Laboratoire de Biochimie Théorique, CNRS UPR 9080, Institut de Biologie Physico-Chimique, Paris, France.
Chemphyschem. 2001 Nov 19;2(11):673-7. doi: 10.1002/1439-7641(20011119)2:11<673::AID-CPHC673>3.0.CO;2-S.
Free energy profiles of opening of a centrally placed A:T pair within a DNA oligomer exhibits two regimes: Elastic deformation due to hydrogen bond rupture and a roughly linear region due to loss of stacking and solvation. Thymine opens equally easily into the minor and major grooves, while adenine favors the major groove direction. No significant variations from canonical backbone conformations were observed; however base opening induces considerable changes in surrounding solvent distribution, leading finally to a water channel which passes through the double helix.
在 DNA 寡聚体中,中央 A:T 对的打开的自由能曲线呈现两个区域:氢键断裂引起的弹性变形和由于堆积和溶剂化损失引起的大致线性区域。胸腺嘧啶同样容易进入小沟和大沟,而腺嘌呤则倾向于大沟方向。没有观察到与典型骨架构象的显著变化;然而,碱基的打开导致周围溶剂分布发生相当大的变化,最终形成一个穿过双螺旋的水通道。