This Article Full Text Full Text (PDF) 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 Enders, O. Articles by Kolb, H.-A. Search for Related Content PubMed PubMed Citation Articles by Enders, O. Articles by Kolb, H.-A.

Structural Calorimetry of Main Transition of Supported DMPC Bilayers by Temperature-Controlled AFM

Institute of Biophysics, University Hannover, Hannover, Germany

Correspondence: Address reprint requests to H.-A. Kolb, Institute of Biophysics, University Hannover, Herrenhäuser Str. 2, D-30419 Hannover, Germany. Fax: 49-511-762-5916; E-mail: kolb{at}biophysik.uni-hannover.de.

Atomic force microscopy at high temperature resolution () provided a quantitative structural calorimetry of the transition from the fluid (L)- to the gel (P_ß')-phase of supported dimyristoylphosphatidylcholine bilayers. Besides a determination of the main transition temperature (T₀) and the van't Hoff transition enthalpy (H_vH), the structural analysis in the nm-scale at T close to T₀ of the ripple phase allowed an experimental estimation of the area of cooperative units from small lipid domains. Thereby, the corresponding transition enthalpy (H) of single molecules could be determined. The lipid organization and the corresponding parameters T₀ and H_vH (H) were modulated by heptanol or external Ca²⁺ and compared with physiological findings. The size of the cooperative unit was not significantly affected by the presence of 1 mM heptanol. The observed linear relationship of H_vH and T₀ was discussed in terms of a change in heat capacity.

This article has been cited by other articles:

				S. Garcia-Manyes, G. Oncins, and F. Sanz Effect of Temperature on the Nanomechanics of Lipid Bilayers Studied by Force Spectroscopy Biophys. J., December 1, 2005; 89(6): 4261 - 4274. [Abstract] [Full Text] [PDF]

				A. Charrier and F. Thibaudau Main Phase Transitions in Supported Lipid Single-Bilayer Biophys. J., August 1, 2005; 89(2): 1094 - 1101. [Abstract] [Full Text] [PDF]