PHOTOCYCLE AND PROTON TRANSLOCATION IN BACTERIORHODOPSIN Bacteriorhodopsin (bR), a natural photochromic protein from Halobacterium salinarum (formerly H. halo
نویسنده
چکیده
This review deals with the role of carboxylic amino acids in the proton transport activity of bacteriorhodopsin. The main focus is on the infrared data, which allow direct monitoring of the protonation/deprotonation of specific residues dur ing the proton movement in the course of the photocycle. Additional attention is paid to the potential use of carboxylic acids in proteins as internal sensors, based on the sensitivity of their IR frequencies to the immediate environment.
منابع مشابه
Photoexcitation of the O intermediate of bacteriorhodopsin and its mutant E204Q
The light-driven proton pump, bacteriorhodopsin (bR), in Halobacterium salinarum carries out its function proceeding through intermediates named J, K, L, M, N, and O (for recent reviews see [1, 2]). To understand the molecular mechanism of light-energy transduction many methods are used [3]. One of them, photoexcitation of the intermediates, provides valuable information on their particular rôl...
متن کاملG-protein-coupled receptor domain overexpression in Halobacterium salinarum: long-range transmembrane interactions in heptahelical membrane proteins.
The aminergic alpha(2b)-adrenergic receptor (alpha(2b)-AR) third intracellular loop (alpha(2b)-AR 3i) mediates receptor subcellular compartmentalization and signal transduction processes via ligand-dependent interaction with G(i)- and G(o)- proteins. To understand the structural origins of these processes we engineered several lengths of alpha(2b)-AR 3i into the third intracellular loop of the ...
متن کاملVoltage Dependence of Proton Pumping by Bacteriorhodopsin Mutants with Altered Lifetime of the M Intermediate
The light-driven proton pump bacteriorhodopsin (BR) from Halobacterium salinarum is tightly regulated by the [H(+)] gradient and transmembrane potential. BR exhibits optoelectric properties, since spectral changes during the photocycle are kinetically controlled by voltage, which predestines BR for optical storage or processing devices. BR mutants with prolonged lifetime of the blue-shifted M i...
متن کاملA light-driven proton pump from Haloterrigena turkmenica: functional expression in Escherichia coli membrane and coupling with a H+ co-transporter.
A gene encoding putative retinal protein was cloned from Haloterrigena turkmenica (JCM9743). The deduced amino acid sequence was most closely related to that of deltarhodopsin, which functions as a light-driven H+ pump and was identified in a novel strain Haloterrigena sp. arg-4 (K. Ihara, T. Uemura, I. Katagiri, T. Kitajima-Ihara, Y. Sugiyama, Y. Kimura, Y. Mukohata, Evolution of the archaeal ...
متن کاملFTIR spectroscopy of bacteriorhodopsin microcrystals at Beamline 1.4
Bacteriorhodopsin (bR) is the sole protein component of the purple membrane of Halobacterium salinarium . The function of bR in vivo is to convert solar energy into a pH gradient across the cell membrane which the organism uses to drive ATP synthesis . Bacteriorhodopsin undergoes a light-induced cycle of physicochemical changes for for every proton it pumps out of the cell. The photocycle of bR...
متن کامل