Peptidic Ligands for Kappa Opioid Receptors

描述(申请人提供)：由于吗啡等MU阿片类镇痛剂的严重副作用，人们对开发其他类型阿片受体的配基作为药理工具和潜在的治疗剂有相当大的兴趣。Kappa(K)阿片受体参与多种生理和药理作用，包括外周和中枢介导的镇痛。药物滥用，特别是阿片类药物和可卡因的滥用是一个重大问题，给个人和社会都造成了后果。Kappa受体激动剂和拮抗剂可能分别用于治疗可卡因和阿片类药物滥用。Kappa受体配体还具有许多其他潜在的治疗应用，包括作为神经保护剂和潜在的艾滋病治疗。配体，特别是多肽与Kappa阿片受体的相互作用似乎比配体与Mu或Delta阿片受体的相互作用更为复杂。因此，本研究的长期目标是考察具有高kappa阿片受体亲和力和选择性的新型多肽配体，这些配体可以作为药理学工具在分子水平上更好地了解Kappa受体-多肽之间的相互作用。这项建议结合了多种方法(合成、构象分析和药理学评价)和迭代策略来探索结构-活性关系(SAR)，并开发多肽配体(既有激动剂又有拮抗剂)与kappa受体相互作用的药理模型。本研究有三个具体的目的：1)探索强啡肽A类似物N端序列的SAR；2)探索这些肽的C端序列的修饰，以了解不同肽配体上的碱性残基在Kappa受体相互作用中的作用；3)研究与强啡肽A无关的具有高Kappa受体亲和力的新型小肽。除了确定可用于研究Kappa阿片受体的重要药理学工具外，这项研究还应大大促进我们对多肽配体如何与这些受体相互作用的理解。这些见解将是对非肽配体的补充，并可能对开发新的kappa受体配体非常重要，包括具有潜在治疗益处的药物。

DESCRIPTION (provided by applicant): Because of the serious side effects associated with mu opioid analgesics such as morphine there is considerable interest in developing ligands for other opioid receptor types as both pharmacological tools and potential therapeutic agents. Kappa (k) opioid receptors are involved in a variety of physiological and pharmacological effects, including peripheral as well as centrally mediated analgesia. Drug abuse, particularly opioid and cocaine abuse, is a major problem, resulting in consequences for both the individual and society. Kappa receptor agonists and antagonists may find utility in the treatment of cocaine and opioid abuse, respectively. Kappa receptor ligands also have a number of other potential therapeutic applications, including as neuroprotective agents and potentially in the treatment of AIDS. The interactions of ligands, particularly peptides, with Kappa opioid receptors appear to be more complex than the interactions of ligands with mu or delta opioid receptors. Therefore the long-term objectives of this research are to examine novel peptidic ligands with high kappa opioid receptor affinity and selectivity that can be used as pharmacological tools to better understand Kappa receptor-peptide interactions at a molecular level. This proposal uses a combination of approaches (synthesis, conformational analysis, and pharmacological evaluation) and an iterative strategy to explore structure-activity relationships (SAR) and develop pharmacophoric models for the interactions of peptide ligands, both agonists and antagonists, with kappa receptors. This research has three specific aims: 1) to explore the SAR of the N-terminal sequences of dynorphin A analogs; 2) to explore modifications in the C-terminal sequence of these peptides to understand the roles of basic residues in different peptide ligands for Kappa receptor interaction, and 3) to study novel small peptides unrelated to dynorphin A that have high kappa receptor affinity. In addition to identifying important pharmacological tools that can be used to study Kappa opioid receptors, this research should significantly advance our understanding of how peptide ligands interact with these receptors. These insights will be complimentary to those found for non-peptide ligands and could be very important in the development of new kappa receptor ligands, including agents with potential therapeutic benefit.