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1.
AAPS PharmSciTech ; 25(8): 254, 2024 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-39443345

RESUMEN

Bacterial keratitis (BK) is a serious ocular infection that can lead to vision impairment or blindness if not treated promptly. Herein, we report the development of a versatile composite hydrogel consisting of silk fibroin and sodium alginate, reinforced by antibiotic-loaded mesoporous silica nanoparticles (MSNs) for the treatment of BK. The drug delivery system is constructed by incorporating vancomycin- and ceftazidime-loaded MSNs into the hydrogel network. The synthesized MSNs were found to be spherical in shape with an average size of about 95 nm. The loading capacities of both drugs were approximately 45% and 43%, for vancomycin and ceftazidime respectively. Moreover, the formulation exhibited a sustained release profile, with 92% of vancomycin and 90% of ceftazidime released over a 24 h period. The cytocompatibility of the drug carrier was also confirmed by MTT assay results. In addition, we performed molecular dynamics (MD) simulations to better reflect the drug-drug and drug-MSN interactions. The results obtained from RMSD, number of contacts, and MSD analyses perfectly corroborated the experimental findings. In brief, the designed drug-MSN@hydrogel could mark an intriguing new chapter in the treatment of BK.


Asunto(s)
Antibacterianos , Portadores de Fármacos , Hidrogeles , Queratitis , Nanopartículas , Dióxido de Silicio , Vancomicina , Dióxido de Silicio/química , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Antibacterianos/química , Nanopartículas/química , Queratitis/tratamiento farmacológico , Queratitis/microbiología , Portadores de Fármacos/química , Hidrogeles/química , Vancomicina/administración & dosificación , Vancomicina/química , Sistemas de Liberación de Medicamentos/métodos , Ceftazidima/administración & dosificación , Ceftazidima/química , Porosidad , Liberación de Fármacos , Simulación de Dinámica Molecular , Alginatos/química , Fibroínas/química , Humanos
2.
Comput Biol Med ; 183: 109245, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39388840

RESUMEN

Understanding how proteins behave dynamically and undergo conformational changes is essential to comprehending their biological roles. This review article examines the potent tool of using Molecular Dynamics simulations in conjunction with Principal Component Analysis (PCA) to explore protein dynamics. Molecular dynamics data can be made easier to read by removing prominent patterns through the use of PCA, a sophisticated dimensionality reduction approach. Researchers can obtain critical insights into the fundamental principles governing protein function by using PCA on MD simulation data. We provide a systematic approach to PCA that includes data collection, input coordinate selection, and result interpretation. Protein collective movements and fundamental dynamics are made visible by PCA, which makes it possible to identify conformational substates that are crucial to function. By means of principal component analysis, scientists are able to observe and measure large-scale movements, like hinge bending and domain motions, as well as pinpoint areas of protein structural stiffness and flexibility. Moreover, PCA allows temporal separation, distinguishing slower global motions from faster local changes. A strong foundation for researching protein dynamics is provided by the combination of PCA and Molecular Dynamics simulations, which have applications in drug development and enhance our comprehension of intricate biological systems.

3.
Arch Biochem Biophys ; 761: 110151, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39265694

RESUMEN

Important biological structures known for their exceptional mechanical qualities, lipid bilayers are essential to many cellular functions. Fluidity, elasticity, permeability, stiffness, tensile strength, compressibility, shear viscosity, line tension, and curvature elasticity are some of the fundamental characteristics affecting their behavior. The purpose of this review is to examine these characteristics in more detail by molecular dynamics simulation, elucidating their importance and the elements that lead to their appearance in lipid bilayers. Comprehending the mechanical characteristics of lipid bilayers is critical for creating medications, drug delivery systems, and biomaterials that interact with biological membranes because it allows one to understand how these materials respond to different stresses and deformations. The influence of mechanical characteristics on important lipid bilayer properties is examined in this review. The mechanical properties of lipid bilayers were clarified through the use of molecular dynamics simulation analysis techniques, including bilayer thickness, stress-strain analysis, lipid bilayer area compressibility, membrane bending rigidity, and time- or ensemble-averaged the area per lipid evaluation. We explain the significance of molecular dynamics simulation analysis methods, providing important new information about the stability and dynamic behavior of the bilayer. In the end, we hope to use molecular dynamics simulation to provide a comprehensive understanding of the mechanical properties and behavior of lipid bilayers, laying the groundwork for further studies and applications. Taken together, careful investigation of these mechanical aspects deepens our understanding of the adaptive capacities and functional roles of lipid bilayers in biological environments.

