2001 Volume 41 Issue 6 Pages 284-289
The presence of multiple types of cone visual pigments with different absorption maxima is one of the molecular bases of colour vision. Because all of the visual pigments investigated so far contain 11-cis-retinal or its derivatives, the spectral shift would reflect the specific interaction of 11-cis-retinal with nearby amino acid residues. In addition, there is a unique mechanism of spectral red-shift observed in the visual pigments that have a chloride binding site. Here, we summarize recent investigations on the mechanism of spectral tuning in visual pigments including those having a chloride-binding site.
