Füglistaller P, Suter F, Zuber H
Biol Chem Hoppe Seyler. 1986 Jul;367(7):601-14. doi: 10.1515/bchm3.1986.367.2.601.
Phycobilisomes from the cyanobacterium Mastigocladus laminosus cultured in white and red light were isolated and compared with respect to the phycoerythrocyanin (PEC) and linker polypeptide contents. It was verified that the production of PEC is induced by low light intensities. A PEC complex, (alpha PEC beta PEC)6LR34.5,PEC, and a phycocyanin (PC) complex, (alpha PC beta PC)6LR34.5,PC, were isolated from phycobilisomes by Cellex-D anion exchange chromatography and sucrose density gradient centrifugation. The absorption and fluorescence emission maxima of the PEC complex are at 575 and 620 nm and those of the PC complex are at 631 and 647 nm, respectively. The extinction coefficients of the two complexes were determined. From different experiments it was concluded that PEC is present as a hexameric complex, (alpha PEC beta PEC)6LR34.5,PEC, in the phycobilisome. The two linker polypeptides LR34.5,PEC and LR34.5,PC were isolated from their phycobiliprotein complexes by gel filtration on Bio-Gel P-100 in 50% formic acid. A 5-kDa terminal segment of both linker polypeptides was found to influence the hexamer formation of the phycobiliproteins. The same segments have been described to be responsible for the hexamer-hexamer linkage (Yu, M.-H. & Glazer, A.N. (1982) J. Biol. Chem. 257, 3429-3433). A 8.9-kDa linker polypeptide, LR(C)8.9, was isolated from a PEC fraction of the Cellex-D column by Bio-Gel P-100 gel filtration in 50% formic acid. Localisation of this protein within the phycobilisome was attempted. Its most probable function is to terminate the phycobilisomal rods at the end distal to the allophycocyanin core.
分离在白光和红光下培养的蓝藻 Mastigocladus laminosus 的藻胆体，并比较藻红胆青素（PEC）和连接多肽的含量。已证实低光强度可诱导 PEC 的产生。通过 Cellex-D 阴离子交换色谱和蔗糖密度梯度离心从藻胆体中分离出 PEC 复合物（αPECβPEC）6LR34.5,PEC 和藻蓝蛋白（PC）复合物（αPCβPC）6LR34.5,PC。PEC 复合物的吸收和荧光发射最大值分别在 575 和 620 nm，PC 复合物的吸收和荧光发射最大值分别在 631 和 647 nm。测定了两种复合物的消光系数。从不同实验得出，PEC 在藻胆体中以六聚体复合物（αPECβPEC）6LR34.5,PEC 的形式存在。通过在 50%甲酸中于 Bio-Gel P-100 上进行凝胶过滤，从其藻胆蛋白复合物中分离出两种连接多肽 LR34.5,PEC 和 LR34.5,PC。发现两种连接多肽的 5 kDa 末端片段会影响藻胆蛋白的六聚体形成。相同的片段已被描述为负责六聚体 - 六聚体连接（Yu，M.-H.和 Glazer，A.N.（1982）J. Biol. Chem. 257，3429 - 3433）。通过在 50%甲酸中于 Bio-Gel P-100 上进行凝胶过滤，从 Cellex-D 柱的 PEC 组分中分离出 8.9 kDa 的连接多肽 LR(C)8.9。尝试确定该蛋白在藻胆体中的定位。其最可能的功能是在远离别藻蓝蛋白核心的末端终止藻胆体棒。
