No abstract

Schistosomiasis remains a serious health issue nowadays for an estimated one billion people in 79 countries around the world. Great efforts have been made to identify good vaccine candidates during the last decades, but only three molecules reached clinical trials so far. The reverse vaccinology approach has become an attractive option for vaccine design, especially regarding parasites like Schistosoma spp. that present limitations for culture maintenance. This strategy also has prompted the construction of multi-epitope based vaccines, with great immunological foreseen properties as well as being less prone to contamination, autoimmunity, and allergenic responses. Therefore, in this study we applied a robust immunoinformatics approach, targeting S. mansoni transmembrane proteins, in order to construct a chimeric antigen. Initially, the search for all hypothetical transmembrane proteins in GeneDB provided a total of 584 sequences. Using the PSORT II and CCTOP servers we reduced this to 37 plasma membrane proteins, from which extracellular domains were used for epitope prediction. Nineteen common MHC-I and MHC-II binding epitopes, from eight proteins, comprised the final multi-epitope construct, along with suitable adjuvants. The final chimeric multi-epitope vaccine was predicted as prone to induce B-cell and IFN-γ based immunity, as well as presented itself as stable and non-allergenic molecule. Finally, molecular docking and molecular dynamics foresee stable interactions between the putative antigen and the immune receptor TLR 4. Our results indicate that the multi-epitope vaccine might stimulate humoral and cellular immune responses and could be a potential vaccine candidate against schistosomiasis.

Computer-assisted drug design (CADD) methods have greatly contributed to the development of new drugs. Among CADD methodologies, virtual screening (VS) can enrich the compound collection with molecules that have the desired physicochemical and pharmacophoric characteristics that are needed to become drugs. Many free tools are available for this purpose, but they are difficult to use and do not have a graphical user interface. Furthermore, several free tools must be used to carry out the entire VS process, requiring the user to process the results of one software program so that they can be used in another program, adding a potential source of human error. Moreover, some software programs require knowledge of advanced computational skills, such as programming languages. This context has motivated us to develop Molecular Architect (MolAr). MolAr is a workflow with a simple and intuitive interface that acts in an integrated and automated form to perform the entire VS process, from protein preparation (homology modeling and protonation state) to virtual screening. MolAr carries out VS through AutoDock Vina, DOCK 6, or a consensus of the two. Two case studies were conducted to demonstrate the performance of MolAr. In the first study, the feasibility of using MolAr for DNA–ligand systems was assessed. Both AutoDock Vina and DOCK 6 showed good results in performing VS in DNA–ligand systems. However, the use of consensus virtual screening was able to enrich the results. According to the area under the ROC curve and the enrichment factors, consensus VS was better able to predict the positions of the active ligands. The second case study was performed on 8 targets from the DUD-E database and 10 active ligands for each target. The results demonstrated that using the final ligand conformation provided by AutoDock Vina as an input for DOCK 6 improved the DOCK 6 ROC curves by up to 42% in VS. These case studies demonstrated that MolAr is capable conducting the VS process and is an easy-to-use and effective tool. MolAr is available for download free of charge at http: //.

Mayaro fever, caused by Mayaro virus (MAYV) is a sub-lethal disease with symptoms that are easily confused with those of dengue fever, except for polyarthralgia, which may culminate in physical incapacitation. Recently, outbreaks of MAYV have been documented in metropolitan areas, and to date, there is no therapy or vaccine available. Moreover, there is no information regarding the three-dimensional structure of the viral proteins of MAYV, which is important in the search for antivirals. In this work, we constructed a three-dimensional model of protein C of MAYV by homology modelling, and this was employed in a manner similar to that of receptors in virtual screening studies to evaluate 590 molecules as prospective antiviral agents. In vitro bioassays were utilized to confirm the potential antiviral activity of the flavonoid epicatechin isolated from Salacia crassifolia (Celastraceae). The virtual screening showed that six flavonoids were promising ligands for protein C. The bioassays showed potent antiviral action of epicatechin, which protected the cells from almost all of the effects of viral infection. An effective concentration (EC) of 0.247 μmol/mL was observed with a selectivity index (SI) of 7. The cytotoxicity assay showed that epicatechin has low toxicity, with a 50% cytotoxic concentration (CC) greater than 1.723 µmol/mL. Epicatechin was found to be twice as potent as the reference antiviral ribavirin. Furthermore, a replication kinetics assay showed a strong inhibitory effect of epicatechin on MAYV growth, with a reduction of at least four logs in virus production. Our results indicate that epicatechin is a promising candidate for further testing as an antiviral agent against Mayaro virus and other alphaviruses.

The NS2B-NS3 protease has been identified as an attractive target for drug development against Zika virus (ZIKV) and combined drug repurposing and structure-based virtual screening has improved the development of antiviral drugs. In this study, we performed a structurebased virtual screening of 1861 Food and Administration (FDA) approved drugs available in DrugBank by the selection and docking validation of crystal structure of ZIKV NS2B-NS3 protease (PDB ID 5H4I) using Glide and DOCK 6 software. The antihistaminic chlorcyclizine (Grid score −24.8 kcal/ mol) exhibited the most promising interaction with NS2B-NS3 protease in comparison to crystallography ligand (Grid score −15.6 kcal/mol) by interaction to Tyr161 by hydrophobic interactions in the binding site of NS2B-NS3 which is recognized as an important amino acid in substrate molecular recognition. Cytotoxicity and global antiviral activity assay in Vero cells by MTT method showed that chlorcyclizine reduced the ZIKV induced cytopathic effect (EC 50 of 69.0 ± 7.3 μM and SI = 1.9), and explicit molecular dynamics simulations implemented on a NAMD program indicated great stability of chlorcyclizine in protease binding site, suggesting the repurposing of chlorcyclizine as a promising finding in anti-ZIKV drug development.

