Botulinum neurotoxin proteins

The most ingenious exocytosis toxins, however, come from the anaerobic bacteria Clostridium botulinum and Clostridium tetani. The former produces the seven botulinum neurotoxins (BoNTs) A-G the latter produces tetanus neurotoxin (TeNT). All eight toxins consist of a heavy (H) chain and a light (L) chain that are associated by an interchain S-S bond. The L-chains enter the cytosol of axon terminals. Importantly, BoNT L-chains mainly enter peripheral cholinergic terminals, whereas the TeNT L-chain mainly enters cerebral and spinal cord GABAergic and glycinergic terminals. The L-chains are the active domains of the toxins. They are zinc-endopeptidases and specifically split the three core proteins of exocytosis, i.e. the SNAREs (Fig. 1 inset). Each ofthe eight toxins splits a... 

G. Schiavo, F. Benfenati, B. Poulain, O. Rossetto, P. Polverino de Laureto, B. R. Das-Gupta, C. Montecucco, Tetanus and Botulinum-B Neurotoxins Block Neurotransmitter Release by Proteolytic Cleavage of Synaptobrevin , Nature 1992a, 359, 832-835 G. Schiavo, O. Rossetto, A. Santucci, B. R. DasGupta, C. Montecucco, Botulinum Neurotoxins are Zinc Proteins , J. Biol. Chem. 1992b, 267, 23479-23483. 

Montecucco C, Schiavo G, Dasgupta BR (1989) Effect of pH on the interaction of botulinum neurotoxins A, B and E with liposomes. Biochem J 259 47-53 Montecucco C, Papini E, Schiavo G (1994) Bacterial protein toxins penetrate cells via a four-step mechanism. FEBS Lett 346 92-8... 

Pellizzari R, Rossetto O, Lozzi L, Giovedi S, Johnson E et al. (1996) Structural determinants of the specificity for synaptic vesicle-associated membrane protein/synaptobrevin of tetanus and botulinum type B and G neurotoxins. J Biol Chem 271 20353-8 Pellizzari R, Mason S, Shone CC, Montecucco C (1997) The interaction of synaptic vesicle-associated membrane protein/synaptobrevin with botulinum neurotoxins D and F. FEBS Lett 409 339 12... 

Rossetto O, Seveso M, Caccin P, Schiavo G, Montecucco C (2001b) Tetanus and botulinum neurotoxins turning bad guys into good by research. Toxicon 39 27—41 Rossetto O, Morbiato L, Rossetto et al. 2006 Caccin P, Rigoni M, Montecucco C (2006) Presynaptic enzymatic neurotoxins. J Neurochem 97 1534—4 5 Roux S, Colasante C, Saint Clomcnt C, Barbier J, Curie T et al. (2005) Internalization of a GFP-tetanus toxin C-terminal fragment fusion protein at mature mouse neuromuscular junctions. Mol Cell Neurosci 30 572-82... 

Rummel A, Eichner T, Weil T, Karnath T, Gutcaits A et al. (2007) Identification of the protein receptor binding site of botulinum neurotoxins B and G proves the double-receptor concept. Proc Natl Acad Sci U S A 104 359-64... 

Williamson LC, Neale EA (1998) Syntaxin and 25-kDa synaptosomal-associated protein differential effects of botulinum neurotoxins Cl and A on neuronal survival. J Neurosci Res 52 569-83 Williamson LC, Halpem JL, Montecucco C, Brown JE, Neale EA (1996) Clostridial neurotoxins and substrate proteolysis in intact neurons botulinum neurotoxin C acts on synaptosomal-associated protein of 25 kDa. J Biol Chem 271 7694-9 Wilson HI, Nicholson GM, Tyler MI, Howden ME (1995) Induction of giant miniature end-plate potentials during blockade of neuromuscular transmission by textilotoxin. Naunyn Schmiede-bergs Arch Pharmacol 352 79-87... 

Blast, J., Chapman, E.R., Link, E., Binz, T., Yamasaki, S., DeC-amilli, P., Sudoff, T.C., Niemann, H., Jahn, R. (1993). Botulinum neurotoxin A selectively cleaves the synaptic protein SNAP-25. Nature 365 160-3. 

Cai, S., Sarkar, H.K., Singh, B.R. (1999). Enhancement of the endopeptidase activity of purified botulinum neurotoxin by its associated proteins and dithiothreitol. Biochemistry 38 6903-10. 

Jin, R., Rummel, A., Binz, T., Brunger, A.T. (2006). Botulinum neurotoxin B recognizes its protein receptor with high affinity and specificity. Nature 444 1092-5. 

Keller, J.E., Neale, E.A. (2001). The role of the synaptic protein SNAP-25 in the potency of botulinum neurotoxin type A. J. Biol. Chem. 276 13476-82. 

Maruta, T., Dolimbek, B.Z., Aoki, K.R., Steward, L.E., Atassi, M.Z. (2004). Mapping of the synaptosome-binding regions on the heavy chain of botulinum neurotoxin A by synthetic overlapping peptides encompassing the entire chain. Protein J. 23 539-52. 

