在光活性黄色蛋白中进行光异构和质子转移
Michael J Thompson1, Donald Bashford, Louis Noodleman
1Department of Molecular Biology, MB4, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
Journal of the American Chemical Society
|July 3, 2003
概括
计算研究揭示了对光活性黄色蛋白 (PYP) 光循环的新见解. 我们澄清了早期的中间体,并挑战了关于染色体质子动态的现有理论.
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:
- 光活性黄色蛋白 (PYP) 是一种细菌光传感器,采用了对库马里尔酸染色体.
- PYP的光循环涉及由蓝光吸收引发的形状变化.
- 之前的研究对早期光循环中间体和染色体质突产生不确定性.
研究的目的:
- 通过计算来研究PYP光循环的早期中间体.
- 解决结构数据和光谱测量之间的争议.
- 阐明染色体光异构化和质子转移动态.
主要方法:
- 使用了时间依赖密度函数理论 (TDDFT).
- 计算包括光异构化和质子转移的能量概况.
- 激发能被计算出来以识别光循环中间体.
主要成果:
- 用于光异构化计算的潜在能量表面与实验光谱参数一致.
- 计算的激发能量支持将一个冷捕获的中间体分配到PYP (B) (I) (0)).
- 在不同温度下PYP (B) 光谱的差异是由染色体质子状态解释的.
结论:
- 在室温下,PYP(B) 中间体具有主要是无质子化的染色体,挑战了先前的信念.
- 在PYP(L) 中介的染色体被计算确定为deprotonated,同意实验.
- 在Glu46和染色体之间质子的移动性比以前认为的要高,影响了PYP的中间理解.
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