Zietz Burkhard, Prokhorenko Valentin I, Holzwarth Alfred R, Gillbro Tomas
Department of Chemistry, Biophysical Chemistry, Umeå University, SE-90187 Umeå, Sweden.
J Phys Chem B. 2006 Jan 26;110(3):1388-93. doi: 10.1021/jp053467a.
Chlorosomes are the light-harvesting organelles of green bacteria, containing mainly special bacteriochlorophylls (BChls) carrying a 3(1)-hydroxy side chain. Artificial aggregates of BChl c, d, and e have been shown to resemble the native chlorosomes in many respects. They are therefore seen as good model systems for understanding the spectroscopic properties of these antenna systems. We have investigated the excitation energy transfer in artificial aggregates of BChl e, containing small amounts of BChl a as an energy acceptor, using steady-state and time-resolved fluorescence. Global analysis of the kinetic data yields two lifetimes attributable to energy transfer: a fast one of 12-20 ps and a slower one of approximately 50 ps. For comparison, BChl e-containing native chlorosomes of Chlorobium phaeobacteroides and chlorosomes in which the energy acceptor had been degraded by alkaline treatment were also studied. A similar behavior is seen in both the artificial and the natural systems. The results suggest that the artificial aggregates of BChls have a potential as antenna systems in future artificial photonic devices.
叶绿体是绿色细菌的光捕获细胞器，主要包含带有3(1)-羟基侧链的特殊细菌叶绿素（BChls）。已表明BChl c、d和e的人工聚集体在许多方面类似于天然叶绿体。因此，它们被视为理解这些天线系统光谱特性的良好模型系统。我们使用稳态和时间分辨荧光研究了含有少量BChl a作为能量受体的BChl e人工聚集体中的激发能量转移。对动力学数据的全局分析得出两个归因于能量转移的寿命：一个快速的12 - 20皮秒，一个较慢的约50皮秒。为了进行比较，还研究了含BChl e的嗜盐绿菌天然叶绿体以及其中能量受体已通过碱性处理降解的叶绿体。在人工和天然系统中都观察到了类似的行为。结果表明，BChls的人工聚集体在未来的人工光子器件中具有作为天线系统的潜力。
