Department of Theoretical Physics, Vilnius University , Saulėtekio al. 9-III, LT-10222 Vilnius, Lithuania.
J Phys Chem B. 2012 Jul 12;116(27):7803-14. doi: 10.1021/jp302817p. Epub 2012 Jun 26.
Using the electrostatic model of intermolecular interactions, we obtain the Frenkel exciton Hamiltonian parameters for the chlorophyll Qy band of a photosynthetic peripheral light harvesting complex LH2 of a purple bacteria Rhodopseudomonas acidophila from structural data. The intermolecular couplings are mostly determined by the chlorophyll relative positions, whereas the molecular transition energies are determined by the background charge distribution of the whole complex. The protonation pattern of titratable residues is used as a tunable parameter. By studying several protonation state scenarios for distinct protein groups and comparing the simulated absorption and circular dichroism spectra to experiment, we determine the most probable configuration of the protonation states of various side groups of the protein.
我们利用分子间相互作用的静电模型，从结构数据中获得了紫色细菌嗜酸红假单胞菌的光合周边光捕获复合物 LH2 的叶绿素 Qy 带的弗伦克尔激子哈密顿参数。分子间耦合主要由叶绿素的相对位置决定，而分子跃迁能量则由整个复合物的背景电荷分布决定。质子化模式被用作可调参数。通过研究不同蛋白质组的几种质子化状态情况，并将模拟的吸收和圆二色光谱与实验进行比较，我们确定了蛋白质各种侧基质子化状态的最可能构型。
