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1.
Int J Mol Sci ; 24(22)2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-38003581

RESUMO

The spike (S) protein of SARS-CoV-2 is a molecular target of great interest for developing drug therapies against COVID-19 because S is responsible for the interaction of the virus with the host cell receptor. Currently, there is no outpatient safety treatment for COVID-19 disease. Furthermore, we consider it of worthy importance to evaluate experimentally the possible interaction of drugs (approved by the Food and Drug Administration) and the S, considering some previously in silico and clinical use. Then, the objective of this study was to demonstrate the in vitro interaction of ivermectin with S. The equilibrium dialysis technique with UV-Vis was performed to obtain the affinity and dissociation constants. In addition, the Drug Affinity Responsive Target Stability (DARTS) technique was used to demonstrate the in vitro interaction of S with ivermectin. The results indicate the interaction between ivermectin and the S with an association and dissociation constant of Ka = 1.22 µM-1 and Kd = 0.81 µM, respectively. The interaction was demonstrated in ratios of 1:50 pmol and 1:100 pmol (S: ivermectin) by the DARTS technique. The results obtained with these two different techniques demonstrate an interaction between S and ivermectin previously explored in silico, suggesting its clinical uses to stop the viral spread among susceptible human hosts.


Assuntos
COVID-19 , Estados Unidos , Humanos , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Ivermectina/farmacologia , Ivermectina/uso terapêutico
2.
Int J Mol Sci ; 23(7)2022 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-35409348

RESUMO

The epidemic caused by the SARS-CoV-2 coronavirus, which has spread rapidly throughout the world, requires urgent and effective treatments considering that the appearance of viral variants limits the efficacy of vaccines. The main protease of SARS-CoV-2 (Mpro) is a highly conserved cysteine proteinase, fundamental for the replication of the coronavirus and with a specific cleavage mechanism that positions it as an attractive therapeutic target for the proposal of irreversible inhibitors. A structure-based strategy combining 3D pharmacophoric modeling, virtual screening, and covalent docking was employed to identify the interactions required for molecular recognition, as well as the spatial orientation of the electrophilic warhead, of various drugs, to achieve a covalent interaction with Cys145 of Mpro. The virtual screening on the structure-based pharmacophoric map of the SARS-CoV-2 Mpro in complex with an inhibitor N3 (reference compound) provided high efficiency by identifying 53 drugs (FDA and DrugBank databases) with probabilities of covalent binding, including N3 (Michael acceptor) and others with a variety of electrophilic warheads. Adding the energy contributions of affinity for non-covalent and covalent docking, 16 promising drugs were obtained. Our findings suggest that the FDA-approved drugs Vaborbactam, Cimetidine, Ixazomib, Scopolamine, and Bicalutamide, as well as the other investigational peptide-like drugs (DB04234, DB03456, DB07224, DB7252, and CMX-2043) are potential covalent inhibitors of SARS-CoV-2 Mpro.


Assuntos
Tratamento Farmacológico da COVID-19 , Reposicionamento de Medicamentos , Antivirais/química , Antivirais/farmacologia , Proteases 3C de Coronavírus , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , SARS-CoV-2
3.
Arch Virol ; 165(4): 891-911, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32060794

