RESUMEN
Sturgeon, with 4 times higher lipid content than silver carp (ubiquitously applied for surimi production in China), affects surimi gelling properties. However, how the flesh lipids affect gelling properties remains unclear. This study investigated how flesh lipids impact surimi gelling properties and elucidated the interaction mechanism between lipids and proteins. Results revealed yellow meat contains 7 times higher lipids than white meat. Stronger ionic protein-protein interactions were replaced by weaker hydrophobic forces and hydrogen bonds in protein-lipid interaction. Protein-lipid interaction zones encapsulated lipid particles, changing protein structure from α-helix to ß-sheet structure thereby gel structure becomes flexible and disordered, significantly diminishing surimi gel strength. Docking analysis validated fatty acid mainly binding at Ala577, Ile461, Arg231, Phe165, His665, and His663 of myosin. This study first reported the weakened surimi gelling properties from the perspective of free fatty acids and myosin interactions, offering a theoretical basis for sturgeon surimi production.
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Proteínas de Peces , Peces , Geles , Lípidos , Animales , Geles/química , Lípidos/química , Proteínas de Peces/química , Proteínas de Peces/metabolismo , Productos Pesqueros/análisis , Interacciones Hidrofóbicas e Hidrofílicas , Enlace de Hidrógeno , Miosinas/química , Miosinas/metabolismo , Simulación del Acoplamiento Molecular , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Carpas/metabolismo , Unión ProteicaRESUMEN
High-moisture extrusion technique with the advantage of high efficiency and low energy consumption is a promising strategy for processing Antarctic krill meat. Consequently, this study aimed to prepare high-moisture textured Antarctic krill meat (HMTAKM) with a rich fiber structure at different water contents (53 %, 57 %, and 61 %) and to reveal the binding and distribution regularity of water molecules, which is closely related to the fiber structure of HMTAKM and has been less studied. The hydrogen-bond network results indicated the presence of at least two or more types of water molecules with different hydrogen bonds. Increasing the water content of HMTAKM promoted the formation of hydrogen bonds between the water molecules and protein molecules, leading to the transition of the ß-sheet to the α-helix. These findings offer a novel viable processing technique for Antarctic krill and a new understanding of the fiber formation of high-moisture textured proteins.
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Euphausiacea , Enlace de Hidrógeno , Agua , Euphausiacea/química , Animales , Agua/química , Agua/metabolismo , Regiones Antárticas , Carne/análisis , Manipulación de AlimentosRESUMEN
Torsemide is a long acting pyridine sulfonylurea diuretic. Torsemide hydrochloride is widely used now, there are only a few organic acid salts reported. Cocrystallization with organic acids is an effective way to improve its solubility. Here, we reported maleate and phthalate of torsemide, in which the organic acid lost a proton transferring to the pyridine of torsemide, and torsemide interacted with organic acid through N+ - Hâ¯O- hydrogen bond to form salts crystal. Surprisingly, maleate showed a clear "spring" pattern in apparent solubility, whereas phthalate had a "spring-parachute" effect. Both crystalline salts kept a higher solubility than torsemide without falling. The "spring-parachute" effect of crystalline salts promoted rapid dissolution of torsemide and kept a high concentration, thereby increasing its bioavailability.
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Cristalización , Sales (Química) , Solubilidad , Torasemida , Torasemida/química , Cristalización/métodos , Sales (Química)/química , Enlace de Hidrógeno , Diuréticos/química , Maleatos/química , Disponibilidad BiológicaRESUMEN
This study investigated the influence of Konjac Glucomannan (KGM) with varying degrees of polymerization (DKGMx) on the gelatinization and retrogradation characteristics of wheat starch, providing new insights into starch-polysaccharide interactions. This research uniquely focuses on the effects of DKGMx, utilizing multidisciplinary approaches including Rapid Visco Analysis (RVA), Differential Scanning Calorimetry (DSC), rheological testing, Low-Field Nuclear Magnetic Resonance (LF-NMR), and molecular simulations to assess the effects of DKGMx on gelatinization temperature, viscosity, structural changes post-retrogradation, and molecular interactions. Our findings revealed that higher degrees of polymerization (DP) of DKGMx significantly enhanced starch's pasting viscosity and stability, whereas lower DP reduced viscosity and interfered with retrogradation. High DP DKGMx promoted retrogradation by modifying moisture distribution. Molecular simulations revealed the interplay between low DP DKGMx and starch molecules. These interactions, characterized by increased hydrogen bonds and tighter binding to more starch chains, inhibited starch molecular rearrangement. Specifically, low DP DKGMx established a dense hydrogen bond network with starch, significantly restricting molecular mobility and rearrangement. This study provides new insights into the role of the DP of DKGMx in modulating wheat starch's properties, offering valuable implications for the functional improvement of starch-based foods and advancing starch science.
