Navegando por Palavras-chave "Tick"

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    BmTI-A, a Kunitz type inhibitor from Rhipicephalus microplus able to interfere in vessel formation
    (Elsevier Science Bv, 2016) Soares, Tatiane S. [UNIFESP]; Oliveira, Felipe [UNIFESP]; Torquato, Ricardo J. S. [UNIFESP]; Sasaki, Sergio D.; Araujo, Mariana S. [UNIFESP]; Paschoalin, Thaysa [UNIFESP]; Tanaka, Aparecida S. [UNIFESP]
    Rhipicephalus microplus is an ectoparasite responsible for transmissions of babesiosis and anaplasmosis causing large losses to livestock production. To survive R. microplus tick produces several active molecules, such as protease inhibitors. This ectoparasite has been described as a rich source of serine protease inhibitors most of them are Kunitz-BPTI members named BmTIs which have no clear function yet. In the present work, we described the expression and functional characterization of rBmTI-A which showed to be similar to the native BmTI-A, a double-headed Kunitz-BPTI inhibitor, capable to inhibit trypsin, human neutrophil elastase (HNE), human plasma kalikrein (HuPK) and human plasmin. rBmTI-A was able to cause a decrease of HUVEC cell viability. Besides, the rBmTI-A showed to be a potent inhibitor of "in vitro" vessel formation. Our results suggested that BmTI-A may participate in the blood acquisition process interfering in the vessel formation during the tick parasite life stage, around 20 days. In conclusion, BmTI-A is a promising molecule to be used in the drug design and development of new method of R. microplus control. (C) 2016 Elsevier B.V. All rights reserved.
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    Characterization of a novel cystatin type 2 from Rhipicephalus microplus midgut
    (Elsevier France-Editions Scientifiques Medicales Elsevier, 2017) Cardoso, Thyago H. S. [UNIFESP]; Lu, Stephen [UNIFESP]; Gonzalez, Boris R. G. [UNIFESP]; Torquato, Ricardo J. S. [UNIFESP]; Tanaka, Aparecida S. [UNIFESP]
    The Rhipicephalus (Boophilus) microplus is an exclusive bovine ectoparasite responsible for the transmission of pathogens that decrease meat, leather and milk productions. Cattle vaccination is an alternative to control tick infestations, but the discovery of potential antigens is still a challenge for researchers. Recently, our group performed a midgut transcriptome of engorged R. microplus tick, and out of 800-ESTs sequences one cystatin-coding sequence was identified and named Rmcystatin-4. In order to understand the physiological role of Rmcystatin-4, the aim of this work was the expression, purification and functional characterization of a novel type 2 cystatin from the tick R. microplus. Rmcystatin-4 gene expression was identified mostly in tick midgut suggesting its possible role in blood digestion control. Our data showed that rRmcystatin-4 was successfully expressed in active form using Pichia pastoris system and the purified inhibitor presented high selectivity to BmCl-1 (Ki = 0.046 nM). Moreover, rRmcystatin-4 was able to impaired BmCl-1 activity towards bovine hemoglobin. (C) 2017 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.
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    Expression and functional characterization of boophilin, a thrombin inhibitor from Rhipicephalus (Boophilus) microplus midgut
    (Elsevier B.V., 2012-07-06) Soares, Tatiane Sanches [UNIFESP]; Watanabe, Renata Midori Okuta [UNIFESP]; Tanaka-Azevedo, Anita Mitico; Torquato, Ricardo Jose Soares [UNIFESP]; Lu, Stephen [UNIFESP]; Figueiredo, Ana Carvalho; Pereira, Pedro Jose Barbosa; Tanaka, Aparecida Sadae [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Inst Butantan; Univ Porto
    Rhipicephalus (Boophilus)microplus is an ectoparasite responsible for an important decrease in meat, milk and leather production, caused both by cattle blood loss and by the transmission of anaplasmosis and babesiosis. R. microplus is a rich source of serine protease inhibitors, including the trypsin inhibitors BmTI-A and BmTI-6, the subtilisin inhibitor BmSI, and the recently described thrombin inhibitor, boophilin. Boophilin is a double Kunitz-type thrombin inhibitor, with the unusual ability to form a ternary complex with a second (non-thrombin) serine proteinase molecule. the large-scale expression and purification of boophilin and of its isolated N-terminal (D1) domain in Pichia pastoris, its expression profile, and the effect of RNAi-mediated gene silencing in tick egg production are reported. Full-length boophilin and D1 were expressed at 21 and 37.5 mg/L of culture, respectively. Purified boophilin inhibited trypsin (K-i 0.65 nM), neutrophil elastase (K-i 21 nM) and bovine thrombin (K-i 57 pM), while D1 inhibited trypsin and neutrophil elastase (K-i of 2.0 and 129 nM, respectively), but not thrombin. Boophilin gene silencing using RNAi resulted in 20% reduction in egg weight production, suggesting that the expression of boophilin in this life stage would be important but not vital, probably due to functional overlap with other serine proteinase inhibitors in the midgut of R. microplus. Considering our data, Boophilin could be combining with other antigen in a vaccine production for tick control. (C) 2012 Elsevier B.V. All rights reserved.
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    Expression of two endoplasmic reticulum stress markers, GRP78 and GADD153, is involved in the mechanism of action of the Amblyomin-X
    (Elsevier B.V., 2012-08-01) Chudzinski-Tavassi, Ana Marisa; Souza, Jean Gabriel de [UNIFESP]; Simons, Simone Michaela; Berra, Carolina Maria; Saito, Renata de Freitas; Chammas, Roger; Morais, Katia Luciano Pereira [UNIFESP]; Inst Butantan; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
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    Identificação de potenciais antígenos do carrapato Rhipicephalus (Boophilus) microplus para o desenvolvimento de vacinas
    (Universidade Federal de São Paulo (UNIFESP), 2020-07-30) Silva, Fernando Allan Abreu [UNIFESP]; Tanaka, Aparecida Sadae [UNIFESP]; Universidade Federal de São Paulo
    The tick Rhipicephalus (Boophilus) microplus is responsible for considerable economic losses to the livestock sector. The main control method of infestation of this parasite is by acaricides and can result in the selection of resistant ticks, environment and products contamination, between other factors. The vaccine is a more sustainable alternative, but the products available on the market are not efficient in the Brazilian territory. Although the tick genome has not yet been elucidated, transcriptomes and proteomes can indicant potential targets for selection of antigens. Two proteins sequences were selected for this work, a sphingomyelinase D – like and a cathepsin A – like from a tick transcriptome. The DNA sequences that codified these two proteins were cloned into the pET14b expression vector and confirmed by DNA sequencing. The analysis of the translated amino acids of cathepsin A – like showed the absence of amino acids residues important for the activity of this enzyme when compared to others cathepsins A sequences. However, it was not possible to confirm experimentally this data since the recombinant protein was not express in bacterial system. In contrast, sphingomyelinase D – like was expressed in bacteria in large quantities, but in the form of inclusion body. The sphingomyelinase D – like was partially purified in the presence of urea. The analysis of sphingomyelinase D – like primary structure showed a replacement of a histidine for an asparagine in an important position for the enzymatic activity. Therefore, the perspective of this work is to obtain the purified sphingomyelinase D – like and carry out its biochemical and functional characterization.