Single Molecule Studies of DNA-Cyanine Dye Interactions

DNA-花青染料相互作用的单分子研究

• 批准号: 6317033
• 负责人: JEFFREY T PETTY
• 金额: $ 12.23万
• 依托单位: FURMAN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6317033
• 关键词: DNA; atomic force microscopy; cations; chemical bond; chemical chain length; chemical kinetics; chemical stability; chemical structure function; computer simulation; cyanine; fluorescence microscopy; fluorescent dye /probe; hydropathy; intermolecular interaction; model design /development; molecular dynamics; molecular shape; nucleic acid sequence; nucleic acid structure; physical model; solutions; stoichiometry; structural biology; thermodynamics; viscosity

DESCRIPTION (provided by applicant): The cyanine dyes are a class of bicyclic aromatic compounds that are highly fluorescent when associated with DNA. The resulting sensitivity of DNA detection has led to applications ranging from medical diagnosis to molecular biology. The cyanine dyes will also serve as useful models to understand critical features of ligand-DNA interactions because they behave as nonclassical intercalators. This research will use single molecule analysis, as well as macroscopic experimental techniques, to investigate important features of the DNA-cyanine dye interaction from thermodynamic, structural, and kinetic standpoints. I. Equilibrium constant and viscosity measurements will be used to characterize the factors that influence the structure and stability of the DNA-dye complex. Dr. Petty will investigate the role of the structure of the dye, the sequence of the DNA, and the solution environment on the dye-DNA association. II. Dimeric cyanine dyes exhibit strong cooperative interactions when bound to DNA fragments. Atomic force microscopy (AFM) will be used to investigate the structures of these cooperative dye-DNA complexes. The unique capabilities of AFM will allow studies such as the sequence dependence of the cooperativity. III. Because of their favorable fluorescence properties, individual cyanine dye molecules will be studied using single molecule fluorescence microscopy. By eliminating the averaging inherent in bulk studies, new perspectives on the dynamics of DNA-ligand interactions are possible. For example, by measuring the rates of association and dissociation of individual molecules, the role of salt in the mechanism of DNA-ligand interaction will be elucidated. Because of the significance of small molecules and enzymes in DNA regulation, the long-term goal of this project is to use single molecule analysis to provide unique perspectives on these DNA-ligand interactions.

描述（由申请人提供）：花青染料是一类双环芳香族化合物，当与 DNA 结合时会发出高荧光。这 DNA 检测的灵敏度导致其应用范围包括 医学诊断到分子生物学。花青染料也将用作 了解配体-DNA 相互作用的关键特征的有用模型 因为它们表现为非经典嵌入器。本研究将使用 单分子分析以及宏观实验技术， 研究DNA-花青染料相互作用的重要特征 热力学、结构和动力学观点。 I. 平衡常数和粘度测量将用于表征 影响DNA-染料复合物结构和稳定性的因素。 佩蒂博士将研究染料结构、序列的作用 DNA 的影响以及溶液环境对染料-DNA 缔合的影响。 二.二聚花青染料与结合时表现出强烈的协同相互作用 DNA 片段。原子力显微镜（AFM）将用于研究 这些协同染料-DNA 复合物的结构。的独特能力 AFM 将允许研究诸如协同性的序列依赖性等。 三．由于其良好的荧光特性，个别花青染料 将使用单分子荧光显微镜研究分子。经过 消除了批量研究中固有的平均，对 DNA-配体相互作用的动力学是可能的。例如，通过测量 单个分子的缔合和解离速率，盐的作用 DNA-配体相互作用的机制将得到阐明。 由于小分子和酶在 DNA 调节中的重要性， 该项目的长期目标是利用单分子分析 为这些 DNA-配体相互作用提供了独特的视角。