Advanced

Protein Influence on Electronic Spectra Modeled by Multipoles and Polarizabilities

Söderhjelm, Pär LU ; Husberg, Charlotte; Strambi, Angela; Olivucci, Massimo and Ryde, Ulf LU (2009) In Journal of Chemical Theory and Computation 5(3). p.649-658
Abstract
We have developed automatic methods to calculate multipoles and anisotropic polarizabilities for all atoms and bond centers in a protein and to include such a model in the calculation of electronic properties at any level of quantum mechanical theory. This approach is applied for the calculation of the electronic spectra of retinal in rhodopsin at the CASPT2//CASSCF level (second-order multiconfigurational perturbation theory) for the wild-type protein, as well as two mutants and isorhodopsin in QM/MM structures based on two crystal structures. We also perform a detailed investigation of the importance and distance dependence of the multipoles and the polarizabilities for both the absolute and the relative absorption energies. It is shown... (More)
We have developed automatic methods to calculate multipoles and anisotropic polarizabilities for all atoms and bond centers in a protein and to include such a model in the calculation of electronic properties at any level of quantum mechanical theory. This approach is applied for the calculation of the electronic spectra of retinal in rhodopsin at the CASPT2//CASSCF level (second-order multiconfigurational perturbation theory) for the wild-type protein, as well as two mutants and isorhodopsin in QM/MM structures based on two crystal structures. We also perform a detailed investigation of the importance and distance dependence of the multipoles and the polarizabilities for both the absolute and the relative absorption energies. It is shown that the model of the surrounding protein strongly influences the spectrum and that different models give widely different results. For example, the Amber 1994 and 2003 force fields give excitation energies that differ by up to 16 kJ/mol. For accurate excitation energies, multipoles up to quadrupoles and anisotropic polarizabilities are needed. However, interactions with residues more than 10 A from the chromophore can be treated with a standard polarizable force field without any dipoles or quadrupoles. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Theory and Computation
volume
5
issue
3
pages
649 - 658
publisher
The American Chemical Society
external identifiers
  • wos:000264085600021
  • scopus:65349179259
ISSN
1549-9618
DOI
10.1021/ct800459t
language
English
LU publication?
yes
id
919a5777-96ad-4b91-902b-ce01917d0389 (old id 1404851)
date added to LUP
2009-06-10 15:46:07
date last changed
2017-07-02 03:31:20
@article{919a5777-96ad-4b91-902b-ce01917d0389,
  abstract     = {We have developed automatic methods to calculate multipoles and anisotropic polarizabilities for all atoms and bond centers in a protein and to include such a model in the calculation of electronic properties at any level of quantum mechanical theory. This approach is applied for the calculation of the electronic spectra of retinal in rhodopsin at the CASPT2//CASSCF level (second-order multiconfigurational perturbation theory) for the wild-type protein, as well as two mutants and isorhodopsin in QM/MM structures based on two crystal structures. We also perform a detailed investigation of the importance and distance dependence of the multipoles and the polarizabilities for both the absolute and the relative absorption energies. It is shown that the model of the surrounding protein strongly influences the spectrum and that different models give widely different results. For example, the Amber 1994 and 2003 force fields give excitation energies that differ by up to 16 kJ/mol. For accurate excitation energies, multipoles up to quadrupoles and anisotropic polarizabilities are needed. However, interactions with residues more than 10 A from the chromophore can be treated with a standard polarizable force field without any dipoles or quadrupoles.},
  author       = {Söderhjelm, Pär and Husberg, Charlotte and Strambi, Angela and Olivucci, Massimo and Ryde, Ulf},
  issn         = {1549-9618},
  language     = {eng},
  number       = {3},
  pages        = {649--658},
  publisher    = {The American Chemical Society},
  series       = {Journal of Chemical Theory and Computation},
  title        = {Protein Influence on Electronic Spectra Modeled by Multipoles and Polarizabilities},
  url          = {http://dx.doi.org/10.1021/ct800459t},
  volume       = {5},
  year         = {2009},
}