Light-Activated Reversible Imine Isomerization: Towards a Photochromic Protein Switch.

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.

SUBMITTER: Berbasova T 

PROVIDER: S-EPMC4835339 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature