IN a previous paper, we have studied the energy transfer mechanism among the PBS-thy-lakoid complex in detail by using steady-state spectra and deconvolution techniques. The ex-perimental results indicated that the en...IN a previous paper, we have studied the energy transfer mechanism among the PBS-thy-lakoid complex in detail by using steady-state spectra and deconvolution techniques. The ex-perimental results indicated that the energy transfer from PBS to two reaction centers of PS Ⅰand PS Ⅱ were parallel, and confirmed the model which was suggested by Mullineaxu.展开更多
The conjugate of R-phycoerythrin (R-PE) and C-phycocyanin (C-PC) was synthesized through a heterobifunctional coupling reagent, N-succinimidyl 3-(2-pyridyldithio) propionate. The molar ratio of R-PE to C-PC was determ...The conjugate of R-phycoerythrin (R-PE) and C-phycocyanin (C-PC) was synthesized through a heterobifunctional coupling reagent, N-succinimidyl 3-(2-pyridyldithio) propionate. The molar ratio of R-PE to C-PC was determined by absorption spectra, and the result was 2:1. The energy transfer phenomena were observed from steady-state fluorescence spectra. The calculated result showed that the energy transfer efficiency from R-PE to C-PC was 88%. The energy transfer kinetics was determined by picosecond time-resolved fluorescence spectra. The time constant of energy transfer from R-PE to C-PC was 80 ps, which was much longer than that in the rood of native phycobilisomes.展开更多
Ultra time-resolved fluorescence spectra were used to study the energy transfer processes and mechanism of complex PEC/PC/APC at 77 K, which was reconstructed with phycobiliproteins (PEC, PC and APC) ofAnabaena variab...Ultra time-resolved fluorescence spectra were used to study the energy transfer processes and mechanism of complex PEC/PC/APC at 77 K, which was reconstructed with phycobiliproteins (PEC, PC and APC) ofAnabaena variabilis, and has intact light-harvesting system and single terminal emitter. The energy transfer relationships between different chromophores especially between rod and core were also discussed based on fluorescence decay kinetic under different detected wavelengths. As a result, we got the possible energy transfer pathways and transfer time constants to be 29 ps between two PEC trimers, 12 ps between PEC and C-PC, 51 ps between rod and core.展开更多
The excitation energy transfer processes in nionomeric phycoerythrocyanins ( PEC)have been studied in detail using steady-state and time-resolved fluorescence spectra techniques as well as the deconvolution fech nique...The excitation energy transfer processes in nionomeric phycoerythrocyanins ( PEC)have been studied in detail using steady-state and time-resolved fluorescence spectra techniques as well as the deconvolution fech nique of spectra.The results indicate that the energy transfer processes should take place between α84 PVB md β8 or β155-PCB chromophores,the time constants of energy transfer are 34.7 and 130 ps individually;the component with lifetime of 1.57 ns originates from the fluorescence lifetime of the terminal emitter of β84 and /or β155 PCB chre-mophores; and the component with lifetime of 515 ps might be assigned to the energy transfer between two PCB chro mophores of β subunit.展开更多
The excitation energy transfer processes in trimeric PEC have been studied by using steady state and time resolved fluorescence spectra techniques in detail. The results indicate that the energy transfer processes sho...The excitation energy transfer processes in trimeric PEC have been studied by using steady state and time resolved fluorescence spectra techniques in detail. The results indicate that the energy transfer processes should take place between α 84 PVB and β 84 or β 155 PCB chromophores with the time constants 34.7 ps and 175-200 ps individually; in contrast with monomeric PEC, from time resolved fluorescence anisotropic spectrum technique, the decay constant of 45 ps which was assigned to the energy transfer time among three β 84 PCB chromophores was observed and the energy levels of β 84 and/or β 155 PCB chromophores were confirmed to turn over in trimeric PEC.展开更多
Excitation energy transfer processes and mechanism in C-PC hexamer have been studied in detail by picosecond time-resolved fluorescencs isotropic and anisotropic spectroscopy methods. The experimental results show tha...Excitation energy transfer processes and mechanism in C-PC hexamer have been studied in detail by picosecond time-resolved fluorescencs isotropic and anisotropic spectroscopy methods. The experimental results show that there are two types of principal channels, with large probability or amplitude, for linking two trimers viam?m and s?s energy transfer pathways, the energy-transfer time constants of them are about 20 and 10 ps, respectively. Indeed, there exists the evidence for energy-transfer channels of s?f steps in the same monomer and threef?f steps in the same trimer of the C-PC hexamer unit, with small probability or amplitude, and the time constants of them might be ca. 50 and 45 ps separately. Also, the present results show that the hexamer possesses an optimal structure for energy-transfer and for the first time confirm that the dominant energy-transfer processes except those between 1 m?2f, 2m?3f and 3m?1f and so on, in isolated C-PC hexamer, could be described by F?rster dipole-dipole resonance mechanism.展开更多
文摘IN a previous paper, we have studied the energy transfer mechanism among the PBS-thy-lakoid complex in detail by using steady-state spectra and deconvolution techniques. The ex-perimental results indicated that the energy transfer from PBS to two reaction centers of PS Ⅰand PS Ⅱ were parallel, and confirmed the model which was suggested by Mullineaxu.