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Mananos , Polimerizacion , Almidón , Triticum , Triticum/química , Almidón/química , Viscosidad , Mananos/química , Enlace de Hidrógeno , Reología , Simulación de Dinámica Molecular , Rastreo Diferencial de CalorimetríaRESUMEN
This study investigates the complexation between tea seed starch (TSS) and tea polyphenols (TPs) at varying concentrations (2.5, 5.0, 7.5, and 10.0 %). The objectives can expand the knowledge of TSS, which is a novel starch, and to examine how TPs influence the structure and physicochemical properties of the complexes. Results indicate that TPs interact with TSS through hydrogen bonding, altering granule morphology and disrupting ordered structure of starch. Depending on the concentration, TPs induce either V-type or non-V-type crystal structures within TSS, which had bearing on iodine binding capacity, swelling, pasting, gelatinization, retrogradation, rheology, and gel structure. In vitro digestibility analysis reveals that TSS-TPs complexes tend to reduce readily digestible starch while increasing resistant starch fractions with higher TP concentrations. Thus, TSS-TPs complexes physicochemical and digestibility properties can be modulated, providing a wide range of potential applications in the food industry.
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Polifenoles , Semillas , Almidón , Té , Polifenoles/química , Almidón/química , Semillas/química , Té/química , Enlace de Hidrógeno , ReologíaRESUMEN
Gelation is a critical property of citrus pectin. However, the roles played by neutral sugar side-chains on acid-induced pectin gelation remain poorly understood. Herein, galactan- or/and arabinan-eliminated pectins (P-G, P-A, and P-AG) were used to investigate the effects of side-chains on gelation. The gel hardness values of citrus pectin, P-G, P-A, and P-AG were 42.6, 39.9, 5.3, and 2.1 g, respectively, suggesting that arabinan contributed more to gelation than galactan. We next found that arabinan branches promoted pectin chain entanglement more effectively than arabinan backbones. Destabilizer addition experiments showed that hydrogen bonding, electrostatic interaction, and hydrophobic interaction were the main forces affecting pectin gel networks and strength, which was further validated by molecular dynamic simulations. The total number of hydrogen bonds between the arabinan branches and galactan/HG (65.7) was significantly higher than that between the arabinan backbones and galactan/HG (39.1), indicating that arabinan branches predominated in terms of such interactions. This study thus elucidated the roles played by neutral-sugar side-chains, especially the arabinan branches of acid-induced pectin gels, in term of enhancing high-methoxyl pectin gelation, and offers novel insights into the structure-gelling relationships of citrus pectin.
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Geles , Enlace de Hidrógeno , Pectinas , Pectinas/química , Geles/química , Polisacáridos/química , Simulación de Dinámica Molecular , Citrus/química , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
In the realm of natural polysaccharides, hydrogen bonding is a prevalent feature, yet its role in enhancing photocatalytic antimicrobial properties has been underexplored. In this paper, heterojunctions formed by graphene oxide (GO) and ZIF-8 were locked in sodium alginate/ carboxylated cellulose nanocrystals via hydrogen bonding networks, designated as SCGZ. The SCGZ films exhibit superior photocatalytic performance compared to either ZIF-8 or heterojunctions. This enhancement is primarily due to two key factors: firstly, the hydrogen bonding network significantly enhances the transfer of protons and holes, thereby improving the separation efficiency of photo-generated carriers; secondly, the hydrogen bonding between the layers facilitates a more efficient charge transfer, which expedites the movement of electrons from ZIF-8 to GO upon illumination. In vitro studies demonstrated that the SCGZ films possess remarkable antibacterial capabilities, achieving 99.75 % and 99.61 % inhibition rates against S. aureus and E. coli, respectively. In vivo animal experiments have shown that SCGZ films can significantly accelerate the healing process of damaged tissues, with a healing efficiency of up to 90.5 %. This research provides additional insights into the development of natural polysaccharide-based multihydrogen bonded macromolecules with enhanced photocatalytic properties.
