This paper is part of the Proceedings of the 13th International Conference on Retinal Proteins, Barcelona, Spain, 15–19 June 2008.
Water-mediated Spectral Shifts in Rhodopsin and Bathorhodopsin†
Article first published online: 13 JAN 2009
© 2009 The Author. Journal Compilation. The American Society of Photobiology
Photochemistry and Photobiology
Volume 85, Issue 2, pages 517–520, March/April 2009
How to Cite
Sekharan, S. (2009), Water-mediated Spectral Shifts in Rhodopsin and Bathorhodopsin. Photochemistry and Photobiology, 85: 517–520. doi: 10.1111/j.1751-1097.2008.00499.x
- Issue published online: 25 FEB 2009
- Article first published online: 13 JAN 2009
- Received 13 August 2008, accepted 30 September 2008
The role of water molecules in spectral tuning of proteins has been left largely unexplored. This topic is important because changing hydrogen bond patterns during the activation process may lead to spectral shifts which can be of diagnostic value for the underlying structures. Arguments put forward in this article are based on spectral shift calculations of the rhodopsin and bathorhodopsin chromophore due to wat2a and 2b in the presence and absence of the counterion and of the amino acids lining the rhodopsin binding pocket. They show, among others, that a single water molecule can shift the absorbance by up to 0.1 eV or 34 nm depending on the environment of the chromophore.