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High-speed atomic force microscopy shows that annexin V stabilizes membranes on the second timescale. Annexins are abundant cytoplasmic proteins that can bind to negatively charged phospholipids in a Ca2+-dependent manner, and are known to play a role in the storage of Ca2+ and membrane healing. Little is known, however, about the dynamic processes of protein– Ca2+–membrane assembly and disassembly. Here we show that high-speed atomic force microscopy (HS-AFM) can be used to repeatedly induce and disrupt annexin assemblies and study their structure, dynamics and interactions. Our HS-AFM set-up is adapted for such biological applications through the integration of a pumping system for buffer exchange and a pulsed laser system for uncaging caged compounds. We find that biochemically identical annexins (annexin V) display different effective Ca2+ and membrane affinities depending on the assembly location, providing a wide Ca2+ buffering regime while maintaining membrane stabilization. We also show that annexin is membrane-recruited and forms stable supramolecular assemblies within ∼5 s in conditions that are comparable to a membrane lesion in a cell. Molecular dynamics simulations provide atomic detail of the role played by Ca2+ in the reversible binding of annexin to the membrane surface. Nature Nanotechnology, 2016.

Recent publications


Water-Controlled Switching in Rotaxanes
Shuangli Du; Haohao Fu; Xueguang Shao; Christophe Chipot; Wensheng Cai;
The Journal of Physical Chemistry C (2018) 122 (16): 9229-9234

Accurate Estimation of the Standard Binding Free Energy of Netropsin with DNA
Hong Zhang; Hugo Gattuso; Elise Dumont; Wensheng Cai; Antonio Monari; Christophe Chipot; Francois Dehez;
Molecules (2018) 23 (2): 129-
BFEE: A User-Friendly Graphical Interface Facilitating Absolute Binding Free-Energy Calculations
Haohao Fu; James C. Gumbart; Haochuan Chen; Xueguang Shao; Wensheng Cai; Christophe Chipot;
Journal of Chemical Information and Modeling (2018) 58 (3): 556-560

News

- Renewal of the Laboratoire International Associé CNRS-University of Illinois at Urbana-Champaign on November 2016
- An update of ParseFEP is available in the latest version of VMD.
- 新的分子动力学讲义 (Dissemination).
 

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