文摘The conjugate of R-phycoerythrin (R-PE) and C-phycocyanin (C-PC) was synthesized through a heterobifunctional coupling reagent, N-succinimidyl 3-(2-pyridyldithio) propionate. The molar ratio of R-PE to C-PC was determined by absorption spectra, and the result was 2:1. The energy transfer phenomena were observed from steady-state fluorescence spectra. The calculated result showed that the energy transfer efficiency from R-PE to C-PC was 88%. The energy transfer kinetics was determined by picosecond time-resolved fluorescence spectra. The time constant of energy transfer from R-PE to C-PC was 80 ps, which was much longer than that in the rood of native phycobilisomes.
文摘Ultra time-resolved fluorescence spectra were used to study the energy transfer processes and mechanism of complex PEC/PC/APC at 77 K, which was reconstructed with phycobiliproteins (PEC, PC and APC) ofAnabaena variabilis, and has intact light-harvesting system and single terminal emitter. The energy transfer relationships between different chromophores especially between rod and core were also discussed based on fluorescence decay kinetic under different detected wavelengths. As a result, we got the possible energy transfer pathways and transfer time constants to be 29 ps between two PEC trimers, 12 ps between PEC and C-PC, 51 ps between rod and core.
基金Project supported hy the National Natural Science Foundation of China
文摘The excitation energy transfer processes in nionomeric phycoerythrocyanins ( PEC)have been studied in detail using steady-state and time-resolved fluorescence spectra techniques as well as the deconvolution fech nique of spectra.The results indicate that the energy transfer processes should take place between α84 PVB md β8 or β155-PCB chromophores,the time constants of energy transfer are 34.7 and 130 ps individually;the component with lifetime of 1.57 ns originates from the fluorescence lifetime of the terminal emitter of β84 and /or β155 PCB chre-mophores; and the component with lifetime of 515 ps might be assigned to the energy transfer between two PCB chro mophores of β subunit.
文摘The excitation energy transfer processes in trimeric PEC have been studied by using steady state and time resolved fluorescence spectra techniques in detail. The results indicate that the energy transfer processes should take place between α 84 PVB and β 84 or β 155 PCB chromophores with the time constants 34.7 ps and 175-200 ps individually; in contrast with monomeric PEC, from time resolved fluorescence anisotropic spectrum technique, the decay constant of 45 ps which was assigned to the energy transfer time among three β 84 PCB chromophores was observed and the energy levels of β 84 and/or β 155 PCB chromophores were confirmed to turn over in trimeric PEC.
文摘Excitation energy transfer processes and mechanism in C-PC hexamer have been studied in detail by picosecond time-resolved fluorescencs isotropic and anisotropic spectroscopy methods. The experimental results show that there are two types of principal channels, with large probability or amplitude, for linking two trimers viam?m and s?s energy transfer pathways, the energy-transfer time constants of them are about 20 and 10 ps, respectively. Indeed, there exists the evidence for energy-transfer channels of s?f steps in the same monomer and threef?f steps in the same trimer of the C-PC hexamer unit, with small probability or amplitude, and the time constants of them might be ca. 50 and 45 ps separately. Also, the present results show that the hexamer possesses an optimal structure for energy-transfer and for the first time confirm that the dominant energy-transfer processes except those between 1 m?2f, 2m?3f and 3m?1f and so on, in isolated C-PC hexamer, could be described by F?rster dipole-dipole resonance mechanism.
