Self-assembly of natural light-harvesting bacteriochlorophylls of green sulfur photosynthetic bacteria in silicate capsules as stable models of chlorosomes.
Self-assembly of natural light-harvesting bacteriochlorophylls of green sulfur photosynthetic bacteria in silicate capsules as stable models of chlorosomes.
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DOI：
10.1021/bc050343s
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发表时间：
2006-07
影响因子：
4.7
通讯作者：
Y. Saga;S. Akai;Tomohiro Miyatake;H. Tamiaki
中科院分区：
文献类型：
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作者：
Y. Saga;S. Akai;Tomohiro Miyatake;H. Tamiaki
来自绿色硫磺光合细菌的天然细菌叶绿素S-c、-d和-e在十八烷基三乙氧基硅烷和正乙氧基硅烷的存在下，在水溶液中自组装，然后烷氧基硅烷在25℃下孵育50h进行缩聚，得到的硅酸盐胶囊中的天然细菌叶绿素自组装显示出与绿色硫磺细菌相应的自然捕光系统(绿化体)相似的可见吸收和圆二色光谱。动态光散射测量表明，硅酸盐胶囊的平均流体力学直径为数百纳米。与常规胶束体系相比，硅酸盐胶囊中的BCHL自聚集体对非离子表面活性剂Triton X-100具有显著的稳定性，Triton X-100易于将BCHL聚集体分解为单体形式。与天然体系相比，硅酸盐胶囊中的BChl对酸性条件下中心镁的脱金属具有更强的耐受性。
Naturally occurring bacteriochlorophyll(BChl)s-c, -d, and -e from green sulfur photosynthetic bacteria were self-assembled in an aqueous solution in the presence of octadecyltriethoxysilane and tetraethoxysilane, followed by polycondensation of the alkoxysilanes by incubation for 50 h at 25 degrees C. The resulting BChl self-assemblies in silicate capsules exhibited visible absorption and circular dichroism spectra similar to the corresponding natural light-harvesting systems (chlorosomes) of green sulfur bacteria. Dynamic light scattering measurements indicated that the silicate capsules had an average hydrodynamic diameter of several hundred nanometers. BChl self-aggregates in silicate capsules were significantly stable to a nonionic surfactant Triton X-100, which was apt to decompose the BChl aggregates to their monomeric form, compared with conventional micelle systems. BChls in silicate capsules were more tolerant to demetalation of the central magnesium under acidic conditions than the natural systems.