Structural and functional characterization of BnSP-7, a Lys49 myotoxic phospholipase A(2) homologue from Bothrops neuwiedi pauloensis Venom

BnSP-7, a Lys49 myotoxic phospholipase A, homologue from Bothrops neuwiedi pauloensis venom, was structurally and functionally characterized. Several biological activities were assayed and compared with those of the chemically modified toxin involving specific amino acid residues, the cDNA produced from the total RNA by RT-PCR contained approximately 400 bp which codified its 121 amino acid residues with a calculated pi and molecular weight of 8.9 and 13,727, respectively. Its amino acid sequence showed strong similarities with several Lys49 phospholipase A, homologues from other Bothrops sp, venoms. By affinity chromatography and gel diffusion, it was demonstrated that heparin formed a complex with BnSP-7, held at least in part by electrostatic interactions. BnSP-7 displayed bactericidal activity and promoted the blockage of the neuromuscular contraction of the chick, biventer cervicis muscle. In addition to its in vivo myotoxic and edema-inducing activity, it disrupted artificial membranes, Both BnSP-7 and the crude venom released creatine kinase from the mouse gastrocnemius muscle and induced the development of a dose-dependent edema. His, Tyr, and Lys residues of the toxin were chemically modified by 4-bromophhenacyl bromide (BPB), 2-nitrobenzenesulfonyl fluoride (NBSF), and acetic anhydride (AA), respectively. Cleavage of its N-terminal octapeptide was achieved with cyanogen bromide (CNBr), the bactericidal action of BnSP-7 on Escherichia coli was almost completely abolished by acetylation or cleavage of the N-terminal octapeptide, the neuromuscular effect induced by BnSP-7 was completely inhibited by heparin, BPB, acetylation, and CNBr treatment. The creatine kinase releasing and edema-inducing effects were partially inhibited by heparin or modification by BPB and almost completely abolished by acetylation or cleavage of the N-terminal octapeptide, the rupture of liposomes by BnSP-7 and crude venom was dose and temperature dependent. Incubation of BnSP-7 with EDTA did not change this effect, suggesting a Ca2+-independent membrane lytic activity. BnSP-7 cross-reacted with antibodies raised against B. moojeni (MjTX-II), B. jararacussu (BthTX-I), and B. asper (Basp-II) myotoxins as well as against the C-terminal peptide (residues 115-129) from Basp-II. (C) 2000 Academic Press.

Studies on the electrochemical disinfection of water containing Escherichia coli using a Dimensionally Stable Anode

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dissociation of enzymatic and pharmacological properties of piratoxins-I and -III, two myotoxic phospholipases A(2) from Bothrops pirajai snake venom

Piratoxins (PrTX) I and III are phospholipases A(2) (PLA(2)s) or PLA(2) homologue myotoxins isolated from Bothrops pirajai snake venom, which also induce myonecrosis, bactericidal activity against Escherichia coli, disruption of artificial membranes, and edema. PrTX-III is a catalytically active hemolytic and anticoagulant Asp49 PLA(2), while PrTX-I is a Lys49 PLA, homologue, which is catalytically inactive on artificial substrates, but promotes blockade of neuromuscular transmission. Chemical modifications of His, Lys, Tyr, and Trp residues of PrTX-I and PrTX-III were performed, together with cleavage of the N-terminal octapeptide by CNBr and inhibition by heparin and EDTA. The lethality, bactericidal activity, myotoxicity, neuromuscular effect, edema inducing effect, catalytic and anticoagulant activities, and the liposome-disruptive activity of the modified toxins were evaluated. A complex pattern of functional differences between the modified and native toxins was observed. However, in general, chemical modifications that significantly affected the diverse pharmacological effects of the toxins did not influence catalytic or membrane disrupting activities. Analysis of structural changes by circular dichroism spectroscopy demonstrated significant changes in the secondary structure only in the case of N-terminal octapeptide cleavage. These data indicate that PrTX-I and PrTX-III possess regions other than the catalytic site, which determine their toxic and pharmacological activities. (C) 2001 Academic Press.

Population analysis of susceptibility to propolis in reference strains of Staphylococcus aureus and Escherichia coli

Susceptibility to several ethanolic extracts of propolis (EEP) concentrations was tested with the population analysis technique in reference strains of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 35218). The results of these tests showed that all bacteria were killed by EEP concentrations approximately equal or higher (2.0% v/v - S. aureus; 10.0% v/v - E. coli) than the respective minimal inhibitory concentrations (MIC). Regarding the susceptibility to propolis, there was a homogeneity of data with the respective time kill curves showing a clear bactericidal effect during 6 to 9 h of exposition.

Naphthopyranone glycosides from Paepalanthus bromelioides

Two new naphtho[2,3-C]pyran-1-one glycosides, paepalantine-9-O-β-D- glucopyranoside and paepalantine-9-O-β-D-allopyranosyl(1 → 6)glucopyranoside, were isolated from an ethanolic extract of capitula from Paepalanthus bromelioides and identified from their spectrometric data.

Advances in prodrug design

The background of prodrug design is presented herein as the basis for introducing new and advanced latent systems, taking into account mainly the versatility of polymers and other macromolecules as carriers. PDEPT (Polymer-Directed Enzyme Prodrug Therapy); PELT (Polymer-Enzyme Liposome Therapy); CDS (Chemical Delivery System); ADEPT(Antibody-Directed Enzyme Prodrug Therapy); GDEPT/VDEPT (Gene-Directed Enzyme Prodrug Therapy/Virus-Directed Enzyme Prodrug Therapy); ODDS (Osteotropic Drug Delivery System) and LEAPT (Lectin-directed enzyme-activated prodrug therapy) are briefly described and some examples are given. © 2005 Bentham Science Publishers Ltd.

Potencial de atividade antimicrobiana in vitro de extratos vegetais do cerrado frente estirpes de Staphylococcus aureus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Imunomodulação por levamisol na imunidade inata e adquirida de pacu (Piaractus mesopotamicus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação rápida do perfil de sensibilidade do agente da tuberculose às drogas sintéticas ou extratos vegetais empregando Mycobacterium tuberculosis contendo o gene da luciferase

Pós-graduação em Biotecnologia - IQ

Desenvolvimento de biocidas inorgânicos a base de óxidos de titânio e silício com prata para desinfecção de águas contaminadas com microrganismo

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Avaliação da indução de resistência no controle do crestamento bacteriano comum do feijão vagem

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ação de indutores bióticos e abióticos no controle da ferrugem do eucalipto, atividade enzimática e expressão gênica durante o processo de infecção

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise químico-farmacêutica de preparações injetáveis de Aztreonam

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alkyl Caffeates as Anti-Helicobacter Pylori and Scavenger of Oxidants Produced by Neutrophils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antimicrobial and Cytotoxic Activity of Fruit Extract from Syzygium cumini (L.) Skeels

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)