Isolation and characterization of an apoptotic and platelet aggregation inhibiting L-amino acid oxidase from Vipera berus berus (common viper) venom.
An L-amino acid oxidase was isolated from the venom of the common viper Vipera berus berus by a three-step procedure combining gel filtration, ion exchange and hydrophobic chromatography. The enzyme is a non-covalently bound homodimer with a monomeric molecular mass of 57.7 kDa. The N-terminal amino acid sequence and the internal peptide sequences show close structural homology with other snake venom L-amino acid oxidases. The purified protein catalyzed oxidative desamination of L-amino acids, the most specific substrate is L-Phe. The best substrates among the studied 20 amino acids were: L-Met, L-Leu, L-Phe, L-Ile, L-Arg and L-His. Five amino acids, L-Ser, L-Pro, Gly, L-Thr and L-Cys, were not oxidized. The enzyme inhibited ADP-induced platelet aggregation dose-dependently with an IC50 of 0.07 microM. The effect was neutralized by catalase. V. berus berus LAAO induced apoptosis in cultured HeLa and K562 cells as shown by DNA fragmentation gel pattern. The induction of apoptosis was inhibited by catalase.
Samel
Mari
M
National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
Vija
Heiki
H
Rönnholm
Gunilla
G
Siigur
Jüri
J
Kalkkinen
Nisse
N
Siigur
Ene
E
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053938:DNA Fragmentation / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D050830:L-Amino Acid Oxidase / Q000302:isolation & purification* / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D014757:Viper Venoms / Q000201:enzymology*
D010975:Platelet Aggregation Inhibitors; D014757:Viper Venoms; D050830:L-Amino Acid Oxidase