Purified PSI complexes from Spinacia Oleracea L. were exposed to the strong light (PFD=2300μmol m-2s-1) for various period. Along with the illumination the photo-damage process of pigments and proteins of PSI complex...Purified PSI complexes from Spinacia Oleracea L. were exposed to the strong light (PFD=2300μmol m-2s-1) for various period. Along with the illumination the photo-damage process of pigments and proteins of PSI complexes was investigated using absorption, fluorescence, circular dichroism (CD) spectroscopy and SDS-PAGE. It was found from the optical absorption spectra that the maximal ab-sorbance of PSI complexes decreased and maximal peaks blue-shifted during the illumination, and the forth derivative spectra demonstrated that the absorbance decreasing at red region mainly resulted from the aborbance decreasing of the long wavelength Chla, implying that the long-wavelength Chla was readily to be bleached. The CD signals contributed by LHCI decreased more rapidly than other CD signals con-tributed by Chla and Carotenoid, indicating that the LHCI was more sensitive to light than core complexes. It was observed by SDS-PAGE that some small polypeptides of PSI complexes were damaged earlier than reaction展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39890390) the State Key Basic Research and Development Program (Grant No. G1998010100) and the Innovative Foundation of Laboratory of Photosynthesis Basic Research
文摘Purified PSI complexes from Spinacia Oleracea L. were exposed to the strong light (PFD=2300μmol m-2s-1) for various period. Along with the illumination the photo-damage process of pigments and proteins of PSI complexes was investigated using absorption, fluorescence, circular dichroism (CD) spectroscopy and SDS-PAGE. It was found from the optical absorption spectra that the maximal ab-sorbance of PSI complexes decreased and maximal peaks blue-shifted during the illumination, and the forth derivative spectra demonstrated that the absorbance decreasing at red region mainly resulted from the aborbance decreasing of the long wavelength Chla, implying that the long-wavelength Chla was readily to be bleached. The CD signals contributed by LHCI decreased more rapidly than other CD signals con-tributed by Chla and Carotenoid, indicating that the LHCI was more sensitive to light than core complexes. It was observed by SDS-PAGE that some small polypeptides of PSI complexes were damaged earlier than reaction
