Polymers Slaved Diffusion in Phospholipid Bilayers---A Study Using Single-Molecule Fluorescence

ORAL

Abstract

The translational diffusion of phospholipids DLPC (1,2-dillauroyl-sn-Glycero-3-phosphocholine) in supported fluid bilayers splits into two populations when polyelectrolytes, quaternized poly-4-vinylpyridine (QPVP), adsorb at incomplete surface coverage. Spatially-resolved measurements using fluorescence correlation spectroscopy (FCS) with two-photon excitation show that a slow mode, whose magnitude scales inversely with the degree of polymerization of the adsorbate, coexists with a fast mode characteristic of naked lipid diffusion. Inner and outer leaflets of the bilayer are affected nearly equally. This offers a new mechanism to explain how nano-sized domains with reduced mobility arise in lipid membranes.

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Authors

  • Liangfang Zhang

    Department of Chemical \& Biomolecular Engineering, UIUC, Department of Chemical and Biomolecular Engineering, UIUC

  • Steve Granick

    University of Illinois Urbana-Champaign, Materials Research Laboratory, UIUC, Department of Materials Science \& Engineering, University of Illinois, 1304 W. Green St., Urbana, IL 61801, Univ. of Illinois at Urbana-Champaign, University of Illinois at Urbana-cChampaign, University of IIllinois at Urbana-Champaign, University of Illinois at Urbana-Champaign, University of Illinois