文献类型：期刊文献

中文题名：阳离子Gemini表面活性剂12-3-12与DNA在模拟体液中的相互作用研究

英文题名：Interaction between Gemini Surfactant 12-3-12 and DNA in Simulated Body Fluid

作者：帅浪[1];宋江闯[1];尚亚卓[1];刘洪来[1]

机构：[1]华东理工大学结构可控先进功能材料及其制备教育部重点实验室,上海200237

年份：2015

卷号：78

期号：2

起止页码：146

中文期刊名：化学通报

外文期刊名：Chemistry

收录：CSTPCD;;Scopus;北大核心:【北大核心2014】；CSCD:【CSCD2015_2016】；

基金：国家自然科学基金项目(21173079;91334203)资助

语种：中文

中文关键词：模拟体液;Gemini表面活性剂;DNA相互作用;分子动力学模拟

外文关键词：Simulated body fluid(SBF),Gemini surfactant,DNA,Interaction,Molecular dynamics simulation

摘要：采用紫外透射光谱、透射电镜、原子力显微镜、圆二色谱(CD)等方法探讨了阳离子Gemini表面活性剂C12H25N+(CH3)2-(CH2)3-(CH3)2N+C12H25·2Br-(12-3-12)与DNA在模拟体液(SBF)中的相互作用。结果表明,SBF中较高反离子浓度不但屏蔽了DNA和12-3-12之间的静电吸引作用,而且促进了12-3-12聚集体的产生和生长,导致低盐条件下体系中出现的沉淀溶解现象的消失。SBF中DNA与12-3-12之间存在强烈的相互作用;随着12-3-12的加入,表面活性剂分子在DNA链周围聚集,类网络结构的DNA逐渐变为类似于串珠的复合物,随后出现尺寸较大的类球形复合物以及较大复合物与较小表面活性剂聚集体共存的现象。CD谱结果显示,SBF中12-3-12可以诱导DNA的构象发生改变,由自然的B构型变成高度致密的ψ相。分子动力学模拟的离子液体中表面活性剂与带相反电荷聚电解质的相互作用过程及模式与实验结果吻合良好。模拟结果也表明,SBF中较高的反离子浓度提高了聚电解质的可压缩程度,导致相同条件下SBF中聚电解质的均方回旋半径远小于稀盐水溶液(10mmol/L Na Br)体系中的聚电解质均方回旋半径。较强的离子强度不但导致体系中聚电解质和带相反电荷表面活性剂之间的相互作用存在"假饱和"现象,而且也造成体系中表面活性剂在聚电解质周围聚集数显著提高。
Interactions between cationic Gemini surfactant C12H25N+( CH3)2-( CH2)3-( CH3)2N+C12H25·2Br-( 12-3-12) and DNA in simulated body fluid( SBF) were investigated using UV-Vis,TEM,AFM and CD. The results showed that higher anti-ion concentration in SBF not only shielded electrostatic attraction between DNA and12-3-12,but also promoted the emergence and growth of surfactant aggregates,so the precipitate dissolution appeared usually at lower salt condition was prevented. There was strong interaction between DNA and 12-3-12,the surfactant molecules aggregated around the DNA chains as addition of surfactant and correspondingly the DNA with network-like structures turned into complexes with necklace-like structures because of the combination with surfactants.Subsequently,the bigger spherical complexes and the coexistence of bigger complexes and smaller surfactant aggregates were observed in the present system. CD spectra showed that DNA structure turned into condensed ψ phase from typical B conformation because of its interaction with 12-3-12. The results obtained by molecular dynamics simulations are coincide well with the experimental results. That is,higher anti-ion concentration in SBF increases compressibility of polyelectrolyte,which leads to smaller mean square radius of gyration < Rg2> than that in the dilute salt solution( 10 mmol / L Na Br). It seems that the stronger ionic strength in SBF not only leads to 'false saturation'phenomenon between surfactant and oppositely charged polyelectrolyte,but also increases surfactant's aggregation number around polyelectrolyte significantly.