Oakley Mark T, Hirst Jonathan D
School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
J Am Chem Soc. 2006 Sep 27;128(38):12414-5. doi: 10.1021/ja0644125.
Charge-transfer transitions in proteins play a key role in many biophysical processes, from the behavior of redox proteins to photochemical reactions. We present ab initio calculations on a model dipeptide and more approximate calculations of the electronic excited states of proteins which, taken together, provide the most definitive assignment and characterization of charge-transfer transitions in proteins to date. We have calculated from first principles the electronic circular dichroism (CD) spectra of 31 proteins on the basis of their structures. Compared to previous studies, we achieve more accurate calculated CD spectra between 170 and 190 nm, owing mainly to the importance in alpha-helices of a charge-transfer transition from the lone pair on one peptide group to the pi* orbital on the next peptide group.
蛋白质中的电荷转移跃迁在许多生物物理过程中起着关键作用，从氧化还原蛋白的行为到光化学反应。我们对一个模型二肽进行了从头算，并对蛋白质的电子激发态进行了更近似的计算，这些计算共同提供了迄今为止对蛋白质中电荷转移跃迁最明确的归属和表征。我们根据31种蛋白质的结构，从第一性原理计算了它们的电子圆二色（CD）光谱。与之前的研究相比，我们在170至190nm之间获得了更准确的计算CD光谱，这主要归功于α-螺旋中从一个肽基团上的孤对电子到下一个肽基团上的π*轨道的电荷转移跃迁的重要性。
