Enhancing the spectral range of plant and bacterial light-harvesting pigment-protein complexes with various synthetic chromophores incorporated into lipid vesicles.
Enhancing the spectral range of plant and bacterial light-harvesting pigment-protein complexes with various synthetic chromophores incorporated into lipid vesicles.
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通过将各种合成发色团掺入脂质囊泡中，增强植物和细菌光捕获色素-蛋白质复合物的光谱范围。
DOI：
10.1016/j.jphotobiol.2022.112585
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Hancock AM
中科院分区：
文献类型：
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作者：
Hancock AM
在光合生物中发现的捕光（LH）色素蛋白复合物具有高效吸收太阳能并将其转移到反应中心复合物的作用。LH复合物含有一套色素，每种色素都吸收特定波长的光，然而，任何一种蛋白质复合物中色素的天然组合都不能覆盖太阳辐射的全部范围。在这里，我们提供了五种不同的有机“染料”分子（德克萨斯红，ATTO，Cy 7，DiI，DiR）的相对有效性的深入比较，以提高两种不同的LH膜蛋白复合物（主要LHCII从植物和LH 2从紫色光养细菌）的吸收范围。蛋白脂质体自组装从定义的混合物的脂质，蛋白质和染料分子和它们的光学性质进行了定量的吸收和荧光光谱。脂质连接的染料和替代的亲脂性染料被发现是有效的激发能量供体LH蛋白质复合物，而不需要直接的化学或通用的蛋白质修饰。Förster理论参数（例如，光谱重叠），并发现其是有效染料-蛋白质组合的良好预测因子。在测试的最高染料与蛋白质的比例（超过20：1），在整个光谱范围内整合的有效吸收强度增加到其天然水平的1.80%的LH复合物。亲脂性染料可以插入到预形成的膜，虽然它们的有效性被发现取决于有利的物理化学相互作用。最后，我们证明，这些染料也可以有效地增加光谱范围的表面支持模型的光合膜，使用荧光显微镜。这项工作的结果提供了深入了解自组装脂质膜的效用和LH复合物与不同染料相互作用的巨大灵活性。
The Light-Harvesting (LH) pigment-protein complexes found in photosynthetic organisms have the role of absorbing solar energy with high efficiency and transferring it to reaction centre complexes. LH complexes contain a suite of pigments that each absorb light at specific wavelengths, however, the natural combinations of pigments within any one protein complex do not cover the full range of solar radiation. Here, we provide an in-depth comparison of the relative effectiveness of five different organic “dye” molecules (Texas Red, ATTO, Cy7, DiI, DiR) for enhancing the absorption range of two different LH membrane protein complexes (the major LHCII from plants and LH2 from purple phototrophic bacteria). Proteoliposomes were self-assembled from defined mixtures of lipids, proteins and dye molecules and their optical properties were quantified by absorption and fluorescence spectroscopy. Both lipid-linked dyes and alternative lipophilic dyes were found to be effective excitation energy donors to LH protein complexes, without the need for direct chemical or generic modification of the proteins. The Förster theory parameters (e.g., spectral overlap) were compared between each donor-acceptor combination and found to be good predictors of an effective dye-protein combination. At the highest dye-to-protein ratios tested (over 20:1), the effective absorption strength integrated over the full spectral range was increased to ∼180% of its natural level for both LH complexes. Lipophilic dyes could be inserted into pre-formed membranes although their effectiveness was found to depend upon favourable physicochemical interactions. Finally, we demonstrated that these dyes can also be effective at increasing the spectral range of surface-supported models of photosynthetic membranes, using fluorescence microscopy. The results of this work provide insight into the utility of self-assembled lipid membranes and the great flexibility of LH complexes for interacting with different dyes.