BioVenom - Banco de Dados de Venenos de Serpentes Brasileiras - Antiparasitária

Biochemical and functional characterization of an l-amino acid oxidase isolated from Bothrops pirajai snake venom.

Tue, 12 Sep 2006 12:22:47 -0300

Autores:

Izidoro LF, Ribeiro MC, Souza GR, Sant'ana CD, Hamaguchi A, Homsi-Brandeburgo MI, Goulart LR, Beleboni RO, Nomizo A, Sampaio SV, Soares AM, Rodrigues VM.

Resumo:

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 homodimeric acid glycoprotein (approximate Mr and pI of 130,000 and 4.9, respectively) displays high specificity toward hydrophobic/aromatic amino acids, while deglycosylation does not alter its enzymatic activity. The N-terminal LAAO sequence of its first 49 amino acids presented a high similarity between a amino acid sequence with other LAAOs from: Bothrops spp., Crotalus spp., Calloselasma rhodostoma, 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.

Dados de Publicação:
Bioorg Med Chem. 2006 Jun 27; [Epub ahead of print]

Palavras-Chave:
l-amino acid oxidase, snake venom, biochemical and functional characterization

Bothrops moojeni myotoxin-II, a Lys49-phospholipase A2 homologue: an example of function versatility of snake venom proteins

Mon, 14 Aug 2006 09:15:08 -0300

Autores:

Stabeli RG, Amui SF, Sant'Ana CD, Pires MG, Nomizo A, Monteiro MC, Romao PR, Guerra-Sa R, Vieira CA, Giglio JR, Fontes MR, Soares AM.

Resumo:

MjTX-II, a myotoxic phospholipase A(2) (PLA(2)) homologue from Bothrops moojeni venom, was functionally and structurally characterized. The MjTX-II characterization included: (i) functional characterization (antitumoral, antimicrobial and antiparasitic effects); (ii) effects of structural modifications by 4-bromophenacyl bromide (BPB), cyanogen bromide (CNBr), acetic anhydride and 2-nitrobenzenesulphonyl fluoride (NBSF); (iii) enzymatic characterization: inhibition by low molecular weight heparin and EDTA; and (iv) molecular characterization: cDNA sequence and molecular structure prediction. The results demonstrated that MjTX-II displayed antimicrobial activity by growth inhibition against Escherichia coli and Candida albicans, antitumoral activity against Erlich ascitic tumor (EAT), human breast adenocarcinoma (SK-BR-3) and human T leukemia cells (JURKAT) and antiparasitic effects against Schistosoma mansoni and Leishmania spp., which makes MjTX-II a promising molecular model for future therapeutic applications, as well as other multifunctional homologous Lys49-PLA(2)s or even derived peptides. This work provides useful insights into the structural determinants of the action of Lys49-PLA(2) homologues and, together with additional strategies, supports the concept of the presence of others "bioactive sites" distinct from the catalytic site in snake venom myotoxic PLA(2)s.

Dados de Publicação:
Comp Biochem Physiol C Toxicol Pharmacol. 2006 Mar-Apr;142(3-4):371-81. Epub 2006 Jan 24

Atividades Biológicas induzidas pela MjTX-II isolada do veneno de Bothrops moojeni

Tue, 26 Sep 2006 12:10:00 -0300

Pesquisadores envolvidos:
Stabeli RG, Amui SF, Sant'Ana CD, Pires MG, Nomizo A, Monteiro MC, Romao PR, Guerra-Sa R, Vieira CA, Giglio JR, Fontes MR, Soares AM.

Local:
Depto. Análises Clínicas, Toxicológicas e Bromatológicas-FCFRP-USP, Ribeirão Preto-SP.

Ensaios realizados:
Atividade Miotóxica, indução de edema, citotoxicidade, neurotoxicidade

Dados Publicados em:
Artigos Científicos (Periódicos)

Referências de Publicação:

Comp Biochem Physiol C Toxicol Pharmacol. 2006 Mar-Apr;142(3-4):371-81. Epub 2006 Jan 24

Isolation of a new L-amino acid oxidase from Crotalus durissus cascavella venom.

