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1.
Int J Mol Sci ; 25(12)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38928332

RESUMO

CD147 is upregulated in cancers, including aggressive T-ALL. Traditional treatments for T-ALL often entail severe side effects and the risk of relapse, highlighting the need for more efficacious therapies. ADCP contributes to the antitumor response by enhancing the ability of phagocytic cells to engulf cancer cells upon antibody binding. We aimed to engineer CD147KO THP-1 cells and evaluated their differentiation properties compared to the wild type. A humanized anti-CD147 antibody, HuM6-1B9, was also constructed for investing the phagocytic function of CD147KO THP-1 cells mediated by HuM6-1B9 in the phagocytosis of Jurkat T cells. The CD147KO THP-1 was generated by CRISPR/Cas9 and maintained polarization profiles. HuM6-1B9 was produced in CHO-K1 cells and effectively bound to CD147 with high binding affinity (KD: 2.05 ± 0.30 × 10-9 M). Additionally, HuM6-1B9 enhanced the phagocytosis of Jurkat T cells by CD147KO THP-1-derived LPS-activated macrophages (M-LPS), without self-ADCP. The formation of THP-1-derived mMDSC was limited in CD147KO THP-1 cells, highlighting the significant impact of CD147 deletion. Maintaining expression markers and phagocytic function in CD147KO THP-1 macrophages supports future engineering and the application of induced pluripotent stem cell-derived macrophages. The combination of HuM6-1B9 and CD147KO monocyte-derived macrophages holds promise as an alternative strategy for T-ALL.


Assuntos
Basigina , Diferenciação Celular , Fagocitose , Humanos , Células Jurkat , Basigina/metabolismo , Basigina/genética , Células THP-1 , Células Supressoras Mieloides/metabolismo , Células Supressoras Mieloides/imunologia , Anticorpos Monoclonais Humanizados/farmacologia , Animais , Células CHO , Cricetulus , Monócitos/metabolismo , Monócitos/imunologia , Macrófagos/metabolismo , Macrófagos/imunologia , Sistemas CRISPR-Cas
2.
Org Biomol Chem ; 21(36): 7367-7381, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37655509

RESUMO

Turn-on fluorescent chemosensors based on an anthraquinone moiety, N,N'-(9,10-dioxo-9,10-dihydroanthracene-1,8-diyl)bis(2-(bis(pyridin-2-ylmethyl)amino)acetamide) (1) and N,N'-(9,10-dioxo-9,10-dihydroanthracene-2,6-diyl)bis(2-(bis(pyridin-2-ylmethyl)amino)acetamide) (2), have been successfully synthesized with the overall yields of 61% and 90%, respectively. The structures of both chemosensors 1 and 2 were elucidated using several spectroscopic techniques such as 1H NMR, 13C NMR, 2D-NMR, FTIR and HRMS. The target chemosensor 1 is a promising tool for the detection of trace levels of d10 metal ions, such as Zn(II) and Cd(II) ions, by exhibiting a significant fluorescence enhancement via a turn-on photoinduced electron transfer (PET) mechanism with a rapid and highly reproducible signal, and low detection limit values of 0.408 µM and 0.246 µM, for Zn(II) and Cd(II), respectively.

3.
Org Biomol Chem ; 21(40): 8201, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37814908

RESUMO

Correction for 'Turn-on fluorogenic sensors based on an anthraquinone signaling unit for the detection of Zn(II) and Cd(II) ions' by Chawanakorn Kongsak et al., Org. Biomol. Chem., 2023, 21, 7367-7381, https://doi.org/10.1039/D3OB01223A.

4.
Soft Matter ; 17(25): 6248-6258, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34124726

RESUMO

Self-assembly responsiveness to stimuli of polystyrene-block-polyisoprene (PS-b-PI) diblock copolymer materials is explored by means of classical molecular dynamics (MD) and dissipative particle dynamics (DPD) simulations. A concerted relationship between the parameters achieved from atomistic and DPD simulations is obtained for this molecular recognition as clearly pronounced in a phase transition. Effects of temperature, model size and composition on the morphological formation were systematically investigated for the diblock copolymeric system. Structural changes resulting in the evolution of rheology as well as an equilibrium ordered structure were analyzed in terms of order parameters and radial distribution functions. From our models, various morphologies were observed including discrete clusters (sphere-liked morphology), connected clusters (gyroid-liked morphology), hexagonally packed cylinders (HEX), connected cylinders, irregular cylinders, perfect lamellae, perforated lamellae and defected lamellae. Based on this finding, a bottom-up multi-scale simulation of the PS-b-PI diblock copolymer provides a link between equilibrium copolymeric morphologies and the crucial parameters.

