权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Higher structure of pigment in green photosynthetic bacteria

绿色光合细菌色素的高级结构

基本信息

批准号：
05044137
负责人：
MATSUURA Katsumi
金额：
$ 2.88万
依托单位：
Tokyo Metropolitan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05044137/
关键词：
Photosynthetic bacteria Bacteriochlorophyll Chlorosome Light-harvesting pigment Energy transfer

项目摘要

1.The infrared peak of chlorosomes of C.tepidum at 747 nm shifted to 670 nm when suspended in buffer saturated with hexanol, corresponding to the de-organization of higher structure of BChl c in chlorosomes. When the hexanol-treated chlorosomes were slowly diluted with frash buffer, the 670 nm band returned to 750 nm without apparent intermediates. On the other hand, when the hexanol-treated chlorosomes were rapidly mixed with buffer, the 670 nm band returned to 738 nm in hours through intermediary forms with apparent peaks around 710,720 and 730 nm. These results suggest that two different processes of reorganization of BChl c in hexanol-treated chlorosomes are possible. One is through intermediary forms with smaller numbers of pigment molecules. The other is a direct development of larger aggregated forms from the "monomeric" form. This direct process seems to be necessary to form the native aggregated forms.2.Bacteriochlorophyll c in chlorosomes shows two major spectral forms which are different in absorption peaks and CD spectra. In the reorganization of bacteriochlorophyll c after the hexanol treatment of chlorosomes, we have previously shown that the peak wave-lengths of the reorganized forms were depended on the speed of hexanol removal. When hexanol was removed slowly, CD spectrum showed a mixture of two components as in native chlorosomes. Wken it was removed rapidly, the spectrum is a short-wavelength type. In the pigment-lipid aggregates, CD spectra showed the short-wavelength type. However, after the hexanol treatment the mixed CD signal was observed. These results suggest that the two forms can also formed in the pigment-lipid aggregates, and that the longer wavelength form may require the co-existence of the shorter wavelength form.

1.毛壳虫绿小体在747 nm处的红外峰在已醇饱和的缓冲液中漂移到670 nm，对应于绿小体中Bchl-c的高级结构的解体。当用Frash缓冲液缓慢稀释已醇处理的绿体时，670 nm谱带恢复到750 nm，没有明显的中间产物。当已醇处理的绿体与缓冲液快速混合时，670 nm谱带通过中间形式在数小时内恢复到738 nm，在710、720和730 nm附近有明显的峰。这些结果表明，在已醇处理的叶绿体中，Bchl c的重组可能有两种不同的过程。一种是通过具有较少数量的色素分子的中间形式。另一种是从“单体”形式直接发展成更大的聚合形式。这种直接的过程似乎是形成天然聚集形式所必需的。2.叶绿体中的细菌-叶绿素c有两种主要的光谱形式，这两种光谱形式在吸收峰和CD光谱上都不同。在已醇处理叶绿体后细菌-叶绿素c的重组中，我们先前已经证明，重组形式的峰值波长取决于己醇的去除速度。当己醇被缓慢去除时，CD光谱显示出与天然叶绿体一样的两种成分的混合物。当它被快速去除时，光谱是短波长型的。在色素-脂质聚集体中，CD光谱显示为短波长型。然而，在己醇处理后，观察到混合的CD信号。这些结果表明，这两种形式也可以在色素-脂质聚集体中形成，而较长波长的形式可能需要较短波长形式的共存。