EXCITATION ENERGY TRANSFER IN THE LIGHT HARVESTING ANTENNA SYSTEM OF THE RED ALGA Porphyridium cruentum AND THE BLUE-GREEN ALGA Anacystis nidulans: ANALYSIS OF TIME-RESOLVED FLUORESCENCE SPECTRA

1984 ◽  
Vol 39 (2) ◽  
pp. 233-240 ◽  
Author(s):  
I. YAMAZAKI ◽  
M. MIMURO ◽  
T. MURAO ◽  
T. YAMAZAKI ◽  
K. YOSHIHARA ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Excitation Energy Transfer ◽  
Red Alga ◽  
Anacystis Nidulans ◽  
Antenna System ◽  
Blue Green Alga ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Light Harvesting Antenna

scholarly journals Structure of a cyanobacterial photosystem I surrounded by octadecameric IsiA antenna proteins

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Fusamichi Akita ◽  
Ryo Nagao ◽  
Koji Kato ◽  
Yoshiki Nakajima ◽  
Makio Yokono ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Photosystem I ◽  
Fluorescence Spectra ◽  
Protein A ◽  
Excitation Energy Transfer ◽  
Electron Microscopic ◽  
Time Resolved ◽  
Closed Ring ◽  
Membrane Spanning

AbstractIron-stress induced protein A (IsiA) is a chlorophyll-binding membrane-spanning protein in photosynthetic prokaryote cyanobacteria, and is associated with photosystem I (PSI) trimer cores, but its structural and functional significance in light harvesting remains unclear. Here we report a 2.7-Å resolution cryo-electron microscopic structure of a supercomplex between PSI core trimer and IsiA from a thermophilic cyanobacterium Thermosynechococcus vulcanus. The structure showed that 18 IsiA subunits form a closed ring surrounding a PSI trimer core. Detailed arrangement of pigments within the supercomplex, as well as molecular interactions between PSI and IsiA and among IsiAs, were resolved. Time-resolved fluorescence spectra of the PSI–IsiA supercomplex showed clear excitation-energy transfer from IsiA to PSI, strongly indicating that IsiA functions as an energy donor, but not an energy quencher, in the supercomplex. These structural and spectroscopic findings provide important insights into the excitation-energy-transfer and subunit assembly mechanisms in the PSI–IsiA supercomplex.

Charge and Energy Transfer Between CdSe Quantum Dots and Polyaniline

2016 ◽  
Vol 16 (4) ◽  
pp. 3909-3913 ◽  
Author(s):  
Liang Xu ◽  
Xingbin Huang ◽  
Wenjiang Dai ◽  
Punan Sun ◽  
Xuanlin Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Cdse Quantum Dots ◽  
Time Resolved Fluorescence ◽  
Cdse Qds ◽  
Time Resolved ◽  
Two Factors

CdSe quantum dots (QDs) and polyaniline (PAni) were mixed to prepare CdSe QDs/PAni complex. PAni can quench the fluorescence of CdSe QDs. Fluorescence intensity of CdSe QDs/PAni complex is related to the size of CdSe QDs and the concentration of PAni. UV-Vis absorption spectra, fluorescence spectra, time-resolved fluorescence spectroscopy were used to analys the quenching phenomenon. The mechanism of fluorescence quenching is dependent on two factors: on one hand, the Förster resonance energy transfer from CdSe to PAni; on the other hand, PAni can intercept the charge relaxation process of CdSe and lead to the interruption of radiative recombination.

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