Koolhaas M H, van der Zwan G, van Mourik F, van Grondelle R
Department of Theoretical and Physical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands.
Biophys J. 1997 Apr;72(4):1828-41. doi: 10.1016/S0006-3495(97)78829-5.
The origin of the nonconservative nature of the circular dichroism (CD) spectrum of bacteriochlorophyll dimers is investigated. It is shown that coupling between the Qy and Qx transitions can, under rather restricting circumstances, lead to an asymmetrical CD spectrum: only for a limited set of relative orientations of the monomers within the dimer is the spectrum found to be asymmetrical. The relation between intensity and asymmetry of the CD spectrum is elucidated. The results are applied to the B820 subunit of the LH1 antenna system and subsequently to the antenna system LH1 itself. Differences in the geometry of the BChls in LH1 versus the LH2 structure are discussed.
研究了细菌叶绿素二聚体圆二色性（CD）光谱非保守性质的起源。结果表明，在相当严格的条件下，Qy和Qx跃迁之间的耦合可导致不对称的CD光谱：仅当二聚体内单体的相对取向为有限的一组时，才会发现光谱不对称。阐明了CD光谱强度与不对称性之间的关系。将结果应用于LH1天线系统的B820亚基，随后应用于天线系统LH1本身。讨论了LH1与LH2结构中细菌叶绿素（BChls）几何结构的差异。
