botulinum neurotoxin type B light chain

Botulinum neurotoxin type B light chain (BoNT/B-LC) is the catalytic subunit of the neurotoxin produced by the bacterium *Clostridium botulinum*. It functions as a highly specific zinc-dependent endopeptidase that targets and cleaves Vesicle-Associated Membrane Protein 2 (VAMP2), also known as synaptobrevin-2. VAMP2 is a critical component of the SNARE (Soluble NSF Attachment Protein Receptor) complex, which mediates the fusion of intracellular vesicles with the plasma membrane. By cleaving VAMP2, the light chain effectively prevents the exocytosis of neurotransmitters and the transcytosis of various molecules across cellular barriers. In recent biomedical research, BoNT/B-LC is utilized as a precision tool, often delivered via viral vectors (such as AAV), to selectively inhibit transport mechanisms in specific cell types like hypothalamic tanycytes. This application is being explored to understand and potentially treat metabolic disorders, including obesity and type 2 diabetes, by disrupting the communication between the periphery and the central nervous system.

Other names

Botulinum toxin type B light chainBoNT/B catalytic domainLight chain of botulinum neurotoxin type B