Change search
ReferencesLink to record
Permanent link

Direct link
Segregated Phases in Pulmonary Surfactant Membranes Do Not Show Coexistence of Lipid Populations with Differentiated Dynamic Properties
Umeå University, Faculty of Science and Technology, Department of Chemistry.
Show others and affiliations
2009 (English)In: Biophysical Journal, Vol. 97, no 5, 1381-1389 p.Article in journal (Refereed) Published
Abstract [en]

The composition of pulmonary surfactant membranes and films has evolved to support a complex lateral structure, including segregation of ordered/disordered phases maintained up to physiological temperatures. In this study, we have analyzed the temperature-dependent dynamic properties of native surfactant membranes and membranes reconstituted from two surfactant hydrophobic fractions (i.e., all the lipids plus the hydrophobic proteins SP-B and SP-C, or only the total lipid fraction). These preparations show micrometer-sized fluid ordered/disordered phase coexistence, associated with a broad endothermic transition ending close to 37°C. However, both types of membrane exhibit uniform lipid mobility when analyzed by electron paramagnetic resonance with different spin-labeled phospholipids. A similar feature is observed with pulse-field gradient NMR experiments on oriented membranes reconstituted from the two types of surfactant hydrophobic extract. These latter results suggest that lipid dynamics are similar in the coexisting fluid phases observed by fluorescence microscopy. Additionally, it is found that surfactant proteins significantly reduce the average intramolecular lipid mobility and translational diffusion of phospholipids in the membranes, and that removal of cholesterol has a profound impact on both the lateral structure and dynamics of surfactant lipid membranes. We believe that the particular lipid composition of surfactant imposes a highly dynamic framework on the membrane structure, as well as maintains a lateral organization that is poised at the edge of critical transitions occurring under physiological conditions.

Place, publisher, year, edition, pages
Elsevier Inc , 2009. Vol. 97, no 5, 1381-1389 p.
URN: urn:nbn:se:umu:diva-25787DOI: 10.1016/j.bpj.2009.06.040OAI: diva2:233870
Available from: 2009-09-03 Created: 2009-09-03 Last updated: 2011-02-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Orädd, GregerLindblom, Göran
By organisation
Department of Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 89 hits
ReferencesLink to record
Permanent link

Direct link