Synthetic mimic of key light-sensitive molecule rhodopsin could lead to light-sensitive artificial cells
Triggered by light at two different wavelengths, the 'foldamer' molecule switches between two geometries.
An artificial mimic of rhodopsin, a protein that resides in cell membranes in the retina, has been created by Jonathan Clayden and colleagues at the University of Bristol’s School of Chemistry (Bristol, England), along with collaborators at the Universities of Manchester and Hull.1 The absorption of light by rhodopsin is the first step in the biochemistry of vision; rhodopsin is also used in many areas of photonics and biophotonics research.
The new molecule is a "foldamer" that contains a chromophore switchable between two configurations by different wavelengths of light, and an oligoamide that aids insertion into biological membranes and also communicates changes in configuration along the molecule.
Using molecular design features taken from some antibiotic molecules that also bind to membranes, the researchers were able to design and build a molecule that finds its way into a membrane and switches between different shapes in response to light of specific wavelengths.
The work revealed that unlike many natural molecules, these artificial structures have similar properties in solution and in membranes, making the prediction of their behavior much more reliable.
"This is the first time an artificial mimic of rhodopsin has been created: a discovery that could lead to new ways of building light-sensitive artificial cells and could allow scientists to bypass the usual communication mechanisms used by cells," says Clayden.
1. Matteo De Poli et al., Science (2106); doi: 10.1126/science.aad8352