CHEMICAL SYNTHESIS & TARGET IDENTIFICATION OF CERATOSPONGAMIDE

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。炎症性和自身免疫性疾病，如哮喘和类风湿性关节炎，其特征是免疫细胞的聚集，这些细胞对一系列复杂的分泌信号分子做出反应，导致组织损伤。两种被认为是炎症的关键介质的细胞因子是IL-1b和TNF-a。这些细胞因子主要通过改变基因表达模式，在靶组织上发挥不同但重叠的作用。IL-1b和TNF-a通过与不同的细胞表面受体结合来控制基因的表达，从而激活多个蛋白激酶级联反应。我们提出了一种药理学方法来研究这些复杂的信号通路。我们的想法源于最近的一项发现，即一种海洋天然产品Ceratospongamide有效地抑制了IL-1b诱导的基因表达，其IC50为32 NM。我们试图阐明其作用机制。谷氨酰胺是一种大环七肽，由半胱氨酸和苏氨酸侧链环化到肽骨架上形成两个额外的环(噻唑和恶唑啉)来限制构象。我们将合成能够识别其细胞靶标的Ceratospongamide及其衍生物。用于亲和纯化的放射性标记和固定化衍生物都将使用现代合成方法来合成。在加州大学旧金山分校设施获得的质谱学测量将是至关重要的，原因有两个：(1)表征合成中间体和(2)识别Ceratospongamine的蛋白质靶标。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Inflammatory and autoimmune diseases, such as asthma and rheumatoid arthritis, are characterized by the accumulation of immune cells that cause tissue damage in response to a complex array of secreted signaling molecules. Two cytokines thought to be critical mediators of inflammation are IL-1b and TNF-a. These cytokines exert distinct yet overlapping effects on target tissues, primarily by altering patterns of gene expression. IL-1b and TNF-a control gene expression by binding to distinct cell surface receptors, whereupon multiple protein kinase cascades are activated. We propose a pharmacological approach to study these complex signaling pathways. Our idea derives from the recent discovery that a marine natural product, ceratospongamide, potently inhibits gene expression induced by IL-1b with an IC50 of 32 nM. We seek to elucidate its mechanism of action. Ceratospongamide is a macrocyclic heptapeptide that is conformationally constrained by two additional rings (thiazole and oxazoline) formed by the cyclization of cysteine and threonine side chains onto the peptide backbone. We will synthesize ceratospongamide and derivatives that will enable the identification of its cellular targets. both radiolabeled and immobilized derivatives for affinity purification will be synthesized using modern synthetic methodology. Mass spectrometry measurements obtained at the UCSF Facility will be essential for two reasons: (1) characterizing synthetic intermediates and (2) identifying ceratospongamide's protein target.