RESUMO

Pandemics caused by influenza A virus (IAV) are responsible for the deaths of millions of humans around the world. One of these pandemics occurred in Mexico in 2009. Despite the impact of IAV on human health, there is no effective vaccine. Gene mutations and translocation of genome segments of different IAV subtypes infecting a single host cell make the development of a universal vaccine difficult. The design of immunogenic peptides using bioinformatics tools could be an interesting strategy to increase the success of vaccines. In this work, we used the predicted amino acid sequences of the neuraminidase (NA) and hemagglutinin (HA) proteins of different IAV subtypes to perform multiple alignments, epitope predictions, molecular dynamics simulations, and experimental validation. Peptide selection was based on the following criteria: promiscuity, protein surface exposure, and the degree of conservation among different medically relevant IAV strains. These peptides were tested using immunological assays to test their ability to induce production of antibodies against IAV. We immunized rabbits and mice and measured the levels of IgG and IgA antibodies in serum samples and nasal washes. Rabbit antibodies against the peptides P11 and P14 (both of which are hybrids of NA and HA) recognized HA from both group 1 (H1, H2, and H5) and group 2 (H3 and H7) IAV and also recognized the purified NA protein from the viral stock (influenza A Puerto Rico/916/34). IgG antibodies from rabbits immunized with P11 and P14 were capable of recognizing viral particles and inhibited virus hemagglutination. Additionally, intranasal immunization of mice with P11 and P14 induced specific IgG and IgA antibodies in serum and nasal mucosa, respectively. Interestingly, the IgG antibodies were found to have neutralizing capability. In conclusion, the peptides designed through in silico studies were validated in experimental assays.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Sequência de Aminoácidos , Animais , Biologia Computacional , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Imunização , Vírus da Influenza A/química , Vírus da Influenza A/genética , Vacinas contra Influenza/química , Vacinas contra Influenza/genética , Influenza Humana/imunologia , Influenza Humana/virologia , Camundongos , Camundongos Endogâmicos BALB C , Neuraminidase/química , Neuraminidase/genética , Neuraminidase/imunologia , Coelhos , Alinhamento de Sequência , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/imunologia
4.
Molecules ; 25(23)2020 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-33260370

RESUMO

The worldwide health emergency of the SARS-CoV-2 pandemic and the absence of a specific treatment for this new coronavirus have led to the use of computational strategies (drug repositioning) to search for treatments. The aim of this work is to identify FDA (Food and Drug Administration)-approved drugs with the potential for binding to the spike structural glycoprotein at the hinge site, receptor binding motif (RBM), and fusion peptide (FP) using molecular docking simulations. Drugs that bind to amino acids are crucial for conformational changes, receptor recognition, and fusion of the viral membrane with the cell membrane. The results revealed some drugs that bind to hinge site amino acids (varenicline, or steroids such as betamethasone while other drugs bind to crucial amino acids in the RBM (naldemedine, atovaquone, cefotetan) or FP (azilsartan, maraviroc, and difluprednate); saquinavir binds both the RBM and the FP. Therefore, these drugs could inhibit spike glycoprotein and prevent viral entry as possible anti-COVID-19 drugs. Several drugs are in clinical studies; by focusing on other pharmacological agents (candesartan, atovaquone, losartan, maviroc and ritonavir) in this work we propose an additional target: the spike glycoprotein. These results can impact the proposed use of treatments that inhibit the first steps of the virus replication cycle.


Assuntos
Antivirais/farmacologia , Reposicionamento de Medicamentos/métodos , Glicoproteína da Espícula de Coronavírus/química , Antivirais/química , Simulação por Computador , Ligantes , Fusão de Membrana/efeitos dos fármacos , Modelos Moleculares , Simulação de Acoplamento Molecular , Conformação Proteica , Glicoproteína da Espícula de Coronavírus/metabolismo , Vareniclina/química , Vareniclina/metabolismo , Vareniclina/farmacologia
5.
Molecules ; 25(9)2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32397642

