Identification and molecular cloning of insecticidal toxins from the venom of the brown spider Loxosceles intermedia

Toxicon. 2004 Sep 1;44(3):273-80. doi: 10.1016/j.toxicon.2004.05.028.

Abstract

The venom of Loxosceles intermedia was investigated for the presence of insecticidal toxins active against Spodoptera frugiperda (Lepdoptera: Noctuidade), an insect that has caused great reductions in corn production in Brazil. A combination of gel filtration (Sephadex G-100) and ion-exchange chromatography (Carboxymethyl Cellulose, CM 52) resulted in four major fractions that were submitted to biological assay. Fraction 4 was further purified by a reverse phase HPLC (C18 Column) resulting in peptides active against Spodoptera frugiperda. Three new potential insecticidal toxins named LiTx x 1, LiTx x 2 and LiTx x 3 were identified. The partial amino terminal sequences of these peptides were obtained and used to clone the corresponding cDNAs with the help of degenerate oligonucleotides. The amino acid sequence deduced from the cDNA of LiTx x 1, LiTx x 2 and LiTx x 3 revealed mature proteins of approximately 7.4, 7.9 and 5.6 kDa.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Brazil
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Cluster Analysis
  • DNA, Complementary / genetics
  • Molecular Sequence Data
  • Moths / drug effects*
  • Oligonucleotides
  • Organophosphorus Compounds
  • Peptides / toxicity*
  • Sequence Analysis, DNA
  • Sequence Homology
  • Spider Venoms / genetics*
  • Spider Venoms / toxicity*
  • Spiders*

Substances

  • 2-(4-isothiocyanatophenoxy)-1,3,2-dioxaphosphinene 2-oxide
  • DNA, Complementary
  • Oligonucleotides
  • Organophosphorus Compounds
  • Peptides
  • Spider Venoms