Made available in DSpace on 2014-10-09T12:28:37Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:29Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Resumo: As aranhas do gênero Phoneutria (Aranae, Ctenidae) são comumente conhecidas como "aranha armadeira" ou "aranha da banana", devido à posição de ataque/defesa que elas assumem contra uma presa/competidor e devido sua alta incidência nas plantações de bananas. Estas aranhas são solitárias, errantes (não constroem teias), muito agressivas e responsáveis por muitos casos graves de acidentes por envenenamento e de morte registrados. Estas aranhas são amplamente distribuídas nas regiões temperadas da América do Sul, com várias espécies já descritas. A espécie Phoneutria nigriventer é mais comum nas regiões centroeste e sudeste do Brasil. Um grande número de neurotoxinas tem sido purificado de venenos de aranhas do gênero Phoneutria. No entanto, as neurotoxinas não - protéicas de baixa massa molecular precisam ser isoladas e caracterizadas estrutural e funcionalmente. Essas toxinas são de potencial interesse na neuroquímica como ferramentas para investigações do sistema nervoso. O objetivo do presente estudo foi a caracterização estrutural e funcional da "Nigriventrina", uma nova neurotoxina não-protéica de baixa massa molecular, isolada da fração hidrofílica do veneno da aranha Phoneutria nigriventer por (RPHPLC) sob gradiente de acetonitrila. A elucidação estrutural foi realizada com HRESIMS, ESI-MS, ESI-MS/MS e espectroscopia de Ressonância Magnética Nuclear 1D e 2D. A toxina apresentou massa molecular de 422Da (C12H14N4O13) e foi caracterizada como hidrazil-dioxopiperidina. A caracterização biológica foi realizada pela aplicação icv da Nigriventrina em cérebro de rato, seguido pelo acompanhamento da expressão da proteína Fos e dupla marcação imunoistoquímica. Todos os neurônios duplamente marcados foram associados ao receptor ionotrópico de glutamato NMDA (N-metil-D-aspartato), subtipo NMDA-NR1. A Nigriventrina apresentou afinidade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The spiders of the genus Phoneutria (Aranae, Ctenidae) are commonly known as "armed spider" or "banana spider", because of the attack-defense position that they assume against a prey/competitor and their high incidence in banana plantations. These spiders are solitary, wandering (no web), very aggressive, responsible for many cases of severe envenomation and recorded mortality. These spiders are widely distributed in the warm regions of South America, and several species have been described. The Phoneutria nigriventer are the most common in central and south-eastern regions of Brazil. A large number of neurotoxins have been purified from the venoms of Phoneutria spiders. However, the non-proteic low molecular mass neurotoxins must be isolated and structural and functionally characterized. These toxins have an interesting potential in neurochemistry as tools for investigations of nervous system. The objective of the present study was the structural and functional characterization of "Nigriventrine", a novel non-proteic low molecular mass neurotoxin, isolated from the hydrophilic fraction of Phoneutria nigriventer spider venom by (RP-HPLC) under gradient of acetonitrile. The structural elucidation was carried out with HRESIMS, ESI-MS, ESI-MS/MS and Nuclear Magnetic Resonance 1D and 2D spectroscopy. The toxin presented molecular mass of 422Da (C12H14N4O13) and was characterized as hydroxyl-hydrazyl-dioxopiperidine. The biological characterization was performed by the i.c.v application of nigriventrine in rat brain, followed by the monitoring of the expression of Fos protein and doublelabeling immunohistochemistry. All doubly labeled neurons were associated to Nmethyl- D- aspartate/subtype of ionotropic glutamate receptor (NMDA-NR1). The nigriventrine presented affinity mainly to cortical regions, which are linked to perceptions and the voluntary muscles control of the animals... (Complete abstract click electronic access below) / Orientador: Mario Sergio Palma / Coorientador: Marta do Nascimento Cordeiro / Banca: Michael Richardson / Banca: Yara Curi / Banca: Claudio Francisco Tormena / Banca: Roberta Cornelio Ferreira Nocelli / Doutor

