Buchvarov Ivan, Wang Qiang, Raytchev Milen, Trifonov Anton, Fiebig Torsten
Eugene F. Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA.
Proc Natl Acad Sci U S A. 2007 Mar 20;104(12):4794-7. doi: 10.1073/pnas.0606757104. Epub 2007 Mar 12.
The mechanism that nature applies to dissipate excess energy from solar UV light absorption in DNA is fundamental, because its efficiency determines the vulnerability of all genetic material to photodamage and subsequent mutations. Using femtosecond time-resolved broadband spectroscopy, we have traced the electronic excitation in both time and space along the base stack in a series of single-stranded and double-stranded DNA oligonucleotides. The obtained results demonstrate not only the presence of delocalized electronic domains (excitons) as a result of UV light absorption, but also reveal the spatial extent of the excitons.
自然界用于消散因DNA吸收太阳紫外光而产生的多余能量的机制至关重要，因为其效率决定了所有遗传物质对光损伤及后续突变的易感性。利用飞秒时间分辨宽带光谱技术，我们在一系列单链和双链DNA寡核苷酸中，沿着碱基堆积在时间和空间上追踪了电子激发过程。所获得的结果不仅证明了由于紫外光吸收而存在离域电子域（激子），还揭示了激子的空间范围。
