Abstract
We examined the shift of absorption maxima between the chlamydomonas-type channelrhodopsins (ChRs) and bacteriorhodopsin (BR). Starting from the BR X-ray structure, we modeled the color tuning in the binding pockets of the ChRs by mutating up to 28 amino acids in the vicinity of the chromophore. By applying the efficient self-consistent charge density functional tight binding (SCC-DFTB) method in a quantum mechanical/molecular mechanical (QM/MM) framework, including explicit polarization and calculating excitation energies with the semiempirical OM2/MRCI method and the ab initio SORCI method, we have shown that multiple mutations in the binding pocket of BR causes large hypsochromic shifts that are of the same order as the experimentally observed shifts of the absorption maxima between BR and the ChRs. This study further demonstrates that mutations in the proximity of the Schiff base and complex counterion lead to a stronger but more flexible interaction with the retinal, which could serve as a possible explanation for the spectral patterns found in the ChRs.
| Original language | English |
|---|---|
| Pages (from-to) | 15119-15128 |
| Number of pages | 10 |
| Journal | Journal of Physical Chemistry B |
| Volume | 115 |
| Issue number | 50 |
| DOIs | |
| Publication status | Published - 2011 Dec 22 |
| Externally published | Yes |
Fingerprint
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry
Cite this
Color tuning in binding pocket models of the chlamydomonas-type channelrhodopsins. / Welke, Kai; Frähmcke, Jan S.; Watanabe, Hiroshi; Hegemann, Peter; Elstner, Marcus.
In: Journal of Physical Chemistry B, Vol. 115, No. 50, 22.12.2011, p. 15119-15128.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Color tuning in binding pocket models of the chlamydomonas-type channelrhodopsins
AU - Welke, Kai
AU - Frähmcke, Jan S.
AU - Watanabe, Hiroshi
AU - Hegemann, Peter
AU - Elstner, Marcus
PY - 2011/12/22
Y1 - 2011/12/22
N2 - We examined the shift of absorption maxima between the chlamydomonas-type channelrhodopsins (ChRs) and bacteriorhodopsin (BR). Starting from the BR X-ray structure, we modeled the color tuning in the binding pockets of the ChRs by mutating up to 28 amino acids in the vicinity of the chromophore. By applying the efficient self-consistent charge density functional tight binding (SCC-DFTB) method in a quantum mechanical/molecular mechanical (QM/MM) framework, including explicit polarization and calculating excitation energies with the semiempirical OM2/MRCI method and the ab initio SORCI method, we have shown that multiple mutations in the binding pocket of BR causes large hypsochromic shifts that are of the same order as the experimentally observed shifts of the absorption maxima between BR and the ChRs. This study further demonstrates that mutations in the proximity of the Schiff base and complex counterion lead to a stronger but more flexible interaction with the retinal, which could serve as a possible explanation for the spectral patterns found in the ChRs.
AB - We examined the shift of absorption maxima between the chlamydomonas-type channelrhodopsins (ChRs) and bacteriorhodopsin (BR). Starting from the BR X-ray structure, we modeled the color tuning in the binding pockets of the ChRs by mutating up to 28 amino acids in the vicinity of the chromophore. By applying the efficient self-consistent charge density functional tight binding (SCC-DFTB) method in a quantum mechanical/molecular mechanical (QM/MM) framework, including explicit polarization and calculating excitation energies with the semiempirical OM2/MRCI method and the ab initio SORCI method, we have shown that multiple mutations in the binding pocket of BR causes large hypsochromic shifts that are of the same order as the experimentally observed shifts of the absorption maxima between BR and the ChRs. This study further demonstrates that mutations in the proximity of the Schiff base and complex counterion lead to a stronger but more flexible interaction with the retinal, which could serve as a possible explanation for the spectral patterns found in the ChRs.
UR - http://www.scopus.com/inward/record.url?scp=84859397119&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84859397119&partnerID=8YFLogxK
U2 - 10.1021/jp2085457
DO - 10.1021/jp2085457
M3 - Article
C2 - 22077286
AN - SCOPUS:84859397119
VL - 115
SP - 15119
EP - 15128
JO - Journal of Physical Chemistry B Materials
JF - Journal of Physical Chemistry B Materials
SN - 1520-6106
IS - 50
ER -