RESUMO

Peptic ulcer disease, the most common gastrointestinal disorder, is currently treated with several types of drugs, but all have severe side effects. The aim of the present study was to evaluate the gastroprotective activity of juanislamin, isolated from Calea urticifolia, in a rat model of ethanol-induced gastric lesions. Thirty minutes after orally administering a given dose of juanislamin (from 1 to 30 mg/kg) or carbenoxolone (the reference drug, at 1-100 mg/kg) to rats, 1 mL of ethanol was applied, and the animals were sacrificed 2 h later. The stomachs were removed and opened to measure the total area of lesions in each. To examine the possible participation of prostaglandins, nitric oxide and/or sulfhydryl groups in the mechanism of action of juanislamin, the rats received indomethacin, NG-Nitro-l-arginine methyl ester hydrochloride (l-NAME) or N-ethylmaleimide pretreatment, respectively, before being given juanislamin and undergoing the rest of the methodology. Juanislamin inhibited gastric lesions produced by ethanol in a non-dose-dependent manner, showing the maximum gastroprotective effect (100%) at 10 mg/kg. The activity of juanislamin was not modified by pretreatment with indomethacin, l-NAME or N-ethylmaleimide. In conclusion, juanislamin protected the gastric mucosa from ethanol-induced damage, and its mechanism of action apparently does not involve prostaglandins, nitric oxide or sulfhydryl groups.


Assuntos
Antiulcerosos/administração & dosagem , Asteraceae/química , Etanol/toxicidade , Mucosa Gástrica/efeitos dos fármacos , Óxido Nítrico/farmacologia , Prostaglandinas/farmacologia , Úlcera Gástrica/prevenção & controle , Compostos de Sulfidrila/farmacologia , Animais , Carbenoxolona/administração & dosagem , Etilmaleimida/farmacologia , Mucosa Gástrica/patologia , Indometacina/farmacologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Wistar , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológico
6.
J Mol Recognit ; 28(9): 553-64, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25788327

RESUMO

Computational identification of potential epitopes with an immunogenic capacity challenges immunological research. Several methods show considerable success, and together with experimental studies, the efficiency of the algorithms to identify potential peptides with biological activity has improved. Herein, an epitope was designed by combining bioinformatics, docking, and molecular dynamics simulations. The hemagglutinin protein of the H1N1 influenza pandemic strain served as a template, owing to the interest of obtaining a scheme of immunization. Afterward, we performed enzyme-linked immunosorbent assay (ELISA) using the epitope to analyze if any antibodies in human sera before and after the influenza outbreak in 2009 recognize this peptide. Also, a plaque reduction neutralization test induced by virus-neutralizing antibodies and the IgG determination showed the biological activity of this computationally designed peptide. The results of the ELISAs demonstrated that the serum of both prepandemic and pandemic recognized the epitope. Moreover, the plaque reduction neutralization test evidenced the capacity of the designed peptide to neutralize influenza virus in Madin-Darby canine cells.


Assuntos
Epitopos/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Influenza Humana/metabolismo , Peptídeos/metabolismo , Animais , Anticorpos/imunologia , Linhagem Celular , Biologia Computacional , Cães , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Humanos , Influenza Humana/imunologia , Simulação de Dinâmica Molecular , Peptídeos/química , Coelhos
7.
J Clin Med ; 12(4)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36835858

RESUMO

Manifestations of COVID-19 are diverse and range from asymptomatic to severe, critical illness and death. Cases requiring hospital care (in severe and critical illnesses) are associated with comorbidities and hyperactivation of the immune system. Therefore, in this exploratory observational study, we analyzed which parameters are associated with mortality. We evaluated: demographic characteristics (age, sex and comorbidities), laboratory data (albumin, leukocytes, lymphocytes, platelets, ferritin), days of hospital stay, interleukins (IL-2, IL-6, IL-7, IL-10, IL-17) and sP-selectin in 40 Mexican patients admitted to medical emergencies with a confirmed diagnosis of COVID-19, a complete clinical record, and who signed the informed consent. Twenty severe (they required intermediate care with non-invasive ventilation) and twenty critically ill patients (they required mechanical ventilation) were classified, and these were subsequently compared with healthy and recovered subjects. A significant difference was found between the hospitalized groups in the parameters of age, ferritin, days of hospital stay and death with p values = 0.0145, p = 0.0441, p = 0.0001 and p = 0.0001, respectively. In the determination of cytokines and P-selectin, a significant difference was found between the following groups: recovered patients and healthy volunteers compared with hospitalized patients in severe and critical condition. Importantly, IL-7 remained elevated one year later in recovered patients. Taken together, these values determined at the time of hospital admission could be useful to monitor patients closely and evaluate in-hospital progress, hospital discharge, and out-of-hospital progress.

