Membrane shape as a reporter for applied forces.
Recent advances have enabled 3-dimensional reconstructions of biological structures in vivo, ranging in size and complexity from single proteins to multicellular structures. In particular, tomography and confocal microscopy have been exploited to capture detailed 3-dimensional conformations of membranes in cellular processes ranging from viral budding and organelle maintenance to phagocytosis. Despite the wealth of membrane structures available, there is as yet no generic, quantitative method for their interpretation. We propose that by modeling these observed biomembrane shapes as fluid lipid bilayers in mechanical equilibrium, the externally applied forces as well as the pressure, tension, and spontaneous curvature can be computed directly from the shape alone. To illustrate the potential power of this technique, we apply an axial force with optical tweezers to vesicles and explicitly demonstrate that the applied force is equal to the force computed from the membrane conformation.
Lee
Heun Jin
HJ
Department of Applied Physics, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
Peterson
Eric L
EL
Phillips
Rob
R
Klug
William S
WS
Wiggins
Paul A
PA
D022162:Cytoplasmic Vesicles / Q000502:physiology*; D005453:Fluorescence; D007425:Intracellular Membranes / Q000502:physiology*; D008051:Lipid Bilayers / Q000378:metabolism*; D008954:Models, Biological; D052898:Optical Tweezers; D011312:Pressure; D013314:Stress, Mechanical
D008051:Lipid Bilayers