Work

A Photoisomerizing Rhodopsin Mimic Observed at Atomic Resolution

Year: 2016

Type: article

Abstract: The members of the rhodopsin family of proteins are involved in many essential light-dependent processes in biology. Specific photoisomerization of the protein-bound retinylidene PSB at a specified wavelength range of light is at the heart of all of these systems. Nonetheless, it has been difficult to reproduce in an engineered system. We have developed rhodopsin mimics, using intracellular lipid binding protein family members as scaffolds, to study fundamental aspects of protein/chromophore interactions. Herein we describe a system that specifically isomerizes the retinylidene protonated Schiff base both thermally and photochemically. This isomerization has been characterized at atomic resolution by quantitatively interconverting the isomers in the crystal both thermally and photochemically. This event is accompanied by a large pKa change of the imine similar to the pKa changes observed in bacteriorhodopsin and visual opsins during isomerization.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.6b03681

Authors: Meisam Nosrati, Tetyana Berbasova, Chrysoula Vasileiou, Babak Borhan, James H. Geiger

Institution: Michigan State University

Language: English

Topic: Photoreceptor and optogenetics research

Subfield: Cellular and Molecular Neuroscience

Field: Neuroscience

Domain: Life Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Awards: G374797252, Protein/Chromphore Interactions via Protein Design: Interrogation and Application