Low-temperature fluorescence from single chlorosomes, photosynthetic antenna complexes of green filamentous and sulfur bacteria.
Low-temperature fluorescence from single chlorosomes, photosynthetic antenna complexes of green filamentous and sulfur bacteria.
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DOI：
10.1529/biophysj.106.084178
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发表时间：
2006-11
影响因子：
3.4
通讯作者：
Y. Shibata;Y. Saga;H. Tamiaki;S. Itoh
中科院分区：
文献类型：
--
作者：
Y. Shibata;Y. Saga;H. Tamiaki;S. Itoh
从一株绿色丝状细菌（Chloroflexus（Cfl.）aurantiacus）和绿色硫细菌Chlorobium（Cb.）tepidum）在13 K下通过使用共聚焦激光显微镜测量。将叶绿体冷冻在液体溶液中（漂浮的叶绿体）或吸附后的石英板上（吸附的叶绿体）。吸附的单个叶绿体的荧光峰波长比漂浮的短。单浮Cfl.绿色体显示荧光峰位置的分布，其中心在759.0 nm，半峰全宽为6.3 nm。单浮动Cb。绿色体显示782.7 nm的中心，半峰全宽为3.4 nm。随着温度的升高，分布向蓝移，并变宽，特别是在Cb。绿色体，这表明一个大的激子密度的国家刚刚高于最低水平。从BChl-c聚集体到BChl-a分子在基板蛋白质中的能量转移被观察到在漂浮的绿小体中，但在吸附的绿小体中没有。单细胞Cfl中BChl-c荧光峰波长与BChl-a荧光强度呈正相关。绿色体。结果表明，具有较长荧光峰波长的BChl-c聚集体具有更有效的Förster型能量转移到基板BChl-a。
Fluorescence spectra of single chlorosomes isolated from a green filamentous bacterium (Chloroflexus (Cfl.) aurantiacus) and a green sulfur bacterium (Chlorobium (Cb.) tepidum) were measured by using a confocal laser microscope at 13 K. Chlorosomes were frozen either in a liquid solution (floating chlorosome) or on a quartz plate after being adsorbed (adsorbed chlorosome). Fluorescence peak wavelengths were shorter for the adsorbed single chlorosomes than for the floating ones. Single floating Cfl. chlorosomes showed a distribution of fluorescence peak positions having a center at 759.0 nm with a full width at half maximum of 6.3 nm. Single floating Cb. chlorosomes showed a 782.7 nm center with a full width at half-maximum of 3.4 nm. The distribution shifted to the blue and became wider with increasing temperature, especially in Cb. chlorosomes, suggesting a large excitonic density of states just above the lowest level. Energy transfer from BChl-c aggregates to BChl-a molecules in the baseplate proteins was observed in the floating chlorosomes but not in the adsorbed ones. A positive correlation was found between the peak wavelength of BChl-c fluorescence and the intensity of BChl-a fluorescence in single Cfl. chlorosomes. The results suggest that the BChl-c aggregates with longer wavelengths of the fluorescence peaks have a more efficient Förster-type energy transfer to the baseplate BChl-a.