Studies of Antitumor,Anti HIV Cyclic Depsipeptides

描述：(申请人提供)最近从太平洋不同浅水海绵中分离的三个环多肽家族， 显示出对多种肿瘤细胞系的细胞毒性(平均1C50= 75 ng/mL)，最值得注意的是包括多药耐药细胞系。三个都是 家庭还保护T细胞免受HIV-1感染(EC50=3.6 ng/mL)。 此外，我们实验室的初步研究表明，在 这些分子中至少有一个可以诱导肿瘤细胞的凋亡。它们的起源 这些影响中的哪些目前尚不清楚。这些家族有许多共同的结构特征，包括一些新的、非蛋白生成的氨基 酸，但尚未完全从结构上表征。的第一个目标 这一建议是为了完成对这些天然产物的结构阐明 产物经固相合成、相关研究、核磁共振波谱分析 和分子模型。这个项目的第二个目标是调查 通过合成和使用这些分子的细胞作用模式 荧光标记的衍生物和亲和标记探针。《荧光报》 探测器将被用来研究细胞定位，并调查这种情况 分子可以穿过质膜。亲和探针将用于标记 这些分子的高亲和力结合位点并确定潜在的 受体蛋白。这个项目的第三个目标是剖析所扮演的角色 这些分子中的许多新残基。这将通过以下方式实现 突变选定残基并检测其对结构、细胞毒性的影响 和/或与细胞受体的相互作用。结构形式的组合 研究和细胞毒性分析将被用来创建一个药效团模型 这解释了这三个家庭都有类似的活动。发展中的 药效团模型将允许设计非肽类似物， 模仿天然产物的活动。这个项目的最终目标是 将以FMD为内源性蛋白配体的受体为环状 脱脂肽。针对一种环状脱脂肽的单抗 半抗原将被用来寻找这样的蛋白质配体。

DESCRIPTION: (provided by applicant) Three families of cyclic depsipeptides, all recently isolated from different shallow water sponges in the Pacific, display cytotoxicity against a broad spectrum of tumor cell lines (mean 1C50= 75 ng/mL), most notably including multidrug-resistant cell lines. All three families also protect T-cells against infection by HIV-1 (EC50= 3.6 ng/mL). Additionally, preliminary studies in our laboratory have indicated that at least one of these molecules may induce apoptosis in tumor cells. The origins of these effects are unknown at present. These families share many common structural features, including a number of novel, non-proteinogenic amino acids, but have not been fully structurally characterized. The first goal of this proposal is to complete the structural elucidation of these natural products through solid phase synthesis, correlation studies, NMR spectroscopy and molecular modeling. The second goal of this project is to investigate the cellular modes of action of these molecules through the synthesis and use of fluorescently labeled derivatives and affinity labeling probes. The fluorescent probes will be used to study cellular localization and investigate whether such molecules can cross plasma membranes. The affinity probes will be used to label high affinity binding sites for these molecules and to identify potential receptor proteins. A third goal of this project is to dissect the roles played by many of the novel residues in these molecules. This will be accomplished by mutating selected residues and examining the effects on structure, cytotoxicity and/or interaction with a cellular receptor. The combination of structural studies and cytotoxicity assays will be used to create a pharmacophore model that accounts for the similar activities of all three families. Development of a pharmacophore model will permit the design of non-peptidic analogues that mimic the activities of the natural products. The final goal of this project will be to fmd an endogenous protein ligand to the receptor for the cyclic depsipeptides. Monoclonal antibodies raised against a cyclic depsipeptide hapten will be used to search for such a protein ligand.