Corrections to the Saffman-Delbruck mobility for membrane bound proteins.
Recent experiments (Gambin, Y., R. Lopez-Esparza, M. Reffay, E. Sierecki, N. S. Gov, M. Genest, R. S. Hodes, and W. Urbach. 2006. Proc. Natl. Acad. Sci. USA. 103:2098-2102) have called into question the applicability of the Saffman-Delbrück diffusivity for proteins embedded in the lipid bilayers. We present a simple argument to account for this observation that should be generically valid for a large class of transmembrane and membrane bound proteins. Whenever the protein-lipid interactions locally deform the membrane, that deformation generates new hydrodynamic stresses on the protein-membrane complex leading to a suppression of its mobility. We show that this suppression depends on the protein size in a manner consistent with the work of Gambin et al.
Naji
Ali
A
Department of Physics and Department of Chemistry & Biochemistry, University of California, Santa Barbara, California, USA.
Levine
Alex J
AJ
Pincus
P A
PA
D016477:Artifacts; D003198:Computer Simulation; D004058:Diffusion; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D010713:Phosphatidylcholines / Q000737:chemistry*
D008051:Lipid Bilayers; D008565:Membrane Proteins; D010713:Phosphatidylcholines