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Alginatos , Antibacterianos , Celulosa , Escherichia coli , Grafito , Nanopartículas , Staphylococcus aureus , Cicatrización de Heridas , Alginatos/química , Alginatos/farmacología , Celulosa/química , Celulosa/farmacología , Nanopartículas/química , Cicatrización de Heridas/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Escherichia coli/efectos de los fármacos , Animales , Grafito/química , Grafito/farmacología , Esterilización/métodos , Enlace de Hidrógeno , Ratones , Pruebas de Sensibilidad Microbiana , CatálisisRESUMEN
The binding mechanism of molecular interaction between bicalutamide and human serum albumin (HSA) in a pH 7.4 phosphate buffer was studied using various spectroscopic techniques in combination with molecular modeling. Fluorescence data revealed that the fluorescence quenching of HSA by bicalutamide was a static quenching procedure. The binding constants and number of binding sites were evaluated at different temperatures. The thermodynamic parameters, ΔH and ΔS, were calculated to be 4.30 × 104 J·mol-1 and 245 J·mol-1·K-1, respectively, suggesting that the binding of bicalutamide to HSA was driven mainly by hydrophobic interactions and hydrogen bonds. The displacement studies indicated neither Sudlow's site I nor II but subdomain IB as the main binding site for bicalutamide on HSA. The binding distance between bicalutamide and HSA was determined to be 3.54 nm based on the Förster theory. Analysis of circular dichroism, synchronous, and 3D fluorescence spectra demonstrated that HSA conformation was slightly altered in the presence of bicalutamide.
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Anilidas , Nitrilos , Albúmina Sérica Humana , Espectrometría de Fluorescencia , Termodinámica , Compuestos de Tosilo , Compuestos de Tosilo/química , Anilidas/química , Anilidas/metabolismo , Nitrilos/química , Nitrilos/metabolismo , Humanos , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Dicroismo Circular , Sitios de Unión , Modelos Moleculares , Interacciones Hidrofóbicas e Hidrofílicas , Enlace de HidrógenoRESUMEN
The ribosome utilizes hydrogen bonding between mRNA codons and aminoacyl-tRNAs to ensure rapid and accurate protein production. Chemical modification of mRNA nucleobases can adjust the strength and pattern of this hydrogen bonding to alter protein synthesis. We investigate how the N1-methylpseudouridine (m1Ψ) modification, commonly incorporated into therapeutic and vaccine mRNA sequences, influences the speed and fidelity of translation. We find that m1Ψ does not substantially change the rate constants for amino acid addition by cognate tRNAs or termination by release factors. However, we also find that m1Ψ can subtly modulate the fidelity of amino acid incorporation in a codon-position and tRNA dependent manner in vitro and in human cells. Our computational modeling shows that altered energetics of mRNA:tRNA interactions largely account for the context dependence of the low levels of miscoding we observe on Ψ and m1Ψ containing codons. The outcome of translation on modified mRNA bases is thus governed by the sequence context in which they occur.
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Codón , Biosíntesis de Proteínas , Seudouridina , ARN Mensajero , ARN de Transferencia , Seudouridina/metabolismo , Seudouridina/análogos & derivados , ARN Mensajero/metabolismo , ARN Mensajero/genética , Humanos , Codón/genética , ARN de Transferencia/metabolismo , ARN de Transferencia/genética , Ribosomas/metabolismo , Enlace de Hidrógeno , Células HEK293RESUMEN
The oriented design of reticular materials as emitters can significantly enhance the sensitivity of electrochemiluminescence (ECL) sensing analysis for disease markers. However, due to the structural fragility of hydrogen bonds, relational research on hydrogen-bonded organic frameworks (HOFs) has not been thoroughly conducted. Additionally, the modulation of luminescence behavior through HOFs has been rarely reported. In view of this, hydrogen-bonded biohybrid organic frameworks (HBOFs) were synthesized and recruited for ECL immunoassay applications. HBOFs was easily prepared using 6,6',6â³,6â´-(pyrene-1,3,6,8-tetrayl)tetrakis(2-naphthoic acid) as linkers via bovine serum albumin (BSA) activated hydrogen-bonded cross-linking. The material exhibited good fluorescence emission characteristics. And the highly ordered topological structure and molecular motion limitation mediated by BSA overcome aggregation-caused quenching and generate strong aggregation induced emission, expressing hydrogen-bond interaction enhanced ECL (HIE-ECL) activity with the participation of tri-n-propylamine. Furthermore, a sandwich immunosensor was constructed employing cobalt-based metal-phenolic network (CMPN) coated ferrocene nanoparticles (FNPs) as quenchers (CMPN@FNPs). Signal closure can be achieved by annihilating the excited state through electron transfer from both CMPN and FNPs. Using a universal disease marker, carcinoembryonic antigen, as the analysis model, the signal-off sensor obtained a detection limit of 0.47 pg/mL within the detection range of 1 pg/mL - 50 ng/mL. The synthesis and application of highly stable HBOFs triggered by proteins provide a reference for the development of new reticular ECL signal labels, and electron transfer model provides flexible solutions for more sensitive sensing analysis.
