Abstract
As most biological species, photosynthetic lifeforms have evolved to function optimally, despite thermal disorder and with fault tolerance. It remains a challenge to understand how this is achieved. To address this challenge, the function of the protein-pigment complex photosystem I (PSI) of the cyanobacterium Synechococcus elongatus is investigated theoretically. The recently obtained high-resolution structure of this complex exhibits an aggregate of 96 chlorophylls that are electronically coupled to function as a light-harvesting antenna complex. This paper constructs an effective Hamiltonian for the chlorophyll aggregate to describe excitation transfer dynamics and spectral properties of PSI. For this purpose, a new kinetic expansion method, the sojourn expansion, is introduced. Our study shows that at room temperature fluctuations of site energies have little effect on the calculated excitation lifetime and quantum yield, which compare favorably with experimental results: The efficiency of the system is found to be robust against "pruning" of individual chlorophylls. An optimality of the arrangement of chlorophylls is identified through the quantum yield in comparison with an ensemble of randomly oriented chlorophylls, though the quantum yield is seen to change only within a narrow interval in such an ensemble.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7948-7960 |
| Number of pages | 13 |
| Journal | Journal of Physical Chemistry B |
| Volume | 106 |
| Issue number | 32 |
| DOIs | |
| State | Published - Aug 15 2002 |
Fingerprint
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
Cite this
Robustness and optimality of light harvesting in cyanobacterial photosystem I. / Sener, Melih K.; Lu, Deyu; Ritz, Thorsten; Park, Sanghyun; Fromme, Petra; Schulten, Klaus.
In: Journal of Physical Chemistry B, Vol. 106, No. 32, 15.08.2002, p. 7948-7960.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Robustness and optimality of light harvesting in cyanobacterial photosystem I
AU - Sener, Melih K.
AU - Lu, Deyu
AU - Ritz, Thorsten
AU - Park, Sanghyun
AU - Fromme, Petra
AU - Schulten, Klaus
PY - 2002/8/15
Y1 - 2002/8/15
N2 - As most biological species, photosynthetic lifeforms have evolved to function optimally, despite thermal disorder and with fault tolerance. It remains a challenge to understand how this is achieved. To address this challenge, the function of the protein-pigment complex photosystem I (PSI) of the cyanobacterium Synechococcus elongatus is investigated theoretically. The recently obtained high-resolution structure of this complex exhibits an aggregate of 96 chlorophylls that are electronically coupled to function as a light-harvesting antenna complex. This paper constructs an effective Hamiltonian for the chlorophyll aggregate to describe excitation transfer dynamics and spectral properties of PSI. For this purpose, a new kinetic expansion method, the sojourn expansion, is introduced. Our study shows that at room temperature fluctuations of site energies have little effect on the calculated excitation lifetime and quantum yield, which compare favorably with experimental results: The efficiency of the system is found to be robust against "pruning" of individual chlorophylls. An optimality of the arrangement of chlorophylls is identified through the quantum yield in comparison with an ensemble of randomly oriented chlorophylls, though the quantum yield is seen to change only within a narrow interval in such an ensemble.
AB - As most biological species, photosynthetic lifeforms have evolved to function optimally, despite thermal disorder and with fault tolerance. It remains a challenge to understand how this is achieved. To address this challenge, the function of the protein-pigment complex photosystem I (PSI) of the cyanobacterium Synechococcus elongatus is investigated theoretically. The recently obtained high-resolution structure of this complex exhibits an aggregate of 96 chlorophylls that are electronically coupled to function as a light-harvesting antenna complex. This paper constructs an effective Hamiltonian for the chlorophyll aggregate to describe excitation transfer dynamics and spectral properties of PSI. For this purpose, a new kinetic expansion method, the sojourn expansion, is introduced. Our study shows that at room temperature fluctuations of site energies have little effect on the calculated excitation lifetime and quantum yield, which compare favorably with experimental results: The efficiency of the system is found to be robust against "pruning" of individual chlorophylls. An optimality of the arrangement of chlorophylls is identified through the quantum yield in comparison with an ensemble of randomly oriented chlorophylls, though the quantum yield is seen to change only within a narrow interval in such an ensemble.
UR - http://www.scopus.com/inward/record.url?scp=0037104747&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037104747&partnerID=8YFLogxK
U2 - 10.1021/jp020708v
DO - 10.1021/jp020708v
M3 - Article
AN - SCOPUS:0037104747
VL - 106
SP - 7948
EP - 7960
JO - Journal of Physical Chemistry B Materials
JF - Journal of Physical Chemistry B Materials
SN - 1520-6106
IS - 32
ER -