SCI和EI收录∣中国化工学会会刊

›› 2009, Vol. 17 ›› Issue (5): 829-834.

• • 上一篇    下一篇

Effects of Ionic Surfactants on Bacterial Luciferase and α-Amylase

闫桑田, 李安, 郑浩, 罗明芳, 邢新会   

  1. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • 收稿日期:2009-03-03 修回日期:2009-06-03 出版日期:2009-10-28 发布日期:2009-10-28
  • 通讯作者: XING Xinhui,E-mail:xhxing@tsinghua.edu.cn
  • 基金资助:
    Supported by the National Natural Science Foundation of China (20676071,20836004)

Effects of Ionic Surfactants on Bacterial Luciferase and α-Amylase

YAN Sangtian, LI An, ZHENG Hao, LUO Mingfang, XING Xinhui   

  1. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2009-03-03 Revised:2009-06-03 Online:2009-10-28 Published:2009-10-28
  • Supported by:
    Supported by the National Natural Science Foundation of China (20676071,20836004)

摘要: In order to study the effects of ionic surfactants on bacterial luciferase,the cationic surfactant dodecyltrimethylammonium biomide (DTAB) and anionic surfactant sodium dodecylsulfate (SDS) were chosen.For comparison with bacterial luciferase,α-amylase was used since these two enzymes have similar electrostatic potential and charged active sites.After the enzymes were treated with the surfactants,the catalytic properties of bacterial luciferase andα-amylase were assayed,and fluorescence spectroscopy and circular dichroism (CD) were used to analyze the alteration of the protein structure.The results showed that when the DTAB concentration was low,the cationic surfactant DTAB enhanced the enzymatic activities of bacterial luciferase andα-amylase.On the other hand,the anionic surfactant SDS did not alter the enzymatic activity.The main interaction of cationic surfactant DTAB and the negatively charged surface of the proteins was the ionic interaction,which could alter the environment for the enzyme to work when the DTAB/enzyme molar ratio was low.However,at high cationic surfactant concentration,the ionic interaction and hydrophobic interaction might destroy the secondary and tertiary structures of the proteins,leading to the loss of enzymatic activities.

关键词: luciferase, α-amylase, ionic surfactant, surfactant-enzyme interaction

Abstract: In order to study the effects of ionic surfactants on bacterial luciferase,the cationic surfactant dodecyltrimethylammonium biomide (DTAB) and anionic surfactant sodium dodecylsulfate (SDS) were chosen.For comparison with bacterial luciferase,α-amylase was used since these two enzymes have similar electrostatic potential and charged active sites.After the enzymes were treated with the surfactants,the catalytic properties of bacterial luciferase andα-amylase were assayed,and fluorescence spectroscopy and circular dichroism (CD) were used to analyze the alteration of the protein structure.The results showed that when the DTAB concentration was low,the cationic surfactant DTAB enhanced the enzymatic activities of bacterial luciferase andα-amylase.On the other hand,the anionic surfactant SDS did not alter the enzymatic activity.The main interaction of cationic surfactant DTAB and the negatively charged surface of the proteins was the ionic interaction,which could alter the environment for the enzyme to work when the DTAB/enzyme molar ratio was low.However,at high cationic surfactant concentration,the ionic interaction and hydrophobic interaction might destroy the secondary and tertiary structures of the proteins,leading to the loss of enzymatic activities.

Key words: luciferase, α-amylase, ionic surfactant, surfactant-enzyme interaction