An investigation of the electrochemical cycle of bacteriorhodopsin analogs with the modified ring

Synthetic Control of Retinal Photochemistry and Photophysics in Solution

“…Addressing other aspects of opsin photochemistry is more complex, and a widely adopted approach has been to prepare pigment analogues containing retinal derivatives with modified backbones. ,− Taken together, these studies point toward protein-induced steric and electrostatic interactions as a primary determinant in the outcome of the photoreaction. − To the best of our knowledge, only one study on the photochemistry of a RPSB with a modified retinal backbone (11- cis -13-demethyl RPSB) in solution has been reported . In our recent exploratory work, we demonstrated that addition of a methyl group to the 10-position of the retinal backbone dramatically affects RPSB solution photochemistry, reducing the ESL by almost 1 order of magnitude from 4 to 0.55 ps toward the lifetime observed in bR (0.5 ps).…”

Investigation of the Spectral Properties of the Crowned Retinals and Bacteriorhodopsin Analogs

“…The spectral parameters of these pigments (ABR-1 a-e) are presented in the Table 1. It should be noted that k max of ABR is located within the wavelength range typical of pigments, in which trimethylcyclohexene ring of the retinal is replaced by other aromatic rings (460-530 nm) [2,5].…”

Carotenoids and polyterpenoids

“…~~ Spectra have been obtained of ,us and ms intermediates in the photocycle of bacteriorhodopsin products containing ring phenyl (71) and fluorophenyl (72) analogues of retinal. 141 The naphthylretinal (75) gave two distinct forms of bacteriorhodopsin analogue which had A,,, at 503 and 442 nm r e ~p e c t i v e l y . ' ~~* ~~~ Although the protein-chromophore interactions were different, the binding sites were the same and the two forms could be interconverted by changes in pH or by…”