Pullman B
Institut de Biologie Physico-Chimique Laboratoire de Biochimie Theorique, associé au C.N.R.S., Paris, France.
J Biomol Struct Dyn. 1983 Dec;1(3):773-94. doi: 10.1080/07391102.1983.10507481.
The molecular electrostatic potential (MEP) and the molecular electrostatic field (MEF) are associated with significantly different patterns of distribution in the nucleic acids and their constituents. In particular, a) while the values of the minimal potentials at the reactive sites of the bases or at the phosphates increase manyfold when going from the subunits to the double helix, the values of the field undergo only very small changes under the same circumstances and b) while the deepest potentials are located in the grooves of the double helix, the greatest fields are concentrated on the phosphates of the backbone. They are also influenced differently by such environmental factors as counterion screening: while the absolute values of the potentials are profoundly reduced, the fields are increased with respect to those of the unscreened acids. MEP and MEF also govern the electrostatics of interaction of DNA with different types of species. The MEP being of particular significance in this respect for interaction with cations and the MEF for the association with neutral dipolar molecules. A number of examples are given to illustrate the significance of this situation for different conformers of DNA.
分子静电势（MEP）和分子静电场（MEF）与核酸及其组成成分中显著不同的分布模式相关。具体而言，a）当从亚基转变为双螺旋时，碱基或磷酸基团反应位点处的最小电势值会增加许多倍，而在相同情况下，电场值仅发生非常小的变化；b）虽然最深的电势位于双螺旋的凹槽中，但最大的电场集中在主链的磷酸基团上。它们还受到诸如抗衡离子屏蔽等环境因素的不同影响：虽然电势的绝对值会大幅降低，但与未屏蔽的酸相比，电场会增强。MEP和MEF还支配着DNA与不同类型物质相互作用的静电学。在这方面，MEP对于与阳离子的相互作用尤为重要，而MEF对于与中性偶极分子的缔合尤为重要。给出了许多例子来说明这种情况对于DNA不同构象的重要性。