8.
RSC Adv ; 13(13): 9078-9090, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36950073

RESUMO

The Human Immunodeficiency Virus (HIV-1) causes Acquired Immunodeficiency Syndrome (AIDS) and a high percentage of deaths. Therefore, it is necessary to design vaccines against HIV-1 for the prevention of AIDS. Bioinformatic tools and theoretical algorisms allow us to understand the structural proteins of viruses to develop vaccines based on immunogenic peptides (epitopes). In this work, we identified the epitopes: P1, P2, P10, P27 and P30 from the gp120 protein of HIV-1. These peptides were administered intranasally alone or with cholera toxin (CT) to BALB/c mice. The population of CD4+, CD8+ T lymphocytes and B cells (CD19/CD138+, IgA+ and IgG+) from nasal-associated lymphoid tissue, nasal passages, cervical and inguinal nodes was determined by flow cytometry. In addition, anti-peptides IgG and IgA from serum, nasal and vaginal washings were measured by ELISA. The results show that peptides administered by i.n. can modulate the immune response of T and B lymphocyte populations, as well as IgA and IgG antibodies secretion in the different sites analyzed. In conclusion, bioinformatics tools help us to select peptides with physicochemical properties that allow the induction of the humoral and cellular responses that depend on the peptide sequence.

9.
Pharmaceuticals (Basel) ; 16(2)2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-37259437

RESUMO

Recently the E protein of SARS-CoV-2 has become a very important target in the potential treatment of COVID-19 since it is known to regulate different stages of the viral cycle. There is biochemical evidence that E protein exists in two forms, as monomer and homopentamer. An in silico screening analysis was carried out employing 5852 ligands (from Zinc databases), and performing an ADMET analysis, remaining a set of 2155 compounds. Furthermore, docking analysis was performed on specific sites and different forms of the E protein. From this study we could identify that the following ligands showed the highest binding affinity: nilotinib, dutasteride, irinotecan, saquinavir and alectinib. We carried out some molecular dynamics simulations and free energy MM-PBSA calculations of the protein-ligand complexes (with the mentioned ligands). Of worthy interest is that saquinavir, nilotinib and alectinib are also considered as a promising multitarget ligand because it seems to inhibit three targets, which play an important role in the viral cycle. On the other side, saquinavir was shown to be able to bind to E protein both in its monomeric as well as pentameric forms. Finally, further experimental assays are needed to probe our hypothesis derived from in silico studies.

10.
Methods Mol Biol ; 2412: 471-479, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34918263

RESUMO

Epitope-based vaccines is one of the most recent methodologies applied in bioinformatics studies. This strategy consists of identifying regions of the protein (peptides or epitopes) which show antigen properties capable of stimulating the immune system against proteins from virus, bacteria, fungi, etc. This chapter describes a general procedure to identify epitopes to be used as epitope vaccine using bioinformatics methods including primary protein sequence analyses, epitope predictor, docking, and molecular dynamics simulations for the selection of T- and B-cell epitopes.


Assuntos
Biologia Computacional , Vacinas , Epitopos de Linfócito B , Epitopos de Linfócito T , Simulação de Dinâmica Molecular , Vacinas de Subunidades Antigênicas
11.
J Med Food ; 25(11): 1059-1065, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35951019

