help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Biophys. J. BioFAST: First Published March 4, 2005. doi:10.1529/biophysj.105.060426
© 2005 by the Biophysical Society.

A more recent version of this article appeared on May 1, 2005.
This Article
Right arrow Full Text (Rapid PDF)
Right arrow All Versions of this Article:
biophysj.105.060426v1
88/5/3191    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Author home page(s):
Rainer A Böckmann
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Böckmann, R. A
Right arrow Articles by Caflisch, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Böckmann, R. A
Right arrow Articles by Caflisch, A.

BIOPHYSICAL THEORY AND MODELING

Spontaneous Formation of Detergent Micelles around the Outer Membrane Protein OmpX

Rainer A Böckmann 1* and Amedeo Caflisch 1

1 University of Zürich

* To whom correspondence should be addressed. E-mail: rainer{at}bioc.unizh.ch.

Submitted on January 31, 2005
Revised on February 9, 2005
Accepted on 11 February 2005


  Abstract
The structure and flexibility of the outer membrane protein X (OmpX) in a water-detergent solution and in pure water are investigated by molecular dynamics simulations on the 100ns timescale and compared with NMR data. The simulations allow for an unbiased determination of the structure of detergent micelles and the protein-detergent mixed micelle. The short-chain lipid dihexanoylphosphatidylcholine (DHPC) as a detergent aggregates into pure micelles of about 18 molecules and on the protein surface. The detergent binds in the form of a monolayer ring around the hydrophobic {beta}-barrel of OmpX rather than in a micellar-like oblate. About 40 DHPC lipids are sufficient for an effective suppression of water from the surface of the {beta}-barrel region. The phospholipids bind also on the extracellular, protruding {beta}-sheet.Here, polar interactions between charged amino acids and phosphatidylcholine headgroups act as condensation seed for detergent micelle formation. The polar protein surface remains accessible to water molecules. In total, about 90-100 detergent molecules associate within the protein-detergent mixed micelle, in agreement with experimental estimates. The simulation results indicate that OmpX is not a water pore and support the proposed role of the protruding {beta}-sheet as a 'fishing rod'.

Key Words: DHPC, beta-barrel, mixed micelle, molecular dynamics simulation, protein-detergent micelle, spontaneous aggregation




This article has been cited by other articles:


Home page
 MicrobiologyHome page
A. M. Kolodziejek, D. J. Sinclair, K. S. Seo, D. R. Schnider, C. F. Deobald, H. N. Rohde, A. K. Viall, S. S. Minnich, C. J. Hovde, S. A. Minnich, et al.
Phenotypic characterization of OmpX, an Ail homologue of Yersinia pestis KIM
Microbiology, September 1, 2007; 153(9): 2941 - 2951.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
A. Neumoin, B. Arshava, J. Becker, O. Zerbe, and F. Naider
NMR Studies in Dodecylphosphocholine of a Fragment Containing the Seventh Transmembrane Helix of a G-Protein-Coupled Receptor from Saccharomyces cerevisiae
Biophys. J., July 15, 2007; 93(2): 467 - 482.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
S. Esteban-Martin and J. Salgado
Self-Assembling of Peptide/Membrane Complexes by Atomistic Molecular Dynamics Simulations
Biophys. J., February 1, 2007; 92(3): 903 - 912.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2005 by the Biophysical Society.