Trans/13-cis isomerization is essential for both the photocycle and proton pumping of bacteriorhodopsin

Journal Article · Sun Mar 31 23:00:00 EST 1985 · Biophys. J.; (United States)

DOI:https://doi.org/10.1016/S0006-3495(85)83944-8· OSTI ID:5267140

Chang, C H; Govindjee, R; Ebrey, T; Bagley, K A; Dollinger, G; Eisenstein, L; Marque, J; Roder, H; Vittitow, J; Fang, J M

An analogue of bacteriorhodopsin whose chromophore is based on all-trans retinal was studied. A five-membered ring was built around the 13-14 double bond so as to prohibit trans to 13-cis isomerization. No light-induced photochemical changes were seen, other than those due to a small amount (approximately 5%) of unbleached bacteriorhodopsin remaining in the apomembrane used for regeneration. The techniques used included flash photolysis at room and liquid nitrogen temperatures and Fourier-transform infrared difference spectroscopy. When the trans-fixed pigment was incorporated into phospholipid vesicles, no evidence of light-initiated proton pumping could be found. The results indicate that trans to 13-cis isomerization is essential for the photochemical transformation and function of bacteriorhodopsin.

• Research Organization: Univ. of Illinois, Urbana
• OSTI ID: 5267140
• Journal Information: Biophys. J.; (United States), Journal Name: Biophys. J.; (United States) Vol. 4; ISSN BIOJA
• Country of Publication: United States
• Language: English

Related Subjects

550500* -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
BARYONS
CAROTENOIDS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HYDROCARBONS
ISOMERIZATION
MEMBRANE TRANSPORT
NUCLEONS
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
PIGMENTS
PROTEINS
PROTONS
RHODOPSIN
SPECTROPHOTOMETRY
TERPENES