Nakamura Kaori, Karimata Hisae, Ohmichi Tatsuo, Miyoshi Daisuke, Sugimoto Naoki
Department of Chemistry, Faculty of Science and Engineering, Konan University 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan.
Nucleic Acids Symp Ser (Oxf). 2007(51):167-8. doi: 10.1093/nass/nrm084.
We investigated molecular crowding effects on the thermodynamic stability of Hoogsteen and Watson-Crick base pairs in an intramolecular duplex and triplex. The melting temperature (Tm) of Hoogsteen base pair formations in the triplex and the duplex increased 3.7 degrees C and 3.2 degrees C, respectively, by adding 20 wt% PEG 200. On the other hand, the Tm of Watson-Crick base pair formations in the triplex and the duplex decreased 5.7 degrees C and 5.2 degrees C, respectively. These results suggested that molecular crowding conditions generally stabilized and destabilized Hoogsteen and Watson-Crick base pairs, respectively, even in the different DNA structures.
我们研究了分子拥挤对分子内双链体和三链体中Hoogsteen碱基对和沃森-克里克碱基对热力学稳定性的影响。通过添加20 wt%的聚乙二醇200（PEG 200），三链体和双链体中Hoogsteen碱基对形成的解链温度（Tm）分别升高了3.7摄氏度和3.2摄氏度。另一方面，三链体和双链体中沃森-克里克碱基对形成的Tm分别降低了5.7摄氏度和5.2摄氏度。这些结果表明，即使在不同的DNA结构中，分子拥挤条件通常分别使Hoogsteen碱基对稳定而使沃森-克里克碱基对不稳定。
