MAPPING THE PEPTIDE BINDING SITES OF SP AND SK RECEPTORS

描述（改编自申请人的摘要）：三个- SP和SK受体结合口袋的空间结构 将根据它们的跨膜α-螺旋来定义， 通过确定共价连接的位点， 一系列含有光反应性氨基酸的SP和SK衍生物， 沿氨基酸沿着分布在不同位置的对苯甲酰基苯丙氨酸 两种肽的序列。对于每个光亲和配体，氨基 变成共价标记的结合位点的酸残基将 通过最初对纯化的受体片段进行微测序来确定 在位点特异性抗体的帮助下定位在一级序列中 和质谱分析。对相似和 这些结合结构域的独特特征应该提供对 肽选择性和受体激活的分子基础。一 相关项目将确定一个附件的网站 非肽SP拮抗剂的氚化光反应性叠氮衍生物 CP-96345了解网站之间的关系， 肽激动剂和非肽拮抗剂可以提供对 该化合物的拮抗作用的机制，以及 从整个项目中获得的信息可以促进 合理设计用于临床实体的治疗剂， 这些肽参与其中。

DESCRIPTION (adapted from the applicant's abstract): The three- dimensional structure of the binding pockets of the SP and SK receptors will be 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 residue of the binding site that becomes covalently labelled will be determined by microsequencing of purified receptor fragments initially located in the primary sequence with the aid of site-specific antibodies and mass 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 will be to determine 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.