DIYNENE ANTIBIOTICS AND THEIR DNA CLEAVAGE CHEMISTRY

二炔抗生素及其 DNA 裂解化学

• 批准号: 2095928
• 负责人: CRAIG ARTHUR TOWNSEND
• 金额: $ 16.92万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-05-10 至 1996-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2095928
• 关键词: DNA footprinting; DNA repair; antineoplastic antibiotics; chemical binding; chemical cleavage; deuterium; gel electrophoresis; hydroxyl radical; neoplasm /cancer pharmacology; nuclear magnetic resonance spectroscopy; radiotracer

The neocarzinostatin chromophore, calicheamicin lambda 1 I, esperamicin A1, and dynemicin A1 are representative members of the growing class of diynene antitumor antibiotics. Each of these compounds is capable of causing single- and double-strand DNA cleavages at very low concentrations (nM) in the presence of thiols and molecular oxygen. The in vitro and in vivo activity of these compounds has given hope that, through preferential uptake or selective delivery to cancer cells, for example, by the agency of a monoclonal antibody, effective therapies might be possible. Several such strategies are currently under investigation, and at least one is in Phase II clinical trials at present. More broadly, the successful design of sequence-selective DNA cleaving agents based on a thorough understanding of effective natural products is of enormous potential utility in molecular biology. Described in this new application is a set of diverse but interlocking experimental approaches to a detailed understanding of the thiol activation, sequence recognition, binding and reaction of calicheamicin with DNA. Calicheamicin is striking among the diynene antitumor antibiotics for its high potency, its high sequence selectively and its propensity for double-strand scissions. The cleavage preferences of the drug will be surveyed for an evolutionary broad group of DNA's. These preferred sites will be examined in greater detail in synthetic oligonucleotides using a variety of structural and kinetic techniques. Atom transfer experiments will secure the identities of hydrogens lost from the DNA backbone and reveal unambiguously the orientation of the drug in the minor groove. These findings will be compared with results from hydroxyl radical footprinting experiments and careful analyses of the mobilities of the cleavage fragments on high resolution gel electrophoresis. The DNA fragments will also be characterized by chemical and spectroscopic means to establish the kinetics of the various steps of drug activation and DNA cleavage will be examined to determining the overall dynamics of the process. Finally, NMR experiments are proposed to give more refined structural information aided by molecular modeling.

新制癌菌素发色团、加利车霉素 lambda 1 I、埃斯帕霉素 A1 和动力霉素 A1 是不断增长的类别的代表成员 二炔类抗肿瘤抗生素。 这些化合物中的每一种都能够 在极低的温度下引起单链和双链 DNA 切割 硫醇和分子氧存在下的浓度（nM）。 这 这些化合物的体外和体内活性给人们带来了希望， 通过优先摄取或选择性递送至癌细胞， 例如，通过单克隆抗体的作用，有效的疗法 也许有可能。 目前正在实施多项此类战略 调查，至少一项正在进行 II 期临床试验 展示。 更广泛地说，序列选择性 DNA 的成功设计 基于对有效天然物质的透彻理解的裂解剂 产品在分子生物学中具有巨大的潜在用途。 这个新应用程序描述的是一组不同但相互关联的 详细了解硫醇的实验方法 加利车霉素的激活、序列识别、结合和反应 与DNA。 加利车霉素在二炔类抗肿瘤药物中引人注目 抗生素因其高效力、高序列选择性及其 双链断裂的倾向。 的裂解偏好 将对药物进行广泛的进化 DNA 组调查。 这些 优选位点将在合成中进行更详细的检查 使用各种结构和动力学技术的寡核苷酸。 原子转移实验将确保丢失的氢的身份 从 DNA 主链中分离出来，并明确地揭示了 DNA 的方向 药物在小沟内。 这些发现将与结果进行比较 来自羟基自由基足迹实验和仔细分析 裂解片段在高分辨率凝胶上的迁移率 电泳。 DNA 片段的特征还在于 化学和光谱手段来建立各种动力学 将检查药物激活和 DNA 切割的步骤以确定 过程的整体动态。 最后，核磁共振实验 提议在分子辅助下提供更精细的结构信息 造型。