Characterization and cytotoxicity of L-amino acid oxidase from the venom of king cobra (Ophiophagus hannah).
The aim of this project was to determine the cytotoxic components from the venom of king cobra, Ophiophagus hannah. Venom was purified by a combination of gel-filtration, ion-exchange and reversed-phase chromatographic steps. The biochemical properties of the cytotoxic component were consistent with those of L-amino acid oxidase. The molecular weight of the enzyme was estimated to be 150,000 by gel filtration and 70,000 under the denaturing conditions of SDS-PAGE, indicating a dimer. It has an isoelectric point of 4.5 and is a glycoprotein. The N-terminal sequence of L-amino acid oxidase from the king cobra venom was determined to be SVINLEESFQEPEYE. The cytotoxicity of L-amino acid oxidase was observed in stomach cancer, murine melanoma, fibrosarcoma, colorectal cancer and Chinese hamster ovary cell lines. Cytotoxicity resulted in the loss of ability in attachment and inhibition of cell proliferation. The cytotoxic protein decreased the level of cell proliferation by 74% according to [3H]thymidine uptake assay. The mechanism of enzyme action may be related to the inhibition of thymidine incorporation and an interaction with DNA.
Ahn
M Y
MY
Division of Toxicology, College of Pharmacy, Sungkyunkwan University, Suwon, Korea.
Lee
B M
BM
Kim
Y S
YS
D000594:Amino Acid Oxidoreductases / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D016466:CHO Cells; D002470:Cell Survival / Q000187:drug effects; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000378:metabolism; D004546:Elapid Venoms / Q000201:enzymology*; D006801:Humans; D050830:L-Amino Acid Oxidase; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013936:Thymidine / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000596:Amino Acids; D004268:DNA-Binding Proteins; D004546:Elapid Venoms; D000594:Amino Acid Oxidoreductases; D050830:L-Amino Acid Oxidase; D013936:Thymidine