Haranczyk Maciej, Gutowski Maciej, Li Xiang, Bowen Kit H
J Phys Chem B. 2007 Dec 27;111(51):14073-6. doi: 10.1021/jp077439z. Epub 2007 Dec 4.
It is believed that guanine, a basic component of DNA and RNA, has the smallest affinity to an excess electron among all nucleic acid bases. Our experimental and computational findings indicate, however, that many so far neglected tautomers of guanine support adiabatically bound anionic states in the gas phase. The computed values of electron vertical detachment energy for the most stable anionic tautomers are within a broad range of the dominant feature of the photoelectron spectrum. We suggest that guanine might be the strongest excess electron acceptor among nucleic acid bases. Thus it might be critical to radiobiological damage of DNA and it might contribute to those chemical transformations of DNA that proceed through bound anionic states.
人们认为，鸟嘌呤作为DNA和RNA的一种基本成分，在所有核酸碱基中与多余电子的亲和力最小。然而，我们的实验和计算结果表明，鸟嘌呤的许多迄今被忽视的互变异构体在气相中支持绝热束缚阴离子态。最稳定的阴离子互变异构体的电子垂直脱离能的计算值在光电子能谱主要特征的很宽范围内。我们认为鸟嘌呤可能是核酸碱基中最强的多余电子受体。因此，它可能对DNA的放射生物学损伤至关重要，并且可能促成通过束缚阴离子态进行的DNA的那些化学转化。
