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1.
Sci Rep ; 10(1): 10462, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32591593

RESUMO

Histone deacetylases (HDACs) belong to a family of enzymes that remove acetyl groups from the ɛ-amino of histone and nonhistone proteins. Additionally, HDACs participate in the genesis and development of cancer diseases as promising therapeutic targets to treat cancer. Therefore, in this work, we designed and evaluated a set of hydroxamic acid derivatives that contain a hydrophobic moiety as antiproliferative HDAC inhibitors. For the chemical structure design, in silico tools (molecular docking, molecular dynamic (MD) simulations, ADME/Tox properties were used to target Zn2+ atoms and HDAC hydrophobic cavities. The most promising compounds were assayed in different cancer cell lines, including hepatocellular carcinoma (HepG2), pancreatic cancer (MIA PaCa-2), breast cancer (MCF-7 and HCC1954), renal cancer (RCC4-VHL and RCC4-VA) and neuroblastoma (SH-SY5Y). Molecular docking and MD simulations coupled to the MMGBSA approach showed that the target compounds have affinity for HDAC1, HDAC6 and HDAC8. Of all the compounds evaluated, YSL-109 showed the best activity against hepatocellular carcinoma (HepG2 cell line, IC50 = 3.39 µM), breast cancer (MCF-7 cell line, IC50 = 3.41 µM; HCC1954 cell line, IC50 = 3.41 µM) and neuroblastoma (SH-SY5Y cell line, IC50 = 6.42 µM). In vitro inhibition assays of compound YSL-109 against the HDACs showed IC50 values of 259.439 µM for HDAC1, 0.537 nM for HDAC6 and 2.24 µM for HDAC8.

2.
Toxicol Appl Pharmacol ; 399: 115033, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32387339

RESUMO

N-(2-hydroxyphenyl)-2-propylpentamide (HO-AAVPA) is a novel arylamide derivative of valproic acid (VPA) designed in silico, with better antioxidant and antiproliferative effect on cancer cell lines than VPA. This study was aimed to evaluate the anticonvulsant activity, the toxicity and teratogenicity produced in HO-AAVPA-treated CD1 mice using VPA as positive control. With the maximal electroshock (MES)- and pentylenetetrazole (PTZ)-induced seizure models, HO-AAVPA reduced the time of hind limb extension, stupor and recovery, the number of clonic and tonic seizures and the mortality rate in a dose-dependent manner, obtaining an ED50 of 370 and 348 mg/kg for MES and PTZ, respectively. On the rotarod test, mice administered with 600 mg/kg HO-AAVPA manifested reduced locomotor activity (2.78%); while HO-AAVPA at 300 mg/kg and VPA at 500 mg/kg gave a similar outcome (∼60%). The LD50 of 936.80 mg/kg herein found for HO-AAVPA reflects moderate toxicity. Concerning teratogenicity, the administration of HO-AAVPA to pregnant females at 300 and 600 mg/kg on gestation day (GD) 8.5 generated less visceral and skeletal alterations in the fetuses, as well as, minor rate of modifications in the expression pattern of the neuronal marker Tuj1 and endothelial marker PECAM1 in embryos, that those induced by VPA administration. Altered embryonic development occurred with less frequency and severity with HO-AAVPA at 600 mg/kg than VPA at 500 mg/kg. In conclusion, the protective effect against convulsions provided by HO-AAVPA was comparable to that of VPA in the MES and PZT seizure models, showed lower toxicity and less damage to embryonic and fetal development.

3.
J Med Chem ; 63(11): 5734-5751, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32392053

RESUMO

Leishmania (L.) infantum causes visceral, cutaneous, and mucosal leishmaniasis in humans and canine leishmaniasis in dogs. Herein, we describe that O-alkyl hydroxamate derivatives displayed potent and selective in vitro activity against the amastigote stage of L. infantum while no activity was observed against promastigotes. Compound 5 showed potent in vivo activity against L. infantum. Moreover, the combination of compound 5 supported on gold nanoparticles and meglumine antimoniate was also effective in vivo and improved the activity of these compounds compared to that of the individual treatment. Docking studies showed that compound 5 did not reach highly conserved pocket C and established interactions with the semiconserved residues V44, A45, R242, and E243 in pocket A of LiSIR2rp1. The surface space determined by these four amino acids is not conserved in human sirtuins. Compound 5 represents a new class of selective ligands with antileishmanial activity.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32324521

