将2-His-1-Glu非海姆铁中心引入髓质蛋白,从而赋予氧化还原酶活性
Ying-Wu Lin1, Natasha Yeung, Yi-Gui Gao
1Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|July 1, 2010
概括
研究人员在精液的肌球蛋白中设计了一种新的2-His-1-Glu金属中心,创建了一个新的氧化还原酶 (NOR) 模型. 这种工程蛋白与铜或铁具有显著的NOR活性,为酶功能提供了洞察力.
科学领域:
- 生物化学 生物化学
- 酶工程是什么? 酶工程是什么?
- 结构生物学 结构生物学
背景情况:
- 非海姆铁酶利用一个保存的2-His-1-Glu金属中心.
- 精卵菌球蛋白 (swMb) 是一种特征很好的蛋白质,可以进行工程.
研究的目的:
- 为了设计一个2-His-1-Glu金属中心进入swMb.
- 为了研究不同金属离子的工程蛋白质的氧化还原酶 (NOR) 活性.
- 通过结构和光谱研究来阐明NOR活动的机制.
主要方法:
- 用于设计swMb (Fe(B) Mb(-His)) 中的2-His-1-Glu金属中心,使用了位点定向的突变发生.
- 高分辨率的X射线晶体学确定了Cu (II) -CN (II) -Fe (B) -Mb (His) 的结构.
- 电子磁共振 (EPR) 光谱分析了氧化还原过程中的反应中间体.
主要成果:
- 一个功能性的2-His-1-Glu金属中心成功地被设计成swMb.
- (I) - 铁 (B) - (His) 和铁 (II) - 铁 (B) - (Mb) - (His) 均表现出氧化还原酶 (NOR) 活性,而铜表现出更高的活动.
- 结构和EPR数据揭示了Cu和Fe结合酶的独特中间体,突出显示了金属连接体和结合金属的作用.
结论:
- 工程化Fe(B) Mb(-His) 作为NOR.的新型蛋白质模型.
- 工程金属连接体 (Glu29) 和结合金属离子 (Cu或Fe) 都对NOR活动至关重要.
- 这项工作为新发现的gNOR酶家族提供了洞察力.
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