Davies D B, Djimant L N, Baranovsky S F, Veselkov A N
Department of Chemistry, Birbeck College, University of London, UK.
Biopolymers. 1997 Sep;42(3):285-95. doi: 10.1002/(SICI)1097-0282(199709)42:3<285::AID-BIP2>3.0.CO;2-I.
The thermodynamical parameters (free energy, enthalpy, and entropy) of complex formation between ethidium bromide and single-stranded and double-stranded tetranucleotides of different base sequence [5-d(TpGpCpA), 5-d(ApCpGpT), and 5-d(ApGpCpT) have been determined from the temperature dependencies of 500 MHz proton nmr chemical shifts. The analysis enables the contributions to be differentiated for the formation of different types of complexes (1:1, 2:1, 1.2 and 2:2) in aqueous solution. The results have been interpreted in terms of the main types of intermolecular interactions responsible for formation of the different complexes; van der Waals and electrostatic interactions are important for formation of complexes of ethidium bromide with single-stranded tetranucleotides, whereas van der Waals and hydrophobic interactions play a significant role in the binding of the dye to the tetramer duplexes.
通过500兆赫质子核磁共振化学位移的温度依赖性，已测定了溴化乙锭与不同碱基序列的单链和双链四核核苷酸[5-d(TpGpCpA)、5-d(ApCpGpT)和5-d(ApGpCpT)]之间形成复合物的热力学参数（自由能、焓和熵）。该分析能够区分在水溶液中形成不同类型复合物（1:1、2:1、1:2和2:2）的贡献。已根据负责形成不同复合物的主要分子间相互作用类型对结果进行了解释；范德华力和静电相互作用对于溴化乙锭与单链四核核苷酸形成复合物很重要，而范德华力和疏水相互作用在染料与四聚体双链体的结合中起重要作用。