4.
Nanomedicine (Lond) ; 19(23): 1931-1951, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39143926

RESUMEN

Despite the development of new generations of antibiotics, vancomycin remained as a high-efficacy antibiotic for treating the infections caused by MRSA. Researchers have explored various nanoformulations, aiming to enhance the therapeutic efficacy of vancomycin. Such novel formulations improve the effectiveness of drug cargoes in treating bacterial infections and minimizing the risk of adverse effects. The vast of researches have focuses on enhancing the permeation ability of vancomycin through different biological barriers especially those of gastrointestinal tract. Increasing the drug loading and tuning the drug release from nanocarrier are other important goal for many conducted studies. This study reviews the newest nano-based formulations for vancomycin as a key antibiotic in treating hospitalized bacterial infections.


[Box: see text].


Asunto(s)
Antibacterianos , Sistemas de Liberación de Medicamentos , Nanoestructuras , Vancomicina , Vancomicina/administración & dosificación , Vancomicina/química , Humanos , Antibacterianos/administración & dosificación , Antibacterianos/química , Antibacterianos/farmacología , Sistemas de Liberación de Medicamentos/métodos , Nanoestructuras/química , Animales , Portadores de Fármacos/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Liberación de Fármacos , Infecciones Estafilocócicas/tratamiento farmacológico
5.
Sci Rep ; 14(1): 13183, 2024 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-38851799

RESUMEN

Excessive Cu2+ intake can cause neurological disorders (e.g. Wilson's disease) and adversely affect the gastrointestinal, liver, and kidney organs. The presence of Cu2+ is strongly linked to the emergence and progression of Wilson's disease (WD), and accurately measuring the amount of copper is a crucial step in diagnosing WD at an early stage in a clinical setting. In this work, CQDs were fabricated through a facile technique as a novel fluorescence-based sensing platform for detecting Cu(II) in aqueous solutions, and in the serum samples of healthy and affected individuals by WD. The CQDs interact with Cu(II) ions to produce Turn-on and Turn-off states at nano-molar and micro-molar levels, respectively, with LODs of 0.001 µM and 1 µM. In fact, the Cu2+ ions can act like a bridge between two CQDs by which the charge and electron transfer between the CQDs may increase, possibly can have significant effects on the spectroscopic features of the CQDs. To the best of our knowledge, this is the first reported research that can detect Cu(II) at low levels using two different complexation states, with promising results in testing serum. The potential of the sensor to detect Cu(II) was tested on serum samples from healthy and affected individuals by WD, and compared to results obtained by ICP-OES. Astonishingly, the results showed an excellent correlation between the measured Cu(II) levels using the proposed technique and ICP-OES, indicating the high potential of the fluorimetric CQD-based probe for Cu(II) detection. The accuracy, sensitivity, selectivity, high precision, accuracy, and applicability of the probe toward Cu(II) ions make it a potential diagnostic tool for Wilson's disease in a clinical setting.


Asunto(s)
Cobre , Degeneración Hepatolenticular , Degeneración Hepatolenticular/diagnóstico , Degeneración Hepatolenticular/sangre , Cobre/sangre , Humanos , Espectrometría de Fluorescencia/métodos , Límite de Detección
6.
J Biomol Struct Dyn ; : 1-13, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38285617

RESUMEN

In this study, the inhibitory potential of 99 fungal derived secondary metabolites was predicted against SARS-CoV-2 main protease by using of computational approaches. This protein plays an important role in replication and is one of the important targets to inhibit viral reproduction. Among the 99 reported compounds, the 9 of them with the highest binding energy to Mpro obtained from the molecular docking method were selected for the molecular dynamic simulations. The compounds were then investigated by using the SwissADME serve to evaluate the compounds in terms of pharmacokinetic and druglikness properties. The overall results of different analysis show that the compound RKS-1778 is potentially more effective than others and form strong complexes with viral protease. It also had better pharmacokinetic properties than other metabolites, so predicted to be a suitable candidate as anti SARS-CoV-2 bioactive.Communicated by Ramaswamy H. Sarma.