MORAES, Janne Keila Sousa. Aspectos estruturais da toxina da soja (SBTX) e sua participação na defesa vegetal. xviii, 133 f. : Dissertação (Mestrado em Bioquímica) - Universidade Federal do Ceará, Fortaleza-CE, 2007. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-05-25T13:09:16Z No. of bitstreams: 1 2007_dis_jksmoraes.pdf: 1562360 bytes, checksum: 11d738b376765025a92cd19e28a5f414 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-05T20:07:07Z (GMT) No. of bitstreams: 1 2007_dis_jksmoraes.pdf: 1562360 bytes, checksum: 11d738b376765025a92cd19e28a5f414 (MD5) / Made available in DSpace on 2016-07-05T20:07:07Z (GMT). No. of bitstreams: 1 2007_dis_jksmoraes.pdf: 1562360 bytes, checksum: 11d738b376765025a92cd19e28a5f414 (MD5) Previous issue date: 2007 / This work describes the structural characterization of the soybean toxin (SBTX), isolated from seeds by Siebra (2004). In addition, it is discussed the involvement of this protein in plant defense against pathogens. SBTX was isolated using ammonium sulfate fractionation (20-55%), ion exchange and gel filtration chromatographies. Judging by the SDS-PAGE patterns, it was reported to SBTX an apparent molecular mass of 44 kDa, composed of subunits of 27 kDa and 17 kDa, both linked by disulfide bond. NH2-terminal sequencing of electroblotted samples showed that 44 and 27 kDa bands possess identical NH2-terminal amino acid sequences, ADPTFGFTPLGLSEKANLQIMKAYD that differs from that of the 17 kDa band, PNPKVFFDMTIGGQSAGRIVMEEYA. In the fluorescence spectroscopy, excitation of the toxin solution at 280 m gave a maximum emission in 332 m, which is typically for tryptophan residues buried inside the protein. The secondary structure of SBTX by circular dicroism classified this protein as belonging to alpha- and beta class, showing 35% -helix, 13% -sheet and strand, 27% -turn, 25% random coil and 1% aromatic residues and disulfide bonds. SBTX (50 gP/mL) inhibited the spore germination of the filamentous fungi Aspergillus niger and Penicillium herguei, but did not inhibit those of Fusarium solani e F. oxysporum, even at concentrations ten times higher. Nevertheless, SBTX did not interfere in the vegetative growth of the fungus cited above. On the other hand, SBTX slowed the growth of the yeasts Candida albicans and Kluyveromyces marxiannus, but did not have effect on Saccharomyces cerevisiae, suggesting that its effect would be species-specific. The mechanism by which SBTX acts seems to be not related to alteration of the plasmatic membrane permeability. The treatment of soybean seeds with 50 M jasmonic acid, for 24 h, led to remarkable increase in SBTX content. The results suggest that SBTX may have a role in the plant defense strategy against pathogens / Este trabalho descreve a caracterização estrutural da toxina de soja (SBTX), isolada de sementes por Siebra (2004), e discute o envolvimento desta proteína na defesa da planta contra patógenos. A SBTX foi purificada por precipitação do extrato total com sulfato de amônio (20-55%) e cromatografias de troca iônica e filtração em gel. Por PAGE-SDS, SBTX apresentou massa molecular aparente de 44 kDa, originando duas subunidades, uma de 27 kDa e outra de 17 kDa, quando tratada com 5% de -mercaptoetanol por 15 minutos. A proteína intacta (44 kDa) e a subunidade de 27 kDa apresentaram a mesma seqüência NH2-terminal ADPTFGFTPLGLSEKANLQIMKAYD. Já a subunidade de 17 kDa mostrou uma outra seqüência NH2-terminal, representada por PNPKVFFDMTIGGSAGRIVMEEYA. Por espectroscopia de fluorescência, foi observado que a excitação de uma solução aquosa de SBTX, a 280 m, provocou emissão máxima a 332 m, que é típico da contribuição de resíduos de triptofano enterrados no interior da molécula. A análise da estrutura secundária da SBTX por dicroísmo circular classificou esta toxina como pertencente à classe alfa e beta, apresentando 35% de α-hélice, 13% de fitas e folhas β, 27% de volta­β, 25% de estrutura não ordenada e 1% de resíduos aromáticos e pontes dissulfeto. SBTX (0,05 µgP/µL) inibiu a germinação dos esporos dos fungos filamentosos Aspergillus niger e Penicillium herguei, mas não teve ação sobre Fusarium solani e F. oxysporum, mesmo em concentração dez vezes maior. Todavia, essa toxina não interferiu no crescimento de hifas de nenhum dos fungos citados. Por outro lado, a SBTX retardou o crescimento das leveduras Candida albicans e Kluyveromyces marxiannus, mas não de Saccharomyces cerevisiae, sugerindo ser o seu efeito espécie-específico. O mecanismo pela qual a SBTX atua parece não estar relacionado com alteração da permeabilidade da membrana plasmática. O tratamento das sementes de soja com ácido jasmônico 50 µM, por 24 h, induziu aumento expressivo no conteúdo de SBTX. Os resultados obtidos sugerem que SBTX pode ter um papel na estratégia de defesa vegetal contra patógenos

