Gundermann Kathi, Büchel Claudia
Institute of Molecular Biosciences, University of Frankfurt, Frankfurt, Germany.
Biochim Biophys Acta. 2012 Jul;1817(7):1044-52. doi: 10.1016/j.bbabio.2012.03.008. Epub 2012 Mar 14.
Fucoxanthin-chlorophyll complexes (FCP) from the centric diatom Cyclotella meneghiniana were isolated and the trimeric FCPa complex was reconstituted into liposomes at different lipid to Chl a ratios. The fluorescence yield of the complexes in different environments was calculated from room temperature fluorescence emission spectra and compared to the aggregated state of FCPa. FCPa surrounded by high amounts of lipids resembled detergent solubilised complexes and with decreasing lipid levels, i.e. in a situation where protein contacts were increasingly favoured, the fluorescence yield of FCPa gradually decreased. In addition, the yield displayed a strong pH-dependency in case of lower lipid contents. The further reduction in fluorescence yield brought about by the conversion of diadinoxanthin to diatoxanthin was pH independent and only depended on the amount of diatoxanthin synthesised. The implications of these data for non-photochemical quenching in centric diatoms are discussed.
从中心硅藻小环藻中分离出岩藻黄质 - 叶绿素复合物（FCP），并将三聚体FCPa复合物以不同的脂质与叶绿素a比例重构到脂质体中。根据室温荧光发射光谱计算不同环境中复合物的荧光产率，并与FCPa的聚集状态进行比较。被大量脂质包围的FCPa类似于去污剂溶解的复合物，随着脂质水平的降低，即在蛋白质接触越来越受青睐的情况下，FCPa的荧光产率逐渐降低。此外，在脂质含量较低的情况下，产率表现出强烈的pH依赖性。由二异丁基甲酮转化为二丁基甲酮引起的荧光产率的进一步降低与pH无关，仅取决于合成的二丁基甲酮的量。讨论了这些数据对中心硅藻中非光化学猝灭的影响。
