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PDBsum entry 1h5o
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Solution structure of crotamine, A na+ channel affecting toxin from crotalus durissus terrificus venom.
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Authors
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G.Nicastro,
L.Franzoni,
C.De chiara,
A.C.Mancin,
J.R.Giglio,
A.Spisni.
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Ref.
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Eur J Biochem, 2003,
270,
1969-1979.
[DOI no: ]
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PubMed id
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Abstract
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Crotamine is a component of the venom of the snake Crotalus durissus terrificus
and it belongs to the myotoxin protein family. It is a 42 amino acid toxin
cross-linked by three disulfide bridges and characterized by a mild toxicity
(LD50 = 820 micro g per 25 g body weight, i.p. injection) when compared to other
members of the same family. Nonetheless, it possesses a wide spectrum of
biological functions. In fact, besides being able to specifically modify
voltage-sensitive Na+ channel, it has been suggested to exhibit analgesic
activity and to be myonecrotic. Here we report its solution structure determined
by proton NMR spectroscopy. The secondary structure comprises a short N-terminal
alpha-helix and a small antiparallel triple-stranded beta-sheet arranged in an
alphabeta1beta2beta3 topology never found among toxins active on ion channels.
Interestingly, some scorpion toxins characterized by a biological activity on
Na+ channels similar to the one reported for crotamine, exhibit an alpha/beta
fold, though with a beta1alphabeta2beta3 topology. In addition, as the
antibacterial beta-defensins, crotamine interacts with lipid membranes. A
comparison of crotamine with human beta-defensins shows a similar fold and a
comparable net positive potential surface. To the best of our knowledge, this is
the first report on the structure of a toxin from snake venom active on Na+
channel.
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Figure 5.
Fig. 5. Solution structure of crotamine. Stereo view of the
26 NMR models superimposed over the backbone atoms of residues
2–39.
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Figure 6.
Fig. 6. Comparison of the electrostatic potential surface
between crotamine (A and B), AaHII (PDB accession no. 1PTX) (C
and D) and HBD3(PDB accession no. 1KJ6)(E and F). Positively and
negatively charged regions are coloured in blue and red,
respectively. The orientation in A, C and E is the same as in
Fig. 7 Go- . The
views in B, D and F result from a 180° rotation of A, C and
E around their vertical axis.
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The above figures are
reprinted
by permission from the Federation of European Biochemical Societies:
Eur J Biochem
(2003,
270,
1969-1979)
copyright 2003.
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Secondary reference #1
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Title
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The analgesic activity of crotamine, A neurotoxin from crotalus durissus terrificus (south american rattlesnake) venom: a biochemical and pharmacological study.
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Authors
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A.C.Mancin,
A.M.Soares,
S.H.Andrião-Escarso,
V.M.Faça,
L.J.Greene,
S.Zuccolotto,
I.R.Pelá,
J.R.Giglio.
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Ref.
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Toxicon, 1998,
36,
1927-1937.
[DOI no: ]
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PubMed id
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