Gingrich J C, Blaha L K, Glazer A N
J Cell Biol. 1982 Feb;92(2):261-8. doi: 10.1083/jcb.92.2.261.
Synechocystis 6701 phycobilisomes contain phycoerythrin, phycocyanin, and allophycocyanin in a molar ratio of approximately 2:2:1, and other polypeptides of 99-, 46-, 33.5-, 31.5-, 30.5-, and 27-kdaltons. Wild-type phycobilisomes consist of a core of three cylindrical elements in an equilateral array surrounded by a fanlike array of six rods each made up of 3-4 stacked disks. Twelve nitrosoguanidine-induced mutants were isolated which produced phycobilisomes containing between 0 and 53% of the wild-type level of phycoerythrin and grossly altered levels of the 30.5- and 31.5-kdalton polypeptides. Assembly defects in these mutant particles were shown to be limited to the phycoerythrin portions of the rod substructures of the phycobilisome. Quantitative analysis of phycobilisomes from wild-type and mutant cells, grown either in white light or chromatically adapted to red light, indicated a molar ratio of the 30.5- and 31.5-kdalton polypeptides to phycoerythrin of 1:6, i.e., one 30.5- or one 31.5-kdaltons polypeptide per (alpha beta)6 phycoerythrin hexamer. Presence of the phycoerythrin-31.5-kdalton complex in phycobilisomes did not require the presence of the 30.5-kdalton polypeptide. The converse situation was not observed. These and earlier studies (R. C. Williams, J. C. Gingrich, and A. N. Glazer. 1980. J. Cell Biol. 85:558-566) show that the average rod in wild type Synechocystis 6701 phycobilisomes consists of four stacked disk-shaped complexes: phycocyanin (alpha beta)6-27 kdalton, phycocyanin (alpha beta)6-33.5 kdalton, phycoerythrin (alpha beta)6-31.5 kdalton, and phycoerythrin-30.5 kdalton, listed in order starting with the disk proximal to the core.
聚球藻6701的藻胆体含有藻红蛋白、藻蓝蛋白和别藻蓝蛋白，其摩尔比约为2:2:1，还含有99、46、33.5、31.5、30.5和27千道尔顿的其他多肽。野生型藻胆体由三个呈等边阵列的圆柱形元件组成的核心以及由六个棒状结构组成的扇形阵列包围，每个棒状结构由3 - 4个堆叠的圆盘组成。分离出了12个经亚硝基胍诱导的突变体，它们产生的藻胆体中藻红蛋白含量在野生型水平的0%至53%之间，并且30.5和31.5千道尔顿多肽的水平发生了显著改变。这些突变颗粒中的组装缺陷被证明仅限于藻胆体棒状亚结构的藻红蛋白部分。对在白光下生长或经色适应于红光的野生型和突变体细胞的藻胆体进行定量分析表明，30.5和31.5千道尔顿多肽与藻红蛋白的摩尔比为1:6，即每(αβ)6藻红蛋白六聚体中有一个30.5或一个31.5千道尔顿的多肽。藻胆体中藻红蛋白 - 31.5千道尔顿复合物的存在不需要30.5千道尔顿多肽的存在。但未观察到相反的情况。这些研究以及早期的研究（R.C.威廉姆斯、J.C.金里奇和A.N.格拉泽。1980年。《细胞生物学杂志》85:558 - 566）表明，野生型聚球藻6701藻胆体中的平均棒状结构由四个堆叠的盘状复合物组成：藻蓝蛋白(αβ)6 - 27千道尔顿、藻蓝蛋白(αβ)6 - 33.5千道尔顿、藻红蛋白(αβ)6 - 31.5千道尔顿和藻红蛋白 - 30.5千道尔顿，从靠近核心的圆盘开始按顺序列出。
