Complexation of DNA with cationic surfactants as studied by small-angle X-ray scattering  

作　　者：NIU Lin YAN JingJing YANG XuYan BURGER Christian RONG LiXia HSIAO Benjamin LIANG DeHai 

机构地区：[1]Beijing National Laboratory for Molecular Sciences, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education [2]Department of Polymer Science and Engineering, College of Chemistry and Molecular Engineering, Peking University [3]Department of Chemistry, State University of New York at Stony Brook

出　　处：《Science China Chemistry》2014年第12期1738-1745,共8页中国科学（化学英文版）

基　　金：financially supported by the National Natural Science Foundation of China(21174007);the National Basic Research Program of China(2012CB821500)

摘　　要：The phase behaviors of the complex formed by didodecyldimethylammonium bromide（DDAB）and cetyltrimethylammonium bromide（CTAB）interacting with three different types of DNAs,salmon testes DNA（~2000 bp）,21-bp double-stranded oligonucleotides（oligo-ds DNA）,and 21-nt single-stranded oligonucleotides（oligo-ss DNA）were studied by synchrotron small-angle X-ray scattering.It was found that the DNA length and flexibility,together with the positive/negative charge ratio,determined the final structure.At higher charge ratios,the DNA length exhibited negligible effect.Both oligo-ds DNA and salmon DNA formed inverted hexagonal packing of cylinders with CTAB,as well as bilayered lamella with DDAB.However,at lower charge ratios,oligo-ds DNA formed a distorted hexagonal phase with CTAB and a new structure with DDAB,which was different from the behaviors of salmon DNA.The flexible oligo-ss DNA formed rich structures that were subject to environmental disturbance.Kinetic study also indicated that the structures of the complex formed by oligo-ss DNA took much longer to mature than the structures formed by oligo-ds DNA.We attributed this result to the conformational adjustment of oligo-ss DNA in the complex.建筑群的阶段行为由 didodecyldimethylammonium 溴化物( DDAB )和与 DNA 的三种不同类型交往的 cetyltrimethylammonium 溴化物( CTAB )形成了，大马哈鱼睾丸 DNA ( 2000 bp )， 21-bp 双stranded oligonucleotides ( oligo-dsDNA )，并且 21-nt 搁浅单人赛的 oligonucleotides ( oligo-ssDNA )被同步加速器学习散布的小角度的X光检查。和正电荷比率， DNA 长度和灵活性决定了最后的结构，这被发现。在更高的费用比率， DNA 长度展出了可以忽略的效果。oligo-dsDNA 和大马哈鱼 DNA 形成了与 DDAB 的与 CTAB，以及 bilayered 薄片的柱体的转换六角形的收拾行李。在更低的费用比率，然而， oligo-dsDNA 与 DDAB 与 CTAB 和新结构形成了一个弄歪的六角形的阶段，它与大马哈鱼 DNA 的行为不同。灵活 oligo-ssDNA 形成了服从于环境骚乱的富有的结构。运动学习也显示 oligo-ssDNA 形成的建筑群的结构花更长时间比 oligo-dsDNA 形成的结构成熟。我们在建筑群把这结果归因于 oligo-ssDNA 的 conformational 调整。

关 键 词：phase behavior DNA SURFACTANT synchrotron small-angle X-ray scattering kinetics 

分 类 号：O647.2[理学—物理化学]