly to the transporter. This class of compounds reacts with the protein to form a covalent bond between the inhibitor and the protein. Knowledge of where this bond is formed, that is, which amino acid in the sequence is involved, allows the binding site to begin to be localized. Mutagenesis studies can then further probe the region. With a range of irreversible inhibitors, including irreversible cocaine analogs, a map of the cocaine binding site can be constructed. To identify the substrate binding region, analogs of the substrate dopamine, will be used that irreversibly react with the transporter. Thus regions important in both inhibition and transport will be identified. The combined results will help to construct a picture of the ligand binding regions critical for human dopamine transporter function and inhibition. Without adequate structural information, it is not possible to understand the mechanism of this important membrane bound protein when functioning normally or in response to acute or chronic drugs of abuse. Identification of domains, and residues within domains, involved in substrate and inhibitor binding is an important first step in understanding the mechanism of this and related transporters.