Antitumoural Effect of anl-Amino Acid Oxidase Isolated from Bothrops jararaca Snake Venom.

Anl-amino acid oxidase (BjarLAAO-I) from Bothrops jararaca snake venom was highly purified using a stepwise sequential chromatography on Sephadex G-75, Benzamidine Sepharose and Phenyl Sepharose. Purified BjarLAAO-I showed a molecular weight around 60,000 under reducing conditions and about 125,000 in the native form, when analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively. BjarLAAO-I is a homodimeric acidic glycoprotein, pI ~5.0, and N-terminal sequence showing close structural homology with other snake venom LAAOs. The purified enzyme catalysed the oxidative deamination ofl-amino acids, the most specific substrate beingl-Phe. Five amino acids,l-Ser,l-Pro,l-Gly,l-Thr andl-Cys were not oxidized, clearly indicating a significant specificity. BjarLAAO-I significantly inhibited Ehrlich ascites tumour growth and induced an influx of polymorphonuclear cells, as well as spontaneous liberation of H₂O₂ from peritoneal macrophages. Later, BjarLAAO-I induced mononuclear influx and peritoneal macrophage spreading. Animals treated with BjarLAAO-I showed higher survival time. [ABSTRACT FROM AUTHOR]