Purificação de isoformas de fosfolipase A2 a partir do veneno total de Crotalus durissus terrificus e estudo de seus efeitos em mitocondrias isoladas

Orientador: Benedito de Oliveira FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: A crotoxina, isolada e cristalizada em 1938 por Slotta e Fraenkel-Conrat a partir do veneno total de Crotalus durissus terrificus mostrou ser um complexo resultante da interação quaternária de duas sub-unidades representadas por uma proteína ácida com massa molecular de 9 kDa denominada crotapotina e um componente básico, com massa molecular de 14,5 kDa que foi identificado como sendo uma fosfolipase A2 (PLA2 ). Esta última é considerada o principal componente responsável pelo desencadeamento dos efeitos farmacológicos induzidos pelo complexo crotoxina. Estudos mais recentes demonstraram a ocorrência de várias isoformas de PLA2, presentes em diferentes lotes de veneno coletados de várias serpentes, sendo tais isoformas decorrentes da expressão de diferentes RNAs mensageiros. As PLA2 (EC 3.1.1.4.) são enzimas que catalisam especificamente a reação de hidrólise da ligação acil-ester na posição sn-2 de fosfoglicerídeos numa reação dependente de álcio, liberando quantidades equimolares de ácidos graxos livres e lisofosfolipídeos. Já foi demonstrado que trações puras de PLA2 apresentam efeitos inibitórios marcantes sobre várias funções mitocondriais, reduzindo as atividades da NADH oxidase, das succinato e NADH-desidrogenase e da capacidade de fosforilação. Além disso, as PLA2 podem modificar a microviscosidade da fase lipídica da bicamada hidrofóbica de membranas, afetando a atividade funcional de enzimas ligadas à membrana, e, através desse mecanismo, regular vários processos metabólicos. No presente trabalho purificamos e caracterizamos, a partir da crotoxina, três isoformas de PLA2 (F1, F2 e F3) com elevado grau de pureza. As isoformas apresentaram massa molecular aparente com valor igual a 15 kDa e alta homologia seqüencial dos 20 resíduos N-terminais em comparação a isoformas já descritas na literatura. o efeito de cada isoforma de PLA2 purificada sobre mitocôndrias isoladas de fígado de rato foi determinado através de consumo de oxigênio durante o estado respiratório 4 e de inchamento mitocondrial. FI apresentou um estímulo dose dependente do consumo de oxigênio enquanto F2 e F3 causaram estímulo apenas em baixas concentrações e inibição em quantidades maiores. Esses efeitos foram completamente abolidos quando soro albumina bovina a 0,1% ou EGTA a 0,5mM estavam presentes no meio de incubação. Usando-se o inchamento mitocondrial como um parâmetro comparativo, todas as isoformas apresentaram o mesmo comportamento com intensidades diferentes, levando à permeabilização da membrana mitocondrial. Neste caso, a adição de EGTA preveniu o inchamento enquanto a soro albumina bovina foi ineficiente, indicando que o microambiente lipídico foi realmente afetado. Esses resultados sugerem que ácidos graxos livres liberados pela ação das isoformas são diretamente responsáveis pelos efeitos observados nos experimentos de consumo de oxigênio. A proteção oferecida pela CSA contra o inchamento causado pelas isoformas, principalmente quando estas estavam presentes em baixas concentrações, sugere que a ligação da CSA a um sítio da membrana mitocondrial protege esta última contra o ataque das PLA2. Já a pequena proteção oferecida pelo CAT, bem como o prevalecimento do pequeno efeito protetor do CAT quando utilizamos simultaneamente CSA e CAT, sugerem que a ligação do CAT ao seu sítio no carreador ADP/ATP impede a proteção conferida pela CSAAbstract: Crotoxin, isolated and cristalized in 1938 by Slotta and Fraenkel-Conrat from Crotalus durissus terrificus venom showed to be a complex resultant from the quaternary association between two sub-units: an acidic protein with a molecular mass of 9 kDa named crotapotin and a basic component, with a molecular mass of 14.5 kDa which was identified as a phospholipase A2 (PLA2). This last one is considered to be the main component responsible for the pharmacological effects induced by the crotoxin complex. Recent studies have demonstrated the existence of several PLA2 isoforms which were present in different venom batches collected from several snakes. These isoforms result from the expression of different menssager RNAs. The PLA2 (EC 3.1.1.4) are enzimes that specifically catalyse the hydrolysis of the acyl-ester bond at the sn-2 position of phosphoglycerides in a calcium dependent reaction, producing equimolar amounts of ftee fatty acids and Iysophospholipids. It has already been demonstrated that purified PLA2 fractions show marked inhibitory effects on several mitochondrial features, decreasing NADH-oxidase, succinate and NADH-dehydrogenase activities and phosphorylation capacity. It is also known that PLA2 can modify the microviscosity of the lipid phase of the hydrophobic membrane bilayer, affecting the functional activity of membrane-bound enzymes, and through this mechanism regulate various metabolic processes. In the present work, we have purified and characterized, from crotoxin, three PLA2 isoforms (F1, F2 and F3) with high degree of purity. The isoforms presented an apparent molecular mass of 15 kDa and a high degree of homology regarding the 20 N terminal aminoacid residues when compared to other isoforms already described in the literature. The effect of each purified phospholipase A2 isoform on isolated rat liver mitochondria was determined through mitochondrial swelling and Oz consumption during respiratory state 4. FI showed a dose-dependent stimulation of O2 consumption while F2 and F3 caused stimulation only at low doses and inhibition at higher amounts. These effects were completely suppressed by the presence of 0.1% bovine serum albumin or 0.5mM EGTA in the incubation medium. Taking the mitochondrial swelling as a comparative parameter, alI of them presented the same behaviour at different intensities, leading to permeabilization of the mitochondrial membrane. In this case, addition of EGTA prevented it whereas bovine serum albumin was ineffective, indicating that the lipid microenvironrnent was actualIy,affected. These results suggest that free fatty acids must be directly responsible for the observed effects induced by hospholipase A2 isoforms on oxygen consumption experiments. The protection confered by cyclosporin-A on swelling induced by the isoforms, mainly when they were present in low concentrations, suggests that cyclosporin-A binding to a mitochondrial membrane site protects the membrane against the phospholipase A2 attack. On the other hand, the smalI protection confered by CAT, as well as the prevailment of the small protective CAT effect when we used both CSA and CAT, suggest that the CAT binding to the ADP/ ATP carrier inhibits the protection confered by CSAMestradoBioquimicaMestre em Ciências Biológica