7.
J Biomol Struct Dyn ; : 1-24, 2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37723861

RESUMEN

The merger of COVID-19 and seasonal influenza infections is considered a potentially serious threat to public health. These two viral agents can cause extensive and severe lower and upper respiratory tract infections with lung damage with host factors. Today, the development of vaccination has been shown to reduce the risk of hospitalization and mortality from the COVID-19 virus and influenza epidemics. Therefore, this study contributes to an immunoinformatics approach to producing a vaccine that can elicit strong and specific immune responses against COVID-19 and influenza A and B viruses. The NCBI, GISAID, and Uniprot databases were used to retrieve sequences. Linear B cell, Cytotoxic T lymphocyte, and Helper T lymphocyte epitopes were predicted using the online servers. Population coverage of MHC I epitopes worldwide for SARS-CoV-2, Influenza virus H3N2, H3N2, and Yamagata/Victoria were 99.93%, 68.67%, 68.38%, and 85.45%, respectively. Candidate epitopes were linked by GGGGS, GPGPG, and KK linkers. Different epitopes were permutated several times to form different peptides and then screened for antigenicity, allergenicity, and toxicity. The vaccine construct was analyzed for physicochemical properties, conformational B-cell epitopes, interaction with Toll-like receptors, and IFN-gamma-induced. Immune stimulation response of final construct was evaluated using C-IMMSIM. Eventually, the final construct sequence was codon-optimized for Escherichia coli K12 and Homo sapiens to design a multi-epitope vaccine and mRNA vaccine. In conclusion, due to the variable nature of SARS-CoV-2 and influenza proteins, the design of a multi-epitope vaccine can protect against all their standard variants, but laboratory validation is required.Communicated by Ramaswamy H. Sarma.

8.
J Biomol Struct Dyn ; : 1-11, 2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37608542

RESUMEN

In this study the efficacy of different edible lipids for drug permeation enhancement of vancomycin through biological membrane was investigated using molecular dynamic simulation. In this regard, at first the ability of the lipids for complex formation with the drug was evaluated for number of most common edible lipids including tripalmitin (TPA), trimyristin (TMY), labrafil (LAB), glycerol monostearate (GMS), glycerol monooleate (GMO), Distearoylphosphorylethanolamine (DSPE), dipalmitoylphosphatidylethanolamine (DPPE), Dipalmitoylphosphatidylcholine (DPPC), cholesterol (CL), stearic acid (SA), palmitic acid (PA) and oleic acid (OA). Then the complexes were pulled thorough a bilayer membrane while the changes in force were probed. The results showed that besides the SA, PA and OA the other examined lipids were able to perform a perfect molecular complex with the drug. Also the results of pulling simulation revealed that the least of force was needed for drug transmittance through the membrane when it was covered by LAB, TMY and DSPE. These results indicated that these lipids can be the excellent materials of choice as permeation enhancer for preparing a proper oral formulation of vancomycin.Communicated by Ramaswamy H. Sarma.

9.
J Int Med Res ; 51(7): 3000605231190473, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37523589

RESUMEN

Corneal diseases are among the most common causes of blindness worldwide. Regardless of the etiology, corneal opacity- or globe integrity-threatening conditions may necessitate corneal replacement procedures. Several procedure types are currently available to address these issues, based on the complexity and extent of injury. Corneal allograft or keratoplasty is considered to be first-line treatment in many cases. However, a significant proportion of the world's population are reported to have no access to this option due to limitations in donor preparation. Thus, providing an appropriate, safe, and efficient synthetic implant (e.g., artificial cornea) may revolutionize this field. Nanotechnology, with its potential applications, has garnered a lot of recent attention in this area, however, there is seemingly a long way to go. This narrative review provides a brief overview of the therapeutic interventions for corneal pathologies, followed by a summary of current biomaterials used in corneal regeneration and a discussion of the nanotechnologies that can aid in the production of superior implants.