RESUMO

BACKGROUND: Our research group has developed some Valproic Acid (VPA) derivatives employed as antiproliferative compounds targeting HDAC8 enzyme. However, some of these compounds are poorly water soluble. OBJECTIVE: Furthermore, we employed the four generation of Polyamidoamine (G4 PAMAM) dendrimers as drug carrier of these compounds to increase their water solubility for further in vitro evaluation. METHODS: VPA derivatives were subjected to Molecular Docking and dynamics (MD) simulations to evaluate their affinity on G4 PAMAM. Then, HPLC-UV/VIS, 1H NMR, MALDI-TOF and atomic force microscopy were employed to establish the formation of the drug-G4 PAMAM complexes. RESULTS: The docking results show that amide groups of VPA derivatives make polar interactions with G4 PAMAM whereas MD simulations corroborated the stability of the complexes. HPLC UV/VIS experiments showed an increase of the drug water solubility directly proportional to the amount of G4 PAMAM. 1H NMR show a disappearance of the proton amine group signals, correlating with docking results. MALDI-TOF and atomic force microscopy suggested the drug-G4 PAMAM dendrimer complexes formation. In vitro studies showed that G4 PAMAM has toxicity in the micromolar concentration in MDA-MB-231, MCF7 and 3T3-L1 cell lines. VPA CF-G4 PAMAM dendrimer complex showed anti-proliferative properties in the micromolar concentration in MCF-7 and 3T3L1, and in the milimolar concentration in MDA-MB-231, whereas VPA MFG4 PAMAM dendrimer complex didn't show effects on the three cell lines employed. CONCLUSION: These results demonstrate that G4 PAMAM dendrimers are capable to transport poorly watersoluble aryl-VPA derivate compounds to increasing its cytotoxic activity against neoplastic cell lines.

5.
Exp Gerontol ; 136: 110951, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32305596

RESUMO

Late-onset Alzheimer disease (LOAD) is the most frequent cause of dementia in elderly adults. However, the factors determining disease onset remain unclear. In the elderly, the activation and expression of the gene encoding RE-1 silencing transcription factor (REST) may be a determinant of neuroprotective mechanisms and good amyloidogenic pathway management. In the present study, the minimal promoter region of REST1 was genetically and epigenetically analyzed in blood samples from 21 subjects with LOAD and 20 cognitively healthy elderly subjects. Genomic DNA was isolated, treated with bisulfite and pyrosequenced, and gene expression was determined using real-time PCR. Notably, subjects with LOAD exhibited hypermethylation and significantly diminished expression of REST1 compared with healthy subjects (p = 0.001). In the LOAD group, the gene expression of CAT, SOD2 and GPX also showed a significant decrease and an increase in malondialdehyde. A docking analysis revealed that the first zinc finger protein Sp1 recognized and bound the methylated sequence in subjects with LOAD differently than the binding observed in control subjects. These results reveal that in patients with LOAD the methylation of specific sites in the promoter sequence of REST suppresses its expression and this could be regulating the decreased expression of CAT, SOD and GPX, besides interfering with the action of transcription factors as Sp1.

6.
J Pharm Pharmacol ; 72(7): 938-955, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32307724

RESUMO

OBJECTIVES: N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA), a derivative of valproic acid (VPA), has been proposed as a potential anticancer agent due to its improved antiproliferative effects in some cancer cell lines. Although there is evidence that VPA is metabolized by cytochrome P450 2C11 rat isoform, HO-AAVPA CYP-mediated metabolism has not yet been fully explored. Therefore, in this work, the biotransformation of HO-AAVPA by CYP2C11 was investigated. METHODS: Kinetic parameters and spectral interaction between HO-AAVPA and CYP were evaluated using rat liver microsomes. The participation of CYP2C11 in metabolism of HO-AAVPA was confirmed by cimetidine (CIM) inhibition assay. Docking and molecular dynamics simulations coupled to MMGBSA methods were used in theoretical study. KEY FINDINGS: HO-AAVPA is metabolized by CYP enzymes (KM  = 38.94 µm), yielding a hydroxylated metabolite according to its HPLC retention time (5.4 min) and MS analysis (252.2 m/z). In addition, CIM inhibition in rat liver microsomes (Ki  = 59.23 µm) confirmed that CYP2C11 is mainly involved in HO-AAVPA metabolism. Furthermore, HO-AAVPA interacts with CYP2C11 as a type I ligand. HO-AAVPA is stabilized at the CYP2C11 ligand recognition site through a map of interactions similar to other typical CYP2C11 substrates. CONCLUSION: Therefore, rat liver CYP2C11 isoform is able to metabolize HO-AAVPA.