Currently, although we are not jeopardized by global conflicts, but when the threat of chemical or biological attack, especially from the side of some of terrorist groups or a belligerent state, is still real, it is necessary to use all possible available measures for the conservation of global security against conventional weapons and weapons of mass destruction. The aim of this thesis is the following: To analyze texts of both stated Conventions and thus to get a consolidated view on the issue of biological and chemical weapons from the legislative point of view. To obtain, on the basis of the analysis and systematic comparison of particular provisions, an overview of identical and different elements in both Conventions. On the basis of results of the mutual comparison of particular provisions of both Conventions, to assess, according to their versions, meaning and extent, the influence on performance of both Conventions. After meeting these objectives it was possible to provide an answer to the stated research question: Are the measures formulated in international Conventions on the Prohibition of Biological and Chemical weapons sufficient in their importance, versions and extent, including the effective control? For the purpose of this thesis, theoretical part is focused especially on defining biological and chemical weapons and effective warfare agents. Furthermore, in order to obtain the idea of the importance of existence of international Conventions on the Prohibition of Biological and Chemical Weapons there is given a brief history of the use of these weapons in armed conflicts and a history accompanying negotiations regarding their prohibition. For completeness, the current state of biological and chemical weapons and compliance with both Conventions are given in conclusion. Second part of the thesis is devoted to the analysis and comparison of texts of both Conventions, so objectives of the thesis could be achieved and the research question could be answered. Stated objectives were achieved with the assistance of methods of the qualitative research. After detailed analysis of both texts and systematic assessment of individual measures contained in them, there were detected especially the range and overall text of each Convention. Subsequently, identical and different articles were mutually compared in order to observe the differences, which could have an impact on the performance of both conventions. After overall review of compliances and differences, and after the assessment of the scale, version and meaning of particular different provisions, the research question could be answered, and at the same time basic recommendations, whose importance may represent means to more efficient implementation of individual provisions of Conventions, could be defined. On the basis of results of comparison of particular provisions of both Conventions, in response to the research question it is necessary to state, that actions formulated in CWC, including its Annexes, appear to be sufficient for compliance with arising obligations. While measures contained in BWC, in particular in terms of the absence of any control measures, which could be used as an effective feedback regarding the implementation of provisions of the Convention, optionality to declare information on activities unrestricted by the Convention and inaccurate definition of components seem to be insufficient in its version, extent and meaning for this purpose. Essential reformation regarding the implementation of the objectives of BWC would be adoption of a complex of control measures according to the design of CWC, which has major impact on the objectives of the Convention. Proposed completion of existing articles, in case of which the change in wording would extend the scope of their versions and increase the emphasis on some areas of contained provisions for more efficient implementation of the Convention, may be also beneficial.

