Biophysical Society Thematic Meeting - October 13-15, 2015

Biophysics of Proteins at Surfaces: Assembly, Activation, Signaling

Thursday Speaker Abstracts

High-speed Atomic Force Microscopy: The Dynamics and Interaction of Protein and Membrane Surfaces Simon Scheuring , Lorena Redondo, Atsushi Miyagi, Felix Rico, Ignacio Casuso. INSERM / Aix-Marseille University, Marseille, France. The advent of high-speed atomic force microscopy (HS-AFM; [1]) has opened a novel research field for the dynamic analysis of single bio-molecules [2,3,4,5]. The endosomal sorting complex required for transport (ESCRT) mediates membrane remodeling in cells. We used HS-AFM to study the ESCRT-III complex, i.e. Snf7. HS-AFM movies reveal Snf7 complex formation from filaments to maturated assemblies: Interfilament dynamics provide basis for a mechanistic understanding of tension generation for membrane fission [6]. Annexin-V (A5) binds to negatively charged lipid bilayers in the presence of Ca2+ for membrane healing. Using a HS- AFM coupled to a buffer exchange flow system, we found two classes with different apparent affinity in the reversible association-dissociation of A5 to the membrane [7]. [1] T. Ando, et al., Proceedings of the National Academy of Sciences 98, 12468 (2001) [2] I. Casuso, et al., Nature Nanotechnology, 7, 525 (2012) [3] A. Colom, et al., Journal of Molecular Biology, 423, 249 (2012) [4] A. Colom, et al., Nature Communications, DOI:10.1038/ncomms3155 (2013)

[5] F. Rico, et al., Science, 342, 741 (2013) [6] N. Chiaruttini, et al., in press (2015) [7] A. Miyagi, et al., submitted (2015)

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