Lipid-Protein Interactions Alter Line Tensions and Domain Size Distributions in Lung Surfactant Monolayers
Author(s)
Dhar, Prajnaparamita; Eck, Elizabeth; Israelachvili, Jacob N.; Lee, Dong Woog; Min, Younjin; Ramachandran, Arun; Waring, Alan J.; Zasadzinski, Joseph A.; ... Show more Show less![Thumbnail](/bitstream/handle/1721.1/91631/Dhar-2012-Lipid-Protein%20Intera.pdf.jpg?sequence=6&isAllowed=y)
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The size distribution of domains in phase-separated lung surfactant monolayers influences monolayer viscoelasticity and compressibility which, in turn, influence monolayer collapse and set the compression at which the minimum surface tension is reached. The surfactant-specific protein SP-B decreases the mean domain size and polydispersity as shown by fluorescence microscopy. From the images, the line tension and dipole density difference are determined by comparing the measured size distributions with a theory derived by minimizing the free energy associated with the domain energy and mixing entropy. We find that SP-B increases the line tension, dipole density difference, and the compressibility modulus at surface pressures up to the squeeze-out pressure. The increase in line tension due to SP-B indicates the protein avoids domain boundaries due to its solubility in the more fluid regions of the film.
Date issued
2012-01Department
Massachusetts Institute of Technology. Department of Chemical EngineeringJournal
Biophysical Journal
Publisher
Elsevier
Citation
Dhar, Prajnaparamita, Elizabeth Eck, Jacob N. Israelachvili, Dong Woog Lee, Younjin Min, Arun Ramachandran, Alan J. Waring, and Joseph A. Zasadzinski. “Lipid-Protein Interactions Alter Line Tensions and Domain Size Distributions in Lung Surfactant Monolayers.” Biophysical Journal 102, no. 1 (January 2012): 56–65. © 2012 Biophysical Society
Version: Final published version
ISSN
00063495
1542-0086