Made available in DSpace on 2014-06-11T19:26:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-14Bitstream added on 2014-06-13T19:54:07Z : No. of bitstreams: 1 mendes_drp_me_jabo.pdf: 752950 bytes, checksum: da4434743daf49841f285c3909094a1c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Proteínas inseticidas derivadas de Bacillus thuringiensis (Bt) são os inseticidas biológicos mais amplamente utilizados. O trabalho teve por objetivo avaliação da toxicidade das proteínas de Bt, Cry1Ia e Vip3Aa, expressas em Escherichia coli BL21 (DE3), a fim de verificar a eficiência destas toxinas na mortalidade de Spodoptera frugiperda. Para tanto, empregou-se um par de iniciadores específicos para amplificar o fragmento correspondente ao gene vip3Aa completo contendo 2370 pb. O fragmento obtido foi clonado no vetor pET SUMO e transformado em células de E. coli BL21 (DE3) por choque térmico. A expressão das proteínas Vip3Aa e Cry1Ia previamente clonado, foi induzida por tiogalactopiranosídeo de isopropila (IPTG), e as proteínas recombinantes com peso molecular de, aproximadamente, 100 e 81 KDa respectivamente, foram detectadas por SDS-PAGE e Western Blot. Para avaliação da toxicidade os bioensaios foram realizados com as lagartas de primeiro instar que foram alimentadas com dietas artificiais contendo, na superfície, cinco diferentes concentrações da toxina Cry1Ia e cinco diferentes concentrações da toxina Vip3Aa recombinante. Os bioensaios foram estabelecidos em delineamento inteiramente casualizado, com 16 lagartas por repetição, totalizando 4 repetições por tratamento. A quantificação de lagartas mortas pela ação do B. thuringiensis, foi determinada pela CL50. Os resultados demonstraram a eficiência do sistema bacteriano na expressão das proteínas Vip3Aa e Cry1Ia de B. thuringiensis, resultando em toxinas recombinantes com elevada toxicidade frente às lagartas de S. frugiperda, o que sugere o uso destes genes na obtenção de plantas transgênicas, únicas ou piramidada, resistentes a esta praga / Insecticidal proteins derived from Bacillus thuringiensis (Bt) are the most widely used biological insecticides. The study aimed to evaluate the toxicity of Bt proteins, Cry1Ia Vip3Aa and expressed in Escherichia coli BL21 (DE3) to verify the efficiency of these toxins on the mortality of Spodoptera frugiperda. For this we used a pair of specific primers to amplify the fragment corresponding to the gene vip3Aa complete containing 2370 bp. The fragment was cloned into pET SUMO vector and transformed into cells of E. coli BL21 (DE3) by heat shock. The expression of proteins Vip3Aa and Cry1Ia previously cloned, was induced by isopropyl tiogalactopiranosídeo (IPTG), and the recombinant proteins with a molecular weight of approximately 100 and 81 kDa respectively, were detected by SDS-PAGE and Western blot. To evaluate the toxicity bioassays were performed with first instar caterpillars that were fed diets containing artificial, in surface, whit five different toxin concentrations of Cry1Ia and five different concentrations of recombinant toxin Vip3Aa. Bioassays were established in a randomized design, with 16 larvae per repetition, totaling four replicates per treatment. The quantification caterpillar dead by the action of B. thuringiensis, was determined by LC50. The results demonstrated the efficiency of the bacterial system in protein expression Vip3Aa Cry1Ia of B. thuringiensis toxins, resulting in recombinants with high toxicity against the larvae of S. frugiperda, suggesting the use of these genes in the production of transgenic plants, single or pyramided resistant to this pest

