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来自高热性细菌Aquifex aeolicus的膜结合酶I:酶激活,氧化还原中间体和耐氧性
Maria-Eirini Pandelia1, Vincent Fourmond, Pascale Tron-Infossi
1Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D45470, Mülheim a.d. Ruhr, Germany.
Journal of the American Chemical Society
|May 6, 2010
概括
来自Aquifex aeolicus的膜结合酶显示出增强的氧气耐受性和更快的活性,使其更适合H2氧化. 它的活性部位与氧气的相互作用使用先进的光谱学进行了详细研究.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 生物物理学的生物物理.
背景情况:
- 来自Aquifex aeolicus的膜结合酶 (Hase I) 是一种因高温稳定性和耐氧性而闻名的氧化还原酶.
- 了解其催化机制和与氧的相互作用对于生物技术应用至关重要.
研究的目的:
- 为了研究Aquifex aeolicus Hase I与分子氧的相互作用.
- 阐明酶活性部位的结构细节和氧化还原化学.
- 了解氧气失活和重新激活的机制.
主要方法:
- 蛋白膜电化学被用来研究催化活性和氧相互作用.
- 福里埃变换红外光谱 (FTIR) 与现场电化学相结合,确定了活性部位的结构细节和氧化还原状态.
主要成果:
- [NiFe]活性位点协调与标准化酶相似,具有保留的Fe ((CN)) ((2) CO部分.
- 检测到四种催化中间体 (Ni-B,Ni-SI(a),Ni-C,Ni-R),与中点潜力相比,中性化酶的潜力转移为正值.
- 氧气通过在活性部位形成无活性的Ni-B状态来抑制酶,类似于无氧无活化.
结论:
- 由于其氧化还原潜力,Aquifex aeolicus Hase I更适合于H2氧化而不是生产.
- 从非活性Ni-B状态的重新激活速度明显快于中性化酶,尽管热力学不利.
- 这项研究提供了对这种高热友酶的酶机制和氧耐受性的洞察.
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