Asunto(s)
Enfermedades de la Córnea , Ingeniería de Tejidos , Humanos , Ingeniería de Tejidos/métodos , Materiales Biocompatibles/uso terapéutico , Córnea/cirugía , Enfermedades de la Córnea/cirugía , Nanotecnología
10.
BMC Bioinformatics ; 24(1): 65, 2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36829112

RESUMEN

BACKGROUND: It seems that several members of intestinal gut microbiota like Streptococcus bovis, Bacteroides fragilis, Helicobacter pylori, Fusobacterium nucleatum, Enterococcus faecalis, Escherichia coli, Peptostreptococcus anaerobius may be considered as the causative agents of Colorectal Cancer (CRC). The present study used bioinformatics and immunoinformatics approaches to design a potential epitope-based multi-epitope vaccine to prevent CRC with optimal population coverage. METHODS: In this study, ten amino acid sequences of CRC-related pathogens were retrieved from the NCBI database. Three ABCpred, BCPREDS and LBtope online servers were considered for B cells prediction and the IEDB server for T cells (CD4+ and CD8+) prediction. Then, validation, allergenicity, toxicity and physicochemical analysis of all sequences were performed using web servers. A total of three linkers, AAY, GPGPG, and KK were used to bind CTL, HTL and BCL epitopes, respectively. In addition, the final construct was subjected to disulfide engineering, molecular docking, immune simulation and codon adaptation to design an effective vaccine production strategy. RESULTS: A total of 19 sequences of different lengths for linear B-cell epitopes, 19 and 18 sequences were considered as epitopes of CD4+ T and CD8+ cells, respectively. The predicted epitopes were joined by appropriate linkers because they play an important role in producing an extended conformation and protein folding. The final multi-epitope construct and Toll-like receptor 4 (TLR4) were evaluated by molecular docking, which revealed stable and strong binding interactions. Immunity simulation of the vaccine showed significantly high levels of immunoglobulins, helper T cells, cytotoxic T cells and INF-γ. CONCLUSION: Finally, the results showed that the designed multi-epitope vaccine could serve as an excellent prophylactic candidate against CRC-associated pathogens, but in vitro and animal studies are needed to justify our findings for its use as a possible preventive measure.


Asunto(s)
Neoplasias Colorrectales , Epítopos de Linfocito T , Animales , Simulación del Acoplamiento Molecular , Epítopos de Linfocito T/química , Vacunas de Subunidad/química , Epítopos de Linfocito B , Biología Computacional/métodos
11.
J Biomol Struct Dyn ; 41(19): 10117-10124, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-36476279

RESUMEN

In this study, the interaction of an anticonvulsant drug that used in the treatment of epilepsy, Lamotrigine (LTG) with the most important transport protein of the blood, human serum albumin (HSA) has been studied by using the electrochemical methods and molecular modeling techniques. For this purpose, a simple carbon paste electrode (CPE) was applied for electrocatalytic oxidation and investigation of LTG interaction with HSA. The stoichiometry of the complex between LTG and HSA and the binding constant (Kb) of the reaction were calculated from the calibration curves. The results show that binding of LTG to HSA formed two complexes with different stoichiometries with Kb1 (2.46 × 103) and Kb2 (1.75 × 107), respectively. In agreement with the experimental data, molecular modeling approach also confirmed that LTG can bind to the subdomain IIA and IB of HSA.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Anticonvulsivantes , Albúmina Sérica Humana , Humanos , Albúmina Sérica Humana/química , Lamotrigina , Simulación del Acoplamiento Molecular , Unión Proteica , Sitios de Unión , Termodinámica , Espectrometría de Fluorescencia , Dicroismo Circular
12.
Environ Res ; 214(Pt 3): 113966, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35952738

