Section of Plant Biology, Cornell University, Ithaca, New York 14853.
Plant Physiol. 1986 Mar;80(3):732-8. doi: 10.1104/pp.80.3.732.
Three pigment-protein complexes were isolated from the marine diatom Phaeodactylum tricornutum (Bohlin) by treatment of thylakoid membrane fragments with 1% Triton X-100 at 4 degrees C followed by centrifugation on sucrose density gradients. The major complex contains chlorophyll a, c(1), c(2), and the carotenoid fucoxanthin (chlorophyll a: c(1): c(2): fucoxanthin = 1.0: 0.09: 0.28: 2.22) bound to an apoprotein doublet of 16.4 and 16.9 kilodaltons. This complex accounts for >70% of the total pigment and 20 to 40% of the protein in the thylakoid membranes. Efficient coupling of chlorophyll c and fucoxanthin absorption to chlorophyll a fluorescence supports a light-harvesting function for the complex. A minor light-harvesting complex containing chlorophyll a, c(1), and c(2) but no fucoxanthin (chlorophyll a: c(1): c(2) = 1.0: 0.23: 0.26) was also isolated at Triton: chlorophyll a ratios between 20 and 40. These pigments are bound to a similar molecular weight apoprotein doublet. The third complex isolated was the P700-chlorophyll a protein, the reaction center of photosystem I, which showed characteristics similar to those isolated from other plant sources. The yield of the chlorophyll a/c-fucoxanthin complex was shown to respond strongly to changes in light intensity during growth, accounting for most of the changes in cellular pigmentation.
三个色素-蛋白复合物从海洋硅藻三角褐指藻（Bohlin）中分离出来，方法是用 1%的 Triton X-100 在 4 摄氏度处理类囊体膜碎片，然后在蔗糖密度梯度上离心。主要的复合物含有叶绿素 a、c(1)、c(2)和类胡萝卜素叶黄素（叶绿素 a：c(1)：c(2)：叶黄素=1.0:0.09:0.28:2.22）与 16.4 和 16.9 千道尔顿的脱辅基蛋白二聚体结合。该复合物占类囊体膜中总色素的>70%和蛋白质的 20-40%。叶绿素 c 和叶黄素吸收与叶绿素 a 荧光的有效偶联支持该复合物的光捕获功能。还分离到一个含有叶绿素 a、c(1)和 c(2)但不含叶黄素的较小光捕获复合物（叶绿素 a：c(1)：c(2)=1.0:0.23:0.26），在 Triton：叶绿素 a 比为 20-40 时也可以分离出来。这些色素与类似分子量的脱辅基蛋白二聚体结合。分离出的第三个复合物是 P700-叶绿素 a 蛋白，是光系统 I 的反应中心，其特征与从其他植物来源分离出的复合物相似。叶绿素 a/c-叶黄素复合物的产量被证明对生长过程中的光强变化有强烈的响应，占细胞色素着色变化的大部分。