RESUMO

This study evaluated the effects of long-term intake of nutritive sweeteners (NSs) and non-nutritive sweeteners (NNSs) on body weight, food and energy intake, blood pressure, metabolic parameters, and memory retention in rats. Sixty male Sprague-Dawley rats were randomly divided into six groups (n = 10 per group): control (water),10% sucrose (SUC), aspartame (ASP), sucralose (SCA), stevia (STV), and 5% xylitol (XYL). Pure NSs (SUC and XYL) and NNSs were added to the drinking water for 18 weeks. ASP, SCA, and STV dosage was based on the estimated daily intake limit: 4.1, 2.0, and 3.4 mg/kg/day, respectively. Chronic access to NNSs did not result in any difference in total weight gain of the rats, while it was significantly elevated in the SUC group compared with the control and NNSs groups. Food intake was significantly lower in all NNSs groups compared with SUC and control groups. Sweetened beverage intake volumes were significantly diminished in all NNSs groups compared with intake in SUC and control groups. Total calories consumed were lower for the STV and XYL groups compared with all other groups. Blood pressure and glucose metabolism did not differ significantly between the groups. All sweeteners increased total cholesterol, low-density lipoprotein, and triglyceride levels. Short-term memory was significantly impaired in the ASP group in the novel object recognition task, while long-term memory was impaired in SUC and STV groups. These metabolic and behavioral results suggest that the long-term intake of NSs or NNSs can be associated with peripheral and central effects.


Assuntos
Adoçantes não Calóricos , Stevia , Animais , Masculino , Ratos , Adoçantes não Calóricos/efeitos adversos , Ratos Sprague-Dawley , Edulcorantes , Peso Corporal , Cognição
12.
Vaccines (Basel) ; 10(11)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36366353

RESUMO

After the outbreak of SARS-CoV-2 by the end of 2019, the vaccine development strategies became a worldwide priority. Furthermore, the appearances of novel SARS-CoV-2 variants challenge researchers to develop new pharmacological or preventive strategies. However, vaccines still represent an efficient way to control the SARS-CoV-2 pandemic worldwide. This review describes the importance of bioinformatic and immunoinformatic tools (in silico) for guide vaccine design. In silico strategies permit the identification of epitopes (immunogenic peptides) which could be used as potential vaccines, as well as nonacarriers such as: vector viral based vaccines, RNA-based vaccines and dendrimers through immunoinformatics. Currently, nucleic acid and protein sequential as well structural analyses through bioinformatic tools allow us to get immunogenic epitopes which can induce immune response alone or in complex with nanocarriers. One of the advantages of in silico techniques is that they facilitate the identification of epitopes, while accelerating the process and helping to economize some stages of the development of safe vaccines.

13.
J Trace Elem Med Biol ; 69: 126901, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34801850

RESUMO

BACKGROUND: It has been reported that boron induces changes in the immune response, including in inflammatory processes. Recently, the effect of boric acid has been documented on the differentiation of lymphocyte clusters in mice and rats. However, the differences among boron-containing compounds (BCC) have been poorly explored. METHODS: In this study, we analyzed the effects after oral administration of boric acid (BOR), methylboronic (MET), 3-thyenylboronic (3TB), 4-hydroxymethyl-phenylboronic (4MP) and 4-methanesulfonyl-phenylboronic (4SP) acids on the populations of lymphocytes from spleen and Peyer's patch (PP) as well as on antibodies. Groups of six male BALB/c were orally treated with 4.6 mg/kg of body weight with BOR, MET, 3TB, 4MP, and 4SP/daily for 10 days or vehicle (VEH) as a control group. After euthanasia, the spleen and small intestine were dissected. We conducted flow cytometry assays to assess B, CD3+ T, CD4+ T, and CD8+ T cells. Levels of IgG and IgM in serum, and IgA in intestinal fluid samples were analyzed by enzyme immunoassay. RESULTS: In particular, we observed the effects of the administration of boronic acids on the number of lymphocytes; these changes were more notable in spleen than in PP. We found different profiles for each boron-containing compound, that is BOR induced an increase in the percentage of CD8+ T and CD19+/IgA+ cells in spleen, but a decrease in CD8+ T and B220+/CD19+ cells in PP. Meanwhile MET induced a decrease of CD4+ T in spleen, but induced an increase of CD4+ T cells and a decrease in the number of CD8+ T cells in PP. Boronic acids with an aromatic ring moiety induced changes in serum immunoglobulins levels, while 3TB acid induced a notable increase in S-IgA. CONCLUSIONS: Effects in lymphocyte populations and antibodies are different for each tested compound. These results highlight the establishment of the necessary structure-activity relationship for BCC as immunomodulatory drugs. This is relevant in the biomedical field due to their attractiveness for selecting compounds to develop therapeutic tools.