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Técnicas Biosensibles , Técnicas Electroquímicas , Enlace de Hidrógeno , Mediciones Luminiscentes , Albúmina Sérica Bovina , Técnicas Biosensibles/métodos , Inmunoensayo/métodos , Técnicas Electroquímicas/métodos , Mediciones Luminiscentes/métodos , Humanos , Albúmina Sérica Bovina/química , Animales , Estructuras Metalorgánicas/química , Límite de Detección , Bovinos , Metalocenos/química , Compuestos Ferrosos/química , Anticuerpos Inmovilizados/química , Biomarcadores/análisis , Cobalto/químicaRESUMEN
This study aimed to assess the formation of nevirapine (NVP) co-amorphs systems (CAM) with different co-formers (lamivudine-3TC, citric acid-CAc, and urea) through combined screening techniques as computational and thermal studies, solubility studies; in addition to develop and characterize suitable NVP-CAM. NVP-CAM were obtained using the quench-cooling method, and characterized by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and polarized light microscopy (PLM), in addition to in vitro dissolution in pH 6.8. The screening results indicated intermolecular interactions occurring between NVP and 3TC; NVP and CAc, where shifts in the melting temperature of NVP were verified. The presence of CAc impacted the NVP equilibrium solubility, due to hydrogen bonds. DSC thermograms evidenced the reduction and shifting of the endothermic peaks of NVP in the presence of its co-formers, suggesting partial miscibility of the compounds. Amorphization was proven by XRD and PLM assays. In vitro dissolution study exhibited a significant increase in solubility and dissolution efficiency of NVP-CAM compared to free NVP. Combined use of screening studies was useful for the development of stable and amorphous NVP-CAM, with increased NVP solubility, making CAM promising systems for combined antiretroviral therapy.
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Rastreo Diferencial de Calorimetría , Química Farmacéutica , Nevirapina , Solubilidad , Difracción de Rayos X , Nevirapina/química , Rastreo Diferencial de Calorimetría/métodos , Difracción de Rayos X/métodos , Química Farmacéutica/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Composición de Medicamentos/métodos , Lamivudine/química , Enlace de Hidrógeno , Fármacos Anti-VIH/químicaRESUMEN
The hydrophobic effect is the main factor that drives the folding of polypeptide chains. In this study, we have examined the influence of the hydrophobic effect in the context of the main mechanical forces approach, mainly in relation to the establishment of specific interplays, such as hydrophobic and CH-π cloud interactions. By adopting three oligopeptides as model systems to assess folding features, we demonstrate herein that these finely tuned interactions dominate over electrostatic interactions, including H-bonds and electrostatic attractions/repulsions. The folding mechanism analysed here demonstrates cooperation at the single-residue level, for which we propose the terminology of "single residues cooperative folding". Overall, hydrophobic and CH-π cloud interactions produce the main output of the hydrophobic effect and govern the folding mechanism, as demonstrated in this study with small polypeptide chains, which in turn represent the main secondary structures in proteins.
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Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Oligopéptidos , Pliegue de Proteína , Oligopéptidos/química , Electricidad Estática , Estructura Secundaria de Proteína , Modelos Moleculares , TermodinámicaRESUMEN
Graphitic carbon nitride (g-C3N4, CN) has emerged as a promising photocatalytic material due to its inherent stability, antibacterial properties, and eco-friendliness. However, its tendency to aggregate and limited dispersion hinder its efficacy in practical antibacterial applications. To address these limitations, this study focuses on developing a composite hydrogel coating, in which sodium alginate (SA) molecules interact electrostatically and through hydrogen bonding to anchor CN, thereby significantly improving its dispersion. The optimal CN loading of 35% results in a hydrogel with a tensile strength of 120 MPa and an antibacterial rate of 99.87% within 6 h. The enhanced mechanical properties are attributed to hydrogen bonding between the -NH2 groups of CN and the -OH groups of SA, while the -OH groups of SA facilitate the attraction of photogenerated holes from CN, promoting carrier transfer and separation, thereby strengthening the antibacterial action. Moreover, the hydrogel coating exhibits excellent antibacterial and corrosion resistance capabilities against Pseudomonas aeruginosa on 316L stainless steel (316L SS), laying the foundation for advanced antimicrobial and anticorrosion hydrogel systems.
