Scientists have completely decrypted the structure of deadly botulinum toxin

Swedish researchers have made a breakthrough in medicine by creating the first complete molecular model of the structure, stabilization, delivery, and release of botulinum toxin. This substance is recognized as the most powerful natural poison, with a toxicity a million times greater than that of cobra venom. The work of the international team led by Professor of Neurochemistry Paul Stenmark was published in the authoritative scientific journal Science Advances.

Botulinum toxin is produced by the bacterium Clostridium botulinum and causes severe food poisoning — botulism. However, despite its deadly danger, this toxin has found wide application in clinical practice. It is used to treat chronic migraines, muscle spasms, hyperhidrosis, and in cosmetology. The key to understanding its dual nature lies in its complex mechanism of action. In natural conditions, the toxin does not function independently, but as part of a large protein complex consisting of 14 separate components.

It is this complex that has become the subject of research by scientists. As Paul Stenmark explained, this structure protects the poison from destruction in the aggressive environment of the gastrointestinal tract and ensures its transport from the intestine into the bloodstream. Only then is the toxin released and reaches its final destination—the neuromuscular junctions—via the bloodstream, blocking their function. To visualize the entire complex, scientists used an advanced method of cryo-electron microscopy, which has been recognized with a Nobel Prize. The technique involves instantly freezing molecules and then creating thousands of images that are combined into a highly accurate three-dimensional image with near-atomic resolution.

The object of study was a complex of toxins found in the drug NeuroBloc, which is closely related to the well-known Botox. The resulting molecular diagram of unprecedented complexity, comprising tens of thousands of atoms, opens up fundamentally new possibilities for science and pharmacology. This discovery will enable the development of more effective and safer therapeutic agents based on botulinum toxin, as well as the creation of the first effective antidotes for the emergency treatment of botulism.