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Title: Fluorescence Spectroscopy, Exciton Dynamics and Photochemistry of Single Allophycocyanin Trimers

Abstract

We report a study of the spectroscopy and exciton dynamics of the allophycocyanin trimer (APC), a light harvesting protein complex from cyanobacteria, by room-temperature single-molecule measurements of fluorescence spectra, lifetimes, intensity trajectories and polarization modulation. Emission spectra of individual APC trimers are found to be homogeneous on the time scale of seconds. In contrast, their emission lifetimes are found to be widely distributed, because of generation of exciton traps during the course of measurements. The intensity trajectories and polarization modulation experiments indicate reversible ixciton trap formation within the three quasi-independent pairs of strong interacting a84 and B84 chromophores in APC, as well a photobleaching of individual chromophores. Comparison experiments under continuous wave and pulsed excitation reveal a two-photon mechanism for generating exciton traps and/or photobleaching, which involves exciton-exciton annihilation. These single-molecule experiments provide new insights into exciton dynamics and photochemistry of light-harvesting complexes.

Authors:
 [1];  [2]
  1. ASSOC WESTERN UNIVERSITY
  2. HARVARD UNIVERSITY
Publication Date:
Research Org.:
Pacific Northwest National Lab., Richland, WA (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
15001947
Report Number(s):
PNNL-SA-30274
KC0301020; TRN: US0400537
DOE Contract Number:  
AC06-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry B
Additional Journal Information:
Journal Volume: 102; Journal Issue: 50; Other Information: PBD: 1 Jan 1998
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ANNIHILATION; CYANOBACTERIA; EMISSION SPECTRA; EXCITATION; EXCITONS; FLUORESCENCE; FLUORESCENCE SPECTROSCOPY; HARVESTING; MODULATION; PHOTOCHEMISTRY; POLARIZATION; PROTEINS; SPECTRA; SPECTROSCOPY; TRAJECTORIES

Citation Formats

Ying, Liming, and Xie, Xiaoliang. Fluorescence Spectroscopy, Exciton Dynamics and Photochemistry of Single Allophycocyanin Trimers. United States: N. p., 1998. Web. doi:10.1021/jp983227d.
Ying, Liming, & Xie, Xiaoliang. Fluorescence Spectroscopy, Exciton Dynamics and Photochemistry of Single Allophycocyanin Trimers. United States. https://doi.org/10.1021/jp983227d
Ying, Liming, and Xie, Xiaoliang. 1998. "Fluorescence Spectroscopy, Exciton Dynamics and Photochemistry of Single Allophycocyanin Trimers". United States. https://doi.org/10.1021/jp983227d.
@article{osti_15001947,
title = {Fluorescence Spectroscopy, Exciton Dynamics and Photochemistry of Single Allophycocyanin Trimers},
author = {Ying, Liming and Xie, Xiaoliang},
abstractNote = {We report a study of the spectroscopy and exciton dynamics of the allophycocyanin trimer (APC), a light harvesting protein complex from cyanobacteria, by room-temperature single-molecule measurements of fluorescence spectra, lifetimes, intensity trajectories and polarization modulation. Emission spectra of individual APC trimers are found to be homogeneous on the time scale of seconds. In contrast, their emission lifetimes are found to be widely distributed, because of generation of exciton traps during the course of measurements. The intensity trajectories and polarization modulation experiments indicate reversible ixciton trap formation within the three quasi-independent pairs of strong interacting a84 and B84 chromophores in APC, as well a photobleaching of individual chromophores. Comparison experiments under continuous wave and pulsed excitation reveal a two-photon mechanism for generating exciton traps and/or photobleaching, which involves exciton-exciton annihilation. These single-molecule experiments provide new insights into exciton dynamics and photochemistry of light-harvesting complexes.},
doi = {10.1021/jp983227d},
url = {https://www.osti.gov/biblio/15001947}, journal = {Journal of Physical Chemistry B},
number = 50,
volume = 102,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1998},
month = {Thu Jan 01 00:00:00 EST 1998}
}