5.
Org Biomol Chem ; 19(41): 9081, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34657953

RESUMO

Correction for 'Synthesis and application of methyl itaconate-anthracene adducts in configuration assignment of chiral secondary alcohols by 1H NMR' by Puracheth Rithchumpon et al., Org. Biomol. Chem., 2021, DOI: 10.1039/D1OB01387D.

6.
Org Biomol Chem ; 19(41): 8955-8967, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34581721

RESUMO

Novel chiral derivatising agents (CDAs) such as methyl itaconate-anthracene adducts (MIAs) were reported for the absolute configuration determination of chiral secondary alcohols by the 1H NMR technique. These adducts were facilely prepared through well-known reactions, and furthermore, commercially available starting materials. According to these synthetic routes, the desired MIAs were afforded in 6 steps with 49% overall yield from dimethyl itaconate. Moreover, the represented MIAs provided significantly large differences of chemical shift values (ΔδSR). No racemisation from the tertiary characteristics of the adjacent alpha carbon was observed.

7.
Molecules ; 26(3)2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33573083

RESUMO

Collagen contains hydroxyproline (Hyp), which is a unique amino acid. Three collagen-derived small peptides (Gly-Pro-Hyp, Pro-Hyp, and Gly-Hyp) interacting across a lipid bilayer (POPC model membrane) for cellular uptakes of these collagen-derived small peptides were studied using accelerated molecular dynamics simulation. The ligands were investigated for their binding modes, hydrogen bonds in each coordinate frame, and mean square displacement (MSD) in the Z direction. The lipid bilayers were evaluated for mass and electron density profiles of the lipid molecules, surface area of the head groups, and root mean square deviation (RMSD). The simulation results show that hydrogen bonding between the small collagen peptides and plasma membrane plays a significant role in their internalization. The translocation of the small collagen peptides across the cell membranes was shown. Pro-Hyp laterally condensed the membrane, resulting in an increase in the bilayer thickness and rigidity. Perception regarding molecular behaviors of collagen-derived peptides within the cell membrane, including their interactions, provides the novel design of specific bioactive collagen peptides for their applications.


Assuntos
Colágeno/química , Bicamadas Lipídicas/química , Peptídeos/química , Sequência de Aminoácidos/genética , Transporte Biológico/genética , Dicroísmo Circular , Colágeno/genética , Simulação por Computador , Dipeptídeos/química , Dipeptídeos/genética , Ligação de Hidrogênio/efeitos dos fármacos , Hidroxiprolina/química , Peptídeos/genética , Ligação Proteica/genética , Conformação Proteica
8.
Molecules ; 26(15)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34361694

RESUMO

Extracellular signal-regulated kinases 1 and 2 (ERK1/2) play key roles in promoting cell survival and proliferation through the phosphorylation of various substrates. Remarkable antitumour activity is found in many inhibitors that act upstream of the ERK pathway. However, drug-resistant tumour cells invariably emerge after their use due to the reactivation of ERK1/2 signalling. ERK1/2 inhibitors have shown clinical efficacy as a therapeutic strategy for the treatment of tumours with mitogen-activated protein kinase (MAPK) upstream target mutations. These inhibitors may be used as a possible strategy to overcome acquired resistance to MAPK inhibitors. Here, we report a class of repeat proteins-designed ankyrin repeat protein (DARPin) macromolecules targeting ERK2 as inhibitors. The structural basis of ERK2-DARPin interactions based on molecular dynamics (MD) simulations was studied. The information was then used to predict stabilizing mutations employing a web-based algorithm, MAESTRO. To evaluate whether these design strategies were successfully deployed, we performed all-atom, explicit-solvent molecular dynamics (MD) simulations. Two mutations, Ala → Asp and Ser → Leu, were found to perform better than the original sequence (DARPin E40) based on the associated energy and key residues involved in protein-protein interaction. MD simulations and analysis of the data obtained on these mutations supported our predictions.


