title: L-Amino acid oxidase from Naja naja oxiana venom.
abstract: A new l-amino acid oxidase (LAAO) was isolated from the Central Asian cobra Naja naja oxiana venom by size exclusion, ion exchange and hydrophobic chromatography. The N-terminal sequence and the internal peptide sequences share high similarity with other snake venom l-amino acid oxidases, especially with those isolated from elapid venoms. The enzyme is stable at low temperatures (-20 degrees C, -70 degrees C) and loses its activity by heating at 70 degrees C. Specific substrates for the isolated protein are l-phenylalanine, l-tryptophan, l-methionine and l-leucine. The enzyme has antibacterial activity inhibiting the growth of Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria. N. naja oxiana LAAO dose-dependently inhibited ADP- or collagen-induced platelet aggregation with IC(50) of 0.094 microM and 0.036 microM, respectively. The antibacterial and anti-aggregating activity was abolished by catalase.
authors.affiliation: National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
authors.forename: Mari
authors.initials: M
authors.lastname: Samel
authors.forename: Külli
authors.initials: K
authors.lastname: Tõnismägi
authors.forename: Gunilla
authors.initials: G
authors.lastname: Rönnholm
authors.forename: Heiki
authors.initials: H
authors.lastname: Vija
authors.forename: Jüri
authors.initials: J
authors.lastname: Siigur
authors.forename: Nisse
authors.initials: N
authors.lastname: Kalkkinen
authors.forename: Ene
authors.initials: E
authors.lastname: Siigur
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004546:Elapid Venoms / Q000201:enzymology*; D017815:Elapidae; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000187:drug effects; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D000890:Anti-Infective Agents; D004546:Elapid Venoms; D000594:Amino Acid Oxidoreductases