2003年
Time-resolved step-scan FTIR investigation on the primary donor of the reaction center from the green sulfur bacterium Chlorobium tepidum
PHOTOSYNTHESIS RESEARCH
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- 巻
- 75
- 号
- 2
- 開始ページ
- 161
- 終了ページ
- 169
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1023/A:1022867317267
- 出版者・発行元
- KLUWER ACADEMIC PUBL
The vibrational properties of the primary donor P-840 in the reaction center (RC) of the green sulfur bacterium Chlorobium tepidum and its interactions with the surrounding protein environment have been investigated by Fourier transform infrared (FTIR) difference spectroscopy at cryogenic temperatures. By using the step-scan technique with a time resolution of 5 mus on RCs that had been depleted of the iron-sulfur electron acceptors, the formation and decay of the triplet state P-3(840) have been followed in infrared for the first time. The P-3(840)/P-840 FTIR difference spectrum is compared to the P-840(+)/P-840 FTIR difference spectrum measured under identical conditions on untreated RCs and recorded with the same step-scan set-up. The latter P-840(+)/P-840 difference spectrum is essentially the same as those measured under steady-state conditions using the more conventional continuous illumination method. Comparison of the P-3(840)/P-840 and P-840(+)/P-840 spectra provides unambiguous assignment of the vibration of the 9-keto C=O group(s) of P-840 at 1684 cm(-1) as the only common negative band in the two spectra. This frequency corresponds to carbonyl group(s) free from hydrogen bonding interactions. The obtained results are discussed in the framework of the structure and photochemistry of the primary donor P-840.
- リンク情報
- ID情報
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- DOI : 10.1023/A:1022867317267
- ISSN : 0166-8595
- Web of Science ID : WOS:000181506700006