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CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
内在的性主导了罗多素的可见/近紫外线CD光谱
Gennaro Pescitelli1, Narasimha Sreerama, Piero Salvadori
1Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, Via Risorgimento 35, I-56126 Pisa, Italy.
Journal of the American Chemical Society
|April 19, 2008
概括
罗多素中可见的和近紫外线的圆形二极化 (CD) 波段主要来自视网膜 (retPSB) 染色体的质子化希夫基的固有性. 与蛋白质群体相互作用的贡献很小,特别是在β频段.
科学领域:
- 生物物理学的生物物理.
- 计算化学的计算化学
- 频谱学是一种光谱学.
背景情况:
- rhodopsin 中可见的 (alpha) 和近紫外线 (beta) 圆形二极化 (CD) 带的起源仍在争论中.
- 具体来说,尚不清楚这些带是由于视网膜染色体 (retPSB) 质子化希夫基的内在性,还是由于染色体与周围蛋白质残留物之间的相互作用而产生的.
研究的目的:
- 通过计算来确定内在染色体性和蛋白质合对罗多素CD光谱的贡献.
- 为了阐明罗多普辛中观察到的α-和β-CD波段的主要来源.
主要方法:
- 使用时间依赖密度函数理论 (TDDFT) 和ZINDO方法计算了retPSB染色体的内在CD.
- 采用第一阶扰动理论来评估 retPSB 转换和蛋白质染色体转换 (pi-pi* 和 n-pi*) 之间的合的影响.
- 对八种结构进行了计算,这些结构来自于四种罗多素的晶体结构,与TDDFT对Okada et al. (1U19) 结构产生最可靠的结果.
主要成果:
- 对α和β频段的内在旋转强度分别计算为0.62 +/- 0.00 DBM和0.90 +/- 0.03 DBM.
- 发现与蛋白质组合的贡献为α频段的-0.32 +/- 0.05 DBM,β频段的-0.01 +/- 0.03 DBM.
- 结果表明,retPSB染色体的内在性是两个CD频段的主导因素.
结论:
- 罗多素的可见和近紫外线CD波段主要由retPSB染色体的内在性决定.
- 在retPSB染色体和蛋白质组之间合效应的贡献在α频段显著较小,而在β频段则可以忽略不计.
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