MAPPING THE PEPTIDE-BINDING SITES OF SP AND SK RECEPTORS

描述(改编自申请人的摘要)：3- SP和SK受体结合袋的空间结构 将根据它们的跨膜α-螺旋和 通过确定共价连接位置来确定胞外结构域 一系列含光活性氨基酸的SP和SK衍生物 对苯甲酰基苯丙氨酸沿氨基酸分布在不同位置 这两个多肽的序列。对于每个光亲和配体，氨基 成为共价标记的结合位点酸残基 最初通过对纯化的受体片段进行显微测序来确定 在位点特异性抗体的帮助下位于初级序列中 和质谱学。相似与相似的比较分析 这些结合结构域的不同特征应该提供对 多肽选择性和受体激活的分子基础。一个 相关项目将确定附着点的一个 非肽类SP拮抗剂的氚化光反应叠氮衍生物 CP-96,345。了解两个地点之间的关系 多肽激动剂和非肽拮抗剂可以提供对 探讨了该化合物的拮抗作用机制，并对其拮抗机制进行了探讨。 从整个项目中获得的信息可能会推动 临床实体治疗用药的合理设计 这些多肽参与其中。

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.