Wed, 13 Sep 2006 12:29:36 -0300

Autores:

Toyama MH, Toyama Dde O, Passero LF, Laurenti MD, Corbett CE, Tomokane TY, Fonseca FV, Antunes E, Joazeiro PP, Beriam LO, Martins MA, Monteiro HS, Fonteles MC.

Resumo:

A novel l-amino acid oxidase (LAO) (Casca LAO) from Crotalus durissus cascavella venom was purified to a high degree of molecular homogeneity using a combination of molecular exclusion and ion-exchange chromatography system. The purified monomer of LAO presented a molecular mass of 68 kDa and pI estimated in 5.43, which were determined by two-dimensional electrophoresis. The 71st N-terminal amino acid sequence of the LAO from Crotalus durissus cascavella presented a high amino acid sequence similarities with other LAOs from Colloselasma rhosostoma, Crotalus adamanteus, Agkistrodon h. blomhoffi, Agkistrodon h. halys and Trimeresurus stejnegeri. LAO displayed a Michaelis-Menten behavior with a kilometer of 46.7 microM and an optimum pH for enzymatic activity of 6.5. Casca LAO induced a dose-dependent platelet aggregation, which was abolished by catalase and inhibited by indomethacin and aspirin. These results suggest that the production of H2O2 is involved in subsequent activation of inflammatory enzymes, such as thromboxane. Casca LAO also inhibited the bacterial growth of Gram-negative (Xanthomonas axonopodis pv passiflorae) and Gram-positive (S. mutans) strains. Electron microscopy assessments of both bacterial strains suggest that the hydrogen peroxide produced by LAO induce bacterial membrane rupture and consequently loss of cytoplasmatic content. This LAO exhibited a high antileishmanic activity against the promastigote of Leishmania amazonensis in vitro, its activity was dependent on the production of hydrogen peroxide, and the 50% inhibitory concentration was estimated in 2.39 microg/ml.

Dados de Publicação:
Toxicon. 2006 Jan;47(1):47-57. Epub 2005 Nov 22.

Palavras-Chave:
l-amino acid oxidase, Crotalus durissus cascavella;antibacterial; antimicrobial; hydrogen peroxide; gyroxin; leishmanicidal

Anti-protozoary, Anti-bacterial and antitumor activity of L-Amino Acid Oxidase from Bothrops moojeni “in vitro”

Fri, 15 Sep 2006 14:54:53 -0300

Pesquisadores envolvidos:
Malta-Neto, N.R.1; Stabeli, R.G.2; Marcussi, S.1; Monteiro M.C.2; Romão P.R.T.2;3; Nomizo, A.4;

Local:
1Unidade de Biotecnologia UNAERP, Ribeirão Preto-SP; 2Departamento de Bioquímica e Imunologia and Departamento de Farmacologia, FMRP/USP, Ribeirão Preto-SP; 3Departamento de Imunologia, UNISUL-Tuba

Dados Publicados em:
Eventos (Congressos, Simpósios, etc)

Referências de Publicação:

SBTX 2004

Bothrops moojeni venom kills Leishmania spp. with hydrogen peroxide generated by its L-amino acid oxidase.

Tue, 12 Sep 2006 03:18:55 -0300

Autores:

Tempone AG, Andrade HF Jr, Spencer PJ, Lourenco CO, Rogero JR, Nascimento N.

Resumo:

Leishmaniasis is an endemic tropical disease in South America, with few therapeutic approaches. Snake venoms are complex protein mixtures with biological actions that could be used as tools for drug development. Here we show that Bothrops moojeni crude venom presented a killing effect in vitro against Leishmania spp. promastigotes, but not with amastigotes, as determined by a viability assay using the mitochondrial oxidative function. Purification of active fractions from crude venom was performed by molecular exclusion and ion exchange chromatography. Anti-Leishmania and l-amino acid oxidase (L-AAO, EC.1.4.3.2.) activities co-eluted in the same fractions. The molecular weight of the active enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa by SDS--PAGE, with a 4.8 isoelectric point. Using substrate subtraction and catalase for scavenging, the action of L-AAO was demonstrated to be hydrogen-peroxide-dependent. Copyright 2001 Academic Press.

Dados de Publicação:
Biochem Biophys Res Commun. 2001 Jan 26;280(3):620-4.

Palavras-Chave:
l-amino acid oxidase, snake venom, Leishmania