Proteomic Profiling Of Skeletal Muscle In An Animal Model Of Overtraining.

Excessive training (i.e. overtraining, OT) may result in underperformance, which can be characterized by the time needed to re-establish performance (i.e. functional overreaching (FOR), nonfunctional overreaching, OT syndrome). The present study is an initial screening for proteins presenting altered abundance in the red (RG) and white (WG) portions of the gastrocnemius muscle from rats submitted to an OT protocol that induced FOR. In the RG, compared to the nontrained control, FOR demonstrated an increased abundance of proteins normally related to adaptation to endurance training (e.g. proteins of oxidative phosphorylation complexes, proteins related to lipid metabolism, antioxidants, and chaperones). In the WG, spots identified as mitochondrial aconitase and a component of the succinate dehydrogenase complex were downregulated in FOR, as were proteins related to myofibril stabilization; these latter were upregulated in the RG. This initial study shows that skeletal muscles with different fiber-type compositions respond differently to an OT period. Also, it is likely that actin-interacting proteins have an important role in muscle adaptation to endurance exercise.122663-

Proteomic profiling of skeletal muscle in an animal model of overtraining

Excessive training (i.e. overtraining, OT) may result in underperformance, which can be characterized by the time needed to re-establish performance (i.e. functional overreaching (FOR), nonfunctional overreaching, OT syndrome). The present study is an initial screening for proteins presenting altered abundance in the red (RG) and white (WG) portions of the gastrocnemius muscle from rats submitted to an OT protocol that induced FOR. In the RG, compared to the nontrained control, FOR demonstrated an increased abundance of proteins normally related to adaptation to endurance training (e.g. proteins of oxidative phosphorylation complexes, proteins related to lipid metabolism, antioxidants, and chaperones). In the WG, spots identified as mitochondrial aconitase and a component of the succinate dehydrogenase complex were downregulated in FOR, as were proteins related to myofibril stabilization; these latter were upregulated in the RG. This initial study shows that skeletal muscles with different fiber-type compositions respond differently to an OT period. Also, it is likely that actin-interacting proteins have an important role in muscle adaptation to endurance exercise121726632667CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informação07/50480-

