双酸中铁基的光谱特性
Idelisa Ayala1, Kevin Range, Darrin York
1Department of Biochemistry, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota 55108-1022, USA.
Journal of the American Chemical Society
|May 9, 2002
概括
使用紫外线光解产生了反氧活性铁素基. 通过EPR和FT-IR光谱学观察到铁基pi系统和氨基/胺基组之间的意想不到的相互作用.
科学领域:
- 生物化学 生物化学
- 频谱学是一种光谱学.
- 蛋白质基化学 蛋白质基化学
背景情况:
- 反氧活性氨酸残留物对于光系统II等酶的电子转移至关重要.
- 研究蛋白质中氧化还原活性氨基酸的结构对于理解酶机制至关重要.
- 磁共振和振动光谱是这项调查的关键技术.
研究的目的:
- 为了研究紫外线光解产生的铁基的结构.
- 探索基与基中的相邻氨基或基之间的相互作用.
- 为解释基于蛋白质的铁基提供光谱基础.
主要方法:
- 在77K的紫外线光解产生来自多晶氨酸或二的氨酸基.
- 电子磁共振 (EPR) 谱学用于研究基质结构.
- 反应诱导的里叶变换红外 (FT-IR) 光谱与同位素标记 ((13) C, (15) N) 探测结构变化.
主要成果:
- 来自 (13) C 标记型氨酸的 EPR 和 FT-IR 结果证实了中性氨酸基的产生.
- 标记为15N的样本中出乎意料的同位素转移表明了tyrosyl基的pi系统与氨基组之间的相互作用.
- 来自二的光谱显示了tyrosyl基和胺键之间依赖序列的相互作用.
结论:
- 一种自旋两极化机制可能会调解基和氨基/胺基之间的相互作用,通过NH力常数的变化来检测.
- 密度函数计算支持旋转密度转移到氨基和碳酸盐组,受形状的影响.
- 这些发现推动了对生物系统中氧化还原活性铁基的光谱解释.
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