Unnatural Base Pairs as DNA Bioprobes

作为 DNA 生物探针的非天然碱基对

• 批准号: 7070793
• 负责人: Katherine L Seley-Radtke
• 金额: $ 3.33万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE COUNTY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7070793
• 关键词: Unnatural; Base; Pairs; DNA; Bioprobes

DESCRIPTION (provided by applicant): This proposal is aimed at using a series of unnatural nucleosides to interrogate nucleic acid structure and function. Drawing inspiration from Nelson Leonard's benzene-expanded adenosine analogues, we will vary the width of the nucleobases, and subsequently the DNA helix, by introduction of diversity into the natural purine and pyrimidine scaffolds. Incorporation of either a pyrrole, thiophene or furan spacer ring into the heteroaromatic architecture will provide unique structural advantages not possible with previously studied base pairs. This research will address some fundamental scientific questions by providing new insights into the physical aspects of DNA helix stability and the role that electrostatics and base stacking play. It will also provide useful data regarding the effect nucleobase shape, base stacking and electrostatics have on DNA polymerase replication. We predict that the advantages provided by the heteroaromatic spacer rings will contribute significantly to enhanced base stacking, due to increased electrostatic surface area, as well as increased dispersion and van der Waals forces and polarizability. Furthermore, the heteroaromatic spacer rings possess the ability to hydrogen bond with cations or with water present in the spine of hydration of the helix. As a result, we also predict a significant increase in DNA helix stability will be observed. In addition, these extended bases are fluorescent and could prove useful in many applications, such self-reporters of helix formation, tracking single point mutations, as well as in synthetic DNA microarrays. The initial aims of this study are to (i) design, synthesize and characterize a series of extended pyrimidines and expanded purine nucleosides; (ii) to incorporate the unnatural nucleosides into DNA duplexes of varying length and composition; (iii) to computationally, spectroscopically, thermodynamically and structurally characterize the resulting helices; and (iv) evaluate their effect on DNA polymerase fidelity.

描述（由申请人提供）：