EPOTHILONE AFFINITY LABELS

抗MT药物继续受到人们的极大兴趣 作为潜在的临床有用的抗肿瘤药物的开发。几个 对微管蛋白和紫杉醇具有类似紫杉醇活性的新天然产物 最近发现了微管。在这些化合物中，有一种是新世硫酮。 是最有前途和最令人兴奋的。这组化合物可以是 从菌源分离，规模化生产 可行。埃普西酮A和B已被证明等同于 紫杉醇促进微管蛋白组装和竞争性抑制作用 [3H]紫杉醇与微管结合。埃博西酮也是相似的 紫杉醇的抗细胞增殖活性。然而，这些 化合物对抗性细胞的活性要大得多。 P-糖蛋白多药过表达对紫杉醇的影响 转运蛋白或改变后的β-微管蛋白的表达。因此， 这些化合物有可能克服两种不同的 细胞对紫杉醇的抗性机制。 目前对药物与药物之间的相互作用知之甚少。 微管。这些信息将有助于设计新的和 更好的衍生品。在结合位点上获得的信息将 对指导网站的未来工作也是极其重要的 微管蛋白的诱变。可以采用多种方法 被用来获取这些信息，包括我们正在 结合部位多肽的提出和鉴定 光亲和标记和荧光光谱的应用 研究互动的细节。 微管蛋白结合研究的结果表明， 紫杉醇和依维酮的结合部位是相同的。然而， 埃博西酮是细胞内有效的细胞毒剂的事实 对紫杉醇产生抗药性的原因是 β-微管蛋白，表明这些位点可能是重叠的，而不是 一模一样。 我们的计划是通过以下途径制备伊波硫酮亲和标签 微管蛋白的发射合成和全合成及其评价 组装活性和细胞毒性。荧光环磷酰胺将是 用于研究微管和微管与微管的相互作用 Epothilone光亲和技术将鉴定 感受器。

Anti-MT drugs continue to receive great interest for their development as potential clinically useful antitumor agents. Several new natural products with taxol-like activity towards tubulin and microtubules have been identified recently. Of these, the epothiones are the most promising and exciting. This group of compounds can be isolated from bacterial source, making large scale production feasible. Epothilone A and B have been shown to be equipotent to taxol in stimulating tubulin assembly and competitively inhibiting [3H]taxol binding to microtubules. The epothilones are also similar to taxol in their anti-cell proliferative activity. However, these compounds have much greater activity toward cells that are resistant to taxol due to the over-expression of the P-glycoprotein multidrug transporter or to the expression of an altered Beta-tubulin. Thus, these compounds have the potential of overcoming two different mechanisms of cell resistance to taxol. Very little is known yet about the interaction of drugs with microtubules. Such information would be useful for designing new and better derivatives. Information obtained on the binding site will also be extremely important for future work on the site directed mutagenesis of the tubulin protein. A variety of approaches can be taken to obtain this information, including those which we are proposing, identification of peptides in the binding site through photo affinity labeling and the use of fluorescence spectroscopy to study detail of the interaction. The results of the tubulin binding studies would suggest that the binding sites for taxol and epothilone are identical. However, the fact that the epothilones are effective cytotoxic agents in cells that are resistant to taxol because of the expression of an altered Beta-tubulin, indicates that the sites may be overlapping rather than identical. It is the plan to prepare epothilone affinity labels through emisynthesis and total synthesis and evaluate them for tubulin assembly activity and cytotoxicity. Fluorescent epothilones will be used to study the interaction with microtubules and tubulin and the epothilone photo affinity will identify the ligand binding sites in the receptor.