基质与胺酸合成酶2相互作用的光谱研究,一种多功能α-KG依赖的非血红铁酶:与机制和反应性相关联
J Zhou1, W L Kelly, B O Bachmann
1Contribution from the Departments of Chemistry, Stanford University, Stanford, California 94305, USA.
Journal of the American Chemical Society
|July 27, 2001
概括
克拉瓦马纳酸合成酶2 (CS2) 使用一种铁性活性位点来催化多个氧化反应. 铁的协调不和是合反应和酶功能的关键.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 结构生物学 结构生物学
背景情况:
- 克拉夫马纳酸合成酶2 (CS2) 是一种多功能酶,对克拉夫兰酸生物合成至关重要.
- 它催化了几种氧化反应,使用单个铁性活性位点和α-谷氨酸 (alpha-KG) 作为辅基.
研究的目的:
- 阐明CS2在其催化循环期间的结构功能关系.
- 研究铁协调在CS2多样化的酶活性中的作用.
主要方法:
- 光谱技术包括吸收,循环二元化 (CD),磁性循环二元化 (MCD) 和可变温度,可变场 MCD (VTVH MCD).
- 酶-基质和酶-辅基质相互作用的分析.
主要成果:
- 休息的CS2/Fe(II) 呈现出六坐标活性位点;α-KG结合得非常明显.
- 在基质和α-KG结合时,活性位变为五坐标,促进合反应.
- 六坐标铁性物种的不同程度与脱反应和酶失活相关.
- 在不同的基质复合体中观察到具有相似结构的五坐标铁性物种.
结论:
- 在CS2中Fe(II) 位点的协调性不和对于合α-KG氧化脱氧化与基质氧化至关重要.
- 酶调节水与铁性物种结合的影响反应性.
- 了解这些机制,可以了解CS2的催化多功能性.
相关概念视频
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