Assuntos
Ácidos Bóricos , Nódulos Linfáticos Agregados , Animais , Boro/farmacologia , Ácidos Borônicos/farmacologia , Linfócitos T CD8-Positivos , Imunidade , Imunoglobulina A , Agentes de Imunomodulação , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ratos
14.
World J Gastroenterol ; 27(34): 5630-5665, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34629792

RESUMO

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has affected millions of people globally. It was declared a pandemic by the World Health Organization in March 2020. The hyperinflammatory response to the entry of SARS-CoV-2 into the host through angiotensin-converting enzyme 2 is the result of a "cytokine storm" and the high oxidative stress responsible for the associated symptomatology. Not only respiratory symptoms are reported, but gastrointestinal symptoms (diarrhea, vomiting, and nausea) and liver abnormalities (high levels of aspartate aminotransferase, alanine aminotransferase transaminases, and bilirubin) are observed in at least 30% of patients. Reduced food intake and a delay in medical services may lead to malnutrition, which increases mortality and poor outcomes. This review provides some strategies to identify malnutrition and establishes nutritional approaches for the management of COVID-19 and liver injury, taking energy and nutrient requirements and their impact on the immune response into account. The roles of certain phytochemicals in the prevention of the disease or as promising target drugs in the treatment of this disease are also considered.


Assuntos
COVID-19 , Peptidil Dipeptidase A , Humanos , Fígado , Compostos Fitoquímicos/uso terapêutico , SARS-CoV-2
15.
Arch Virol ; 155(6): 847-56, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20390312

RESUMO

A DENV-2 plasmid named pEII*EIII/NS1*,containing sequences encoding portions of the envelope protein that are potentially involved in the induction of neutralizing antibodies and a portion of the NS1 sequence that is involved in protection, is reported in this work. The synthesized subunit protein was recognized by human sera from infected patients and had the predicted size. The immunogenicity of this construct was evaluated using a mouse model in a prime-boost vaccination approach. The priming was performed using the plasmid pEII*EIII/NS1*, followed by a boost with recombinant full-length GST-E and GST-NS1 fusion proteins. The mice showed specific antibody responses to the E and NS1 proteins, as detected by ELISA, compared to the response of animals vaccinated with the parental plasmid. Interestingly, some animals had neutralizing antibodies. These results show that EII*, EIII and NS1* sequences could be considered for the design ofa recombinant subunit vaccine against dengue disease.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Dengue/imunologia , Dengue/imunologia , Plasmídeos/imunologia , Proteínas do Envelope Viral/imunologia , Proteínas não Estruturais Virais/imunologia , Animais , Células COS , Linhagem Celular , Chlorocebus aethiops , Cricetinae , Dengue/virologia , Vacinas contra Dengue/genética , Vacinas contra Dengue/imunologia , Modelos Animais de Doenças , Humanos , Imunização Secundária , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/genética , Vacinação , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Proteínas do Envelope Viral/genética , Proteínas não Estruturais Virais/genética
16.
J Pharm Biomed Anal ; 162: 130-139, 2019 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-30236821

