PATHWAYS OF PROTON-TRANSFER IN THE LIGHT-DRIVEN PUMP BACTERIORHODOPSIN

Authors
Citation
Jk. Lanyi, PATHWAYS OF PROTON-TRANSFER IN THE LIGHT-DRIVEN PUMP BACTERIORHODOPSIN, Experientia, 49(6-7), 1993, pp. 514-517
Citations number
46
Categorie Soggetti
Multidisciplinary Sciences
Journal title
ISSN journal
00144754
Volume
49
Issue
6-7
Year of publication
1993
Pages
514 - 517
Database
ISI
SICI code
0014-4754(1993)49:6-7<514:POPITL>2.0.ZU;2-R
Abstract
The mechanism of proton transport in the light-driven pump bacteriorho dopsin is beginning to be understood. Light causes the all-trans to 13 -cis isomerization of the retinal chromophore. This sets off a sequent ial and directed series of transient decreases in the pK(a)'s of a) th e retinal Schiff base, b) an extracellular proton release complex whic h includes asp-85, and c) a cytoplasmic proton uptake complex which in cludes asp-96. The timing of these pK(a) changes during the photoreact ion cycle causes sequential proton transfers which result in the net m ovement of a proton across the protein, from the cytoplasmic to the ex tracellular surface.