| Effects of hydrophobic surfactant proteins on collapse of pulmonary surfactant monolayers. | |
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MedLine Citation:
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PMID: 17720730 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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To determine if hydrophobic surfactant proteins affect the stability of pulmonary surfactant monolayers at an air/water interface, the studies reported here compared the kinetics of collapse for the complete set of lipids in calf surfactant with and without the proteins. Monomolecular films spread at the surface of captive bubbles were compressed at 37 degrees C to surface pressures above 46 mN/m, at which collapse first occurred. The rate of area-compression required to maintain a constant surface pressure was measured to directly determine the rate of collapse. For films with and without the proteins, higher surface pressures initially produced faster collapse, but the rates then reached a maximum and decreased to values <0.04 min(-1) above 53 mN/m. The maximum rate for the lipids with the proteins (1.22 +/- 0.28 min(-1)) was almost twice the value for the lipids alone (0.71 +/- 0.15 min(-1)). Because small increments in surface pressure produced large shifts in the rate close to the fastest collapse, compressions at a series of constant speeds also established the threshold rate required to achieve high surface pressure as an indirect indication of the fastest collapse. Both samples produced a sharply defined threshold that occurred at slightly faster compression with the proteins present, supporting the conclusion of the direct measurements that the proteins produce a faster maximum rate of collapse. Our results indicate that at 47-53 mN/m, the hydrophobic surfactant proteins destabilize the compressed monolayers and tend to limit access to the higher surface pressures at which the lipid films become metastable. |
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Authors:
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Florence Lhert; Wenfei Yan; Samares C Biswas; Stephen B Hall |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural Date: 2007-08-24 |
Journal Detail:
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Title: Biophysical journal Volume: 93 ISSN: 1542-0086 ISO Abbreviation: Biophys. J. Publication Date: 2007 Dec |
Date Detail:
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Created Date: 2007-11-29 Completed Date: 2008-01-16 Revised Date: 2009-11-18 |
Medline Journal Info:
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Nlm Unique ID: 0370626 Medline TA: Biophys J Country: United States |
Other Details:
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Languages: eng Pagination: 4237-43 Citation Subset: IM |
Affiliation:
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Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon 97239, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Hydrophobicity Membranes, Artificial* Molecular Conformation Phase Transition Phospholipids / chemistry* Pulmonary Surfactant-Associated Proteins / chemistry* Pulmonary Surfactants / chemistry* Surface Properties |
| Grant Support | |
ID/Acronym/Agency:
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HL60914/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Membranes, Artificial; 0/Phospholipids; 0/Pulmonary Surfactant-Associated Proteins; 0/Pulmonary Surfactants |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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