Assuntos
Anquirinas/metabolismo , Desenho de Fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Simulação de Dinâmica Molecular , Inibidores de Proteínas Quinases/metabolismo , Algoritmos , Anquirinas/química , Anquirinas/genética , Humanos , Ligação de Hidrogênio , Ligantes , Sistema de Sinalização das MAP Quinases/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Mutação , Neoplasias/genética , Neoplasias/metabolismo , Fosforilação/efeitos dos fármacos , Ligação Proteica , Conformação Proteica em alfa-Hélice , Estabilidade Proteica
9.
Molecules ; 26(11)2021 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-34071102

RESUMO

Dengue virus (DENV) infection causes mild to severe illness in humans that can lead to fatality in severe cases. Currently, no specific drug is available for the treatment of DENV infection. Thus, the development of an anti-DENV drug is urgently required. Cordycepin (3'-deoxyadenosine), which is a major bioactive compound in Cordyceps (ascomycete) fungus that has been used for centuries in Chinese traditional medicine, was reported to exhibit antiviral activity. However, the anti-DENV activity of cordycepin is unknown. We hypothesized that cordycepin exerts anti-DENV activity and that, as an adenosine derivative, it inhibits DENV replication. To test this hypothesis, we investigated the anti-DENV activity of cordycepin in DENV-infected Vero cells. Cordycepin treatment significantly decreased DENV protein at a half-maximal effective concentration (EC50) of 26.94 µM. Moreover, DENV RNA was dramatically decreased in cordycepin-treated Vero cells, indicating its effectiveness in inhibiting viral RNA replication. Via in silico molecular docking, the binding of cordycepin to DENV non-structural protein 5 (NS5), which is an important enzyme for RNA synthesis, at both the methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, was predicted. The results of this study demonstrate that cordycepin is able to inhibit DENV replication, which portends its potential as an anti-dengue therapy.


Assuntos
Vírus da Dengue/efeitos dos fármacos , Desoxiadenosinas/farmacologia , Replicação Viral/efeitos dos fármacos , Animais , Antivirais/farmacologia , Chlorocebus aethiops , Dengue/tratamento farmacológico , Vírus da Dengue/metabolismo , Desoxiadenosinas/metabolismo , Simulação de Acoplamento Molecular , RNA Viral/genética , RNA Polimerase Dependente de RNA/metabolismo , Células Vero/virologia , Proteínas não Estruturais Virais/metabolismo
10.
Molecules ; 26(18)2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34577167

RESUMO

Protein-protein interaction plays an essential role in almost all cellular processes and biological functions. Coupling molecular dynamics (MD) simulations and nanoparticle tracking analysis (NTA) assay offered a simple, rapid, and direct approach in monitoring the protein-protein binding process and predicting the binding affinity. Our case study of designed ankyrin repeats proteins (DARPins)-AnkGAG1D4 and the single point mutated AnkGAG1D4-Y56A for HIV-1 capsid protein (CA) were investigated. As reported, AnkGAG1D4 bound with CA for inhibitory activity; however, it lost its inhibitory strength when tyrosine at residue 56 AnkGAG1D4, the most key residue was replaced by alanine (AnkGAG1D4-Y56A). Through NTA, the binding of DARPins and CA was measured by monitoring the increment of the hydrodynamic radius of the AnkGAG1D4-gold conjugated nanoparticles (AnkGAG1D4-GNP) and AnkGAG1D4-Y56A-GNP upon interaction with CA in buffer solution. The size of the AnkGAG1D4-GNP increased when it interacted with CA but not AnkGAG1D4-Y56A-GNP. In addition, a much higher binding free energy (∆GB) of AnkGAG1D4-Y56A (-31 kcal/mol) obtained from MD further suggested affinity for CA completely reduced compared to AnkGAG1D4 (-60 kcal/mol). The possible mechanism of the protein-protein binding was explored in detail by decomposing the binding free energy for crucial residues identification and hydrogen bond analysis.


