Cloning and characterization of the cDNAs encoding Na+ channel-specific toxins 1 and 2 of the scorpion Centruroides noxius Hoffmann

Toxicon. 1995 Sep;33(9):1161-70. doi: 10.1016/0041-0101(95)00058-t.

Abstract

Using a cDNA library prepared from venomous glands of the Mexican scorpion Centruroides noxius Hoffmann the genes that encode toxins 1 and 2 were identified, cloned and sequenced. In view of the proposed mechanism for processing the mature peptides coded by these two genes, the corresponding peptide-toxins were sequenced de novo. Mass spectrometric and 1H-NMR analyses of the C-terminal peptide produced by enzymatic digestion of both toxins indicated that the last residue is serine-amide. Sequence comparison revealed that these two genes have a similarity of 56% and 80% at the amino acid and nucleotide levels, respectively. Small corrections to the published primary structures were introduced: Cn toxin 1 has an extra serine residue at position 65 and the residue in position 60 is a proline, while the amino acids at positions 34 and 35 of Cn 2 are, respectively, tyrosine and glycine. Sequence comparison of toxins from the genus Centruroides suggests the presence of at least three classes of distinct peptides in these venoms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular*
  • DNA, Complementary / chemistry*
  • DNA, Complementary / metabolism
  • Magnetic Resonance Spectroscopy
  • Molecular Sequence Data
  • Neurotoxins / genetics*
  • Scorpion Venoms / chemistry*
  • Scorpion Venoms / genetics
  • Sequence Homology, Amino Acid
  • Sodium Channels / drug effects*
  • Sodium Channels / metabolism

Substances

  • DNA, Complementary
  • Neurotoxins
  • Scorpion Venoms
  • Sodium Channels

Associated data

  • GENBANK/S81093
  • GENBANK/S81096