Mechanism of Proton Transport in Bacteriorhodopsin
نویسندگان
چکیده
منابع مشابه
Mechanism of primary proton transfer in bacteriorhodopsin.
Recent structures of putative intermediates in the bacteriorhodopsin photocycle have provided valuable snapshots of the mechanism by which protons are pumped across the membrane. However, key steps remain highly controversial, particularly the proton transfer occurring immediately after retinal trans-->cis photoisomerization. The gradual release of stored energy is inherently nonequilibrium: wh...
متن کاملBacteriorhodopsin: a high-resolution structural view of vectorial proton transport.
Recent 3-D structures of several intermediates in the photocycle of bacteriorhodopsin (bR) provide a detailed structural picture of this molecular proton pump in action. In this review, we describe the sequence of conformational changes of bR following the photoisomerization of its all-trans retinal chromophore, which is covalently bound via a protonated Schiff base to Lys216 in helix G, to a 1...
متن کاملProton affinity changes driving unidirectional proton transport in the bacteriorhodopsin photocycle.
Bacteriorhodopsin is the smallest autonomous light-driven proton pump. Proposals as to how it achieves the directionality of its trans-membrane proton transport fall into two categories: accessibility-switch models in which proton transfer pathways in different parts of the molecule are opened and closed during the photocycle, and affinity-switch models, which focus on changes in proton affinit...
متن کاملUnraveling the mechanism of proton translocation in the extracellular half-channel of bacteriorhodopsin.
Bacteriorhodopsin, a light activated protein that creates a proton gradient in halobacteria, has long served as a simple model of proton pumps. Within bacteriorhodopsin, several key sites undergo protonation changes during the photocycle, moving protons from the higher pH cytoplasm to the lower pH extracellular side. The mechanism underlying the long-range proton translocation between the centr...
متن کاملProton transport by bacteriorhodopsin in planar membranes assembled from air-water interface films
Bacteriorhodopsin, in known amounts and controlled orientation, is incorporated into planar membrane films. These films are formed by the sequential transfer of two air-water interface films onto a thin, hydrophilic, electrically conductive support cast from nitrocellulose. The films are easily accessible to electrical measurements and to control of the ionic milieu on either side of the membra...
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ژورنال
عنوان ژورنال: Seibutsu Butsuri
سال: 1999
ISSN: 0582-4052,1347-4219
DOI: 10.2142/biophys.39.s60_1