RESUMO

N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) is a novel valproic acid derivative that has shown anti-proliferative activity against epitheloid cervix carcinoma (HeLa), rhabdomyosarcoma (A204), and several breast cancer cell lines. The aim of this research was to evaluate the pharmacokinetic profile and tissue distribution of HO-AAVPA in Wistar rats, as well as its human serum albumin binding potential by experimental and in silico methods. A single dose of HO-AAVPA was given to male rats by intravenous, intragastric or intraperitoneal routes at doses of 25, 100, and 100 mg/kg, respectively. Then, blood samples were drawn at predetermined intervals of time, and the HO-AAVPA concentration in the plasma was quantified with a validated HPLC method. The elimination half-life (t1/2) was approximately 222 min, and the systemic clearance (CL) and apparent volume of distribution (Vd) were 2.20 mL/min/kg and 0.70 L/kg, respectively. The absolute oral bioavailability of HO-AAVPA was 33.8%, and the binding rate of HO-AAVPA with rat plasma proteins was between 66.2% and 83.0%. Additionally, in silico, UV and Raman spectroscopy data showed weak interactions between the test compound and human serum albumin. Thus, the results that were obtained demonstrated that despite its low oral bioavailability, the potential anticancer agent HO-AAVPA exhibits acceptable pharmacokinetic properties that would allow it to reach its site of action and exert its pharmacological effect in Wistar Rats, and it has a convenient profile for future assays to evaluate its human applications.


Assuntos
Amidas/farmacocinética , Antineoplásicos/farmacocinética , Pentanos/farmacocinética , Albumina Sérica Humana/metabolismo , Ácido Valproico/farmacocinética , Administração Oral , Amidas/administração & dosagem , Amidas/sangue , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Sítios de Ligação , Disponibilidade Biológica , Injeções Intraperitoneais , Injeções Intravenosas , Masculino , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Pentanos/administração & dosagem , Pentanos/sangue , Ligação Proteica , Ratos Wistar , Distribuição Tecidual , Ácido Valproico/administração & dosagem , Ácido Valproico/sangue
17.
Colloids Surf B Biointerfaces ; 177: 77-93, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30711762

RESUMO

Peptide epitopes have been widely used to develop synthetic vaccines and immunotherapies. However, peptide epitopes may exhibit poor absorption or immunogenicity due to their low molecular weights. Conversely, fourth-generation polyamidoamine (G4-PAMAM) dendrimers are nonimmunogenic and relatively nontoxic synthetic nanoparticles that have been used as adjuvants and nanocarriers of small peptides and to improve nasal absorption. Based on this information, we hypothesized that the combination of intranasal immunization and G4-PAMAM dendrimers would be useful for enhancing the antibody responses of HIV-1 gp120 peptide epitopes. Therefore, we first used structural data, peptide epitope predictors and docking and MD simulations on MHC-II to identify two peptide epitopes on the CD4 binding site of HIV-1 gp120. The formation of G4-PAMAM-peptide complexes was evaluated in silico (molecular docking studies using different G4-PAMAM conformations retrieved from MD simulations as well as the MMGBSA approach) and validated experimentally (electrophoresis, 1H NMR and cryo-TEM). Next, the G4-PAMAM dendrimer-peptide complexes were administered intranasally to groups of female BALB/cJ mice. The results showed that both peptides were immunogenic at the systemic and mucosal levels (nasal and vaginal), and G4-PAMAM dendrimer-peptide complexes improved IgG and IgA responses in serum and nasal washes. Thus, G4-PAMAM dendrimers have potential for use as adjuvants and nanocarriers of peptides.


Assuntos
Simulação por Computador , Dendrímeros/química , Proteína gp120 do Envelope de HIV/química , HIV-1/química , HIV-1/imunologia , Modelos Moleculares , Nylons/química , Peptídeos/química , Peptídeos/imunologia , Animais , Feminino , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Peptídeos/genética
18.
Biochem Biophys Res Commun ; 370(4): 547-51, 2008 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-18355443

RESUMO

Although the molecular interaction of MDM2 with the transactivation domain of p53 has been thoroughly studied, there is very limited information regarding the steps involved in the recognition mechanism between these proteins. On this basis, we performed four high-temperature molecular dynamics simulations in explicit solvent to gain insight into the interactions involved in the fist contact toward the formation of the complex. We found that the presence of specific intermolecular aromatic pairs at the interface of the complex, around the native-like state of MDM2, is consistent among independent molecular dynamics runs. This observation suggests that aromatic-aromatic interactions are closely related to the first contact between MDM2 and p53. Thus, we propose that aromatic-aromatic interactions are an important, and probably essential, requirement for the formation and stabilization of the MDM2-p53 complex.


