Use of polymers to promote membrane fusion at the molecular level

COLL 135

Tonya L. Kuhl, Department of Chemical Engineering and Materials Science, University of California at Davis, One Shields Ave, Davis, CA 95616, S. A. Safran, Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 76100, Israel, and Jacob N Israelachvili, Chemical Engineering, University of California, Santa Barbara, CA 93106.
Although poly ethylene glycol (PEG) is widely used in a multiple of biological applications ranging from protein separation, cell fusion, and creating biocompatible surfaces, the forces responsible for these unusual characteristics have remained elusive. Through a variety of techniques ranging from direct surface force measurements (SFA) quasi-elastic light scattering, and 31P-NMR, we have measured the forces between bilayers across aqueous solutions containing PEG. Very different interactions are measured depending on the polymer type, molecular weight and concentration. Some conditions result in repulsion, others in weak adhesion, while still others in strong adhesion and fusion. The implications of the results for testing current theories of polymer mediated interactions in bio-membrane interactions as well as a general membrane fusion mechanism/pathway will be described and illustrated.
 

Nanoscale Imaging of Biological Systems

Division of Colloid and Surface Chemistry
The 225th ACS National Meeting, New Orleans, LA, March 23-27, 2003