UV-Induced Structural Changes of Model DNA Helices Probed by Optical Spectroscopy

作者：Banyasz Akos; Karpati Szilvia; Lazzarotto Elodie; Markovitsi Dimitra^*; Douki Thierry

来源：Journal of Physical Chemistry C, 2009, 113(27): 11747-11750.

DOI：10.1021/jp901841s

Chemical alterations of DNA, if not repaired, may lead to carcinogenic mutations. Structural modifications of the helix around the lesion enable its recognition by repair enzymes. We have used absorption spectroscopy and mass spectrometry to detect structural changes provoked by cyclobutane thymine dimers, the major lesion induced by UV radiation. We found that fort-nation of a cyclobutane dimer in the model duplex (dA)(20).(dT)(20) destroys base stacking on the adenine strand. The physical background of this novel approach is the existence of charge-transfer states among neighboring bases, whose contribution to the hypochromism of the helix disappears following destacking.

• 出版日期2009-7-9
• 单位中国地震局