The Primary Duct of Bothrops jararaca Glandular Apparatus Secretes Toxins

Submitted by Sandra Infurna ([email protected]) on 2018-09-27T15:39:15Z No. of bitstreams: 1 joseantonio_portesjr_etal_IOC_2018.pdf: 6165008 bytes, checksum: b14c5e58fb2db4ccaae9c736e6652f8f (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-09-27T15:47:59Z (GMT) No. of bitstreams: 1 joseantonio_portesjr_etal_IOC_2018.pdf: 6165008 bytes, checksum: b14c5e58fb2db4ccaae9c736e6652f8f (MD5)Made available in DSpace on 2018-09-27T15:47:59Z (GMT). No. of bitstreams: 1 joseantonio_portesjr_etal_IOC_2018.pdf: 6165008 bytes, checksum: b14c5e58fb2db4ccaae9c736e6652f8f (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Toxinologia. Rio de Janeiro, RJ. Brasil / Instituto Nacional de Ciência e Tecnologia em Toxinas. Brasília, DF, Brasil.Instituto Butantan. Laboratório de Farmacologia. São Paulo, SP, Brasil.Instituto Butantan. Laboratório de Imunopatologia. São Paulo, SP, Brasil.Instituto Butantan. Laboratório de Farmacologia. São Paulo, SP, Brasil.Instituto Butantan. Laboratório de Biologia Celular. São Paulo, SP, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Toxinologia. Rio de Janeiro, RJ. Brasil / Instituto Nacional de Ciência e Tecnologia em Toxinas. Brasília, DF, Brasil.Instituto Butantan. Laboratório de Farmacologia. São Paulo, SP, Brasil / Instituto Nacional de Ciência e Tecnologia em Toxinas. Brasília, DF, Brasil.Despite numerous studies concerning morphology and venom production and secretion in the main venom gland (and some data on the accessory gland) of the venom glandular apparatus of Viperidae snakes, the primary duct has been overlooked. We characterized the primary duct of the Bothrops jararaca snake by morphological analysis, immunohistochemistry and proteomics. The duct has a pseudostratified epithelium with secretory columnar cells with vesicles of various electrondensities, as well as mitochondria-rich, dark, basal, and horizontal cells. Morphological analysis, at different periods after venom extraction, showed that the primary duct has a long cycle of synthesis and secretion, as do the main venom and accessory glands; however, the duct has a mixed mode venom storage, both in the lumen and in secretory vesicles. Mouse anti-B. jararaca venom serum strongly stained the primary duct's epithelium. Subsequent proteomic analysis revealed the synthesis of venom toxins-mainly C-type lectin/C-type lectin-like proteins. We propose that the primary duct's toxin synthesis products complement the final venom bolus. Finally, we hypothesize that the primary duct and the accessory gland (components of the venom glandular apparatus) are part of the evolutionary path from a salivary gland towards the main venom gland

Revisiting the Therapeutic Potential of Bothrops jararaca Venom: Screening for Novel Activities Using Connectivity Mapping

