Cianfarani Niccolò, Calcinoni Andrea, Agostini Alessandro, Elias Eduard, Bortolus Marco, Croce Roberta, Carbonera Donatella
Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy.
Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, De Boelelaan 1100, 1081 HZ Amsterdam, The Netherlands.
J Phys Chem Lett. 2025 Feb 20;16(7):1720-1728. doi: 10.1021/acs.jpclett.4c03463. Epub 2025 Feb 10.
Chlorophyll (Chl ) can be successfully introduced in reconstituted LHCII with minimal interference with the energy equilibration processes within the complex, thereby facilitating the development of plant light-harvesting complexes (LHCs) with enhanced capabilities for light absorption in the far-red spectrum. In this study, we address whether Chl introduction affects LHCII's ability to protect itself from photo-oxidation, a crucial point for successfully exploiting modified complexes to extend light harvesting in plants. Here we focus on incorporating Chl into Lhcb1 (the monomeric unit of LHCII), specifically studying the Chl triplet quenching by carotenoids using time-resolved electron paramagnetic resonance (TR-EPR) and optically detected magnetic resonance (ODMR). We also characterize the A2 mutant of LHCII, in which the Chl 612 is removed, to assist in determining the triplet quenching sites on the Lhcb1 complex reconstituted with Chl . We found that far-red absorbing LHCII incorporating Chl maintains the efficiency of the photoprotective process.
叶绿素（Chl ）能够成功引入重组的光系统II捕光复合体（LHCII）中，且对该复合体内部的能量平衡过程干扰极小，从而有助于开发具有增强远红光吸收能力的植物捕光复合体（LHCs）。在本研究中，我们探讨了引入Chl 是否会影响LHCII保护自身免受光氧化的能力，这是成功利用修饰后的复合体来扩展植物光捕获的关键问题。在这里，我们专注于将Chl 掺入Lhcb1（LHCII的单体单元），具体使用时间分辨电子顺磁共振（TR-EPR）和光探测磁共振（ODMR）研究类胡萝卜素对Chl 三重态的猝灭作用。我们还对LHCII的A2突变体进行了表征，其中Chl 612被去除，以帮助确定用Chl 重构的Lhcb1复合体上的三重态猝灭位点。我们发现，掺入Chl 的吸收远红光的LHCII保持了光保护过程的效率。
