Shubin V V, Tsuprun V L, Bezsmertnaya I N, Karapetyan N V
A.N. Bakh Institute of Biochemistry, Russian Academy of Sciences, Moscow.
FEBS Lett. 1993 Nov 8;334(1):79-82. doi: 10.1016/0014-5793(93)81685-s.
Oligomeric and monomeric forms of chlorophyll-protein complexes of photosystem I (PSI) have been isolated from the mesophilic cyanobacterium Spirulina [(1992) FEBS Lett. 309, 340-342]. Electron microscopic analysis of the complexes showed that the oligomeric form is a trimer of the shape and dimensions similar to those of the trimer from thermophilic cyanobacteria. The chlorophyl ratio in the isolated trimer and monomer was found to be 7:3. The trimeric form of PSI complex in contrast to the monomeric one contains the chlorophyll emitting at 760 nm (77K), which is also found in Spirulina membranes and therefore could be used as an intrinsic probe for the trimeric complex. The 77K circular dichroism spectrum of the trimeric form is much more similar to that of Spirulina membranes than the spectrum of the monomer. Thus, the trimeric PSI complexes exist and dominate in the Spirulina membranes.
已从嗜温蓝藻螺旋藻中分离出光系统I（PSI）叶绿素 - 蛋白复合物的寡聚体和单体形式[（1992年）《欧洲生物化学学会联合会快报》309, 340 - 342]。对这些复合物的电子显微镜分析表明，寡聚体形式是一种三聚体，其形状和尺寸与嗜热蓝藻的三聚体相似。在分离出的三聚体和单体中，叶绿素比例为7:3。与单体形式相比，PSI复合物的三聚体形式含有在760 nm（77K）处发射的叶绿素，这在螺旋藻膜中也有发现，因此可作为三聚体复合物的内在探针。三聚体形式的77K圆二色光谱比单体光谱更类似于螺旋藻膜的光谱。因此，三聚体PSI复合物存在于螺旋藻膜中并占主导地位。
