Isolation, structural, and functional characterization of an apoptosis-inducing L-amino acid oxidase from leaf-nosed viper (Eristocophis macmahoni) snake venom

Arch Biochem Biophys. 2000 Dec 15;384(2):216-26. doi: 10.1006/abbi.2000.2130.


The enzyme L-amino acid oxidase (LAO) from the leaf-nosed viper (Eristocophis macmahoni) snake venom was purified to homogeneity in a single step using high performance liquid chromatography on a Nucleosil 7C18 reverse phase column. The molecular mass of the purified enzyme was 58734.0 Da, as determined by matrix-assisted laser desorption/ionization mass spectrometry. The N-terminal amino acid sequence (ADDKNPLEEAFREADYEVFLEIAKNGL) and the chemical composition of the purified LNV-LAO shows close structural homology with other L-amino acid oxidases isolated from different snake venoms. The secondary structural contents analysis of LAO, established by means of circular dichroism, revealed ca. 49% alpha-helix, 19% beta-sheet, 10% beta-turn, and 22% random coil structure. The purified LNV-LAO not only retained its specific enzymatic activity (73.46 U/mg), determined against L-leucine as a substrate, but also exhibited potent haemolytic (1-10 microg/ml), edema- (MED 4.8 microg/ml) and human platelet aggregation-inducing (ED50 33 microg/ml) properties. Unlike other haemorrhagic snake venom L-amino acid oxidases, the LNV-LAO does not produce haemorrhage. In addition to these local effects, the purified LNV-LAO showed apoptosis-inducing activity in the MM6 cell culture assay. After 18 h treatment with 25-100 microg/ml of LAO, the typical DNA fragmentation pattern of apoptotic cells was observed by means of fluorescent microscopy and agarose gel electrophoresis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Oxidoreductases / chemistry*
  • Amino Acid Oxidoreductases / isolation & purification
  • Amino Acid Oxidoreductases / pharmacology*
  • Amino Acid Sequence
  • Animals
  • Apoptosis / drug effects*
  • Cell Line
  • Cell Nucleus / ultrastructure
  • Chromatography, High Pressure Liquid
  • DNA Fragmentation
  • Edema / chemically induced
  • Hemolysis / drug effects
  • Hemorrhage / chemically induced
  • Humans
  • L-Amino Acid Oxidase
  • Mice
  • Molecular Sequence Data
  • Platelet Aggregation / drug effects
  • Protein Structure, Secondary
  • Sequence Homology, Amino Acid
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Structure-Activity Relationship
  • Viper Venoms / enzymology*


  • Viper Venoms
  • Amino Acid Oxidoreductases
  • L-Amino Acid Oxidase