NOVEL ANALOGS OF INFLAMMATORY MEDIATORS

补体衍生的介质，称为过敏性毒素，在 白细胞的黏附、趋化(即动员)和隔离 和巨噬细胞。这些因子，C3a和C5a，有选择性的受体 通过跨膜激活细胞的循环和组织细胞类型 信号机制。因为这些体液因素会刺激炎症 细胞，从而促进它们向损伤部位的迁移和隔离， 这些因子的细胞受体是调节的主要目标。 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 跨膜细胞激活的机制和提供途径 操纵随后的生理反应(即炎症)。 C3a因子的合成类似物现在已经成功地设计出来 表现出比自然因素大10倍的活性。型号 C5a的合成肽将基于C3a类似物设计 研究了C5a分子的三维模型结构。 合成了长达21个残基的C末端C5a多肽 制造并具有弱活性(0.01-1%)。人工合成C5a多肽活性 将通过整合主站点和多个子站点进行优化 将结构域结合到配体类似物中。将标识子站点域 通过对人类C5a分子进行定点突变。一种组合 将使用诱变和合成肽研究来绘制表面图 C5a和C5a受体之间的相互作用。我们期待着设计 复杂的线状或分支C5a多肽，通过结合多个不同的 结合部位，以优化协同结合作用和 从而增强结合亲和力。如果这个简化模拟的概念 设计证明是成功的，功能活跃的合成类似物可能是 专为众多淋巴因子和各种其他生物活性配体而设计。 C5a的合成激动剂将用于受体映射， 受体分离和细胞鉴定。记者团体和调查 附着在合成的类似物上将被用来分析细胞 配体的贩运和激活机制。另一个目标是 该项目将设计C5a的特异性拮抗剂基于 激动剂数据。C5a的有效拮抗剂有望具有潜力 作为选择性抗炎药在急性损伤中的临床价值， 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.