EXCITED STATE DYNAMICS OF DNA BASE PAIRS

DNA 碱基对的激发态动力学

• 批准号: 0911564
• 负责人: Mattanjah de Vries
• 金额: $ 55.5万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0911564&HistoricalAwards=false
• 关键词: EXCITED; STATE; DYNAMICS; DNA; BASE

In this award, funded by the Experimental Physical Chemistry Program of the Division of Chemistry, Professor Mattanjah S. de Vries of the University of California Santa Barbara, together with his undergraduate, graduate and high school student researchers, will investigate the photochemistry and in particular the excited state dynamics of isolated nucleobases and their clusters with each other and with water. Following absorption of UV light, DNA bases can avoid chemical transformation by very rapidly diffusing the excitation energy to heat, in a process called internal conversion, which can safely be transferred to the environment. Thus a short lived excited state provides photochemical stability. This process strongly depends on molecular structure and is remarkably prevalent in the specific forms in which nucleobases occur in biological contexts. These short lived states have been difficult to study experimentally and therefore most evidence for these processes is still indirect. This project will employ novel gas phase techniques for these studies in collaboration with Professor Pavel Hobza in Prague, whose group will apply the newest computational modeling techniques for analysis. Professor de Vries will engage students in his efforts and contribute to the Bay Area Museum-School Online Science Learning Collaboratory Pilot Projec.How DNA responds to radiation is relevant to human health because radiation damage can affect genetic propagation and lead to cancer. DNA photochemistry is also important for our understanding of how life on earth developed, because prebiotic chemistry presumably occurred before formation of an oxygen rich atmosphere and thus under more energetic UV irradiation than what reaches the earth?s surface today. To understand this photochemistry in detail and at the molecular level we need to study it in isolated nucleobases and base pairs and compare the results with quantum chemical modeling. This approach allows Professor de Vries and his collaborators to observe intrinsic molecular properties and understand how those shape the bulk behavior of biological systems. Therefore, this research will contribute to the most basic understanding of fundamental processes that govern the molecular building blocks of life. These topics, in combination with cutting-edge laser and computational techniques, lend themselves extraordinary well to outreach activities, which this group traditionally undertakes. These activities include mentoring undergraduates, K-12 outreach activities, participation in the Bay Area Museum-School Online Science Learning Collaboratory Pilot Project, and collaboration with the students at Jackson State University, a historically black college in Mississippi.

在这个奖项，由化学系实验物理化学计划资助，教授Mattanjah S。来自加州圣巴巴拉大学的de弗里斯和他的本科生、研究生和高中生研究人员将研究光化学，特别是孤立的核碱基及其簇之间以及与水之间的激发态动力学。在吸收UV光之后，DNA碱基可以通过非常快速地将激发能量扩散到热量来避免化学转化，这一过程称为内部转换，可以安全地转移到环境中。因此，短寿命的激发态提供光化学稳定性。这一过程强烈依赖于分子结构，并且在生物学背景下发生的核碱基的特定形式中非常普遍。这些短暂的状态很难通过实验研究，因此这些过程的大多数证据仍然是间接的。该项目将与布拉格的Pavel Hobza教授合作，采用新颖的气相技术进行这些研究，该小组将采用最新的计算建模技术进行分析。教授德弗里斯将从事学生在他的努力，并有助于海湾地区博物馆学校在线科学学习合作实验室试点项目。DNA如何对辐射的反应是关系到人类健康，因为辐射损伤会影响遗传繁殖，并导致癌症。DNA光化学对于我们了解地球上生命如何发展也很重要，因为生命前的化学反应可能发生在富氧大气形成之前，因此受到比到达地球的紫外线辐射能量更高的紫外线辐射？今天的表面。为了在分子水平上详细了解这种光化学反应，我们需要在分离的核碱基和碱基对中研究它，并将结果与量子化学模型进行比较。这种方法使de弗里斯教授和他的合作者能够观察内在的分子特性，并了解这些特性如何塑造生物系统的整体行为。因此，这项研究将有助于对控制生命分子构建模块的基本过程的最基本理解。这些专题，加上先进的激光和计算技术，非常适合这一群体传统上开展的外联活动。这些活动包括指导本科生，K-12外展活动，参与湾区博物馆学校在线科学学习合作实验室试点项目，以及与杰克逊州立大学的学生合作，这是一所位于密西西比的历史悠久的黑人大学。