Pérez Alberto, Sponer Jiri, Jurecka Petr, Hobza Pavel, Luque F Javier, Orozco Modesto
Molecular Modeling Unit, IRBB-PCB, Josep Samitier 1-5, Barcelona 08028, Spain.
Chemistry. 2005 Aug 19;11(17):5062-6. doi: 10.1002/chem.200500255.
The intrinsic stability of Watson-Crick d(AT) and r(AU) hydrogen bonds was analyzed by employing a variety of quantum-mechanical techniques, such as energy calculations, determination of reactivity indexes, and analysis of electron density topology. The analyses were performed not only for equilibrium gas-phase geometries, but also on hundreds of conformations derived from molecular dynamics (MD) and database analysis. None of our results support the idea that r(AU) hydrogen bonds are intrinsically more stable than those of d(AT). Instead, our data are in accordance with the traditional view that the greater stability of RNA relative to DNA is attributable to a variety of effects (e.g., stacking, sugar puckering, solvation) rather than to a significant difference in the hydrogen bonding of DNA and RNA base pairs.
通过采用多种量子力学技术，如能量计算、反应性指数的测定以及电子密度拓扑分析，对沃森-克里克d(AT)和r(AU)氢键的内在稳定性进行了分析。这些分析不仅针对平衡气相几何结构进行，还针对从分子动力学(MD)和数据库分析中获得的数百种构象进行。我们的结果均不支持r(AU)氢键本质上比d(AT)氢键更稳定这一观点。相反，我们的数据与传统观点一致，即RNA相对于DNA具有更高的稳定性归因于多种效应（例如，堆积、糖环构象、溶剂化），而非DNA和RNA碱基对氢键存在显著差异。
