Abstract

The predominance of the maximum at 800 nm for the light-harvesting complex LH4 (B800) and at 850 nm for LH2 (B800-850) from Rps. palustris is determined by the composition of αβ-polypeptides and pigments. In low light (LL) for Rps. palustris, strain KM 286 (1e5), along with LH4, the LL LH2 complex was synthesized with the same absorption at 800 and 850 nm. It differed from the LH4 and LH2 complex, which is synthesized under high illumination, in the composition and content of carotenoids (Car) and bacteriochlorophyll a (BChl a). LH4 differed from LL LH2 and LH2 by an additional emission maximum at 766 nm in the BChl a fluorescence spectra. All three complexes had approximately the same level (about 45%) of the energy transfer efficiency from Car to BChl a. Isolation of LL LH2 complex from Rps. palustris confirms the hypothesis of the synthesis in these bacteria under low light conditions of other types of complexes, except LH4, which is due to the multiple biosynthesis genes of αβ-polypeptides and the possibility of their various combinations.

中文翻译：

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当在低光照条件下生长大红假单胞菌时，检测到一种新型的光收集复合体。

摘要

来自Rps的光捕获复合物LH4（B800）在800 nm处最大，而LH2（B800-850）在850 nm处最大。palustris由αβ多肽和色素的组成决定。在低照度（LL）下为Rps。palustris菌株KM 286（1e5）与LH4一起合成了LL LH2络合物，在800和850 nm处具有相同的吸收率。它不同于在高光照下合成的LH4和LH2复合物，其类胡萝卜素（Car）和细菌叶绿素a（BChl a）的组成和含量。LH4与LL LH2和LH2的区别在于BChl a中在766 nm处有一个额外的最大发射荧光光谱。从Car到BChl a，所有三个复合物的能量传递效率都大致相同（约45％）。从Rps中分离LL LH2复合物。palustris证实了在低光照条件下这些细菌中其他类型的复合物（LH4除外）合成的假说，这是由于αβ-多肽的多个生物合成基因以及它们各种组合的可能性。