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Alginatos , Antibacterianos , Grafito , Hidrogeles , Pseudomonas aeruginosa , Alginatos/química , Antibacterianos/farmacología , Antibacterianos/química , Pseudomonas aeruginosa/efectos de los fármacos , Hidrogeles/química , Hidrogeles/farmacología , Grafito/química , Grafito/farmacología , Compuestos de Nitrógeno/química , Compuestos de Nitrógeno/farmacología , Corrosión , Pruebas de Sensibilidad Microbiana , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Enlace de Hidrógeno , Acero Inoxidable/químicaRESUMEN
A computational study based on derivatives of the anticancer VCp2Cl2 compound and their interaction with representative models of deoxyribonucleic acid (DNA) is presented. The derivatives were obtained by substituting the cyclopentadienes of VCp2Cl2 with H2O, NH3, OH-, Cl-, O2- and C2O42- ligands. The oxidation states IV and V of vanadium were considered, so a total of 20 derivative complexes are included. The complexes interactions with DNA were studied using two different models, the first model considers the interactions of the complexes with the pair Guanine-Cytosine (G-C) and the second involves the interaction of the complexes with adjacent pairs, that is, d(GG). This study compares methodologies based on density functional theory with coupled cluster like calculations (DLPNO-CCSD(T)), the gold standard of electronic structure methods. Furthermore, the change in the electron density of the hydrogen bonds that keep bonded the G-C pair and d(GG) pairs, due to the presence of vanadium (IV) and (V) complexes is rationalize. To this aim, quantities obtained from the topology of the electron densities are inspected, particularly the value of the electron density at the hydrogen bond critical points. The approach allowed to identify vanadium complexes that lead to significant changes in the hydrogen bonds indicated above, a key aspect in the understanding, development, and proposal of mechanisms of action between metal complexes and DNA.
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Antineoplásicos , Complejos de Coordinación , ADN , Vanadio , ADN/química , ADN/metabolismo , Vanadio/química , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Enlace de Hidrógeno , Compuestos de Vanadio/química , Compuestos de Vanadio/farmacología , Humanos , Teoría Funcional de la DensidadRESUMEN
The present study deals with the in-silico analyses of several flavonoid derivatives to explore COVID-19 through pharmacophore modelling, molecular docking, molecular dynamics, drug-likeness, and ADME properties. The initial literature study revealed that many flavonoids, including luteolin, quercetin, kaempferol, and baicalin may be useful against SARS ß-coronaviruses, prompting the selection of their potential derivatives to investigate their abilities as inhibitors of COVID-19. The findings were streamlined using in silico molecular docking, which revealed promising energy-binding interactions between all flavonoid derivatives and the targeted protein. Notably, compounds 8, 9, 13, and 15 demonstrated higher potency against the coronavirus Mpro protein (PDB ID 6M2N). Compound 8 has a -7.2 Kcal/mol affinity for the protein and binds to it by hydrogen bonding with Gln192 and π-sulfur bonding with Met-165. Compound 9 exhibited a significant interaction with the main protease, demonstrating an affinity of -7.9 kcal/mol. Gln-192, Glu-189, Pro-168, and His-41 were the principle amino acid residues involved in this interaction. The docking score for compound 13 is -7.5 Kcal/mol, and it binds to the protease enzyme by making interactions with Leu-41, π-sigma, and Gln-189. These interactions include hydrogen bonding and π-sulfur. The major protease and compound 15 were found to bind with a favourable affinity of -6.8 Kcal/mol. This finding was further validated through molecular dynamic simulation for 1ns, analysing parameters such as RMSD, RMSF, and RoG profiles. The RoG values for all four of the compounds varied significantly (35.2-36.4). The results demonstrated the stability of the selected compounds during the simulation. After passing the stability testing, the compounds underwent screening for ADME and drug-likeness properties, fulfilling all the necessary criteria. The findings of the study may support further efforts for the discovery and development of safe drugs to treat COVID-19.
