Cucumber ( Cucumis sativus L.) LHC_Ⅱ complex, which consists of only one subunit (27 kD), was isolated and purified. 2_D crystallization was performed by batch method. The crystal is 0.7 μm×1.0 μm, and diff...Cucumber ( Cucumis sativus L.) LHC_Ⅱ complex, which consists of only one subunit (27 kD), was isolated and purified. 2_D crystallization was performed by batch method. The crystal is 0.7 μm×1.0 μm, and diffracts to 30 ?. The projection map of the negatively stained two_dimensional crystal of LHC_Ⅱ complex shows that the crystal has p3 symmetry, lattice constant 15.4 nm×15.4 nm, which is different from the LHC_Ⅱ of spinach (Spinacia oleracea L.) and pea (Pisum satium L.). A continuous tomographic tilt series, containing 12 projections from the two_dimensional crystal was subjected to 3_D reconstruction. The 3_D model represents that LHC_Ⅱ complex consists of 6 monomers. These trimer and dimer interactions build up the six member ring.展开更多
With reference to the recent achivements about the structure, spectra and kinetics of light_harvesting complex (LHCⅡ) in PSⅡ of higher plants, a four_level model was provided to simulate the energy transfer process ...With reference to the recent achivements about the structure, spectra and kinetics of light_harvesting complex (LHCⅡ) in PSⅡ of higher plants, a four_level model was provided to simulate the energy transfer process from LHC Ⅱ to the reaction center. On the basis of this model, a set of rate equation was established. Analysis of its algebra solution led to a general picture of energy transfer process in LHC Ⅱ of higher plants and the strong interaction among pigment molecules in this process. Based on the spectra, kinetics and biological structural data providing some information of energy transfer path and energy dissipation mechanism, it has been found that energy transfer mainly happened between the pigments whose energy level was most closely adjacent, the loss of energy had a close relation to the process of energy transfer and tended to increase with the decrease of energy level. The protective mechanism of antenna system was also discussed.展开更多
文摘Cucumber ( Cucumis sativus L.) LHC_Ⅱ complex, which consists of only one subunit (27 kD), was isolated and purified. 2_D crystallization was performed by batch method. The crystal is 0.7 μm×1.0 μm, and diffracts to 30 ?. The projection map of the negatively stained two_dimensional crystal of LHC_Ⅱ complex shows that the crystal has p3 symmetry, lattice constant 15.4 nm×15.4 nm, which is different from the LHC_Ⅱ of spinach (Spinacia oleracea L.) and pea (Pisum satium L.). A continuous tomographic tilt series, containing 12 projections from the two_dimensional crystal was subjected to 3_D reconstruction. The 3_D model represents that LHC_Ⅱ complex consists of 6 monomers. These trimer and dimer interactions build up the six member ring.
文摘With reference to the recent achivements about the structure, spectra and kinetics of light_harvesting complex (LHCⅡ) in PSⅡ of higher plants, a four_level model was provided to simulate the energy transfer process from LHC Ⅱ to the reaction center. On the basis of this model, a set of rate equation was established. Analysis of its algebra solution led to a general picture of energy transfer process in LHC Ⅱ of higher plants and the strong interaction among pigment molecules in this process. Based on the spectra, kinetics and biological structural data providing some information of energy transfer path and energy dissipation mechanism, it has been found that energy transfer mainly happened between the pigments whose energy level was most closely adjacent, the loss of energy had a close relation to the process of energy transfer and tended to increase with the decrease of energy level. The protective mechanism of antenna system was also discussed.
