Substrate specificity of king cobra (Ophiophagus hannah) venom L-amino acid oxidase

Int J Biochem. 1991;23(3):323-7. doi: 10.1016/0020-711x(91)90114-3.


1. Substrate specificity of purified king cobra (Ophiophagus hannah) venom L-amino acid oxidase was investigated. 2. The enzyme was highly specific for the L-enantiomer of amino acid. Effective oxidation of L-amino acid by the enzyme requires the presence of a free primary alpha-amino group but the alpha-carboxylate group is not as critical for the catalysis. 3. The enzyme was very active against L-Lys, L-Phe, L-Leu, L-Tyr, L-Tryp, L-Arg, L-Met, L-ornithine, L-norleucine and L-norvaline and moderately active against L-His, L-cystine and L-Ileu. Other L-amino acids were oxidized slowly or not oxidized. 4. The data suggest the presence of a side chain binding site in the enzyme, and that the binding site comprises at least five 'subsites': the hydrophobic subsites a, b and c; and the two 'amino' binding subsites d and e. Subsite b appears to be able to accommodate two methylene/methyl carbons.

Publication types

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

MeSH terms

  • Amino Acid Oxidoreductases / chemistry
  • Amino Acid Oxidoreductases / metabolism*
  • Amino Acids / chemistry
  • Amino Acids / metabolism
  • Binding Sites
  • Elapid Venoms / analysis*
  • Kinetics
  • L-Amino Acid Oxidase
  • Molecular Structure
  • Oxidation-Reduction
  • Structure-Activity Relationship
  • Substrate Specificity
  • Thermodynamics


  • Amino Acids
  • Elapid Venoms
  • Amino Acid Oxidoreductases
  • L-Amino Acid Oxidase