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Antivirales , Proteasas 3C de Coronavirus , Diseño de Fármacos , Flavonoides , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , SARS-CoV-2 , Flavonoides/química , Flavonoides/farmacología , Antivirales/farmacología , Antivirales/química , SARS-CoV-2/efectos de los fármacos , Humanos , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Proteasas 3C de Coronavirus/química , Proteasas 3C de Coronavirus/metabolismo , COVID-19/virología , Descubrimiento de Drogas/métodos , Enlace de Hidrógeno , Tratamiento Farmacológico de COVID-19 , Betacoronavirus/efectos de los fármacos , Pandemias , Quercetina/química , Quercetina/farmacología , Unión Proteica , Proteínas M de CoronavirusRESUMEN
This study aimed to decipher the interaction between CD26 and caveolin-1, key proteins involved in cell signaling and linked to various diseases. Using computational methods, we predicted their binding conformations and assessed stability through 100 ns molecular dynamics (MD) simulations. We identified two distinct binding conformations (con1 and con4), with con1 exhibiting superior stability. In con1, specific amino acids in CD26, namely GLU237, TYR241, TYR248, and ARG147, were observed to engage in interactions with the F-J chain of Caveolin-1, establishing hydrogen bonds and cation or π-π interactions. Meanwhile, in con4, CD26 amino acids ARG253, LYS250, and TYR248 interacted with the J chain of Caveolin-1 via hydrogen bonds, cation-π interactions, and π-π interactions. Virtual screening also revealed potential small-molecule modulators, including Crocin, Poliumoside, and Canagliflozin, that could impact this interaction. Additionally, predictive analyses were conducted on the potential bioactivity, drug-likeness, and ADMET properties of these three compounds. These findings offer valuable insights into the binding mechanism, paving the way for new therapeutic strategies. However, further validation is required before clinical application. In summary, we provide a detailed understanding of the CD26 and caveolin-1 interaction, identifying key amino acids and potential modulators, essential for developing targeted therapies.
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Aminoácidos , Caveolina 1 , Dipeptidil Peptidasa 4 , Simulación de Dinámica Molecular , Humanos , Aminoácidos/metabolismo , Caveolina 1/metabolismo , Dipeptidil Peptidasa 4/metabolismo , Enlace de Hidrógeno , Unión Proteica , Conformación ProteicaRESUMEN
The high speed enrichment of benzoylurea insecticides (BUs) in complex matrices is an essential and challenging step. The present study focuses on the synthesis of a hierarchical pore nitrogen-doped carbon material for magnetic solid phase extraction (MSPE) of BUs. This material was prepared through the carbonization of a composite material ZIF-67@MCA which assembly with hydrogen-bonded organic frameworks (melamine-cyanurate, MCA) and zeolitic imidazolate framework (ZIF-67) at room temperature. The optimal adsorption effect is achieved when the mass ratio of ZIF-67 to MCA is 1/3, and the carbonization was performed at 600 °C, the such obtained carbon material was denoted as 1/3ZIF-67@MCA-DCs-600. The material was characterized with various physical methods including X-ray diffractometry (XRD), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM), water contact angle measurement, Raman spectrometry. 1/3ZIF-67@MCA-DCs-600 exhibits a macro-mesoporous 3D structure with a high degree of nitrogen doping and relatively large specific surface area, making it suitable for magnetic solid phase extraction (MSPE). The adsorption of BUs with concentration of 100 ng mL-1 can reach equilibrium within 5 s. The interaction between BUs and the adsorbent, facilitated by π-π stacking, hydrophobic interactions, hydrogen bonding forces, as well as the material's porosity, enables efficient extraction recoveries ranging from 45 % to 92 %. The enrichment of BUs was achieved through the establishment of an MSPE method under optimized conditions, which was further coupled with high performance liquid chromatography (HPLC) for the determination of the four BUs. The linear range spans from 5 ng ml-1 to 1000 ng ml-1 with the correlation coefficient (R2) of ≥ 0.99, Meanwhile, the detection limit for these four BUs falls within the range of 0.01 to 0.10 ng ml-1. The material exhibits good reusability and can be reused for at least 5 cycles. Inter day and intra-day precision ranges from 2.1-7.9 % and 1.0-5.4 %, respectively. The method demonstrates a high level of reliability in practical applications for the determination of BUs.
