Light‐Activated Reversible Imine Isomerization: Towards a Photochromic Protein Switch |
| |
| Authors: | Dr Tetyana Berbasova Elizabeth M Santos Meisam Nosrati Dr Chrysoula Vasileiou Prof?Dr James H Geiger Prof Babak Borhan |
| |
| Affiliation: | Department of Chemistry, Michigan State University, East Lansing, MI, USA |
| |
| Abstract: | Mutants of cellular retinoic acid‐binding protein II (CRABPII), engineered to bind all‐trans‐retinal as an iminium species, demonstrate photochromism upon irradiation with light at different wavelengths. UV light irradiation populates the cis‐imine geometry, which has a high pKa, leading to protonation of the imine and subsequent “turn‐on” of color. Yellow light irradiation yields the trans‐imine isomer, which has a depressed pKa, leading to loss of color because the imine is not protonated. The protein‐bound retinylidene chromophore undergoes photoinduced reversible interconversion between the colored and uncolored species, with excellent fatigue resistance. |
| |
| Keywords: | imines isomerization photochemistry protein engineering retinal |
|
|