Assuntos
Proteínas do Capsídeo/metabolismo , Nanopartículas Metálicas/química , Proteínas Recombinantes/metabolismo , Aminoácidos/química , Aminoácidos/metabolismo , Repetição de Anquirina , Sítios de Ligação , Proteínas do Capsídeo/química , Espectroscopia Dielétrica , Ouro/química , HIV-1/química , Ligação de Hidrogênio , Nanopartículas Metálicas/análise , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Mutação Puntual , Ligação Proteica , Proteínas Recombinantes/química , Termodinâmica
11.
Mol Cell Biochem ; 454(1-2): 45-56, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30284191

RESUMO

The most prominent feature of UV-induced photoaged skin is decreased type 1 procollagen. Increase of the TGF-ß/Smad signaling through inhibition of the TßRI dephosphorylation by the GADD34-PP1c phosphatase complex represents a promising strategy for the increase in type 1 collagen production and prevention of UV-induced skin photoaging. In this study, the molecular docking and dynamics simulations, and pharmacophore modeling method were run to investigate a possible binding site as well as binding modes between apigenin, daidzein, asiaticoside, obovatol, and astragaloside IV and PP1c. Through docking study, the possible binding site for these phytochemicals was predicted as the hydrophobic (PP1-substrate binding) groove. The result indicates that PP1 is the significant target of these compounds. Moreover, the 20,000-ps MD simulations present that the binding locations and modes predicted by the docking have been slightly changed considering that the MD simulations proffer more reliable details upon the protein-ligand recognition. The MM-GBSA binding free energy calculations and pharmacophore modeling rationally identify that the highly hydrophobic surfaces/pockets at close proximity of the catalytic core are the most favorable binding locations of the herbal compounds, and that some experimental facts upon a possible mechanism of increase in collagen biosynthesis can be explained. The present study theoretically offers the reliable binding target of the herbal compounds, and therefore helps to understanding the action mechanism for natural small molecules that enhance collagen production.


Assuntos
Colágeno/biossíntese , Inibidores Enzimáticos/farmacologia , Compostos Fitoquímicos/farmacologia , Proteína Fosfatase 1/antagonistas & inibidores , Pele/efeitos dos fármacos , Sítios de Ligação , Compostos de Bifenilo/farmacologia , Domínio Catalítico , Humanos , Isoflavonas/farmacologia , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Éteres Fenílicos/farmacologia , Proteína Fosfatase 1/metabolismo , Saponinas/farmacologia , Pele/enzimologia , Pele/metabolismo , Triterpenos/farmacologia
12.
J Bioenerg Biomembr ; 50(4): 315-327, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29687366

RESUMO

Ligustrum lucidum secoiridoid glucosides have been demonstrated to treat various types of diseases such as inflammation, pain, hepatotoxicity and hyperlipidermic as well as tonic for liver and kidney. Matrix metalloproteinases (MMPs) play a key role upon the pathology of photoaging. The present computational study showed that among the six secoiridoid glucosides (ligustroside, lucidumoside A, lucidumoside C, neonuezhenide, oleoside dimethylester, and oleuropein), ligustroside and lucidumoside A competitively inhibit all MMP-1, MMP-3, and MMP-9 activities in the docking models. The molecular docking analysis revealed a network of interactions between MMP-1, MMP-3, and MMP-9 and the ligands; ligustroside and lucidumoside A, and oxygen-containing and hydrophobic functional groups appear to be responsible for these enhanced interactions. The effect of ligustroside and lucidumoside A on the transcription factor AP-1 action was also investigated using molecular docking and dynamics simulations. The experiments suggested that inhibition of an AP-1-DNA complex formation could be on account of the direct interference of AP-1 binding onto the DNA binding sequence by ligustroside and lucidumoside A. The results suggest that both compounds have the highest potential for application as an anti-aging agent with the MMP inhibitory and anti-transcriptional activities.