RESUMEN

Alginate-grafted polyaniline (Alg-g-PANI) microparticles were synthesized through the grafting of aniline onto functionalized Alg followed by double crosslinking by glutaraldehyde and calcium chloride. The performance of the developed microparticles as adsorbent in simultaneous removal of malachite green (MG) and congo red (CR) dyes were examined by the batch method. Experimental parameters, including adsorbent amount, pH, initial dyes concentrations, and contact time were optimized. Langmuir and Freundlich adsorption models were employed to explore the equilibrium isotherm. As the Langmuir model results, the maximum adsorption capacities (Qm) of microparticles for the MG and CR dyes were obtained as 578.3 and 409.6 mgg-1, respectively. Adsorption kinetics for both dyes were well-fitted with the pseudo-second-order model that confirm the rate-limiting step might be the chemical adsorption. The adsorbent was regenerated via desorption process and was reusable five times without a substantial decrease in its adsorption efficacy in first three cycles. Adsorbent-dyes interactions were computationally evaluated using Gromacs package, and it was found that both MG and CR are able to interact strongly with the adsorbent. In accordance with experimental results, simulation data revealed that MG can be removed more efficiently than those of the CR. As the experimental results, we could conclude that the synthesized Alg-g-PANI microparticles can be used as a nature-inspired adsorbent for simultaneous removals of CR and MG dyes.


Asunto(s)
Colorantes , Contaminantes Químicos del Agua , Adsorción , Aniones , Cationes , Rojo Congo , Concentración de Iones de Hidrógeno , Cinética , Contaminantes Químicos del Agua/análisis
13.
Comput Biol Med ; 146: 105625, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35688710

RESUMEN

The outbreak of COVID-19 has resulted in millions of deaths. Despite all attempts that have been made to combat the pandemic, the re-emergence of new variants complicated SARS-CoV-2 eradication. The ongoing global spread of COVID-19 demands the incessant development of novel agents in vaccination, diagnosis, and therapeutics. Targeting receptor-binding domain (RBD) of spike protein by which the virus identifies host receptor, angiotensin-converting enzyme (ACE2), is a promising strategy for curbing viral infection. This study aims to discover novel peptide inhibitors against SARS-CoV-2 entry using computational approaches. The RBD binding domain of ACE2 was extracted and docked against the RBD. MMPBSA calculations revealed the binding energies of each residue in the template. The residues with unfavorable binding energies were considered as mutation spots by OSPREY. Binding energies of the residues in RBD-ACE2 interface was determined by molecular docking. Peptide inhibitors were designed by the mutation of RBD residues in the virus-receptors complex which had unfavorable energies. Peptide tendency for RBD binding, safety, and allergenicity were the criteria based on which the final hits were screened among the initial library. Molecular dynamics simulations also provided information on the mechanisms of inhibitory action in peptides. The results were finally validated by molecular docking simulations to make sure the peptides are capable of hindering virus-host interaction. Our results introduce three peptides P7 (RAWTFLDKFNHEAEDLRYQSSLASWN), P13 (RASTFLDKFNHEAEDLRYQSSLASWN), and P19 (RADTFLDKFNHEAEDLRYQSSLASWN) as potential effective inhibitors of SARS-CoV-2 entry which could be considered in drug development for COVID-19 treatment.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2 , Sitios de Unión , Humanos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Mutación , Péptidos/metabolismo , Péptidos/farmacología , Unión Proteica , Glicoproteína de la Espiga del Coronavirus/química
14.
Iran J Pharm Res ; 21(1): e127040, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36942065

RESUMEN

The use of nuclear magnetic resonance (NMR) spectroscopy as a tool for determining pharmaceutical molecules in bulk drugs and their dosage forms is growing. New advancements in benchtop NMR spectrometers with cryogen-free magnets have made this technique more appealing and accessible. Herein, we developed a method using a benchtop NMR spectrometer to quantify phenytoin (PhT) and phenobarbital (PhB) in bulk and combined dosage forms. The results were compared to those obtained by high performance liquid chromatography (HPLC) as a well-characterized procedure. This method is simple, low cost, relatively fast, and non-inferior to HPLC in terms of figures of merit.

