Jump to main content
Jump to site search


Different hydrogen bonding environments of the Retinal protonated Schiff base control the photoisomerization in Channelrhodopsin-2

Abstract

The first event of the channelrhodopsin-2 (ChR2) photocycle, i.e. trans-to-cis photoisomerization, is studied by means of quantum mechanics/molecular mechanics, taking into account the flexible retinal environment in the ground state. By treating the chromophore at the ab initio multiconfigurational level of theory, we can rationalize the experimental findings based on pump-probe spectroscopy, explaining the different and more complex scenario found for ChR2 in comparison to other rhodopsins. In particular, we find that depending on the hydrogen bonding pattern, different excited states are involved, hence making possible to suggest one pattern as the most productive. Moreover, after photoisomerization the structure of the first photocycle intermediate, P1500, is characterized by simulating the infrared spectrum and compared to available experimental data. This was obtained by extensive molecular dynamics, where the chromophore is described by a tuned semi-empirical method based on density functional theory. The results clearly identify the counterion responsible to accept the proton from the retinal Schiff base.

Back to tab navigation

Supplementary files

Publication details

The article was received on 15 Aug 2018, accepted on 11 Oct 2018 and first published on 11 Oct 2018


Article type: Paper
DOI: 10.1039/C8CP05210G
Citation: Phys. Chem. Chem. Phys., 2018, Accepted Manuscript
  •   Request permissions

    Different hydrogen bonding environments of the Retinal protonated Schiff base control the photoisomerization in Channelrhodopsin-2

    Y. Guo, F. E. Beyle, I. Schapiro, M. Elstner and M. Marazzi, Phys. Chem. Chem. Phys., 2018, Accepted Manuscript , DOI: 10.1039/C8CP05210G

Search articles by author

Spotlight

Advertisements