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:
-
- ASSOC WESTERN UNIVERSITY
- 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}
}