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1.
Mol Biol Cell ; 35(7): ar95, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38696259

RESUMEN

Transforming growth factor-ß (TGF-ß) signaling plays a crucial role in pathogenesis, such as accelerating tissue fibrosis and promoting tumor development at the later stages of tumorigenesis by promoting epithelial-mesenchymal transition (EMT), cancer cell migration, and invasion. Targeting TGF-ß signaling is a promising therapeutic approach, but nonspecific inhibition may result in adverse effects. In this study, we focus on the Smad2/3-Smad4 complex, a key component in TGF-ß signaling transduction, as a potential target for cancer therapy. Through a phase-separated condensate-aided biomolecular interaction system, we identified verteporfin (VP) as a small-molecule inhibitor that specifically targets the Smad2/3-Smad4 interaction. VP effectively disrupted the interaction between Smad2/3 and Smad4 and thereby inhibited canonical TGF-ß signaling, but not the interaction between Smad1 and Smad4 in bone morphogenetic protein (BMP) signaling. Furthermore, VP exhibited inhibitory effects on TGF-ß-induced EMT and cell migration. Our findings indicate a novel approach to develop protein-protein interaction inhibitors of the canonical TGF-ß signaling pathway for treatments of related diseases.


Asunto(s)
Movimiento Celular , Transición Epitelial-Mesenquimal , Transducción de Señal , Proteína Smad2 , Proteína smad3 , Proteína Smad4 , Factor de Crecimiento Transformador beta , Verteporfina , Humanos , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta/metabolismo , Proteína Smad4/metabolismo , Transición Epitelial-Mesenquimal/efectos de los fármacos , Proteína smad3/metabolismo , Movimiento Celular/efectos de los fármacos , Proteína Smad2/metabolismo , Verteporfina/farmacología
2.
Langmuir ; 39(48): 17392-17411, 2023 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-37988628

RESUMEN

Droplet boiling on the heating surface is a representative phenomenon in two-phase spray cooling under low volumetric fluxes. In particular, droplet boiling in the transition boiling regime holds the advantages of avoiding heat transfer deterioration in a film boiling regime and achieving comparable high heat transfer capacity in a nucleate boiling regime. While it is known to consist of intermittent liquid contact with the surface and surface dryout, quantifying the ensuing transient heat transfer performance and droplet behavior is very illusive. In this study, droplet boiling in the transition boiling regime on a micropillar array surface is investigated systematically, using the lattice Boltzmann model built up in the lab. The major contents discussed include the transient behaviors of the droplet, motion of the liquid bridge, and pinning/depinning of the three-phase contact line (TPCL), as well as the corresponding heat transfer performance. The evolution of a vapor film pierced by micropillars is analyzed from the views of morphological change and pressure distribution. The thickness of the vapor film is determined by the vapor generation rate dominated by the contact area and effective thermal conductivity, and the vapor escape rate by the permeability. The low permeability under a large pillar side length is responsible for the pressure buildup below the droplet, thus facilitating droplet rebound. The competition between capillary pressure and vapor film pressure dominates the trigger mode of the droplet rebound, i.e., fracture of the liquid bridge or filament and depinning of TPCL. The micropillar array surface is optimized to pursue the best cooling performance by assessing the impact from micropillar geometric dimensions on droplet contact time and area.

3.
J Agric Food Chem ; 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37909051

RESUMEN

Insect chitinase, OfChi-h, from Ostrinia furnacalis, is considered as a promising target for the development of green pesticides. On the basis of the crystal structure of OfChi-h, we successfully obtained a triazolo-quinazolinone scaffold as the novel class of OfChi-h inhibitor via a structure-based virtual screening approach. Rational compound screening enabled us to acquire a potent OfChi-h inhibitor TQ19 with a Ki value of 0.33 µM. Furthermore, the in vivo biological activity of target compounds was assayed. The results showed that compounds TQ8 and TQ19 could dramatically inhibit the growth and development of Ostrinia nubilalis larvae, and most of the compounds showed higher insecticidal activity than hexaflumuron. This present work reveals that triazolo-quinazolinone derivatives can serve as novel candidates for insect growth regulators.

4.
Front Chem ; 10: 1021295, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36405330

RESUMEN

Plant-parasitic nematodes are a main limiting factor for worldwide agriculture. To reduce the global burden of nematode infections, chemical nematicides are still the most effective methods to manage nematodes. With the increasing resistance of nematodes, the development of new anti-nematicides drug is urgent. Nematode chitinases are found to play important roles in various physiological functions, such as larva moulting, hatching from eggshell, and host infection. Inhibition of nematode chitinase is considered a promising strategy for the development of eco-friendly nematicides. In this study, to develop novel nematode chitinase CeCht1 inhibitors, virtual screening of the ZINC database was performed using the pesticide-likeness rules, pharmacophore-based and docking-based approach in turn. Compounds HAU-4 and HAU-7 were identified as potent CeCht1 inhibitors with the IC50 values of 4.2 µM and 10.0 µM, respectively. Moreover, molecular dynamics simulations combined with binding free energy and free energy decomposition calculations were conducted to investigate the basis for the potency of the two inhibitors toward CeCht1. This work gives an insight into the future rational development of novel and potent nematode chitinase inhibitors.