Abstractobjective To entomologically monitor Aedes spp. and correlate the presence of these vectors with the recent epidemic of dengue in Divinopolis, Minas Gerais State, Brazil.methods Ovitraps were installed at 44 points in the city, covering six urban areas, from May 2011 to May 2012. After collection, the eggs were incubated until hatching. In the 4th stage of development, the larvae were classified as Ae. aegypti or Ae. albopictus.results In total, 25 633 Aedes spp. eggs were collected. February was the month with the highest incidence, with 5635 eggs collected and a hatching rate of 46.7%. Ae. aegypti eggs had the highest hatching rate, at 72.3%, whereas Ae. albopictus eggs had 27.7%. Climate and population density influenced the number of eggs found. Indicators of vector presence were positively correlated with the occurrence of dengue cases.conclusion These data reinforce the need for entomological studies, highlight the relevance of Ae. albopictus as a possible disease vector and demonstrate its adaptation. Ae. albopictus, most commonly found in forested areas, comprised a substantial proportion of the urban mosquito population.

Three molecular hybrids containing 1,4-naphthoquinones, 1,3,5-triazines, morpholine and 7-chloroquinoline, which have recognized contributions to the biological activity of many drugs, were synthesized in yields ranging from 43-84%. All hybrids were obtained in three steps starting from readily available reactants: lawsone, cyanuric chloride, morpholine and 4,7-dichloroquinoline. A previous docking study was carried out to identify the binding energy and pharmacophore conformation of the promising anticancer compounds with PI3Kγ (phosphoinositide 3-kinase) and AMPK (5' AMP-activated protein kinase). The cancer activity in human metastatic melanoma cells (SKMEL-103) were performed, and the synthetized compounds presented half maximal inhibitory concentration (IC 50) values around 25 μM. The expressions of PI3K and AMPK were also determined using western blotting technique, and all molecular hybrids negatively modulated both targets.

RESUMO Os bancos de dados são uma ferramenta importante de gerenciamento de informações. A organização de alvos moleculares em um banco específico possibilita a rápida triagem de compostos protótipos e agiliza os ensaios biológicos, diminuindo os custos e o tempo de pesquisa de novos compostos(PDB). O PDB organiza um banco de dados de estruturas de macromoléculas biológicas, sendo atualmente uma ferramenta muito utilizada por diversos grupos de pesquisadores. Atualmente o PDB conta com diversos implementos para facilitar o uso e análise dos dados estruturais disponíveis, tornando-se um recurso extraordinário para a pesquisa biológica.De forma similar, a Triagem Virtual Inversa 2 (TVI) é uma ferramenta que permite a rápida identificação de novos alvos moleculares. Através da TVI é possível fazer a predição da atividade, bem como da seletividade de um composto e com isso obter um grupo de compostos para serem testados em ensaios biológicos. No entanto, embora as metodologias de TVI sejam 1 e-mail: anapaulacarregal@gmail.com Universidade Federal de São João del capazes de encontrar alvos moleculares específicos, nem sempre os ensaios biológicos estão disponíveis para as pesquisas brasileiras, dificultando os projetos de desenvolvimento de fármacos. Assim, o objetivo deste trabalho é a criação do nosso próprio banco de alvos moleculares, denominado de our own molecular targets data bank (OOMT), que será continuamente aperfeiçoado a fim de realizar ensaios de TVI e, posteriormente ensaios biológicos num curto período de tempo, integrando químicos sintéticos, medicinais e biólogos moleculares. O diferencial encontra-se na disponibilidade de realização dos ensaios biológicos no próprio campus. MATERIAL E MÉTODOSTodas as proteínas incluídas no OOMT são objetos de pesquisas experimentais na Universidade Federal de São João del-Rei (UFSJ/CCO). As estruturas cristalográficas foram obtidas do PDB. Para quantificar a similaridade entre o complexo cristalográfico obtido do PDB e o complexo obtido pela ancoragem molecular usando o Autodock Vina 3 , foi realizado um cálculo de desvio médio quadrático (root mean square deviation -RMSD,), através do software Discovery Studio Visualizer 2.5 4 . Aqueles complexos que apresentaram um RMSD menor ou igual a dois, foram incluídos no banco de dados, aqueles cujo valor excedia dois foram descartados. RESULTADOS E DISCUSSÃOA partir dos valores de RMSD foram incluídos 34 alvos no OOMT. A Figura 1 mostra a sobreposição dos ligantes cristalográficos das proteínas com código PDB 3BZ3 em A e 2VV9 em B. Essas proteínas apresentaram valores de RMSD de 0,325 e 0,520, respectivamente. Esses valores indicam que o programa Autodock Vina é capaz de reproduzir de maneira similar as interações intermoleculares dos complexos depositados no PDB.