Schmidt, J.J., Bostian, K.A. (1997). Endoproteinase activity of type A botulinum neurotoxin substrate requirements and activation by serum albumin. J. Protein Chem. 16 19-26. 

Black JD, Dolly JO (1986 b) Interaction of l-labeled neurotoxins with nerve terminals. II. Autoradiographic evidence for its uptake into motor nerves by acceptor-mediated endocytosis. In J. Cell Biol. 103 535-44 Blasi J, Chapman ER, Link E, Binz T, Yamasaki S, DeCamilli P, SudhofTC, Niemann H, Jahn R (1993) Botulinum neurotoxin A selectively cleaves the synaptic protein SNAP-25. In Nature 365 160-3... 

Schiavo G, Poulain B, Rossetto O, Benfenati F, Tauc L, Montecucco C (1992 b) Tetanus toxin is a zinc protein and its inhibition of neurotrasmitter release and protease activity depend on zinc. In EMBOJ. 11 3577-83 Schiavo G, Rossetto O, Santucci A, DasGupta BR, Montecucco C (1992 c) Botulinum neurotoxins are zinc proteins. In J. Biol. Chem. 267 23479-83 Schiavo G, Rossetto O, Catsicas S, Polverino de Laureto P, DasGupta BR, Benfenati F, Montecucco C (1993 a) Identification of the nerve-terminal targets of botulinum neurotoxins serotypes A, D and E. In J. Biol. Chem. 268 23784-7 Schiavo G, Santucci A, DasGupta BR, Metha PP, Jontes J, Benfenati F, Wilson MC, Montecucco C (1993 b) Botulinum neurotoxins serotypes A and E cleave SNAP-25 at distinct COOH-terminal peptide bonds. In FEBS Lett. 335 99-103 Schiavo G, Shone CC, Rossetto O, Alexandre FCG, Montecucco C (1993 c) Botulinum neurotoxin serotype F is a zinc endopeptidase specific for VAMP/synOp-tobrevin. In J. Biol. Chem. 268 11516-9... 

Shone CC, Tranter HS (1995) Growth of Clostridia and preparation of their neurotoxins. In Curr. Top. Microbiol. Immunol. 19 143-60 Shone CC, Quinn CP, Wait R, Hollis B, Fooks SG, Hamblen P (1993) Proteolytic cleavage of synthetic fragments of vesicle-associated membrane protein, isoform-2 by botulinum type B neurotoxin. In Eur. J. Biochem. 217 965-71 Simpson LL (ed)(1989) Botulinum neurotoxin and tetanus toxin. San Diego Academic Press... 

Clostridial neurotoxins are proteins that are produced by the anaerobic bacteria Clostridium tetani (tetanus toxin) and Clostridium botulinum (botulinum neurotoxins). Whereas tetanus toxin (TeTx) comprises a single molecular species, different strains of Clostridium botulinum produce seven different types of botulinum neurotoxin (desig-... 

Blasi J, Chapman ER, Link E et al. (1993a) Botulinum neurotoxin A selectively cleaves the synaptic protein SNAP-25. Nature 365 160-3. 

Middlebrook JL. (1989) Cell surface receptors for protein toxins. In Botulinum neurotoxin and tetanus toxin ( Simpson LL, ed) San Diego Academic Press. 

Williamson LC, Halpern JL, Montecucco C etal. (1996) Clostridial neurotoxins and substrate proteolysis in intact neurons. Botulinum neurotoxin C acts on synaptosomal-associated protein of 25 kDa. J. Biol. Chem. 271 7694-9. 

ACE Angiotensin Converting Enzyme BoNt Botulinum Neurotoxin BMP Bone Morphogentic Protein ECE Endothelin Converting Enzyme NEP Neutral endopeptidase TeNt Tetanus Neurotoxin... 

The botulinum neurotoxins (BoNTs) comprise a family of seven distinct neurotoxic proteins (A-G) produced by immunologically discrete strains of the anaerobic bacterium Clostridium botulinum and in rare cases by Clostridium baratii and Clostridium butyricum (Habermann and Dreyer, 1986 Harvey et ah, 2002 Simpson, 2004). These toxins act on peripheral cholinergic synapses to inhibit spontaneous and impulse-dependent release of acetylcholine (ACh) (Brooks, 1956 Kao et al., 1976). Intoxication by BoNT results in muscle weakness, which can be fatal when the diaphragm and intercostal muscles become sufficiently compromised to impair ventilation (Dickson and Shevky, 1923). The BoNTs are the most potent substances in nature, and exposure to as httle as 1-3 ng/kg may be sufficient to cause human lethahty (GUI, 1982 Middlebrook and Franz, 1997 Amon et al., 2001). 

Schiavo, G., Rossetto, O., Santucci, A., DasGupta, B.R., and Motecucco, C. 1992a. Botulinum neurotoxins are zinc proteins. J. Biol. Chem. 267 23479-23483. 

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