Prev. Article Next Article Table of Contents

Communication

Cholesterol Shows Preference for the Interior of Polyunsaturated Lipid Membranes

Supporting Info

Siewert J. Marrink,*^† Alex H. de Vries,^† Thad. A. Harroun,^‡ John Katsaras,^‡^§ and Stephen R. Wassall^¶

Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands, Department of Physics, Brock University, St. Catharines, ON L2S 3A1, Canada, Canadian Neutron Beam Centre, National Research Council, Chalk River, ON K0J 1J0, Canada, and Department of Physics, Indiana UniversityPurdue University Indianapolis, Indianapolis, Indiana 46202-3273

J. Am. Chem. Soc., 2008, 130 (1), pp 10–11

DOI: 10.1021/ja076641c

Publication Date (Web): December 13, 2007

In papers with more than one author, the asterisk indicates the name of the author to whom inquiries about the paper should be addressed.

†

University of Groningen.

‡

Brock University.

Canadian Neutron Beam Centre.

Indiana University−Purdue University Indianapolis.

, s.j.marrink@rug.nl

Abstract

Recent neutron scattering experiments showed a striking manifestation of the aversion between polyunsaturated fatty acid (PUFA)-containing lipids and cholesterol. Selectively deuterated cholesterol/ 1,2-diarachidonylphosphatidylcholine (DAPC) samples revealed that the hydroxyl of the sterol resides at the center of the bilayer. Here we use a recently parametrized coarse grain simulation model to shed light on these puzzling experimental observations. Using a simulation setup in close correspondence to the experimental conditions, we reproduce the experimental neutron scattering profiles to a large extent. The simulations allow us to analyze the behavior of cholesterol in detail; we show that the interaction of cholesterol with the PUFA chains of DAPC leads to a fast flip-flop rate for the sterol and an increased preference of the sterol for the unusual location embedded between the monolayer leaflets.

View: Full Text HTML | Hi-Res PDF | PDF w/ Links