Interaction of the Fluorophenyl Analog of Retinal with Proteorhodopsin from Exiguobacterium sibiricum

Abstract— We have developed an alternative method for the synthesis of analog natural retinal, which contains p -fluorophenyl fragment instead trimethylcyclohexene ring. The proposed scheme target all-E -isomer retinoid consists using C 5 -phosphonate that terminal nitrile group under Horner–Emmons reaction conditions. It has been shown this is more efficient and provides a higher total yield product than previously described variant. procedure preparation microbial proteorhodopsin ESRh from Exiguobacterium sibiricum , modified chromophore. found that, as in case bacterioopsin Halobacterium salinarum replacement ring chromophore by does not prevent formation artificial pigment F-Phe-ESRh ESRh, preserves cycle photochemical reactions. Certain differences between properties native recombinant its including shift absorption maximum to short-wavelength region, M intermediate at lower pH values, presence “long-lived M,” general slowdown photocycle. reduced stability resulting prolonged exposure visible light also demonstrated.