Publication

A dileucine in the protease of botulinum toxin a underlies its long-lived neuroparalysis

Wang, Jiafu
Zurawski, Tomas H.
Meng, Jianghui
Lawrence, Gary
Olango, Weredeselam M.
Finn, David P.
Wheeler, Larry
Dolly, J. Oliver
Identifiers
http://hdl.handle.net/10379/14366
https://doi.org/10.13025/28054
Publication Date
2010-12-07
Type
Article
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Citation
Wang, Jiafu; Zurawski, Tomas H. Meng, Jianghui; Lawrence, Gary; Olango, Weredeselam M.; Finn, David P.; Wheeler, Larry; Dolly, J. Oliver (2010). A dileucine in the protease of botulinum toxin a underlies its long-lived neuroparalysis. Journal of Biological Chemistry 286 (8), 6375-6385
Abstract
Blockade of neurotransmitter release by botulinum neurotoxin type A (BoNT(A)) underlies the severe neuroparalytic symptoms of human botulism, which can last a few years. The structural basis for this remarkable persistence remains unclear. Herein, recombinant BoNT(A) was found to match the neurotoxicity of that from Clostridium botulinum, producing persistent cleavage of synaptosomal-associated protein of 25 kDa (SNAP-25) and neuromuscular paralysis. When two leucines near the C terminus of the protease light chain of A (LC(A)) were mutated, its inhibition of exocytosis was followed by fast recovery of intact SNAP-25 in cerebellar neurons and neuromuscular transmission in vivo. Deletion of 6-7 N terminus residues diminished BoNT(A) activity but did not alter the longevity of its SNAP-25 cleavage and neuromuscular paralysis. Furthermore, genetically fusing LC(E) to a BoNT(A) enzymically inactive mutant (BoTIM(A)) yielded a novel LC(E)-BoTIM(A) protein that targets neurons, and the BoTIM(A) moiety also delivers and stabilizes the inhibitory LC(E), giving a potent and persistent cleavage of SNAP-25 with associated neuromuscular paralysis. Moreover, its neurotropism was extended to sensory neurons normally insensitive to BoNT(E). LC(E)-BoTIM(A)(AA) with the above-identified dileucine mutated gave transient neuromuscular paralysis similar to BoNT(E), reaffirming that these residues are critical for the persistent action of LC(E)-BoTIM(A) as well as BoNT(A). LC(E)-BoTIM(A) inhibited release of calcitonin gene-related peptide from sensory neurons mediated by transient receptor potential vanilloid type 1 and attenuated capsaicin-evoked nociceptive behavior in rats, following intraplantar injection. Thus, a long acting, versatile composite toxin has been developed with therapeutic potential for pain and conditions caused by overactive cholinergic nerves.
Funder
Publisher
American Society for Biochemistry & Molecular Biology (ASBMB)
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Rights
Attribution-NonCommercial-NoDerivs 3.0 Ireland