Investigation of Temperature Induced Phase Transitions in DOPC and DPPC Phospholipid Bilayers Using Temperature-Controlled Scanning Force Microscopy

TitleInvestigation of Temperature Induced Phase Transitions in DOPC and DPPC Phospholipid Bilayers Using Temperature-Controlled Scanning Force Microscopy
Publication TypeJournal Article
Year of Publication2004
AuthorsLeonenko, Z., E. Finot, H. Ma, T. Dahmns, and D. Cramb
JournalBiophysical Journal
Volume86
Start Page3783
Issue6
Pagination3783-3793
Date Published03/2004
Abstract

Under physiological conditions, multicomponent biological membranes undergo structural changes which help define how the membrane functions. An understanding of biomembrane structure-function relations can be based on knowledge of the physical and chemical properties of pure phospholipid bilayers. Here, we have investigated phase transitions in dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC) bilayers. We demonstrated the existence of several phase transitions in DPPC and DOPC mica-supported bilayers by both atomic force microscopy imaging and force measurements. Supported DPPC bilayers show a broad Lβ–Lα transition. In addition to the main transition we observed structural changes both above and below main transition temperature, which include increase in bilayer coverage and changes in bilayer height. Force measurements provide valuable information on bilayer thickness and phase transitions and are in good agreement with atomic force microscopy imaging data. A De Gennes model was used to characterize the repulsive steric forces as the origin of supported bilayer elastic properties. Both electrostatic and steric forces contribute to the repulsive part of the force plot.

URLhttp://www.sciencedirect.com/science/article/pii/S0006349504744185
DOI10.1529/biophysj.103.036681
Refereed DesignationRefereed
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