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Carbono , Enlace de Hidrógeno , Insecticidas , Nitrógeno , Extracción en Fase Sólida , Insecticidas/análisis , Insecticidas/química , Insecticidas/aislamiento & purificación , Extracción en Fase Sólida/métodos , Adsorción , Carbono/química , Nitrógeno/química , Estructuras Metalorgánicas/química , Porosidad , Triazinas/química , Triazinas/aislamiento & purificación , Límite de Detección , Urea/química , Zeolitas/químicaRESUMEN
Four afatinib derivatives were designed and modeled. These derivatives were compared to the known tyrosine-kinase inhibitors in treating Chronic Myeloid Leukemia, i.e., imatinib and ponatinib. The molecules were evaluated through computational methods, including docking studies, the non-covalent interaction index, Electron Localization and Fukui Functions, in silico ADMET analysis, QTAIM, and Heat Map analysis. The AFA(IV) candidate significantly increases the score value compared to afatinib. Furthermore, AFA(IV) was shown to be relatively similar to the ponatinib profile when evaluating a range of molecular descriptors. The addition of a methylpiperazine ring seems to be well distributed in the structure of afatinib when targeting the BCR-ABL enzyme, providing an important hydrogen bond interaction with the Asp381 residue of the DFG-switch of BCR-ABL active site residue and the AFA(IV) new chemical entities. Finally, in silico toxicity predictions show a favorable index, with some molecules presenting the loss of the irritant properties associated with afatinib in theoretical predictions.
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Afatinib , Proteínas de Fusión bcr-abl , Simulación del Acoplamiento Molecular , Inhibidores de Proteínas Quinasas , Proteínas de Fusión bcr-abl/antagonistas & inhibidores , Proteínas de Fusión bcr-abl/genética , Proteínas de Fusión bcr-abl/química , Afatinib/química , Afatinib/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Humanos , Modelos Moleculares , Simulación por Computador , Mutación , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Enlace de Hidrógeno , Antineoplásicos/química , Antineoplásicos/farmacología , Imidazoles/química , Imidazoles/farmacología , PiridazinasRESUMEN
GroEL, a chaperone protein responsible for peptide and denatured protein folding, undergoes substantial conformational changes driven by ATP binding and hydrolysis during folding. Utilizing these conformational changes, we demonstrated the GroEL-mediated regioselective photocyclodimerization of 2-anthracenecarboxylic acid (AC) using ATP hydrolysis as an external stimulus. We designed and prepared an optimal GroEL mutant to employ in a docking simulation that has been actively used in recent years. Based on the large difference in the motif of hydrogen bonds between AC and GroEL mutant compared with the wild-type, we predicted that GroELMEL, in which the 307â309th amino acid residues were mutated to Ala, could alter the orientation of bound AC in GroEL. The GroELMEL-mediated photocyclodimerization of AC can be used for regioselective inversion upon ATP addition to a moderate extent.
Asunto(s)
Adenosina Trifosfato , Antracenos , Chaperonina 60 , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/química , Hidrólisis , Antracenos/química , Antracenos/metabolismo , Chaperonina 60/química , Chaperonina 60/genética , Chaperonina 60/metabolismo , Simulación del Acoplamiento Molecular , Conformación Proteica , Mutación , Enlace de Hidrógeno , Pliegue de Proteína , Ácidos CarboxílicosRESUMEN
The complexity of plant cell walls on different hierarchical levels still impedes the detailed understanding of biosynthetic pathways, interferes with processing in industry and finally limits applicability of cellulose materials. While there exist many challenges to readily accessing these hierarchies at (sub-) angström resolution, the development of advanced computational methods has the potential to unravel important questions in this field. Here, we summarize the contributions of molecular dynamics simulations in advancing the understanding of the physico-chemical properties of natural fibres. We aim to present a comprehensive view of the advancements and insights gained from molecular dynamics simulations in the field of carbohydrate polymers research. The review holds immense value as a vital reference for researchers seeking to undertake atomistic simulations of plant cell wall constituents. Its significance extends beyond the realm of molecular modeling and chemistry, as it offers a pathway to develop a more profound comprehension of plant cell wall chemistry, interactions, and behavior. By delving into these fundamental aspects, the review provides invaluable insights into future perspectives for exploration. Researchers within the molecular modeling and carbohydrates community can greatly benefit from this resource, enabling them to make significant strides in unraveling the intricacies of plant cell wall dynamics.