循环和构成对辅因子的氧化形式的影响
Douglas R Gisewhite1, Jing Yang2, Benjamin R Williams1
1Department of Chemistry , Bryn Mawr College , Bryn Mawr , Pennsylvania 19010 , United States.
Journal of the American Chemical Society
|September 12, 2018
概括
在多 (MPT) 连接物中,pyran环封闭电子合中心,调节酶活性. 这种分子开关机制调整了pyranopterin酶的氧化还原特性.
科学领域:
- 生物有机化学
- 酶机制
- 有机金属化学
背景情况:
- 单核和酶利用多 (MPT) 连接体.
- MPT 具有与甲烯基组结合的金属结合二醇酸盐.
- 假设MPT的pyran循环/裂变可以调节金属中心的反应性.
研究的目的:
- 调查MPTpyran循环化如何调节dithiolene和pterin部分之间的电子通信.
- 确定pyran循环如何改变催化场的电子环境.
- 设计Mo-MPT辅因子的小分子模型进行详细研究.
主要方法:
- 循环电压测量
- 振动光谱 (FT-IR和拉曼)
- 电子吸收光谱学
- 射线吸收光谱学
主要成果:
- 皮兰环的闭合会导致MoO伸展频率和MoV/IV降低潜力的明显变化.
- 一个dihydropyranopterin连接体通过一个coplanar形状电子连接到Mo-dithiolene组.
- 一个强大的dithiolene → pterin电荷转移是合系统的光谱特征.
- 缺少pyran桥导致pterin旋转,使系统脱.
结论:
- 在Mo-MPT模型中,Pyran循环电子合了烯和滴醇单元.
- 这种合使得缺电子的可以调节环境.
- MPT pyran 循环/切割作为一个分子开关,调节 pyranopterin 酶的氧化还原特性.
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