SCI和EI收录∣中国化工学会会刊

›› 2008, Vol. 16 ›› Issue (6): 923-928.

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Interaction of DNA with Cationic Gemini Surfactant Trimethylene-1, 3-bis(dodecyldimethyl-ammonium bromide) and Anionic Surfactant SDS Mixed System

赵小芳1, 尚亚卓1, 刘洪来1, 胡英1, 姜建文2   

  1. 1. Lab for Advanced Materials and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China;
    2. Department of Chemical & Biomolecular Engineering, National University of Singapore, 117576, Singapore
  • 收稿日期:2008-03-28 修回日期:2008-07-16 出版日期:2008-12-28 发布日期:2008-12-28
  • 通讯作者: SHANG Yazhuo,E-mail:shangyazhuo@ecust.edu.cn
  • 基金资助:
    Supported by the National Natural Science Foundation of China (20706013, 20736002), Program for Changjiang Scholars and Innovative Research Team in University (IRT0721), the 111 Project (B08021) and National University of Singapore

Interaction of DNA with Cationic Gemini Surfactant Trimethylene-1, 3-bis(dodecyldimethyl-ammonium bromide) and Anionic Surfactant SDS Mixed System

ZHAO Xiaofang1, SHANG Yazhuo1, LIU Honglai1, HU Ying1, JIANG Jianwen2   

  1. 1. Lab for Advanced Materials and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China;
    2. Department of Chemical & Biomolecular Engineering, National University of Singapore, 117576, Singapore
  • Received:2008-03-28 Revised:2008-07-16 Online:2008-12-28 Published:2008-12-28
  • Supported by:
    Supported by the National Natural Science Foundation of China (20706013, 20736002), Program for Changjiang Scholars and Innovative Research Team in University (IRT0721), the 111 Project (B08021) and National University of Singapore

摘要: The interaction of DNA with cationic gemini surfactant trimethylene-1,3-bis(dodecyl dimethyl-ammonium bromide)(12-3-12)and anionic surfactant sodium dodecyl sulfate(SDS) mixed system has been investigated by measuring the fluorescence,zeta potential,UV-V is spectrum,and circular dichroism.In the absence of SDS,owing to the electrostatic and hydrophobic interactions,12-3-12 forms micelle-like structure on the DNA chain before the micellization in bulk phase.For the mixed system of 12-3-12 and SDS,the negative charges on SDS can compete against DNA to bind with cationic 12-3-12 because of the stronger interaction between oppositely charged surfactants,and thus,the catanionic mixed micelles are formed before the formation of DNA/12-3-12 complexes.Thereafter,the positive charges on the mixed micelles bind with DNA,and thus,the change of the zeta potential from negative to positive is distinctly different from the system without SDS.Meanwhile,the existence of SDS postpones the exclusion of ethidium bromide(EB) from DNA/EB complexes.The conformation of DNA undergoes a change from native B-form to chiralψ-phase as binding with 12-3-12 process.Upon adding SDS to the DNA/12-3-12 complex solution,however,DNA is released to the bulk and theψ-phase returns to B-form again.

关键词: interaction, DNA, gemini surfactant, SDS, conformation

Abstract: The interaction of DNA with cationic gemini surfactant trimethylene-1,3-bis(dodecyl dimethyl-ammonium bromide)(12-3-12)and anionic surfactant sodium dodecyl sulfate(SDS) mixed system has been investigated by measuring the fluorescence,zeta potential,UV-V is spectrum,and circular dichroism.In the absence of SDS,owing to the electrostatic and hydrophobic interactions,12-3-12 forms micelle-like structure on the DNA chain before the micellization in bulk phase.For the mixed system of 12-3-12 and SDS,the negative charges on SDS can compete against DNA to bind with cationic 12-3-12 because of the stronger interaction between oppositely charged surfactants,and thus,the catanionic mixed micelles are formed before the formation of DNA/12-3-12 complexes.Thereafter,the positive charges on the mixed micelles bind with DNA,and thus,the change of the zeta potential from negative to positive is distinctly different from the system without SDS.Meanwhile,the existence of SDS postpones the exclusion of ethidium bromide(EB) from DNA/EB complexes.The conformation of DNA undergoes a change from native B-form to chiralψ-phase as binding with 12-3-12 process.Upon adding SDS to the DNA/12-3-12 complex solution,however,DNA is released to the bulk and theψ-phase returns to B-form again.

Key words: interaction, DNA, gemini surfactant, SDS, conformation