Spectroscopic evidence for triplet excitation energy transfer among carotenoids in the LH2 complex from photosynthetic bacterium Rhodopseudomonas palustris
文献类型：期刊论文
| 作者 | Feng, J; Wang, Q; Zhang, XJ; Huang, YG; Al, XC; Zhang, XK; Zhang, JP |
| 刊名 | SCIENCE IN CHINA SERIES B-CHEMISTRY
 |
| 出版日期 | 2004-02-01 |
| 卷号 | 47期号:1页码:80-90 |
| 关键词 | Purple Photosynthetic Bacteria Carotenoid Excited-state Time-resolved Spectroscopy |
| ISSN号 | 1006-9291 |
| DOI | 10.1360/03yb0104 |
| 英文摘要 | The LH2 complex from Rhodopsudomonas (Rps.) palustris is unique in the heterogeneous carotenoid compositions. The dynamics of triplet excited state Carotenoids ((3)Car*) has been investigated by means of sub-microsecond time-resolved absorption spectroscopy both at physiological temperature (295 K) and at cryogenic temperature (77 K). Broad and asymmetric T-n <-- T-1 transient absorption was observed at room temperature following the photo-excitation of Car at 532 nm, which suggests the contribution from various carotenoid compositions having different numbers of conjugated C=C double bonds (N-C=C). The triplet absorption bands of different carotenoids, which superimposed at room temperature, could be clearly distinguished upon decreasing the temperature down to 77 K. At room temperature the shorter-wavelength side of the main T-n <-- T-1 absorption band decayed rapidly to reach a spectral equilibration with a characteristic time constant of similar to1 mus, the same spectral dynamics, however, was not observed at 77 K. The aforementioned spectral dynamics can be explained in terms of the triplet-excitation transfer among heterogeneous carotenoid compositions. Global spectral analysis was applied to the time-resolved spectra at room temperature, which revealed two spectral components peaked at 545 and 565 nm, and assignable to the T-n <-- T-1 absorption of Cars with N-C=C=11 and N-C=C=13, respectively. Surprisingly, the decay time constant of a shorter-conjugated Car, i.e. 0.72 mus (aerobic) and 1.36 mus (anaerobic), is smaller than that of a longer-conjugated Car, i.e. 2.12 mus (aerobic) and 3.75 mus (anaerobic), which is contradictory to the general rule of carotenoids and relative polyenes. The results are explained in terms of triplet-excitation transfer among different types of Cars. It is postulated that two Cars with different conjugation lengths coexist in an alpha, beta-subunit in the LH2 complex. |
| 语种 | 英语 |
| WOS记录号 | WOS:000188966900011 |
| 出版者 | SCIENCE CHINA PRESS |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/81851]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Zhang, JP |
| 作者单位 | 1.Chinese Acad Sci, Inst Chem, State Key Lab Struct Chem Unstable & Stable Speci, Beijing 100080, Peoples R China 2.Chinese Acad Sci, Inst Biophys, Natl Lab Biomacromol, Beijing 100101, Peoples R China |
| 推荐引用方式 GB/T 7714 | Feng, J,Wang, Q,Zhang, XJ,et al. Spectroscopic evidence for triplet excitation energy transfer among carotenoids in the LH2 complex from photosynthetic bacterium Rhodopseudomonas palustris[J]. SCIENCE IN CHINA SERIES B-CHEMISTRY,2004,47(1):80-90. |
| APA | Feng, J.,Wang, Q.,Zhang, XJ.,Huang, YG.,Al, XC.,...&Zhang, JP.(2004).Spectroscopic evidence for triplet excitation energy transfer among carotenoids in the LH2 complex from photosynthetic bacterium Rhodopseudomonas palustris.SCIENCE IN CHINA SERIES B-CHEMISTRY,47(1),80-90. |
| MLA | Feng, J,et al."Spectroscopic evidence for triplet excitation energy transfer among carotenoids in the LH2 complex from photosynthetic bacterium Rhodopseudomonas palustris".SCIENCE IN CHINA SERIES B-CHEMISTRY 47.1(2004):80-90. |
入库方式： OAI收割
来源：化学研究所
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