7.
J Biomol Struct Dyn ; : 1-13, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32159448

RESUMO

The number of patients diagnosed with Alzheimer's disease (AD) increases each year, and there are currently few treatment strategies to decrease the symptoms of AD; furthermore, these strategies are not sufficient to reduce memory loss in AD patients. In this work, in vitro and in silico studies were performed to evaluate the effects of fucosterol, which was extracted from an algal source and characterized by liquid chromatography-mass spectra (LC-MS), as an inhibitor of Aß1-42 aggregation. Experimental studies, including protein gel electrophoresis, atomic force microscopy and fluorescence studies with thioflavin T (ThT), highlighted that fucosterol can decrease oligomer formation more than galantamine, which was used as a positive control. Docking and molecular dynamics simulations coupled with an MMGBSA approach showed that fucosterol is capable of recognizing the hydrophobic regions of monomeric Aß1-42, suggesting that fucosterol could affect amyloid-beta (Aß1-42) aggregation by preventing the formation of oligomers, preventing the development of AD.Communicated by Ramaswamy H. Sarma.

8.
J Comput Aided Mol Des ; 34(8): 857-878, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32180123

RESUMO

Valproic acid (VPA) is a compound currently used in clinical practice for the treatment of epilepsy as well as bipolar and mood disorders. VPA targets histone deacetylases (HDACs), which participate in the removal of acetyl groups from lysine in several proteins, regulating a wide variety of functions within the organism. An imbalance or malfunction of these enzymes is associated with the development and progression of several diseases, such as cancer and neurodegenerative diseases. HDACs are divided into four classes, but VPA only targets Class I (HDAC1-3 and 8) and Class IIa (HDAC4-5, 7 and 9) HDACs; however, structural and energetic information regarding the manner by which VPA inhibits these HDACs is lacking. Here, the structural and energetic features that determine this recognition were studied using molecular docking and molecular dynamics (MD) simulation. It was found that VPA reaches the catalytic site in HDAC1-3 and 7, whereas in HDAC6, VPA only reaches the catalytic tunnel. In HDAC4, VPA was bound adjacent to L1 and L2, a zone that participates in corepressor binding, and in HDAC8, VPA was bound to the hydrophobic active site channel (HASC), in line with previous reports.

9.
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
10.
J Mol Neurosci ; 70(2): 180-193, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31768942

RESUMO

Alzheimer's disease (AD) is one of the most complicated neurodegenerative diseases, and several hypotheses have been associated with its development and progression, such as those involving glucose hypometabolism, the cholinergic system, calcium imbalance, inflammation, oxidative imbalance, microtubule instability, and the amyloid cascade, several of which are related to oxidative stress (free radical generation), which contributes to neuronal death. Therefore, several efforts have been made to establish a sporadic AD model that takes into account these hypotheses. One model that replicates the increase in amyloid beta (Aß) and oxidative stress in vivo is the scopolamine model. In the present work, the chronic administration (6 weeks) of scopolamine was used to analyze the neuroprotective effects of apocynin and galantamine. The results showed that scopolamine induced cognitive impairment, which was evaluated 24 h after the final dose was administered. In addition, after scopolamine administration, the Aß and superoxide anion levels were increased, and NADPH oxidase 2 (NOX2), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor kappa B (NFkB) genes were overexpressed. These effects were not observed when either apocynin or galantamine was administered during the last 3 weeks of scopolamine treatment, and although the results from both molecules were related to lower Aß production and, consequently, lower superoxide anion production, they were likely realized through different pathways. That is, both apocynin and galantamine diminished NADPH oxidase expression, but their effects on transcription factor expression differed. Moreover, experiments in silico showed that galantamine did not interact with the active site of beta secretase, whereas diapocynin, an apocynin metabolite, interacted with the beta-site APP-cleaving enzyme (BACE1) at the catalytic site.