Assuntos
Aminoácidos Aromáticos/química , Proteínas Proto-Oncogênicas c-mdm2/química , Proteína Supressora de Tumor p53/química , Animais , Temperatura Alta , Humanos , Ligação Proteica , Conformação Proteica , Temperatura , Proteínas de Xenopus/química
19.
Acta Trop ; 171: 233-238, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28427960

RESUMO

The envelope (E) protein from DENV, contain three functional and structural domains (DI, DII and DIII). Some studies suggest that neutralizing antibodies during natural DENV infection are predominantly against DI and DII, in contrast, low proportion of the antibodies were against DIII. Thus it is necessary to establish the proportion of human antibodies against DENV E protein that bind to DI and DII during the normal course of infection; as an indicator of the quality of the antibody response and to further design new vaccine candidates for DENV. The aim of this study was to express recombinant proteins harboring a 240-aminoacid fragment of the E protein from DI and DII of DENV serotypes 2 and 3 in a eukaryotic S2 system. Further, we evaluate the antibodies against these antigens in samples from patients in acute phase of DF or DHF and compare it with the response of samples from healthy individuals from the same endemic areas and samples from healthy individuals from a non-endemic area (EA and NEA, respectively). These results suggest that the presence of antibodies against rEDI/DII might be used to identify patients at risk for severe disease.


Assuntos
Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Vírus da Dengue/metabolismo , Dengue/prevenção & controle , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Doenças Endêmicas , Regulação Viral da Expressão Gênica , Humanos , Testes de Neutralização , Domínios Proteicos , Proteínas Recombinantes
20.
Eur J Med Chem ; 128: 154-167, 2017 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-28182988

RESUMO

Since the neuraminidase (NA) enzyme of the influenza A virus plays a key role in the process of release of new viral particles from a host cell, it is often a target for new drug design. The emergence of NA mutations, such as H275Y, has led to great resistance against neuraminidase inhibitors, including oseltamivir and zanamivir. Hence, we herein designed a set of derivatives by modifying the amine and/or carboxylic groups of oseltamivir. After being screened for their physicochemical (Lipinski's rule) and toxicological properties, the remaining compounds were submitted to molecular and theoretical studies. The docking simulations provided insights into NA recognition patterns, demonstrating that oseltamivir modified at the carboxylic moiety and coupled with anilines had higher affinity and a better binding pose for NA than the derivatives modified at the amine group. Based on these theoretical studies, the new oseltamivir derivatives may have higher affinity to mutant variants and possibly to other viral subtypes. Accordingly, two compounds were selected for synthesis, which together with their respective intermediates were evaluated for their cytotoxicity and antiviral activities. Their biological activity was then tested in cells infected with the A/Puerto Rico/916/34 (H1N1) influenza virus, and virus yield reduction assays were performed. Additionally, by measuring neuraminidase activity with the neuraminidase assay kit it was found that the compounds produced inhibitory activity on this enzyme. Finally, the infected cells were analysed with atomic force microscopy (AFM), observing morphological changes strongly suggesting that these compounds interfered with cellular release of viral particles.


Assuntos
Antivirais/farmacologia , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Neuraminidase/antagonistas & inibidores , Oseltamivir/farmacologia , Animais , Antivirais/química , Chlorocebus aethiops , Simulação por Computador , Cães , Farmacorresistência Viral , Células HeLa , Humanos , Técnicas In Vitro , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Microscopia de Força Atômica , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/virologia , Oseltamivir/química , Células Vero , Proteínas Virais/antagonistas & inibidores
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