SP RECEPTOR BINDING SITES FOR AGONISTS AND ANTAGONISTS

这一更新是结构和功能研究的继续 P物质（SP）受体。 这一长期目标 建议是在分子水平上了解激动剂的基础 和拮抗剂特异性、受体活化和下游信号传导 事件 我们的方法是使用光反应SP类似物 含有在不同位置取代的对苯甲酰基苯丙氨酸， SP的11个氨基酸序列。 将确定这些光配体在SP受体上的附着 通过MALDI-质谱分析分离的光标记的 受体片段，其通过酶和/或化学方法产生， 受体的分裂。 这些研究将有助于确定SP 结合口袋并在口袋内定位肽。 我们将 开发含二苯甲酮的非肽SP衍生物 拮抗剂作为拮抗剂结合结构域的光探针。 一个 了解多肽结合位点之间的关系 激动剂和非肽拮抗剂形成了基础， 了解拮抗作用的潜在机制，这是至关重要的， 用于药物开发。 光反应肽的利用 激动剂，连同化学交联和免疫检测， 为我们提供了识别特定G蛋白和其他 与SP受体相互作用的调节蛋白。 这种方法 将提供关于信号转导的重要信息 与SP受体相关的机制。 据估计， 今天使用的所有药物中， 通过G蛋白信号通路，这些研究可能提供新的 和有趣的基本临床相关信息。 肽物质P引起了相当大的关注，因为 它的多种生物活性：作为中枢神经递质， 感觉和自主神经系统;作为引起 收缩的平滑肌在胃肠道和作为一个 炎症和免疫反应的介质。 SP已经 与许多感觉和神经生成障碍有关。 的 通过我们的持续努力提供的信息应构成基础， 新型SP受体激动剂的理解和开发， 对手。

This renewal is a continuation of studies on the structure and function of the substance P (SP) receptor. The long term objective of this proposal is to understand, at the molecular level, the basis of agonist and antagonist specificity, receptor activation and downstream signaling events. Our approach will be to use photoreactive SP analogs containing p-benzoylphenylalanine substituted at different positions in the eleven amino acid sequence of SP. The site(s) of covalent attachment of these photoligands on the SP receptor will be determined by MALDI-mass spectrometric analysis of isolated photolabeled receptor fragments, which are generated by enzymatic and/or chemical cleavage of the receptor. These studies will aid in defining the SP binding pocket and orient the peptide within that pocket. We will develop benzophenone-containing derivatives of non-peptide SP antagonists as photoprobes of the antagonist binding domain(s). An understanding of the relationship between the binding sites for peptide agonist and the non-peptide antagonists forms the foundation for understanding underlying mechanisms of antagonism, which is essential for drug development. The availability of photoreactive peptide agonists, together with chemical crosslinking and immunodetection, provides us with tools to identify specific G proteins and other regulatory proteins which interact with the SP receptor. This approach will provide important information about the signal transduction machinery associated with the SP receptor. As it has been estimated that up to 60 percent of all medicines used today exert their effects through G protein signaling pathways, these studies may provide new and interesting information of basic clinical relevance. The peptide substance P has attracted considerable attention because of its multiple biological activities: as a neurotransmitter in the central, sensory and autonomic nervous systems; as an agent that causes contraction of smooth muscle in the gastrointestinal tract and as a mediator of inflammation and immune responses. SP has been implicated in a number of sensory and neurogenerative disorders. The information provided by our continuing effort should form the basis for understanding and development of novel SP receptor agonists and antagonists.