Estimation of molecular averages and equilibrium fluctuations in lipid bilayer systems from the excess heat capacity function

Ernesto Freire, Rodney Biltonen

Research output: Contribution to journalArticlepeer-review

Abstract

It is demonstrated that the bilayer partition function can be numerically obtained from scanning calorimetric data without assuming a particular model for the gel-liquid crystalline transition. From this partition function, the enthalpy, entropy and volume changes accompanying the transition can be calculated. In the limit of very large systems, the method of the grand partition function allows calculation of cluster model distribution functions from which average sizes of gel and liquid-crystal clusters, cluster densities and equilibrium fluctuations are obtained. These results indicate that the main transition in phospholipid bilayers proceeds through the formation of clusters and that these clusters are not static domains but highly fluctuating entities. These fluctuations in cluster size are approximately equal to the average cluster size and give rise to localized density and volume fluctuations. The magnitude of these fluctuations is affected by the radius of curvature of the bilayer and by the addition of small molecular weight compounds to the system.

Original languageEnglish (US)
Pages (from-to)54-68
Number of pages15
JournalBBA - Biomembranes
Volume514
Issue number1
DOIs
StatePublished - Dec 4 1978

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

Fingerprint Dive into the research topics of 'Estimation of molecular averages and equilibrium fluctuations in lipid bilayer systems from the excess heat capacity function'. Together they form a unique fingerprint.

Cite this