Assuntos
Glucosídeos Iridoides/metabolismo , Ligustrum/química , Metaloproteinases da Matriz/metabolismo , Fator de Transcrição AP-1/metabolismo , DNA/metabolismo , Humanos , Iridoides , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Modelos Moleculares , Simulação de Acoplamento Molecular , Ligação Proteica
13.
Mol Cell Biochem ; 442(1-2): 97-109, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29019108

RESUMO

Synaptotagmin 1 (Syt1) is the Ca2+ sensor protein with an essential role in neurotransmitter release. Since the wrinkle formation is due to the excessive muscle fiber stimulation in the face, a helpful stratagem to diminish the wrinkle line intenseness is to weaken the innervating neuron activity through Syt1 inhibition which is one of the possible therapeutic strategies against wrinkles. Recently, experimental evidence showed that botox-like peptides, which are typically used as SNARE modulators, may inhibit Syt1. In this work, we applied molecular modeling to (1) characterize the structural framework and (2) define the atomistic information of the factors for the inhibition mechanism. The modeling identified the plausible binding cleft able to efficiently bind all botox-like peptides. The MD simulations revealed that all peptides induced significant Syt1 rigidity by binding in the cleft of the C2A-C2B interface. The consequence of this binding event is the suppression of the protein motion associated with conformational change of Syt1 from the closed form to the open form. On this basis, this finding may therefore be of subservience for the advancement of novel botox-like molecules for the therapeutic treatment of wrinkle, targeting and modulating the function of Syt1.


Assuntos
Simulação de Acoplamento Molecular , Peptídeos/química , Proteínas SNARE , Sinaptotagmina I/química , Humanos , Proteínas SNARE/antagonistas & inibidores , Proteínas SNARE/química
14.
Toxicol Mech Methods ; 28(1): 1-11, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28678657

RESUMO

Inhibition of P-glycoprotein (P-gp)'s function may conduct significant changes in the prescription drugs' pharmacokinetic profiles and escalate potential risks in taking place of drug/herb-drug interactions. Computational modeling was advanced to scrutinize some bioflavonoids which play roles in herb-drug interactions as P-gp inhibitors utilizing molecular docking and pharmacophore analyses. Twenty-five flavonoids were utilized as ligands for the modeling. The mouse P-gp (code: 4Q9H) was acquired from the PDB. The docking was operated utilizing AutoDock version 4.2.6 (Scripps Research Institute, La Jolla, CA) against the NBD2 of 4Q9H. The result illustrated the high correlation between the docking scores and observed activities of the flavonoids and the putative binding site of these flavonoids was proposed and compared with the site for ATP. To evaluate hotspot amino acid residues within the NBD2, Binding modes for the ligands were achieved using LigandScout to originate the NBD2-flavonoid pharmacophore models. The results asserted that these inhibitors competed with ATP for binding site in the NBD2 (as competitive inhibitors) including the hotspot residues which associated with electrostatic and van der Waals interactions with the flavonoids. In MD simulation of eight delegated complexes selected from the analyzed flavonoid subclasses, RMSD analysis of the trajectories indicated the residues were stable throughout the duration of simulations.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Flavonoides/uso terapêutico , Interações Ervas-Drogas , Extratos Vegetais/uso terapêutico , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Sítios de Ligação , Ligação Competitiva , Flavonoides/química , Flavonoides/metabolismo , Ligantes , Camundongos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade
15.
Toxicol Mech Methods ; 27(4): 253-271, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27996361

RESUMO

In this work, molecular docking, pharmacophore modeling and molecular dynamics (MD) simulation were rendered for the mouse P-glycoprotein (P-gp) (code: 4Q9H) and bioflavonoids; amorphigenin, chrysin, epigallocatechin, formononetin and rotenone including a positive control; verapamil to identify protein-ligand interaction features including binding affinities, interaction characteristics, hot-spot amino acid residues and complex stabilities. These flavonoids occupied the same binding site with high binding affinities and shared the same key residues for their binding interactions and the binding region of the flavonoids was revealed that overlapped the ATP binding region with hydrophobic and hydrophilic interactions suggesting a competitive inhibition mechanism of the compounds. Root mean square deviations (RMSDs) analysis of MD trajectories of the protein-ligand complexes and NBD2 residues, and ligands pointed out these residues were stable throughout the duration of MD simulations. Thus, the applied preliminary structure-based molecular modeling approach of interactions between NBD2 and flavonoids may be gainful to realize the intimate inhibition mechanism of P-gp at NBD2 level and on the basis of the obtained data, it can be concluded that these bioflavonoids have the potential to cause herb-drug interactions or be used as lead molecules for the inhibition of P-gp (as anti-multidrug resistance agents) via the NBD2 blocking mechanism in future.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Biologia Computacional/métodos , Flavonoides/toxicidade , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Sítios de Ligação , Flavonoides/química , Interações Ervas-Drogas , Humanos , Ligantes , Camundongos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Alinhamento de Sequência , Homologia Estrutural de Proteína
16.
Mol Biotechnol ; 66(4): 582-591, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38374320

