Abstract
A primary process in vision is the cis-trans photoisomerization of a chromophore of rhodopsin, called retinal. In the present work, we have performed ultrafast time-resolved spectroscopy of octopus rhodopsin using a sub-5-fs pulse laser. In comparison with our previous study on bacteriorhodopsin, we found that octopus rhodopsin follows similar dynamics after photoexcitation but with different time constants. Spectrogram analysis showed that a C═N stretching mode appeared directly after photoexcitation. After reaching the conical intersection region at 80 fs, the overlapping hydrogen out-of-plane and in-plane C═C-H modes emerged as distinct peaks at ~200 fs, finishing a rapid relaxation along the coordinate related with these modes. The intensities of these peaks and a C═C stretching mode were found to be modulated at a period of ∼500 fs, reflecting torsional motion around the C═C double bond before thermalization with the distribution of structural variations in the all-trans structure in configuration space.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
