Cytotoxic l-amino acid oxidase from Bothrops moojeni: Biochemical and functional characterization

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• 作者：Rodrigo G. Stá ; beli ; Carolina D. Sant’ ; Ana ; Patrí ; cia H. Ribeiro ; Tá ; ssia R. Costa ; Fá ; bio K. Ticli ; Matheus G. Pires ; Auro Nomizo ; Sé ; rgio Albuquerque ; Natael R. Malta-Neto
• 关键词：l-Amino acid oxidase ; Snake venom ; Bothrops moojeni ; Platelet aggregation ; Antimicrobial and cytotoxic effects ; Structure analysis
• 刊名：International Journal of Biological Macromolecules
• 出版年：2007
• 出版时间：1 July 2007
• 年：2007
• 卷：41
• 期：2
• 页码：132-140
• 全文大小：990 K

文摘

An l-amino acid oxidase isolated from Bothrops moojeni snake venom (BmooLAAO-I) was purified to a high degree using sequential CM-Sepharose ion-exchange and phenyl-Sepharose chromatography. When analyzed by mass spectrometry, the purified BmooLAAO-I presented a molecular weight of 64,889 and 130,779 under denaturing and nondenaturing conditions, respectively. BmooLAAO-I is a homodimeric acidic glycoprotein with a pI 4.7, and the N-terminal sequence shows close structural similarity to other snake venom LAAOs. This enzyme was inactivated by freezing or low pH, and secondary structural analysis by circular dichroism revealed 48 % α-helix, 20 % β-sheet, 12 % β-turn, and 20 % random coil structures. BmooLAAO-I exhibited bactericidal, antitumoral, trypanocidal, edematogenic, and platelet-aggregating activities. All of these effects were inhibited by catalase, suggesting that these biological effects are mediated by the production of H₂O₂. BmooLAAO-I induced typical apoptotic DNA fragmentation in HL-60 cells, which was also inhibited by catalase. These results point to the potential use of BmooLAAO-I as a therapeutic agent for treatment of diseases in which induction of H₂O₂ production can be beneficial.