RESUMO

We utilized molecular dynamics (MD) simulations and Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) free energy calculations to investigate the specificity of two oligonucleotide probes, namely probe B and probe D, in detecting single-stranded DNA (ssDNA) within three bacteria families: Enterobacteriaceae, Pasteurellaceae, and Vibrionaceae. Due to the limited understanding of molecular mechanisms in the previous research, we have extended the discussion to focus specifically on investigating the binding process of bacteria-probe DNA duplexes, with an emphasis on analyzing the binding free energy. The role of electrostatic contributions in the specificity between the oligonucleotide probes and the bacterial ssDNAs was investigated and found to be crucial. Our calculations yielded results that were highly consistent with the experimental data. Through our study, we have successfully exhibited the benefits of utilizing in-silico approaches as a powerful virtual-screening tool, particularly in research areas that demand a thorough comprehension of molecular interactions.


Assuntos
DNA de Cadeia Simples , Simulação de Dinâmica Molecular , Sondas de Oligonucleotídeos , DNA de Cadeia Simples/metabolismo , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/química , Sondas de Oligonucleotídeos/genética , Sondas de Oligonucleotídeos/química , DNA Bacteriano/genética , Eletricidade Estática , Termodinâmica , Conformação de Ácido Nucleico
17.
J Phys Chem B ; 127(16): 3651-3662, 2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37071755

RESUMO

The role of water in host-ligand binding was investigated using a combination of molecular dynamics simulation and three-dimensional reference interaction site model theory. Three different hosts were selected (CB6, CB7, and CB8). Six organic molecules were used as representative ligands: dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), acetone, 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO), cyclopentanone (CPN), and pyrrole. From the binding free energy and its components, we divided the ligands into two groups: those with relatively small molecular size (DMSO, DMF, acetone, and pyrrole) and those with relatively large molecular size (DBO and CPN). We established that the solvent water in the CB6 cavity can be completely displaced by small ligands, resulting in a greater binding affinity compared with larger CBs, except in the case of the small pyrrole ligand, due to outstanding intrinsic properties such as the relatively high hydrophobicity and low dipole moment. In the case of the large ligands, the solvent water can be displaced by DBO and CPN in both CB6 and CB7; there were similar tendencies in their binding affinities, with the greatest affinity in the CB7 complexes. However, the tendencies of the binding affinity components are completely different due to the difference between the complex structure and the solvation structure when a ligand binds with a CB structure. The binding affinities suggest that the size fit between the ligand and CB cannot guarantee the greatest binding affinity gain because the binding structure and intrinsic properties of CB and ligand equally play a crucial role.

18.
Sci Rep ; 13(1): 18249, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37880480

RESUMO

Zirconia ceramics have been widely used as dental restorations due to their esthetic appearance and high flexural strength. The bonding of zirconia with resin cement should rely on both mechanical and chemical bonds. This study was performed to investigate the effect of zirconia surface topography and its wettability after surface pretreatments on the microshear bond strength (µSBS) of a resin cement. Zirconia slabs were prepared and randomly divided into 5 groups based on the surface treatment as follows: no treatment (control), air abrasion (AB), etching with hydrofluoric acid (F), the mixture of hydrofluoric acid and nitric acid (FN), or the mixture of hydrochloric acid and nitric acid (CN) for 10 min. The specimens were subjected to investigation of surface roughness characteristics [average roughness (Ra), peak-to-valley average distance (Rpv), skewness (Rsk), and kurtosis (Rku)] using atomic force microscopy (AFM) and measurements of surface contact angle (θc) and µSBS of a resin cement. In addition, the area % of the nanoscale surface irregularity (nSI%) was calculated from the AFM images. The effects of nSI%, Ra and θc on the µSBS were analyzed by multiple linear regression analysis (p < 0.05). Multiple regression analysis revealed that the nSI% was the most predominant factor for the µSBS (p < 0.001). A surface with larger nSI%, higher Ra and relatively lower θc was essential for establishing a reliable resin-zirconia bond.