Made available in DSpace on 2015-01-26T13:21:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-25Bitstream added on 2015-01-26T13:30:39Z : No. of bitstreams: 1 000795967.pdf: 970728 bytes, checksum: 1a9dc450a114117aa840a96d9f584e0e (MD5) / Nos últimos anos, tem crescido o interesse pela identificação de compostos naturais com potencial medicinal. O isotiocianato de alila (AITC), encontrado em plantas da família Cruciferae e composto majoritário da semente de mostarda, vem sendo avaliado quanto a sua atividade antineoplásica em bexiga devido à sua alta biodisponibilidade na urina a após ingestão. Neste estudo foram investigadas as atividades toxicogenética e toxicogenômica do AITC em linhagens celulares de carcinoma de bexiga com diferentes status do gene TP53 (RT4 – TP53 selvagem / T24 – TP53 mutado). As concentrações de AITC testadas nos ensaios de citotoxicidade, sobrevivência celular e clonogênica foram 0,005, 0,0625, 0,0725, 0,0825, 0,0925, 0,125 e 0,25 μM; nos testes do cometa, micronúcleo, ciclo celular, apoptose, morfologia e expressão gênica (ANLN, BAX, BCL-2, CDK-1, SMAD4, S100P e TP53) foram utilizadas as concentrações de 0,005, 0,0625, 0,0725, 0,0825 e 0,0925 μM. Os resultados mostraram aumento de danos primários no DNA (teste do cometa) para todas as concentrações testadas do AITC na linhagem T24 e para as concentrações mais altas (0,0725, 0,0825 e 0,0925 μM) na linhagem RT4; não foram observados aumentos nas frequências de células micronucleadas em ambas as linhagens. Nas análises de ciclo celular e apoptose foram observadas a parada do ciclo na fase G2/M para a linhagem T24 e altas taxas de apoptose precoce e necrose na linhagem RT4. Com relação à expressão gênica, houve aumento da expressão de S100P e BAX e diminuição da expressão de BCL-2 na linhagem RT4 e aumento da expressão de BCL-2, BAX e ANLN e diminuição da expressão de S100P na T24. Nenhuma alteração foi identificada para os genes SMAD4 e CDK1 nas duas linhagens tratadas com o AITC. Concluindo, o AITC foi capaz de induzir lesões primárias no DNA de células de ambas as linhagens de carcinoma de bexiga, mas que não se refletiram ... / Compounds obtained from fruits, vegetables and essential oils have been widely used to treat many diseases. The allyl isothiocyanate (AITC), also known as mustard essential oil, is found in plants of the cruciferous family and is abundant in the mustard seeds. Due to its high bioavailability in urine, AITC has been considered as a promising antineoplastic agent against bladder cancer. Therefore, the aims of this study were to investigate the toxicogenetic and toxicogenomic effects of AITC in the wild-type (RT4) and in a mutant (T24) TP53 bladder transitional carcinoma cell lines. AITC was tested at concentrations of 0.005, 0.0625, 0.0725, 0.0825, 0.0925, 0.125 and 0.25 μM in the cytotoxicity and cell and clonogenic survival assays; in the comet and micronucleus assays, flow cytometry, apoptosis and gene expression (ANLN, BAX, BCL-2, CDK-1, SMAD4, S100P e TP53) evaluations the concentrations of 0.005; 0.0625; 0.0725; 0.0825 e 0.0925 μM were used. The results showed increased primary DNA damage in T24 (0.005, 0.0625, 0.0725, 0.0825 and 0.0925 μM) and RT4 (0.0725, 0.0825 and 0.0925 μM) cells. However, no significant difference was detected in the frequency of micronucleated cells. A significant increase of cells at sub-G1 phase (0.0625, 0.0725 and 0.0825 μM) and significant decrease at S phase (0.005, 0.0625, 0.0725 and 0.0825 μM) were observed in RT4 cells after AITC treatments. In T24 cells, an increased sub-G1 rate (0.0725 and 0.0825 μM) and cell cycle arrest at G2 phase (0.0625, 0.0725 and 0.0825 μM) were detected. Furthermore, it was observed increased apoptosis and necrosis rates and increase of S100P and BAX and decrease of BCL-2 expression in the wild type TP53 cells. For the mutated TP53 cell line, increased expression of BCL-2, BAX and ANLN and decreased expression S100P were observed. No change was detected for the SMAD4 and CDK-1 genes. In conclusion, AITC was able to reach DNA and induce primary damage in both bladder ...