11.
J Mol Graph Model ; 96: 107514, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31877401

RESUMO

Peptide epitopes from HIV-1 gp120 have been used to block the gp120-CD4 complex, whereas their poor absorbable or immunogenic properties prevent them from coupling to generation four polyamidoamine (PAMAM-G4) dendrimers. PAMAM-G4 are synthetic nanoparticles that are relatively nontoxic and nonimmunogenic have been employed as nanocarriers. In a previous study, two peptide epitopes (ABC and PGV04) from gp120 located at the protein-protein interface of the gp120-CD4 complex were identified through protein-protein dissociation. Then, their complexation with G4-PAMAM was evaluated through experimental and theoretical approaches, revealing a stoichiometry of 1:8/9 for G4-PAMAM and ABC or PGV04, respectively, providing important information that can be used to gain insight into the structural and energetic basis of the molecular binding of these G4-PAMAM-peptide systems. In this contribution, we performed ligand diffusion molecular dynamic simulations (LDMDSs) using 1.5 µs combined with the molecular mechanics generalized Born surface area (MMGBSA) approach, a strategy that successfully reproduced experimentally encapsulation on PAMAM-G4-ligand complexes, to explore the mechanism through which ABC and PGV04 are encapsulated by PAMAM-G4 under neutral and acid conditions. Our results reproduce the reported PAMAM-G4-peptide complex stoichiometry, revealing a slower peptide delivery at neutral conditions and a spontaneous release under acidic conditions. LDMDSs show that several peptides can reach stable G4-PAMAM complexes at neutral pH, and only a few are able to encapsulate on dendrimers without impacting dendrimer sphericity. Energetic analysis exploring different generalized Born models revealed that the ABC peptide has better binding properties than PGV04.

12.
Mol Divers ; 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664610

RESUMO

11-Beta hydroxysteroid dehydrogenase type 1 (11ß-HSD1) regulates cortisol levels mainly in adipose, hepatic and brain tissues. There is a relationship between the high activity of this enzyme and the development of obesity and metabolic disorders. The inhibition of 11ß-HSD1 has been shown to attenuate the development of type 2 diabetes mellitus, insulin resistance, metabolic syndrome and other diseases mediated by excessive cortisol production. In this work, fifteen benzothiazole derivatives substituted with electron-withdrawing and electron-donating groups were designed to explore their affinity for 11ß-HSD1 using in silico methods. The results show that (E)-5-((benzo[d]thiazol-2-ylimino)(methylthio)methylamino)-2-hydroxybenzoic acid (C1) has good physicochemical properties and favorable interactions with 11ß-HSD1 through hydrogen bonding and hydrophobic interactions in the catalytic site formed by Y183, S170 and Y177. Furthermore, C1 was synthesized and evaluated in vitro and ex vivo using clobenzorex (CLX) as a reference drug in obese Zucker rats. The in vitro results showed that C1 was a better inhibitor of human 11ß-HSD1 than CLX. The ex vivo assay results demonstrated that C1 was capable of reducing 11ß-HSD1 overexpression in mesenteric adipose tissue. Therefore, C1 was able to decrease the activity and expression of 11ß-HSD1 better than CLX.

13.
Biopolymers ; 110(11): e23333, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31568570

RESUMO

The formation of the KRas4B-PDEδ complex activates different signaling pathways required for the development and maintenance of cancer. Previous experimental and theoretical studies have allowed researchers to design an inhibitor of the KRas4B-PDEδ complex, "Deltarasin." This inhibitor binds to the prenyl-binding pocket of PDEδ and subsequently inhibits the proliferation of human pancreatic ductal adenocarcinoma cells that depend on oncogenic KRas4B. Nevertheless, structural and energetic information about the inhibitory effects of Deltarasin on the KRas4B-PDEδ complex are not available. In this study, we explore the properties of Deltarasin in inhibiting the formation of wild-type and mutant KRas4B-PDEδ complexes present in different cell lines expressing mutant RAS genes (G12D, G12C, G12V, G13D, Q61L, and Q61R) using 1.7 µs molecular dynamics (MD) simulations in combination with the MMGBSA approach. Our results revealed the energetic and structural mechanisms that suggest a higher affinity of Deltarasin for PDEδ than the farnesylated HVR. Moreover, Deltarasin exerts another dissociative effect by binding to the protein-protein dimeric interface of wild-type KRas4B-PDEδ, whereas associative and dissociative effects were observed for mutant KRas4B-PDEδ, providing a mechanistic explanation for the inhibitory effects of Deltarasin on different cancer cell lines.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/metabolismo , Simulação de Dinâmica Molecular , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Adenocarcinoma , Benzimidazóis/farmacologia , Linhagem Celular Tumoral , Humanos , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos
14.
Int J Mol Sci ; 20(18)2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31540261

RESUMO

The Na+, K+-ATPase transports Na+ and K+ across the membrane of all animal cells. In addition to its ion transporting function, the Na+, K+-ATPase acts as a homotypic epithelial cell adhesion molecule via its ß1 subunit. The extracellular region of the Na+, K+-ATPase ß1 subunit includes a single globular immunoglobulin-like domain. We performed Molecular Dynamics simulations of the ectodomain of the ß1 subunit and a refined protein-protein docking prediction. Our results show that the ß1 subunit Ig-like domain maintains an independent structure and dimerizes in an antiparallel fashion. Analysis of the putative interface identified segment Lys221-Tyr229. We generated triple mutations on YFP-ß1 subunit fusion proteins to assess the contribution of these residues. CHO fibroblasts transfected with mutant ß1 subunits showed a significantly decreased cell-cell adhesion. Association of ß1 subunits in vitro was also reduced, as determined by pull-down assays. Altogether, we conclude that two Na+, K+-ATPase molecules recognize each other by a large interface spanning residues 221-229 and 198-207 on their ß1 subunits.


