Section de Biophysique des Protéines et des Membranes, DBCM CEA, 91191, Gif-sur-Yvette, France.
Photosynth Res. 1996 Oct;50(1):5-10. doi: 10.1007/BF00018216.
The publication of a structure for the peripheral light-harvesting complex of a purple photosynthetic bacterium (McDermott et al. (1995), Nature 374: 517-521) provides a framework within which we can begin to understand various functional aspects of these complexes, in particular the relationship between the structure and the red-shift of the bacteriochlorophyll Qy transition. In this article we describe calculations of some of the spectral properties expected for an array of chromophores with the observed geometry. We report the stability of the calculated absorption spectrum to minor structural alterations, and deduce that the observed red shift of the 850 nm Qy transition in the B800-850 antenna complexes is about equally attributable to chromophore-chromophore and chromophore-protein interactions, while chromophore-chromophore interactions predominate in generating the red-shift of the 820 nm Qy transition in B800-820 type peripheral liggt-harvesting complexes. Finally we suggest that the red shift in the absorbance of the monomeric Bchl a found in antenna complexes to 800 nm, from 770 nm as observed in most solvents, is largely attributable to a hydrogen bond with the 2-acetyl group of this chromophore.
紫细菌外周捕光复合物结构的公布（McDermott 等人，1995 年，《自然》374：517-521）为我们理解这些复合物的各种功能方面提供了一个框架，特别是结构与细菌叶绿素 Qy 跃迁红移之间的关系。在本文中，我们描述了用观察到的几何形状对一系列发色团的一些光谱性质的计算。我们报告了计算吸收光谱对微小结构变化的稳定性，并推断出在 B800-850 天线复合物中观察到的 850nm Qy 跃迁的红移大约同等归因于发色团-发色团和发色团-蛋白质相互作用，而发色团-发色团相互作用在产生 B800-820 型外周 liggt-捕光复合物中 820nm Qy 跃迁的红移中占主导地位。最后，我们认为在天线复合物中观察到的单体 Bchl a 的吸光度从 770nm（在大多数溶剂中观察到）红移到 800nm，主要归因于与该发色团的 2-乙酰基的氢键。
