TY - JOUR
T1 - Lipid-protein interactions alter line tensions and domain size distributions in lung surfactant monolayers
AU - Dhar, Prajnaparamita
AU - Eck, Elizabeth
AU - Israelachvili, Jacob N.
AU - Lee, Dong Woog
AU - Min, Younjin
AU - Ramachandran, Arun
AU - Waring, Alan J.
AU - Zasadzinski, Joseph A.
N1 - Funding Information:
Support for this work comes from National Institutes of Health grants No. HL-092158 and No. ES-015330 (to A.J.W.), grant No. HL-51177 (to P.D., E.E., A.J.W., and J.A.Z.), and grant No. GM-076709 (to Y.M., A.R., D.W.L., J.A.Z., and J.N.I.).
PY - 2012/1/4
Y1 - 2012/1/4
N2 - 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.
AB - 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.
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U2 - 10.1016/j.bpj.2011.11.4007
DO - 10.1016/j.bpj.2011.11.4007
M3 - Article
C2 - 22225798
AN - SCOPUS:84855417496
SN - 0006-3495
VL - 102
SP - 56
EP - 65
JO - Biophysical journal
JF - Biophysical journal
IS - 1
ER -