Related Experiment Video
Updated: Jun 13, 2025
11:19
Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
10.6K
Structural basis of α-latrotoxin transition to a cation-selective pore
B U Klink1,2, A Alavizargar2,3, K S Kalyankumar1,2
1Institute for Medical Physics and Biophysics, University Münster, Münster, Germany.
Nature Communications
|October 3, 2024
Summary
Black widow spider venom
Area of Science:
- Neuroscience
- Structural Biology
- Biochemistry
Background:
- Black widow spider venom contains latrotoxins (LTXs), with α-LTX specifically targeting vertebrates.
- α-LTX binds presynaptic nerve terminals, causing massive neurotransmitter release.
- The mechanism of LTX-induced pore formation in presynaptic membranes is poorly understood.
Purpose of the Study:
- To elucidate the structural mechanism of α-LTX-mediated membrane insertion and channel formation.
- To provide structural insights into the tetramerization and pore formation of α-LTX.
Main Methods:
- Cryo-electron microscopy (cryo-EM) to determine structures of α-LTX tetramer in prepore and pore states.
- AlphaFold2-based structural modeling.
- Molecular dynamics simulations.
Main Results:
- Cryo-EM structures revealed dramatic conformational changes in the N-terminal region of α-LTX.
- A stable, 15 nm long, cation-impermeable coiled-coil stalk is formed by rearranged helical bundles.
- An N-terminal helix pair inserts into the membrane, enabling cation-permeable channel assembly.
Conclusions:
- The study reveals a unique mechanism for membrane insertion and channel formation by α-LTX.
- Structural insights provide a framework for developing novel therapeutics and biotechnological applications targeting LTXs.
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