Characterization of chlorophyll-protein complexes isolated from a Siphonous green alga, Bryopsis corticulans
Characterization of chlorophyll-protein complexes isolated from a Siphonous green alga, Bryopsis corticulans
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从虹吸绿藻 Bryopsis corticulans 中分离的叶绿素-蛋白质复合物的表征
DOI：
10.1007/s11120-007-9286-6
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发表时间：
2008-04-01
影响因子：
3.7
通讯作者：
Li, Shuqin
中科院分区：
文献类型：
--
作者：
Chen, Guiying;Niu, Xiaodong;Li, Shuqin
用十二烷基-β-D-麦芽糖苷-聚丙烯酰胺凝胶电泳法从拟青霉的类囊体膜中分离出6个叶绿素-蛋白质复合体。与高等植物不同的是，皮质假单胞菌的PSI核心复合体CP1带的77K荧光发射光谱有两个峰，一个位于675 nm，另一个位于715-717 nm。当激发波长为438或540 nm时，CP1波段715-717 nm的发射峰略高于675 nm的发射峰。当激发波长为480 nm时，715 nm的峰值明显低于675 nm的峰值。CP1的激发光谱表明，675 nm处的激发峰主要来自Chlb的能量，而Chla的能量对激发715-717 nm处的峰起重要作用。研究发现，硅黄质对675 nm和715-717 nm峰均有贡献。根据以上结果，我们认为叶绿素a和管黄质主要负责向PSI的远红区转移能量，而Chlb则是向PSI的红区转移能量的主要来源。对LHCP1和LHCP3的叶绿素组成和光谱特征的分析也表明，较高的Chlb和管黄质含量主要存在于LHCP1中，LHCII的三聚体形式是皮质假单胞菌为了吸收适量的光能而进化出来的，以适应它们的自然生境。
Six chlorophyll-protein complexes are isolated from thylakoid membranes of Bryopsis corticulans by dodecyl-beta-D-maltoside polyacrylamide gel electrophoresis. Unlike that of higher plants, the 77 K fluorescence emission spectrum of the CP1 band, the PSI core complexes of B. corticulans, presents two peaks, one at 675 nm and the other at 715-717 nm. The emission peak at 715-717 nm is slightly higher than that at 675 nm in the CP1 band when excited at 438 or 540 nm. However, the peak at 715 nm is obviously lower than that at 675 nm when excited at 480 nm. The excitation spectra of CP1 demonstrate that the peak at 675 nm is mainly attributed to energy from Chl b while it is the energy from Chl a that plays an important role in exciting the peak at 715-717 nm. Siphonaxanthin is found to contribute to both the 675 nm and 715-717 nm peaks. We propose from the above results that chlorophyll a and siphonaxanthin are mainly responsible for the transfer of energy to the far-red region of PSI while it is Chl b that contributes most of the transfer of energy to the red region of PSI. The analysis of chlorophyll composition and spectral characteristics of LHCP1 and LHCP3 also indicate that higher content of Chl b and siphonaxanthin, mainly presented in LHCP1, the trimeric form of LHCII, are evolved by B. corticulans to absorb an appropriate amount of light energy so as to adapt to their natural habitats.