Abstract
Enhanced spectral resolution of high-frequency electron paramagnetic resonance (EPR) spectroscopy allows for detailed g-tensor analysis of the active paramagnetic pigments in photosynthetic reaction centers. This analysis has been made for the cation radical and triplet state of the primary donor in photosystem I (P700) compared to the same species from chlorophyll a (Chla) in vitro. The data prove that the electronic structures of the primary donor cation and triplet state are very different from those of monomeric Chla. The g-value anisotropy of P700 +̇ is smaller, and the gz component considerably deviates from that of Chla+̇. The triplet state of P700 is also different from ChlaT. In the present study, this difference is resolved because of the high g-value resolution of the high-frequency EPR and characterized by the switching of the directions of the X and Y g-tensor axes with respect to the zero-field axes. These results can be explained either by a delocalized electronic character of the P700 +̇ and P700 T states or by a heteromeric model of the primary donor in photosystem I.
| Original language | English |
|---|---|
| Pages (from-to) | 8911-8916 |
| Number of pages | 6 |
| Journal | Journal of Physical Chemistry B |
| Volume | 106 |
| Issue number | 35 |
| DOIs | |
| Publication status | Published - Sep 5 2002 |
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- Physical and Theoretical Chemistry
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Electronic structure of the P700 special pair from high-frequency electron paramagnetic resonance spectroscopy. / Poluektov, Oleg G.; Utschig, Lisa M.; Schlesselman, Sandra L.; Lakshmi, K. V.; Brudvig, Gary W; Kothe, Gerd; Thurnauer, Marion C.
In: Journal of Physical Chemistry B, Vol. 106, No. 35, 05.09.2002, p. 8911-8916.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Electronic structure of the P700 special pair from high-frequency electron paramagnetic resonance spectroscopy
AU - Poluektov, Oleg G.
AU - Utschig, Lisa M.
AU - Schlesselman, Sandra L.
AU - Lakshmi, K. V.
AU - Brudvig, Gary W
AU - Kothe, Gerd
AU - Thurnauer, Marion C.
PY - 2002/9/5
Y1 - 2002/9/5
N2 - Enhanced spectral resolution of high-frequency electron paramagnetic resonance (EPR) spectroscopy allows for detailed g-tensor analysis of the active paramagnetic pigments in photosynthetic reaction centers. This analysis has been made for the cation radical and triplet state of the primary donor in photosystem I (P700) compared to the same species from chlorophyll a (Chla) in vitro. The data prove that the electronic structures of the primary donor cation and triplet state are very different from those of monomeric Chla. The g-value anisotropy of P700 +̇ is smaller, and the gz component considerably deviates from that of Chla+̇. The triplet state of P700 is also different from ChlaT. In the present study, this difference is resolved because of the high g-value resolution of the high-frequency EPR and characterized by the switching of the directions of the X and Y g-tensor axes with respect to the zero-field axes. These results can be explained either by a delocalized electronic character of the P700 +̇ and P700 T states or by a heteromeric model of the primary donor in photosystem I.
AB - Enhanced spectral resolution of high-frequency electron paramagnetic resonance (EPR) spectroscopy allows for detailed g-tensor analysis of the active paramagnetic pigments in photosynthetic reaction centers. This analysis has been made for the cation radical and triplet state of the primary donor in photosystem I (P700) compared to the same species from chlorophyll a (Chla) in vitro. The data prove that the electronic structures of the primary donor cation and triplet state are very different from those of monomeric Chla. The g-value anisotropy of P700 +̇ is smaller, and the gz component considerably deviates from that of Chla+̇. The triplet state of P700 is also different from ChlaT. In the present study, this difference is resolved because of the high g-value resolution of the high-frequency EPR and characterized by the switching of the directions of the X and Y g-tensor axes with respect to the zero-field axes. These results can be explained either by a delocalized electronic character of the P700 +̇ and P700 T states or by a heteromeric model of the primary donor in photosystem I.
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U2 - 10.1021/jp021465+
DO - 10.1021/jp021465+
M3 - Article
VL - 106
SP - 8911
EP - 8916
JO - Journal of Physical Chemistry B Materials
JF - Journal of Physical Chemistry B Materials
SN - 1520-6106
IS - 35
ER -