15.
J Biomol Struct Dyn ; 40(19): 9042-9052, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33998953

RESUMEN

Today the nano drug delivery systems are among the hot topics in drug design and pharmacy studies. Extensive researches are conducted worldwide for obtaining more effective therapeutics and screen the best drug carrier in-vivo and in-vitro. Considering the high cost of such experiments and the ethical issues linked with in-vivo studies, the in-silico analysis provides the time and cost-effective opportunity to evaluation of physiochemical properties and the interactions between drugs and their carriers. In this study using molecular dynamics (MD) simulation, five commonly used biodegradable biopolymers in pharmaceutical formulations including Chitosan, Alginate, Cyclodextrin, Hyaluronic Acid, and Pectin were investigated as proper carriers for the erythropoietin (EPO) in heat stress. The EPO was simulated in different temperatures of 298 and 343 K and the ability of polymers for temperature stabilization of the protein was evaluated comparatively. Overall, the results obtained in this study suggest that the pectin polysaccharide is the preferable carrier than others in term of protein stability in high temperatures and using for the delivery of erythropoietin.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Quitosano , Polímeros , Polímeros/química , Simulación de Dinámica Molecular , Portadores de Fármacos/química , Quitosano/química , Alginatos/química , Pectinas/química
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 262: 120148, 2021 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-34247037

RESUMEN

Gemcitabine hydrochloride is an established chemotherapeutic agent in several solid tumors. In spite of outstanding therapeutic efficacy, there are some serious fetal side effects with gemcitabine in higher concentrations which necessitate developing a sensitive sensor for its quantification. Herein, a fluorescent metal-nanoparticles conjugated carbon quantum dot (MN-CQD) was prepared by a mixture of citric acid/ammonia sulfate and different metals using hydrothermal method. Based on the primary experiments, the efficiency of Ag nanoparticle-CQDs for gemcitabine determination was found to be much better than others. The AgNp-CQDs fluorescence was quenched by gemcitabine anticancer drug via photo-induced charge transfer which renders the system into fluorescence "OFF" status. Under the experimental conditions, the linear range of detection was 0.003-0.1 µM in an aqueous solution with a correlation coefficient of 0.96 and a limit of detection equal to 0.002 µM. The relative standard deviation (RSD) for gemcitabine determination was 3.4% (n = 3). Finally, after optimizing the conditions, the concentration of analyte was determined in real samples including human plasma and urine. These results confirm that the as prepared fluorescence based nanosensor can be used for sensitive quantification of gemcitabine in real samples.


Asunto(s)
Nanopartículas del Metal , Puntos Cuánticos , Carbono , Desoxicitidina/análogos & derivados , Humanos , Plata , Gemcitabina
17.
Comput Biol Med ; 135: 104613, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34242870

RESUMEN

The newly emerged Coronavirus Disease 2019 (COVID-19) rapidly outspread worldwide and now is one of the biggest infectious pandemics in human society. In this study, the inhibitory potential of 99 secondary metabolites obtained from endophytic fungi was investigated against the new coronavirus RNA-dependent RNA polymerase (RdRp) using computational methods. A sequence of blind and targeted molecular dockings was performed to predict the more potent compounds on the viral enzyme. In the next step, the five selected compounds were further evaluated by molecular dynamics (MD) simulation. Moreover, the pharmacokinetics of the metabolites was assessed using SwissADME server. The results of molecular docking showed that compounds 18-methoxy cytochalasin J, (22E,24R)-stigmasta-5,7,22-trien-3-ß-ol, beauvericin, dankasterone B, and pyrrocidine A had higher binding energy than others. The findings of MD and SwissADME demonstrated that two fungal metabolites, 18-methoxy cytochalasin J and pyrrocidine A had better results than others in terms of protein instability, strong complex formation, and pharmacokinetic properties. In conclusion, it is recommended to further evaluate the compounds 18-methoxy cytochalasin J and pyrrocidine A in the laboratory as good candidates for inhibiting COVID-19.


Asunto(s)
Antivirales/farmacología , ARN Polimerasa Dependiente de ARN de Coronavirus/antagonistas & inhibidores , Hongos/química , SARS-CoV-2/efectos de los fármacos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , ARN Polimerasa Dependiente del ARN
18.
Res Pharm Sci ; 16(1): 58-70, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33953775

