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Substrate specificity of lentil seedling amine oxidase
Author(s) -
Medda Rosaria,
Padiglia Alessandra,
Pedersen Jens Z.,
Lorrai Anita,
Floris Giovanni
Publication year - 1996
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549600201223
Subject(s) - hypotaurine , diamine oxidase , oxidative deamination , biochemistry , putrescine , monoamine oxidase , substrate (aquarium) , enzyme , chemistry , cadaverine , tyramine , benzylamine , amine oxidase , cysteic acid , amine oxidase (copper containing) , peroxidase , amino acid , biology , taurine , organic chemistry , cystine , cysteine , ecology
Copper diamine oxidase from lentil (Lens culinaris) seedlings was shown to be able to catalyze the oxidative deamination of a wide range of aliphatic and aromatic monoamine compounds, including some amino acids. Although the catalytic efficiencies were only 1‐3% of that measured with the diamine substrate putrescine, they were still comparable to those of specialized monoamine oxidases. In particular, the lentil enzyme oxidized benzylamine and histamine with Km and Vmax values similar to those found for the mammalian enzymes benzylamine oxidase and histaminase. Cysteamine was found to be a substrate of the enzyme, whereas hypotaurine and taurine were found to be neither substrates nor inhibitors of the enzyme. Quite unexpectedly the aminoacids L‐ornithine and L‐lysine were oxidized by lentil enzyme, and β‐alanine and γ‐aminobutyric acid were oxidized only at high concentrations of enzyme. These results suggest that enzymes normally classified as diamine oxidases could in fact have a more diversified role in metabolism than recognized so far.