This Article Full Text Full Text (PDF) supplemental All Versions of this Article: biophysj.105.065581v1 89/6/4261    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 Garcia-Manyes, S. Articles by Sanz, F. Search for Related Content PubMed PubMed Citation Articles by Garcia-Manyes, S. Articles by Sanz, F.

Effect of Temperature on the Nanomechanics of Lipid Bilayers Studied by Force Spectroscopy

Department of Physical Chemistry, Universitat de Barcelona, 08028 Barcelona, Spain

Correspondence: Address reprint requests to Fausto Sanz, Tel.: 34 934021240; Fax: 34 934021231; E-mail: fsanz{at}ub.edu.

The effect of temperature on the nanomechanical response of supported lipid bilayers has been studied by force spectroscopy with atomic force microscopy. We have experimentally proved that the force needed to puncture the lipid bilayer (F_y) is temperature dependent. The quantitative measurement of the evolution of F_y with temperature has been related to the structural changes that the surface undergoes as observed through atomic force microscopy images. These studies were carried out with three different phosphatidylcholine bilayers with different main phase transition temperature (T_M), namely, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, and 2-dilauroyl-sn-glycero-3-phosphocholine. The solid-like phase shows a much higher F_y than the liquid-like phase, which also exhibits a jump in the force curve. Within the solid-like phase, F_y decreases as temperature is increased and suddenly drops as it approaches T_M. Interestingly, a "well" in the F_y versus temperature plot occurs around T_M, thus proving an "anomalous mechanical softening" around T_M. Such mechanical softening has been predicted by experimental techniques and also by molecular dynamics simulations and interpreted in terms of water ordering around the phospholipid headgroups. Ion binding has been demonstrated to increase F_y, and its influence on both solid and liquid phases has also been discussed.

This article has been cited by other articles:

				G. Oncins, L. Picas, J. Hernandez-Borrell, S. Garcia-Manyes, and F. Sanz Thermal Response of Langmuir-Blodgett Films of Dipalmitoylphosphatidylcholine Studied by Atomic Force Microscopy and Force Spectroscopy Biophys. J., October 15, 2007; 93(8): 2713 - 2725. [Abstract] [Full Text] [PDF]

				T. A. Spurlin and A. A. Gewirth Poly-L-Lysine-Induced Morphology Changes in Mixed Anionic/Zwitterionic and Neat Zwitterionic-Supported Phospholipid Bilayers Biophys. J., October 15, 2006; 91(8): 2919 - 2927. [Abstract] [Full Text] [PDF]