| Project/Area Number |
05044137
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
MATSUURA Katsumi Faculty of Science, Tokyo Metropolitan University, 理学部, 助教授 (30181689)
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| Co-Investigator(Kenkyū-buntansha) |
MILLER Mette Inst.Biochem., Odense University, Institute Biochem., 助教授
OLSON J.m. Inst.Biochem., Odense University, Institute Biochem., 教授
MIMURO Mamoru National Institute for Basic Biology, 基礎生物学研究所, 助手 (40142004)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1994: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Photosynthetic bacteria / Bacteriochlorophyll / Chlorosome / Light-harvesting pigment / Energy transfer |
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| Research Abstract |
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.
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