Cytotoxic L-amino acid oxidase from Bothrops moojeni: biochemical and functional characterization.
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 approximately 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% alpha-helix, 20% beta-sheet, 12% beta-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 H(2)O(2). 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 H(2)O(2) production can be beneficial.
Stábeli
Rodrigo G
RG
Laboratório de Bioquímica do Instituto de Pesquisas em Patologias Tropicais (IPEPATRO), Universidade Federal de Rondônia, UNIR, Porto Velho-RO, Brazil.
Sant'Ana
Carolina D
CD
Ribeiro
Patrícia H
PH
Costa
Tássia R
TR
Ticli
Fábio K
FK
Pires
Matheus G
MG
Nomizo
Auro
A
Albuquerque
Sérgio
S
Malta-Neto
Natael R
NR
Marins
Mozart
M
Sampaio
Suely V
SV
Soares
Andreimar M
AM
D000594:Amino Acid Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000818:Animals; D017837:Bothrops; D002374:Catalase / Q000494:pharmacology; D002853:Chromatography, Liquid; D003435:Crotalid Venoms / Q000201:enzymology*; D053938:DNA Fragmentation / Q000187:drug effects*; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D017433:Protein Structure, Secondary
D003435:Crotalid Venoms; D006861:Hydrogen Peroxide; D002374:Catalase; D000594:Amino Acid Oxidoreductases