Contact
    Start Publications Lipid-Protein Interactions Alter Line Tensions and Domain Size ...
    ←  Publication Finder
    KSV NIMA

    Lipid-Protein Interactions Alter Line Tensions and Domain Size Distributions in Lung Surfactant Monolayers

    Year: 2012

    Journal: BioPhysical Journal, 2012, 102 (1), 56-65, 20131009

    Authors: Prajnaparamita Dhar, Elizabeth Eck, Jacob N. Israelachvili, Dong Woog Lee, Younjin Min, Arun Ramachandran, Alan J. Waring, Joseph A. Zasadzinski

    Organizations: Department of Chemical Engineering, University of Kansas, Lawrence, Kansas, USA; Department of Chemical Engineering, University of California, Santa Barbara, California, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada; Departments of Medicine and Pediatrics, UCLA School of Medicine, Los Angeles, California, USA; Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota, USA

    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.