应用化学 ›› 2009, Vol. 26 ›› Issue (11): 1310-1314.

• 研究论文 • 上一篇    下一篇

Eu3+对过氧化氢酶生物催化活性的影响1

史红霞,周慧,陆天虹,黄晓华*   

  1. (江苏省生物功能材料重点实验室,南京师范大学化学与环境科学学院 南京 210097)
  • 收稿日期:2008-10-30 修回日期:2009-01-15 出版日期:2009-11-10 发布日期:2009-11-10
  • 通讯作者: 黄晓华,女,教授; E-mail:wxxhhuang@yahoo.com; 研究方向:生物无机化学
  • 基金资助:
    国家自然科学基金(20471030)国家发改委稀土专项基金(IFZ2051210,GFZ20612108)资助项目

Effect of Eu3+ on Biocatalytic Activity of Catalase1

SHI Hong-Xia, ZHOU Hui, LU Tian-Gong, HUANG Xiao-Hua*   

  1. (Jiangsu Key Laboratory of Biofunctional Materials,College of Chemistry and
    Environmental Science,Nanjing Normal University,Nanjing 210097)
  • Received:2008-10-30 Revised:2009-01-15 Published:2009-11-10 Online:2009-11-10

摘要:

为了了解稀土微肥使植物增产的化学机理,用紫外-可见(UV-Vis)吸收光谱、同步荧光光谱和电化学方法法研究了Eu3+与过氧化氢酶(CAT)的相互作用。结果表明,由于稀土离子易与O键合,因此,Eu3+主要与CAT肽链上的氨基酸残基中的羰基氧配位,引起肽链构象的变化,而构象的变化又会诱导CAT中的血红素结构的变化。当Eu3+浓度低时,Eu3+与CAT发生相互作用能使血红素的非平面性增加,转而使血红素中活性中心Fe(III)的暴露程度增加,因此,使CAT的电化学活性和对H2O2还原的电催化活性提高。但当Eu3+的浓度高时,Eu3+会使CAT中血红素的非平面性降低,使血红素中活性中心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。这说明不同浓度的Eu3+对CAT的生物活性的影响不同,所以选择适当的浓度的Eu3+对植物的生长具有促进作用。

关键词: 过氧化氢酶, 铕, 过氧化氢, 生物电催化活性, 构象

Abstract:

In order to understand the chemical mechanism of the increase in the output of plants by rare earth fertilizers, the interaction between Eu3+ and catalase (CAT) was investigated with the UV-Vis absorption spectroscopy, synchronous fluorescent spectroscopy and electrochemical method. The results indicated that Eu3+ mainly interacts with the carbonyl oxygen in the amino acid residues of the peptide chain of CAT because rare earth ions are easy to coordinate with O, causing the change in the peptide conformation and in turn the change in the structure of the heme group of CAT. When the concentration of Eu3+ is low the interaction between Eu3+ and CAT would introduce the increase in the non-planarity of the heme group of CAT and then the increase in the exposure extent of the active center, Fe(III), leading to the increase in the electrochemical activity and the bioelectrocatalytic activity of CAT for the H2O2 reduction. However, when the concentration of Eu3+ is high Eu3+ would decrease the non-planarity of the heme group and then the exposure extent of Fe(III), leading to the decrease in the electrochemical and the bioelectrocatalytic activities of CAT. These results illustrated that the effects of the different concentration of Eu3+ on the bioactivity of CAT are different. Therefore, selecting the suitable concentration of Eu3+ can promote the growth of plants.

Key words: Catalase, Europium, Hydrogen peroxide, Bioelectrocatalytic activity, Conformation

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