19.
Chemosphere ; 305: 135330, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35724718

RESUMO

To compare efficiency of disulfide and thiol groups in removing mercury from aqueous medium without noteworthy influence from structural differences, a series of new [LnIII(dtba)1.5(H2O)2] (LnIII = EuIII (I), GdIII (II) and TbIII (III), H2dtba = 4,4'-dithiobenzoic acid) were synthesized and characterized. The single crystal structure of I was elucidated and is described. Reaction of II with hydrazine gave IISH containing disulfide and thiol groups. Experimental data confirmed the preserved framework structure and the co-existing of disulfide and thiol groups in IISH. Robustness of II and IISH over a wide range of pH (2-10) was confirmed and their mercury removal performances at different pH were evaluated in terms of removal efficiencies (%R), equilibrium uptake capacities (qe) and distribution constant (Kd). The dependence of these parameters on pH is reported. The best values of %R, qe and Kd could be achieved at pH 10 at which surfaces of the adsorbents were negatively charged; 86%R, 429 mg g-1, and 6.04 × 103 mL g-1 (II), and 98%R, 490 mg g-1 and 5.08 × 104 mL g-1 (IISH). At pH 7, influences of the initial concentration of mercury on performances of the adsorbents as well as the adsorption isotherms and kinetics were examined from which the better performance of IISH has been concluded. The characterization of the adsorptions by the Langmuir model and the pseudo-second-order kinetic as well as their excellent consistency with the experimental data are included. At neutral pH, selectivity to the adsorption of mercury and tolerance to common anions were illustrated. The better affinity between mercury and thiol group and therefore its contribution to the better performance of IISH was then ascertained by a computational study.


Assuntos
Elementos da Série dos Lantanídeos , Mercúrio , Poluentes Químicos da Água , Adsorção , Dissulfetos , Concentração de Íons de Hidrogênio , Cinética , Mercúrio/química , Polímeros , Compostos de Sulfidrila/química , Poluentes Químicos da Água/análise
20.
PLoS One ; 17(12): e0278216, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36454774

RESUMO

Phosphodiesterase 1B (PDE1B) and PDE10A are dual-specificity PDEs that hydrolyse both cyclic adenosine monophosphate and cyclic guanosine monophosphate, and are highly expressed in the striatum. Several reports have suggested that PDE10A inhibitors may present a promising approach for the treatment of positive symptoms of schizophrenia, whereas PDE1B inhibitors may present a novel mechanism to modulate cognitive deficits. Previously, we have reported a novel dual inhibitor of PDE1B and PDE10A, compound 2 [(3-fluorophenyl)(2-methyl-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)methanone] which has shown inhibitory activity for human recombinant PDE1B and PDE10A in vitro. In the present study, the safety profile of compound 2 has been evaluated in rats in the acute oral toxicity study, as well as; the antipsychotic-like effects in the rat model of schizophrenia. Compound 2 was tolerated up to 1 g/kg when administered at a single oral dose. Additionally, compound 2 has strongly suppressed ketamine-induced hyperlocomotion, which presented a model for the positive symptoms of schizophrenia. It has also shown an ability to attenuate social isolation induced by chronic administration of ketamine and enhanced recognition memory of rats ​in the novel object recognition test. Altogether, our results suggest that compound 2 represents a promising therapy for the treatment of the three symptomatic domains of schizophrenia.


Assuntos
Antipsicóticos , Transtornos Cognitivos , Ketamina , Esquizofrenia , Humanos , Animais , Ratos , Antipsicóticos/farmacologia , Antipsicóticos/uso terapêutico , Esquizofrenia/tratamento farmacológico , Inibidores de Fosfodiesterase/farmacologia , Inibidores de Fosfodiesterase/uso terapêutico , Diester Fosfórico Hidrolases
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