U2B26

U2B26 is a bacterial toxin produced by the bacterium Clostridium botulinum, which is responsible for botulism, a severe and potentially life-threatening illness. The toxin is a zinc-dependent metalloprotease that inhibits neurotransmitter release at the neuromuscular junction, leading to paralysis. U2B26 is one of the seven known botulinum neurotoxins, each designated by a letter (A-G) based on their electrophoretic mobility.

The toxin is composed of two subunits: a heavy chain (H) and a light chain (L). The heavy chain is responsible for binding to the target cell and for the enzymatic activity, while the light chain is responsible for the binding to the synaptic vesicle membrane. The toxin is produced as a single-chain precursor that is cleaved into the heavy and light chains by furin-like proteases.

U2B26 is used medically as a therapeutic agent under the trade name Botox, which is approved for the treatment of various conditions, including chronic migraines, cervical dystonia, and hyperhidrosis. The toxin is injected into the affected muscle, where it inhibits the release of acetylcholine, a neurotransmitter that stimulates muscle contraction. This results in a temporary paralysis of the muscle, which can alleviate symptoms such as muscle spasms or excessive sweating.

The use of U2B26 as a therapeutic agent has been controversial due to its potential for misuse, including its use in cosmetic procedures and as a weapon. However, its medical applications have been widely accepted and have significantly improved the quality of life for many patients.