La3+对过氧化氢酶电化学和生物电催化活性的影响
Effect of La3+ on Electrochemical and Bioelectrocatalytic Activity of Catalase
作者单位E-mail
周慧 南京师范大学化学与环境科学学院, 南京, 210097  
丁晓岚 清华大学生物科学与技术系, 北京, 100084  
陆天虹 南京师范大学化学与环境科学学院, 南京, 210097  
黄晓华 南京师范大学化学与环境科学学院, 南京, 210097 wxxhhuang@yahoo.com 
摘要: 本文研究了La3+对过氧化氢酶(CAT)的直接电化学反应活性和对H2O2还原的生物电催化活性的影响。发现当La3+浓度低时,La3+能提高CAT的直接电化学反应活性和对H2O2还原的电催化活性。当La3+浓度高时,La3+会降低CAT的直接电化学反应活性和对H2O2还原的电催化活性。这是由于La3+能与CAT的肽链上的氨基酸残基发生作用而使肽链构象发生变化,导致血红素结构发生变化。当La3+浓度低时,La3+能使血红素的非平面性增加,活性中心Fe(Ⅲ)的暴露程度增加,因此,低浓度的La3+能增加CAT的电化学和生物电催化活性,而高浓度的La3+却会使血红素的非平面性降低,活性中心Fe(Ⅲ)的暴露程度降低,因此,降低了CAT的电化学和生物电催化活性。
关键词: 镧离子  过氧化氢酶  电化学反应  生物电催化活性
基金项目: 国家自然科学基金(No.20471030);国家发展和改革委员会稀土专项基金(No.IFZ2051210,GFZ20612108)
Abstract: The effect of La3+ on the electrochemical activity and the bioelectrocatalytic activity of catalase(CAT) for the H2O2 reduction was investigated.It is found that when the La3+ concentration is low La3+ can increase the electrochemical and bioelectrocatalytic activity of CAT.When the La3+ concentration is high La3+ can decrease the electrochemical and bioelectrocatalytic activity of CAT.This is due to that La3+ can interact with amino acid residues in the peptide of CAT.The interaction would lead to the change in the conformation of the peptide and then the change in the structure of the heme group.When the La3+ concentration is low,La3+ can increase the non-planarity of the heme group,leading to the increase in the exposure extent of the heme active center,Fe(Ⅲ). Thus,La3+ at the low concentration can increase the electrochemical and the bioelectrocatalytic activity of CAT. When the La3+ concentration is high,La3+ can decrease the non-planarity of the heme group,leading to the decrease in the exposure extent of Fe(Ⅲ).Thus,La3+ at the high concentration can decrease the electrochemical and bioelectrocatalytic activity of CAT.
Keywords: lanthanum ion  catalase  electrochemical reaction  bioelectrocatalytic activity
投稿时间:2007-10-15 修订日期:2007-12-22
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周慧,丁晓岚,陆天虹,黄晓华.La3+对过氧化氢酶电化学和生物电催化活性的影响[J].无机化学学报,2008,24(3):388-392.
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