...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Complexes of horseradish peroxidase with formate, acetate, and carbon monoxide.
【24h】

Complexes of horseradish peroxidase with formate, acetate, and carbon monoxide.

机译：辣根过氧化物酶与甲酸，乙酸盐和一氧化碳的复合物。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Carbon monoxide, formate, and acetate interact with horseradish peroxidase (HRP) by binding to subsites within the active site. These ligands also bind to catalases, but their interactions are different in the two types of enzymes. Formate (notionally the "hydrated" form of carbon monoxide) is oxidized to carbon dioxide by compound I in catalase, while no such reaction is reported to occur in HRP, and the CO complex of ferrocatalase can only be obtained indirectly. Here we describe high-resolution crystal structures for HRP in its complexes with carbon monoxide and with formate, and compare these with the previously determined HRP-acetate structure [Berglund, G. I., et al. (2002) Nature 417, 463-468]. A multicrystal X-ray data collection strategy preserved the correct oxidation state of the iron during the experiments. Absorption spectra of the crystals and electron paramagnetic resonance data for the acetate and formate complexes in solution correlate electronic states with the structural results. Formate in ferric HRP and CO in ferrous HRP bind directly to the heme iron with iron-ligand distances of 2.3 and 1.8 A, respectively. CO does not bind to the ferric iron in the crystal. Acetate bound to ferric HRP stacks parallel with the heme plane with its carboxylate group 3.6 A from the heme iron, and without an intervening solvent molecule between the iron and acetate. The positions of the oxygen atoms in the bound ligands outline a potential access route for hydrogen peroxide to the iron. We propose that interactions in this channel ensure deprotonation of the proximal oxygen before binding to the heme iron.
机译：一氧化碳，甲酸和乙酸盐通过与活性位点内的亚位点结合，与辣根过氧化物酶（HRP）相互作用。这些配体也与过氧化氢酶结合，但是在两种类型的酶中它们的相互作用是不同的。在过氧化氢酶中，甲酸酯（名义上是一氧化碳的“水合”形式）被化合物I氧化为二氧化碳，而据报道在HRP中未发生这种反应，并且仅可间接获得铁过氧化氢酶的CO络合物。在这里，我们描述了HRP与一氧化碳和甲酸盐的配合物的高分辨率晶体结构，并将其与先前确定的HRP-乙酸盐结构进行了比较[Berglund，G.I。，等人。 （2002）Nature 417，463-468]。在实验过程中，多晶X射线数据收集策略保留了铁的正确氧化态。溶液中乙酸盐和甲酸盐配合物的晶体吸收光谱和电子顺磁共振数据将电子态与结构结果相关联。铁HRP中的甲酸盐和亚铁HRP中的一氧化碳直接与血红素铁结合，铁配体距离分别为2.3和1.8A。 CO不会与晶体中的三价铁结合。与血红素平面平行的乙酸铁与血红素平面平行结合，其血红素铁中的羧酸根基团为3.6 A，并且铁和乙酸盐之间没有溶剂分子。结合的配体中氧原子的位置勾勒出过氧化氢与铁的潜在接触途径。我们建议该通道中的相互作用确保在与血红素铁结合之前近端氧的去质子化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号