Document Detail


How does a membrane protein achieve a vectorial proton transfer via water molecules?
MedLine Citation:
PMID:  19072873     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We present a detailed mechanism for the proton transfer from a protein-bound protonated water cluster to the bulk water directed by protein side chains in the membrane protein bacteriorhodopsin. We use a combined approach of time-resolved Fourier transform infrared spectroscopy, molecular dynamics simulations, and X-ray structure analysis to elucidate the functional role of a hydrogen bond between Ser193 and Glu204. These two residues seal the internal protonated water cluster from the bulk water and the protein surface. During the photocycle of bacteriorhodopsin, a transient protonation of Glu204 leads to a breaking of this hydrogen bond. This breaking opens the gate to the extracellular bulk water, leading to a subsequent proton release from the protonated water cluster. We show in detail how the protein achieves vectorial proton transfer via protonated water clusters in contrast to random proton transfer in liquid water.
Authors:
Steffen Wolf; Erik Freier; Klaus Gerwert
Related Documents :
11442363 - Influence of chelate effects on the water-exchange mechanism of polyaminecarboxylate co...
16294353 - Probing the water coordination of protein-targeted mri contrast agents by pulsed endor ...
17134183 - Nucleating pattern formation in spin-coated polymer blend films with nanoscale surface ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Chemphyschem : a European journal of chemical physics and physical chemistry     Volume:  9     ISSN:  1439-7641     ISO Abbreviation:  Chemphyschem     Publication Date:  2008 Dec 
Date Detail:
Created Date:  2008-12-22     Completed Date:  2009-01-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100954211     Medline TA:  Chemphyschem     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  2772-8     Citation Subset:  IM    
Affiliation:
Department of Biophysics, ND 04 North, Ruhr-University BochumD-44780 Bochum, Germany.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Bacteriorhodopsins / chemistry
Computer Simulation
Hydrogen Bonding*
Membrane Proteins / chemistry*
Protons*
Spectroscopy, Fourier Transform Infrared
Water / chemistry*
X-Ray Diffraction
Chemical
Reg. No./Substance:
0/Membrane Proteins; 0/Protons; 53026-44-1/Bacteriorhodopsins; 7732-18-5/Water

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Dietary exposure to total and toxic arsenic in Belgium: importance of arsenic speciation in North Se...
Next Document:  With personal and professional gratitude: an editor's thank you to J. Willis Hurst.