Submitted by Sandra Infurna ([email protected]) on 2018-10-05T13:49:56Z No. of bitstreams: 1 carolinaAlves_nicolau_etal_IOC_2081.pdf: 945357 bytes, checksum: bef37e6da5b6ecb11075862afbd0bbee (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-10-05T18:34:49Z (GMT) No. of bitstreams: 1 carolinaAlves_nicolau_etal_IOC_2081.pdf: 945357 bytes, checksum: bef37e6da5b6ecb11075862afbd0bbee (MD5)Made available in DSpace on 2018-10-05T18:34:49Z (GMT). No. of bitstreams: 1 carolinaAlves_nicolau_etal_IOC_2081.pdf: 945357 bytes, checksum: bef37e6da5b6ecb11075862afbd0bbee (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Toxinologia. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Ciência e Tecnologia em Toxinas. Brasília, DF, Brasil / University of Virginia. Department of Microbiology, Immunology and Cancer Biology. Charlottesville, VA, USA.University of Virginia. Department of Microbiology, Immunology and Cancer Biology. Charlottesville, VA, USA.University of Virginia. Department of Microbiology, Immunology and Cancer Biology. Charlottesville, VA, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Toxinologia. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Ciência e Tecnologia em Toxinas. Brasília, DF, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Toxinologia. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Ciência e Tecnologia em Toxinas. Brasília, DF, Brasil.University of Virginia. Department of Microbiology, Immunology and Cancer Biology. Charlottesville, VA, USA.Snake venoms are sources of molecules with proven and potential therapeutic applications. However, most activities assayed in venoms (or their components) are of hemorrhagic, hypotensive, edematogenic, neurotoxic or myotoxic natures. Thus, other relevant activities might remain unknown. Using functional genomics coupled to the connectivity map (C-map) approach, we undertook a wide range indirect search for biological activities within the venom of the South American pit viper Bothrops jararaca. For that effect, venom was incubated with human breast adenocarcinoma cell line (MCF7) followed by RNA extraction and gene expression analysis. A list of 90 differentially expressed genes was submitted to biosimilar drug discovery based on pattern recognition. Among the 100 highest-ranked positively correlated drugs, only the antihypertensive, antimicrobial (both antibiotic and antiparasitic), and antitumor classes had been previously reported for B. jararaca venom. The majority of drug classes identified were related to (1) antimicrobial activity; (2) treatment of neuropsychiatric illnesses (Parkinson's disease, schizophrenia, depression, and epilepsy); (3) treatment of cardiovascular diseases, and (4) anti-inflammatory action. The C-map results also indicated that B. jararaca venom may have components that target G-protein-coupled receptors (muscarinic, serotonergic, histaminergic, dopaminergic, GABA, and adrenergic) and ion channels. Although validation experiments are still necessary, the C-map correlation to drugs with activities previously linked to snake venoms supports the efficacy of this strategy as a broad-spectrum approach for biological activity screening, and rekindles the snake venom-based search for new therapeutic agents

Penicillium citrinum UFV1 β-glucosidases: purification, characterization, and application for biomass saccharification

Abstract Background β-Glucosidases are components of the cellulase system, a family of enzymes that hydrolyze the β-1,4 linkages of cellulose. These proteins have been extensively studied due to the possibility of their use in various biotechnological processes. They have different affinities for substrates (depending on their source) and their activities can be used for saccharification of different types of biomass. In this context, the properties and the synergistic capacity of β-glucosidases from different organisms, to supplement the available commercial cellulase cocktails, need a comprehensive evaluation. Results Two β-glucosidases belonging to GH3 family were secreted by Penicillium citrinum UFV. PcβGlu1 (241 kDa) and PcβGlu2 (95 kDa) presented acidic and thermo-tolerant characteristics. PcβGlu1 showed Michaelis–Menten kinetics for all substrates tested with K m values ranging from 0.09 ± 0.01 (laminarin) to 1.7 ± 0.1 mM (cellobiose, C2) and k cat values ranging from 0.143 ± 0.005 (laminarin) to 8.0 ± 0.2 s−1 (laminaribiose, Lb). PcβGlu2 showed substrate inhibition for 4-methylumbelliferyl-β-d-glucopyranoside (MUβGlu), p-nitrophenyl-β-d-glucopyranoside (pNPβGlu), cellodextrins (C3, C4, and C5), N-octil-β-d-glucopyranoside, and laminaribiose, with K m values ranging from 0.014 ± 0.001 (MUβGlu) to 0.64 ± 0.06 mM (C2) and k cat values ranging from 0.49 ± 0.01 (gentiobiose) to 1.5 ± 0.2 s−1 (C4). Inhibition constants (K i) for PcβGlu2 substrate inhibition ranged from 0.69 ± 0.07 (MUβGlu) to 10 ± 1 mM (Lb). Glucose and cellobiose are competitive inhibitors of PcβGlu1 and PcβGlu2 when pNPβGlu is used as a substrate. For PcβGlu1 inhibition, K i = 1.89 ± 0.08 mM (glucose) and K i = 3.8 ± 0.1 mM (cellobiose); for PcβGlu2, K i = 0.83 ± 0.05 mM (glucose) and K i = 0.95 ± 0.07 mM (cellobiose). The enzymes were tested for saccharification of different biomasses, individually or supplementing a Trichoderma reesei commercial cellulose preparation. PcβGlu2 was able to hydrolyze banana pseudostem and coconut fiber with the same efficiency as the T. reesei cocktail, showing significant synergistic properties with T. reesei enzymes in the hydrolysis of these alternative biomasses. Conclusions The β-glucosidases from P. citrinum UFV1 present different enzymatic properties from each other and might have potential application in several biotechnological processes, such as hydrolysis of different types of biomass