Association of botulinum neurotoxins with synaptic vesicle protein complexes.
Botulinum neurotoxins (BoNTs) elicit flaccid paralysis by cleaving SNARE proteins within peripheral neurons. BoNTs are classified into seven serotypes, termed A-G, based on antibody cross-neutralization. Clostridia produce BoNTs as single-chain toxins that are cleaved into a di-chain protein that comprises an N-terminal zinc metalloprotease domain that is linked by a disulfide bond to the C-terminal translocation/receptor-binding domain. BoNT/A and BoNT/B utilize synaptic vesicle protein 2 (SV2) and synaptotagmin, respectively, as receptors for entry into neurons. Using affinity chromatography, BoNT/A and BoNT/B were found to bind a synaptic vesicle protein complex in CHAPS extracts of synaptic vesicles. Mass spectroscopy identified synaptic vesicle protein 2, synaptotagmin I, synaptophysin, vesicle-associated membrane protein 2, and the vacuolar ATPase-proton pump as components of the BoNT-synaptic vesicle protein complex. BoNT/A and BoNT/B possessed unique density-gradient profiles when bound to synaptic vesicle protein complexes. The identification of BoNT/A and BoNT/B bound to synaptic vesicle protein complexes provides insight into the interactions of BoNT and neuronal receptors.
Baldwin
Michael R
MR
Department of Microbiology and Molecular Genetics, 8701 Watertown Plank Rd., Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Barbieri
Joseph T
JT
D000818:Animals; D001905:Botulinum Toxins / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000378:metabolism*; D009498:Neurotoxins / Q000378:metabolism* / Q000494:pharmacology; D011485:Protein Binding; D050600:SNARE Proteins / Q000187:drug effects / Q000378:metabolism; D013329:Structure-Activity Relationship; D013572:Synaptic Vesicles / Q000187:drug effects / Q000378:metabolism*
D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D009498:Neurotoxins; D050600:SNARE Proteins; D001905:Botulinum Toxins