Theoretical study of the electronic spectrum of plastocyanin
Pierloot, Kristine ; De Kerpel, Jan O A ; Ryde, Ulf LU
and Roos, Björn O.
LU
(1997)
In Journal of the American Chemical Society
119(1).
p.218-226
- Abstract
The electronic spectrum of the blue copper protein plastocyanin has been studied by ab initio multiconfigurational second-order perturbation theory (the CASPT2 method). The six lowest electronic transitions have been calculated and assigned with an error of less than 2000 cm-1. The singly occupied orbital in the ground state is Cu 3d-S(Cys) 3pπ antibonding with some N(His) 2pσ character. The bright blue color originates from an electron transfer to this orbital from the corresponding Cu 3d-S(Cys)3pπ bonding orbital. The influence of different ligand models on the spectrum has been thoroughly studied; Cu(imidazole)2(SCH3)(S(CH3)2)+ as a model of CuHis2CysMet is... (More)
The electronic spectrum of the blue copper protein plastocyanin has been studied by ab initio multiconfigurational second-order perturbation theory (the CASPT2 method). The six lowest electronic transitions have been calculated and assigned with an error of less than 2000 cm-1. The singly occupied orbital in the ground state is Cu 3d-S(Cys) 3pπ antibonding with some N(His) 2pσ character. The bright blue color originates from an electron transfer to this orbital from the corresponding Cu 3d-S(Cys)3pπ bonding orbital. The influence of different ligand models on the spectrum has been thoroughly studied; Cu(imidazole)2(SCH3)(S(CH3)2)+ as a model of CuHis2CysMet is the smallest system that gives converged results.The spectrum is surprisingly sensitive to changes in the geometry, especially in the Cu-S bond distances; a 5 pm change in the Cu-S(Cys) bond length may change the excitation energies by as much as 2000 cm-1. The effect of the surrounding protein and solvent on the transition energies has been modeled by point charges and is found to be significant for some of the transitions (up to 2000 cm-1).
(Less)
- author
- Pierloot, Kristine
; De Kerpel, Jan O A
; Ryde, Ulf
LU
and Roos, Björn O.
LU
- organization
- publishing date
- 1997-01-08
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of the American Chemical Society
- volume
- 119
- issue
- 1
- pages
- 9 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:0031042264
- ISSN
- 0002-7863
- DOI
- 10.1021/ja962381f
- language
- English
- LU publication?
- yes
- id
- e99b8d2b-c945-4795-b40f-d9d1d9971bb2
- date added to LUP
- 2017-02-04 11:34:21
- date last changed
- 2023-04-07 08:39:07
@article{e99b8d2b-c945-4795-b40f-d9d1d9971bb2,
abstract = {{<p>The electronic spectrum of the blue copper protein plastocyanin has been studied by ab initio multiconfigurational second-order perturbation theory (the CASPT2 method). The six lowest electronic transitions have been calculated and assigned with an error of less than 2000 cm<sup>-1</sup>. The singly occupied orbital in the ground state is Cu 3d-S(Cys) 3pπ antibonding with some N(His) 2pσ character. The bright blue color originates from an electron transfer to this orbital from the corresponding Cu 3d-S(Cys)3pπ bonding orbital. The influence of different ligand models on the spectrum has been thoroughly studied; Cu(imidazole)<sub>2</sub>(SCH<sub>3</sub>)(S(CH<sub>3</sub>)<sub>2</sub>)<sup>+</sup> as a model of CuHis<sub>2</sub>CysMet is the smallest system that gives converged results.The spectrum is surprisingly sensitive to changes in the geometry, especially in the Cu-S bond distances; a 5 pm change in the Cu-S(Cys) bond length may change the excitation energies by as much as 2000 cm<sup>-1</sup>. The effect of the surrounding protein and solvent on the transition energies has been modeled by point charges and is found to be significant for some of the transitions (up to 2000 cm<sup>-1</sup>).</p>}},
author = {{Pierloot, Kristine and De Kerpel, Jan O A and Ryde, Ulf and Roos, Björn O.}},
issn = {{0002-7863}},
language = {{eng}},
month = {{01}},
number = {{1}},
pages = {{218--226}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Journal of the American Chemical Society}},
title = {{Theoretical study of the electronic spectrum of plastocyanin}},
url = {{http://dx.doi.org/10.1021/ja962381f}},
doi = {{10.1021/ja962381f}},
volume = {{119}},
year = {{1997}},
}