Cholesterol Research Today is a free monthly online journal that collates and summarizes the latest research about Cholesterol, including details on high cholesterol, hdl, ldl, diet, risks.

Electrochemical and PM-IRRAS studies of the effect of cholesterol on the properties of the headgroup region of a DMPC bilayer supported at a Au(111) electrode.

Bin X, Lipkowski J

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

Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was employed to investigate the interaction of cholesterol with the headgroups of dimyristoylphosphatidycholine (DMPC) molecules under a static electric field. DMPC/cholesterol (7:3 molar ratio) mixtures form a bilayer on a Au(111) electrode surface by fusion and spreading of small unilamellar vesicles. PM-IRRAS experiments provided detailed information concerning the conformation and hydration of headgroups of DMPC bilayers in the presence and absence of 30% cholesterol. The presence of 30% cholesterol increases the space between the headgroups of DMPC molecules and hence increases the hydration of the DMPC/cholesterol mixed bilayer. The conformational state of the headgroups of DMPC molecules in the mixed bilayer is also significantly changed. The phosphate group is closer to the surface compared with the pure DMPC bilayer. The conformation of the -O-C-C-N moiety changes from gauche to trans in the presence of cholesterol.

Published 21 December 2006 in J Phys Chem B Condens Matter Mater Surf Interfaces Biophys, 110(51): 26430-41.
Full-text of this article is available online (may require subscription).

© 2004-2008 Cholesterol Research Today. All Rights Reserved.