Submitted by MARIA LAURA VIOLA AUGUSTO (marialauraa@gmail.com) on 2018-06-15T17:16:40Z No. of bitstreams: 1 augusto_mlv_dr_jabo.pdf: 1777889 bytes, checksum: 32d8b34f05ca40dec4ae93cca2a67527 (MD5) / Approved for entry into archive by Neli Silvia Pereira null (nelisps@fcav.unesp.br) on 2018-06-15T18:34:35Z (GMT) No. of bitstreams: 1 augusto_mlv_dr_jabo.pdf: 1777889 bytes, checksum: 32d8b34f05ca40dec4ae93cca2a67527 (MD5) / Made available in DSpace on 2018-06-15T18:34:35Z (GMT). No. of bitstreams: 1 augusto_mlv_dr_jabo.pdf: 1777889 bytes, checksum: 32d8b34f05ca40dec4ae93cca2a67527 (MD5) Previous issue date: 2018-05-14 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O controle da broca da cana, Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), pode ser feito pela aplicação de inseticidas químicos, mas o uso dessa tática de manejo pode resultar em danos ambientais e ao homem. De forma alternativa e com efeitos negativos reduzidos, o manejo de D. saccharalis e outros insetos-praga pode ser feito pela utilização do entomopatógeno Bacillus thuringiensis. Além do uso de formulações de B. thuringiensis para o controle de pragas, um ou mais genes que codificam proteínas inseticidas Cry e Vip de B. thuringiensis estão presentes nas plantas transgênicas com resistência a insetos comercialmente disponíveis no Brasil. Apesar de alta adoção, efeitos colaterais reduzidos e eficiência das plantas Bt, o uso desta tecnologia pode resultar na seleção de populações de insetos resistentes às plantas transgênicas. Por isso, a busca por novas proteínas e combinações de proteínas com diferentes modos de ação para retardar a evolução da resistência deve ser constante. Nesse cenário, uma quitinase de B. thuringiensis apresenta potencial para ser incorporada em uma nova geração de plantas transgênicas. Quitinases são enzimas que apresentam domínios catalíticos para hidrólise de quitina e domínios ligantes em quitina (CBD) que podem estar envolvidos com a atividade inseticida. A atividade inseticida das quitinases é relacionada com a desestruturação da membrana peritrófica dos insetos e consequente perda de suas propriedades e funções. Além da descoberta de proteínas inseticidas com diferentes modos de ação, é de interesse que essas apresentem interações positivas com outras proteínas inseticidas. No presente trabalho, duas formas de uma quitinase de B. thuringiensis - ChiΔSP (sem o peptídio sinal) e ChiΔSP.CBD (sem o peptídio sinal e sem o domínio ligante em quitina) - foram produzidas de forma heteróloga em Escherichia coli para avaliações bioquímicas e biológicas sobre D. saccharalis. Ensaios bioquímicos das enzimas ChiΔSP e ChiΔSP.CBD indicam que a atividade quitinolítica sobre quitina coloidal de ChiΔSP (3,07±0,15 U/nmol) foi maior que de ChiΔSP.CBD (1,83±0,06 U/nmol), a ligação de ChiΔSP à quitina coloidal também foi superior à ligação de ChiΔSP.CBD e as maiores atividades (60-100% da atividade total) de ChiΔSP e ChiΔSP.CBD foram detectadas a 30 e 40°C em uma ampla faixa de pH (4,0-9,0). Após estimar a CL50 da proteína Vip3Aa42 sobre lagartas neonatas de D. saccharalis em 352,132 ng/cm2 de dieta, foram avaliadas interações entre Vip3Aa42 e ChiΔSP ou ChiΔSP.CBD. Os resultados indicam que a adição isolada de 2,41 nmol/cm2 de ChiΔSP ou ChiΔSP.CBD não resultou na mortalidade de lagartas de D. saccharalis. A combinação da CL50 de Vip3Aa42 com 2,41 nmol/cm2 de ChiΔSP apresentou efeito sinérgico para mortalidade das lagartas (mortalidade de 90%), mas