Elsevier

Toxicon

Volume 34, Issue 9, September 1996, Pages 987-1001
Toxicon

Two neurotoxins (BmK I and BmK II) from the venom of the scorpion Buthus martensi Karsch: purification, amino acid sequences and assessment of specific activity

https://doi.org/10.1016/0041-0101(96)00065-7Get rights and content

Abstract

Two neurotoxins, BmK I and BmK II, were purified from the venom of the Chinese scorpion Buthus martensi Karsch. The complete amino acid sequences of both toxins, each containing 64 amino acid residues, were determined by the automatic sequencing of reduced and S-carboxymethylated toxins and their peptides, obtained after cleavage with TPCK-treated trypsin and Staphylococcus aureus V8 protease, respectively. Toxicity as minimum lethal dose tested by i.c.v. injection in mice showed that BmK I was six times more potent than BmK II. Only two amino acid replacements were found: at position 59 Val in BmK I was replaced by Ile in BmK II, and at position 62 a basic Lys residue in BmK I was substituted by a neutral Asn residue in BmK II. These features suggest that the positively charged residue (Lys or Arg) in the C-terminal position 62 (or 61 or 63) may also play an important role in facilitating the interaction between scorpion neurotoxins and the receptor on sodium channels. The effects of BmK I on nerve excitability were examined with the crayfish axon using intracellular recording and voltage-clamp conditions. The results indicate that BmK I preferentially blocks the sodium channel inactivation process. Thus,

References (26)

  • S. Terakawa et al.

    Lack of effect of a neurotoxin from the scorpion Buthus martensi Karsch on nerve fibers of this scorpion

    Toxicon

    (1989)
  • W.A. Catterall

    Structure and function of voltage-sensitive ion channels

    Science

    (1988)
  • H. Darbon et al.

    Scorpion neurotoxin derivatives suitable as potential markers of sodium channels

    Int. J. Pept. Prot. Res.

    (1983)
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