青素作为一个蛋白质支架,用于一个低坐标的非海姆铁位点,具有小分子结合口袋
Matthew P McLaughlin1, Marius Retegan, Eckhard Bill
1Department of Chemistry, University of Rochester, Rochester, New York 14618, United States.
Journal of the American Chemical Society
|November 22, 2012
概括
伪菌是空中菌的青色素.
科学领域:
- 生物化学 生物化学
- 生物有机化学 生物有机化学
- 结构生物学 结构生物学
背景情况:
- 伪菌 (Pseudomonas aeruginosa azurin) 是一种含铜的蛋白质,参与电子转移.
- 了解蛋白质中的金属离子的协调化学作用对于阐明它们的功能至关重要.
- 铁与氨酸的结合提供了对金属蛋白活性部位特性的洞察力.
研究的目的:
- 为了描述Pseudomonas aeruginosa azurin apoprotein的铁 (II) 复合体.
- 调查结合铁的协调环境和电子特性 (II).
- 为了探索突变对离子与铁的结合的影响 (II) 中心.
主要方法:
- 电子吸收光谱学 电子吸收光谱学
- 莫斯巴乌尔光谱法是使用的.
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
- 在X射线晶体学.
- 量子化学计算中的量子化学计算.
- 局部导向的突变发生.
主要成果:
- 铁 (II) 与 Pseudomonas aeruginosa azurin apoprotein 形成了一个稳定的 1:1 复合体.
- 铁(II) 离子在一个低坐标的伪四面体环境中紧密结合,其中包括His,Cys和Gly45.5.
- 铁 (II) 复合体是氧化还原不活性的.
- 量子化学计算揭示了一个高旋转的铁 (II) 状态,其中一个双重占用的d (z2) 轨道.
- Met121转变为Ala的突变会产生一个可逆离子结合的口袋 (例如,亚化物,化物).
- 亚化物结合产生高旋转铁 (II) 复合体,而化物结合产生低旋转铁 (II) 复合体.
结论:
- Pseudomonas aeruginosa azurin 的阿波蛋白可以在一个独特的协调环境中结合铁.
- 铁 (II) 复合物的电子和结构性质表明一个稳定的,氧化还原无活性状态.
- 改造的Met121Ala突变体展示了调节金属位属性和引入离子结合能力的潜力.
相关概念视频
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