Caracterização bioquímica e funcional de uma nova L-aminoácido oxidase isolada da peçonha da serpente Bothrops pirajai

Abstract

In this work we describe the isolation of a new L-amino acid oxidase (LAAO) referred to as BpirLAAO-I from Bothrops pirajai snake venom, which was highly purified using a combination of molecular exclusion, affinity and hydrophobic chromatography steps. BpirLAAO-I is a homodimeric acidic glycoprotein (approximate Mr and pI of 130,000 and 4.9, respectively), that displays a high specificity towards hydrophobic/aromatic amino acid residues while deglycosylation does not alter its enzymatic activity. The N-terminal LAAO sequence of its first 49 amino acids presented a similarity and other LAAOs from: Bothrops spp, Crotalus spp, Calloselasma rhosostoma, Agkistrodon spp, Trimeresurus spp, Pseudechis australis, Oxyuranus scutellatus, and Notechis scutatus. BpirLAAO-I induces time-dependent platelet aggregation, mouse paw edema, cytotoxic activity against Escherichia coli, Pseudomonas aeruginosa, Leishmania sp and tumor cells, and also a typical fago (M13mp18) DNA fragmentation. Platelet aggregation, leishmanicidal and antitumoral activities were reduced by catalase. Thus, BpirLAAO-I is a multifunctional protein with promising biotechnological and medical applications.