This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.104.048710v1 87/6/3894    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Marrink, S.-J. Articles by Mark, A. E. Search for Related Content PubMed PubMed Citation Articles by Marrink, S.-J. Articles by Mark, A. E.

Molecular View of Hexagonal Phase Formation in Phospholipid Membranes

Department of Biophysical Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands

Correspondence: Address reprint requests to Siewert-Jan Marrink, Tel.: 31-50-363-4339; Fax: 31-50-363-4800; E-mail: marrink{at}chem.rug.nl.

Important biological processes, such as vesicle fusion or budding, require the cell matrix to undergo a transition from a lamellar to a nonlamellar state. Although equilibrium properties of membranes are amenable to detailed theoretical studies, collective rearrangements involved in phase transitions have thus far only been modeled on a qualitative level. Here, for the first time, the complete transition pathway from a multilamellar to an inverted hexagonal phase is elucidated at near-atomic detail using a recently developed coarse-grained molecular dynamics simulation model. Insight is provided into experimentally inaccessible data such as the molecular structure of the intermediates and the kinetics involved. Starting from multilamellar configurations, the spontaneous formation of stalks between the bilayers is observed on a nanosecond timescale at elevated temperatures or reduced hydration levels. The stalks subsequently elongate in a cooperative manner leading to the formation of an inverted hexagonal phase. The rate of stalk elongation is 0.1 nm ns^–1. Within a narrow hydration/temperature/composition range the stalks appear stable and rearrange into the rhombohedral phase.

This article has been cited by other articles:

				S. Yefimov, E. van der Giessen, P. R. Onck, and S. J. Marrink Mechanosensitive Membrane Channels in Action Biophys. J., April 15, 2008; 94(8): 2994 - 3002. [Abstract] [Full Text] [PDF]

				E. R. May, D. I. Kopelevich, and A. Narang Coarse-Grained Molecular Dynamics Simulations of Phase Transitions in Mixed Lipid Systems Containing LPA, DOPA, and DOPE Lipids Biophys. J., February 1, 2008; 94(3): 878 - 890. [Abstract] [Full Text] [PDF]

				S. Esteban-Martin and J. Salgado The Dynamic Orientation of Membrane-Bound Peptides: Bridging Simulations and Experiments Biophys. J., December 15, 2007; 93(12): 4278 - 4288. [Abstract] [Full Text] [PDF]

				S. Baoukina, L. Monticelli, M. Amrein, and D. P. Tieleman The Molecular Mechanism of Monolayer-Bilayer Transformations of Lung Surfactant from Molecular Dynamics Simulations Biophys. J., December 1, 2007; 93(11): 3775 - 3782. [Abstract] [Full Text] [PDF]

				S. Leekumjorn and A. K. Sum Molecular Simulation Study of Structural and Dynamic Properties of Mixed DPPC/DPPE Bilayers Biophys. J., June 1, 2006; 90(11): 3951 - 3965. [Abstract] [Full Text] [PDF]

				Q. Shi and G. A. Voth Multi-Scale Modeling of Phase Separation in Mixed Lipid Bilayers Biophys. J., October 1, 2005; 89(4): 2385 - 2394. [Abstract] [Full Text] [PDF]