NOVEL ANALOGS OF INFLAMMATORY MEDIATORS

补体衍生的介质，称为过敏毒素，在 白细胞的粘附、趋化性（即动员）和隔离 和巨噬细胞。 这些因子，C3 a和C5 a，在选择的细胞表面上具有受体。 通过跨膜激活细胞的循环和组织细胞类型 信号机制 由于这些体液因素刺激炎症 细胞，从而促进它们迁移和隔离到损伤部位， 这些因子的细胞受体是调节这些因子的主要靶点 控制炎症过程。 了解 分子水平上的配体-受体相互作用将有助于阐明 跨膜细胞活化的机制，并提供一种途径， 操纵随后的生理反应（即炎症）。 现在已经成功地设计了因子C3 a的合成类似物， 比天然因子的活性高10倍。 模型 C5 a的合成肽将基于C3 a类似物 研究和C5 a分子的三维模型结构。 已经合成了长度高达21个残基的C-末端C5 a肽， 制得，活性较弱（0.01 - 1%）。 合成C5 a肽活性 将通过合并主站点和多个子站点进行优化 结合结构域转化为配体类似物。 将标识子站点域 通过人C5 a分子的位点特异性诱变。 的组合 诱变和合成肽的研究将被用来映射表面 C5 a和C5 a受体之间的相互作用。 我们期待设计 复杂的线性或支链C5 a肽， 结合位点，以优化协同结合相互作用， 从而增强结合亲和力。 如果这种简化模拟的概念 设计证明是成功的，功能活性合成类似物可能是 专为多种淋巴因子和各种其他生物活性配体设计。 C5 a的合成激动剂将用于受体作图， 受体分离和细胞鉴定。 报告基团和探针 连接到合成类似物将用于分析细胞 配体的运输和活化机制。 的另一个目标 本项目将设计C5 a的位点特异性拮抗剂， 激动剂数据。 有效的C5 a拮抗剂有望成为 作为急性损伤中有用的选择性修复剂的临床价值， 类风湿和自身免疫性疾病。

Complement-derived mediator, called anaphylatoxins, play a major role in adherence, chemotaxis (i.e. mobilization) and sequestration of leukocytes and macrophages. These factors, C3a and C5a, have receptors on selected circulating and tissue cell types that activate cells via a trans-membrane signal mechanism. Since these humoral factors stimulate inflammatory cells, thus promoting their migration and sequestration to sites of injury, the cellular receptors for these factors are a prime target for modulating and controlling the inflammatory process. Understanding the ligand-receptor interactions at the molecular level will help to elucidate mechanisms of trans-membrane cellular activation and provide, an avenue for manipulating the subsequent physiologic response (i.e. inflammation). Synthetic analogs of factor C3a have now been successfully designed that exhibit 10-fold greater activity than does the natural factor. Model synthetic peptides for C5a will be designed based on both the C3a analog studies and the three-dimensional model structure of the C5a molecule. Synthetic C-terminal C5a peptides up to 21 residues in length have been made and are weakly active (0.01 - 1%). Synthetic C5a peptide activity will be optimized by incorporating the primary and multiple sub-site binding domains into ligand analogs. Sub-site domains will be identified by site-specific mutagenesis of the human C5a molecule. A combination of mutagenesis and synthetic peptide studies will be employed to map surface interactions between C5a and the C5a receptor. We anticipate designing complex linear or; branched C5a peptides by incorporating multiple distinct binding sites in order to optimize cooperative binding interactions and thereby enhance binding affinity. If this concept of simplified analog design proves successful, functionally active synthetic analogs may be designed for numerous lymphokines and various other bioactive ligands. Synthetic agonists of C5a will be used for receptor mapping, receptor-isolation and cell identification. Reporter groups and probes attached to the synthetic analogs will be used to analyze cellular trafficking of the ligand and mechanisms of activation. Another goal of this project will be to design site-specific antagonists of C5a based on the agonist data. Effective antagonists for C5a promise to have potential clinical value as selective antiinflammatory agents useful in acute injury, rheumatoid and autoimmune diseases.