This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.104.058347v1 89/1/592    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 Bin, X. Articles by Lipkowski, J. Search for Related Content PubMed PubMed Citation Articles by Bin, X. Articles by Lipkowski, J.

Electrochemical and PM-IRRAS Studies of the Effect of Cholesterol on the Structure of a DMPC Bilayer Supported at an Au (111) Electrode Surface, Part 1: Properties of the Acyl Chains

Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1

Correspondence: Address reprint requests to Jacek Lipkowski, E-mail: lipkowski{at}chembio.uoguelph.ca.

Charge density measurements and polarization modulation infrared reflection absorption spectroscopy were employed to investigate the spreading of small unilamellar vesicles of a dimyristoylphosphatidylcholine (DMPC)/cholesterol (7:3 molar ratio) mixture onto an Au (111) electrode surface. The electrochemical experiments demonstrated that vesicles fuse and spread onto the Au (111) electrode surface, forming a bilayer, at rational potentials –0.4 V < (E – E_pzc) < 0.4 V or field strength <6x10⁷ V m^–1. Polarization modulation infrared reflection absorption spectroscopy experiments provided information concerning the conformation and orientation of the acyl chains of DMPC molecules. Deuterated DMPC was used to subtract the contribution of C-H stretching bands of cholesterol and of the polar head region of DMPC from spectra in the C-H stretching region. The absorption spectra of the C-H stretch bands in the acyl chains were determined in this way. The properties of the DMPC/cholesterol bilayer have been compared with the properties of a pure DMPC bilayer. The presence of 30% cholesterol gives a thicker and more fluid bilayer characterized by a lower capacity and lower tilt angle of the acyl chains.

This article has been cited by other articles:

				H. Bensikaddour, N. Fa, I. Burton, M. Deleu, L. Lins, A. Schanck, R. Brasseur, Y. F. Dufrene, E. Goormaghtigh, and M.-P. Mingeot-Leclercq Characterization of the Interactions between Fluoroquinolone Antibiotics and Lipids: a Multitechnique Approach Biophys. J., April 15, 2008; 94(8): 3035 - 3046. [Abstract] [Full Text] [PDF]