Assuntos
Mutagênese Sítio-Dirigida , ATPase Trocadora de Sódio-Potássio/química , ATPase Trocadora de Sódio-Potássio/metabolismo , Motivos de Aminoácidos , Animais , Células CHO , Cricetulus , Modelos Moleculares , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , ATPase Trocadora de Sódio-Potássio/genética
15.
Gac Med Mex ; 155(4): 417-422, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31486780

RESUMO

Valproic acid is an antiepileptic drug with more than 50 years of clinical use. In the past decade, its anticancer effects were discovered. Analyses in groups of patients who used this drug for years have shown that it decreases the frequency of head and neck cancer. Recent studies show the anticancer effect of combining valproic acid with chemotherapy, biological therapy and antioxidant systems inhibitors, with exceptional results. In this review, we analyze the metabolism of valproic acid and its application against cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias/tratamento farmacológico , Ácido Valproico/administração & dosagem , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Neoplasias/patologia , Ácido Valproico/farmacologia
17.
J Steroid Biochem Mol Biol ; 189: 176-186, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30851383

RESUMO

(-)-Epicatechin (Epi) has been demonstrated to activate pathways involved in GPER-stimulated nitric oxide (NO) production via endothelial NO synthase, known as the eNOS/NO pathway. Previous studies combining synthesis of four Epi derivatives demonstrated that Epi and Epi-prop, Epi-4-prop and Epi-5-prop were able to bind GPER by acting as GPER agonists, whereas docking studies allowed observation of structural details of the binding of these derivatives at the GPER binding site. However, due to the nature of past studies, the theoretical methods employed did not allow observation of structural and energetic details linked to ligand binding at the GPER binding site. In this contribution, we explore the structural and energetic changes coupling the binding of Epi and its four derivatives to GPER. To this end, MD simulations on the microsecond scale (1 µs) with an MMGBSA approach were used for each GPER-ligand complex. Energetic analysis demonstrated that incorporation of several aliphatic chains to Epi contributed to increasing the affinity towards the GPER binding site, thus helping to explain the experimental evidence. Structural analysis demonstrated that Epi, Epi-4-prop and Epi-5-prop share more similar interactions at GPER binding sites with similar conformational behavior than with Epi-prop and Epi-Ms. However, Epi-prop had additional residues that could explain its different but related biological effects.


Assuntos
Catequina/análogos & derivados , Catequina/farmacologia , Receptores Acoplados a Proteínas-G/agonistas , Sítios de Ligação , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Receptores Estrogênicos/química , Receptores Estrogênicos/metabolismo , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/metabolismo , Termodinâmica
18.
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
19.
J Biomol Struct Dyn ; 37(18): 4685-4700, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30661450

RESUMO

Adenosine receptors (ARs) belong to family A of GPCRs that are involved in many diseases, including cerebral and cardiac ischemic diseases, immune and inflammatory disorders, etc. Thus, they represent important therapeutic targets to treat these conditions. Computational techniques such as molecular dynamics (MD) simulations permit researchers to obtain structural information about these proteins, and principal component analysis (PCA) allows for the identification of collective motions. There are available structures for the active form (3QAK) and the inactive form (3EML) of A2AR which permit us to gain insight about their activation/inactivation mechanism. In this work, we have proposed an inverse strategy using MD simulations where the active form was coupled to the antagonist caffeine and the inactive form was coupled to adenosine agonist. Moreover, we have included four reported thermostabilizing mutations in the inactive form to study A2AR structural differences under different conditions. Some observations stand out from the PCA studies. For instance, the apo structures showed remarkable similarities, and the principal components (PCs) were rearranged in a ligand-dependent manner. Additionally, the active conformation was less stable compared to the inactive one. Some PCs inverted their direction in the presence of a ligand, and comparison of the PCs between 3EML and 3EML_ADN showed that adenosine induced major changes in the structure of A2AR. Rearrangement of PCs precedes and drives conformational changes that occur after ligand binding. Knowledge about these conformational changes provides important insights about the activity of A2AR.

20.
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
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