EVALUATING RADIATION CHANGE IN NUCLEIC ACIDS

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。该项目的重点是电离辐射对DNA结构和能量学的影响。报道了鸟嘌呤-胞嘧啶碱基对电离的从头算研究结果。由双质子转移产生的典型GC碱基对和稀有GC碱基对都受到电子的包含，并且观察到几何和能量变化。在B3 LYP理论水平上利用5个基组（6- 31 G（d）、6- 311 G（d）、6 - 311 G（d，p）、aug-cc-pVDZ和DZP++）对这些碱基对进行优化。这两个物种都表现出相当大的非平面性时，电子连接。然而，电子亲合势和相对能量表明，在这些条件下，稀有形式可能是有利的。这可能暗示了DNA在添加电子时利用的新机制。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The focus of this project is the effect of ionizing radiation on DNA structure and energetics. The results of an ab initio study of ionization of guanine-cytosine base pair are reported. Both the canonical GC base pair and the rare GC base pair, created by a double proton transfer are subject to the inclusion of an electron and the geometric and energetic changes were observed. These base pairs were allowed to optimized at the B3LYP level of theory utilizing five basis sets (6-31G(d), 6-311G(d), 6-311G(d,p), aug-cc-pVDZ, and DZP++). Both species showed considerable nonplanarity when the electron is attached. Futhermore, the electron affinities and relative energies show that the rare form may be favored under these conditions. This may suggest a new mechanism that DNA utilizes upon addition of an electron.