nenhum efeito (aditivo, sinérgico ou antagônico) foi observado para a combinação da CL50 de Vip3Aa42 com 2,41 nmol/cm2 de ChiΔSP.CBD. A ausência do CBD em ChiΔSP.CBD e consequentes alterações bioquímicas impediu sinergismo de ChiΔSP.CBD com Vip3Aa42 sobre lagartas de D. saccharalis. / Chemical control is applied to manage the sugarcane borer, Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae). However, this control tactic may result in great damages to the environment and non-target species, including men. Alternativelly, the use of the entomopathogen Bacillus thuringiensis can be made to manage D. saccharalis and other insect pests with reduced undisarable side effects. Beyond the use of formulations of B. thuringiensis for pest control, one or more genes of insecticidal proteins from B. thuringiensis such as Cry and Vip are incorporated into commercially available transgenic plants with insect resistance in Brazil. Despite of the high adoption rate, reduced side effects, and high efficency, the intensive use of this technology may result in the selection of insect-resistant populations to transgenic plants. For this reason, the search for new genes with different modes of action to delay the evolution of resistance must be constant. In this scenario, a chitinase from B. thuringiensis has potential to be incorporated into a new generation of transgenic plants. Chitinases are enzymes of the family of glycosyl hydrolases which catalyze the hydrolysis of chitin. Chitinases present catalytic domains responsible for the hydrolysis of chitin and chitin-binding domains (CBD), both associated to insecticidal activity. Insecticidal activity of chitinases is related to the disruption of the peritrophic membrane of insects, which results in the loss of properties and functions of this structure. In addition to the discovery of insecticidal proteins with different modes of action, positive interactions with other insecticidal proteins is desirable for pest management. In the present work, two forms of a chitinase of B. thuringiensis - ChiΔSP (without signal peptide) and ChiΔSP.CBD (without signal peptide and without the chitin-binding domain) - were produced by heterologous expression in Escherichia coli for biochemical and biological analyses. Chitinolytic activity of ChiΔSP (3.07 ± 0.15 U/nmol) was higher than that observed for ChiΔSP.CBD (1.83 ± 0.06 U/nmol) towards colloidal chitin. The binding of ChiΔSP to colloidal chitin was also higher than that observed for ChiΔSP.CBD, and the ChiΔSP or ChiΔSP.CBD chitinolytic activity (60-100% of total chitinolytic activity) was detected at 30 and 40°C in a broad pH range (4.0-9.0). After estimating the LC50 of the Vip3Aa42 protein at 352,132 ng/cm2 of diet, interactions between combinations of Vip3Aa42 and ChiΔSP or ChiΔSP.CBD were evaluated. Results indicate that the adition of 2,41 nmol/cm2 of ChiΔSP or ChiΔSP.CBD do not result in larval mortality of D. saccharalis. The combination of the LC50 of Vip3Aa42 with 2,41 nmol/cm2 nmol of ChiΔSP resulted in a synergic effect (mortality of 90%), but no effect (aditive, sinergic or antagonic) was observed when the LC50 of Vip3Aa42 was combined to 2,41 nmol/cm2 nmol of ChiΔSP.CBD. Lack of CBD in ChiΔSP.CBD resulted in biochemical changes in this form of B. thuringiensis chitinase which impacted on the sinergic effect of this protein with Vip3Aa42 against D. saccharalis. / CNPq: 140093/2015-0

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