MAPPING PEPTIDE BINDING SITES OF SP & SK RECEPTORS

SP结合口袋的三维结构 和SK受体的定义是关于它们的跨膜 α-螺旋和细胞外结构域，通过确定 共价连接一系列SP和SK衍生物， 光反应性氨基酸对苯甲酰基苯丙氨酸间隔为 沿着这两个氨基酸序列的沿着不同位置 缩氨酸 对于每个光亲和配体， 确定共价标记的结合位点 通过对最初定位于细胞中的纯化受体片段进行微测序， 借助位点特异性抗体和质量的一级序列 光谱法 相似性与差异性的比较分析 这些结合域的特征应该提供对 肽选择性和受体活化的分子基础。 一 相关项目是确定一个附件的网站 非肽SP的氚化光反应性叠氮衍生物 拮抗剂CP-96，345。 理解了 肽激动剂和非肽拮抗剂的位点可以 提供深入了解这种拮抗剂作用的机制， 化合物，以及从整个项目中获得的信息 可促进临床治疗药物的合理设计， 这些肽参与的实体。

The three-dimensional structure of the binding pockets of the SP and SK receptors is being defined with respect to their transmembrane alpha-helices and extracellular domains by determining the sites of covalent attachment of a series of SP and SK derivatives containing the photoreactive amino acid p-benzoylphenylalanine spaced at different positions along the amino acid sequences of the two peptides. For each photoaffinity ligand, the amino acid residues of the binding site that becomes covalently labelled are being determined by microsequencing of purified receptor fragments initially located in the primary sequence with the aid of site-specific antibodies andmass spectrometry. A comparative analysis of the similar and distinctive features of these binding domains should provide insight into the molecular basis of peptide selectivity and receptor activation. A related project is determination of the site of attachment of a tritiated photoreactive azide derivative of the nonpeptide SP antagonist CP-96,345. An understanding of the relationship between the sites for peptide agonists and the nonpeptide antagonist may provide insight into the mechanism of the antagonist effects of this compound, and the information to be gained from the project as a whole may advance the rational design of therapeutic agents for clinical entities in which these peptides participate.