RESUMEN

BACKGROUND AND PURPOSE: Today, color additives such as Allura red (AR) are widely used in different kinds of food products. Pepsin is a globular protein that is secreted as a digestive protease from the main cells in the stomach. Because of the important role of pepsin in protein digestion and because of its importance in digestive diseases the study of the interactions of pepsin with chemical food additives is important. EXPERIMENTAL APPROACH: In this study, the interactions between AR and pepsin were investigated by different computational and experimental approaches such as ultraviolet and fluorescence spectroscopy along with computational molecular modeling. FINDINGS/RESULTS: The experimental results of fluorescence indicated that AR can strongly quench the fluorescence of pepsin through a static quenching. Thermodynamic analysis of the binding phenomena suggests that van der Waals forces and hydrogen bonding played a major role in the complex formation. The results of synchronous fluorescence spectra and furrier transformed infra-red (FTIR) experiments showed that there are no significant structural changes in the protein conformation. Also, examined pepsin protease activity revealed that the activity of pepsin was increased upon ligand binding. In agreement with the experimental results, the computational results showed that hydrogen bonding and van der Waals interactions occurred between AR and binding sites. CONCLUSION AND IMPLICATIONS: From the pharmaceutical point of view, this interaction can help us to get a deeper understanding of the effect of this synthetic dye on food digestion.

19.
Spectrochim Acta A Mol Biomol Spectrosc ; 253: 119523, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33621938

RESUMEN

Pepsin is an aspartic protease that is involved in the digestion of food in the stomach of mammals. Continuous and long-term use of therapeutic agents will cause chronic contact of the drug with pepsin, and as a result, the structure and function of enzyme may change. In this regard the interactions of isoniazid and rifampin as the first line treatments of tuberculosis with pepsin were investigated by various methods such as fluorescence spectroscopy, FTIR, molecular docking and molecular dynamics simulation. Based on the results obtained in this study, the mentioned drugs can form stable complexes with pepsin and the structure of protein changes slightly. According to the results, the major forces in the formation of the protein-drug complex are electrostatic and hydrophobic forces for isoniazid and rifampin respectively and isoniazid shows to form a stronger binding with protein. The FTIR spectrum of the protein shows that little change was occurred in the structure of pepsin in the presence of the drugs. Molecular modeling results of the binding of isoniazid and rifampin to the pepsin confirm laboratory results and show that the binding site of drugs is close to the active site of the enzyme. Also, the activity of pepsin in the presence of both drugs has significantly increased.


Asunto(s)
Isoniazida , Pepsina A , Animales , Simulación del Acoplamiento Molecular , Pepsina A/metabolismo , Unión Proteica , Rifampin
20.
Bioelectrochemistry ; 139: 107744, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33517204

RESUMEN

Prostatic specific antigen (PSA) is known as a biomarker of prostate cancer. In males, prostate cancer is ranked second as leading cause of death out of more than 200 different cancer types1. As a result, early detection of cancer can cause a significant reduction in mortality. PSA concentration directly is related to prostate cancer, so normal serum concentrations in healthy means are 4 ng and above 10 ng as abnormal concentration. Therefore, PSA determination is important to cancer progression. In this study, a free label electrochemical immunosensor was prepared based on a new green platform for the quantitative detection of the PSA. The used platform was formed from quince seed mucilage containing green gold and silver nanoparticles and synthesized by the green method (using Calendula officinalis L. extract). The quince mucilage biopolymer was used as a sub layer to assemble nanoparticles and increase the electrochemical performance. This nanocomposite was used to increase the antibody loading and accelerate the electron transfer, which can increase the biosensor sensitivity. The antibodies of the PSA biomarker were successfully incubated on the green platform. Under the optimal conditions, the electrochemical impedance spectroscopy (EIS) was proportional to the PSA biomarker concentration from 0.1 pg mL-1 to 100 ng mL-1 with low limit of detection (0.078 pg mL-1). The proposed green immunosensor exhibited high stability and reproducibility, which can be used for the quantitative assay of the PSA biomarker in clinical analyses. The results of real sample analysis presented another tool for the PSA biomarker detection in physiologic models.


Asunto(s)
Técnicas Biosensibles/métodos , Espectroscopía Dieléctrica/métodos , Calicreínas/sangre , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/diagnóstico , Biomarcadores de Tumor/sangre , Calendula/química , Oro/química , Tecnología Química Verde/métodos , Humanos , Masculino , Nanopartículas del Metal/química , Nanocompuestos/química , Extractos Vegetales/química , Mucílago de Planta/química , Rosaceae/química , Semillas/química , Plata/química
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