5.
J Agric Food Chem ; 70(38): 12203-12210, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36121180

RESUMEN

Chitinase OfChi-h, from the destructive agricultural pest Ostrinia furnacalis, is considered as a promising target for green pest control and management. In this study, structure-based virtual screening and rational molecular optimization led to the synthesis of a series of azo-aminopyrimidine derivatives as a novel class of OfChi-h inhibitors. Among them, the most potent compound 8f, with a benzyl on the amino group at the 4-position of pyrimidine, exhibited a Ki value of 64.7 nM against OfChi-h. In addition, molecular docking studies were carried out to investigate the basis for the potency of the aminopyrimidines against OfChi-h. Furthermore, the insecticidal activity of the target compounds against Plutella xylostella and Ostrinia nubilalis was assessed, and the potent OfChi-h inhibitors 8f and 8i showed higher insecticidal activity than the control pesticide hexaflumuron. The present work revealed that the azo-aminopyrimidine skeletons characterized by concise chemical structure and high efficiency could be further developed as potential pesticides for the control of lepidopteran pests.


Asunto(s)
Quitinasas , Insecticidas , Mariposas Nocturnas , Animales , Quitinasas/química , Insecticidas/química , Insecticidas/farmacología , Simulación del Acoplamiento Molecular , Mariposas Nocturnas/metabolismo , Pirimidinas , Relación Estructura-Actividad
6.
Entropy (Basel) ; 24(9)2022 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-36141100

RESUMEN

Scholars usually ignore the non-equilibrium condensing effects in turbulence-model comparative studies on supersonic steam ejectors. In this study, a non-equilibrium condensation model considering real physical properties was coupled respectively with seven turbulence models. They are the k-ε Standard, k-ε RNG, k-ε Realizable, k-ω Standard, k-ω SST, Transition SST, and Linear Reynolds Stress Model. Simulation results were compared with the experiment results globally and locally. The complex flow phenomena in the steam ejector captured by different models, including shock waves, choking, non-equilibrium condensation, boundary layer separation, and vortices were discussed. The reasons for the differences in simulation results were explained and compared. The relationship between ejector performance and local flow phenomena was illustrated. The novelty lies in the conclusions that consider the non-equilibrium condensing effects. Results show that the number and type of shock waves predicted by different turbulence models are different. Non-equilibrium condensation and boundary layer separation regions obtained by various turbulence models are different. Comparing the ejector performance and the complex flow phenomena with the experimental results, the k-ω SST model is proposed to simulate supersonic steam ejectors.

7.
Sensors (Basel) ; 22(14)2022 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-35890753

RESUMEN

The quadrature angular diversity aperture (QADA) receiver, consisting of a quadrant photodiode (QPD) and an aperture placed above the QPD, has been investigated for pose estimation for visible light systems. Current work on pose estimation for the QADA receiver uses classical camera sensor algorithms well known in computer vision. To this end, however, the light spot center first has to be obtained based on the RSS. However, this is less straightforward than for camera sensors, as in contrast to such sensors where the relationships are linear, the RSS output from the QADA is a non-linear function of the light spot position. When applying closed form solutions or iterative methods for cameras on a QADA, the non-linearity will degrade their performance. Furthermore, since in practice the aperture is not always perfectly aligned with the QPD, a procedure to calibrate the receiver is needed. Current work on calibration requires additional sophisticated equipment to measure the pose during calibration, which increases the difficulty of implementation. In this paper, we target the above problems for pose estimation and calibration of the QADA receiver. To this end, we first study the effect of the strategy of differencing and normalization on the probability density function (PDF), a commonly applied strategy for the QPD's robustness against RSS variation, and it is shown that the applied strategy results in a complex PDF, which makes an effective and efficient estimation hard to achieve. Therefore, we derive an approximated PDF in a simple closed-form, based on which the calibration and the pose estimation algorithms using the least squares principle are proposed. The proposed calibration does not require any information about the pose of the receiver and is robust to variation of the received power and imperfect knowledge of the radiation pattern of the LED, making it easy to implement. We also derive the corresponding Cramér-Rao lower bound on the misalignment to benchmark the performance of the misalignment and to serve as an indicator to determine the required signal-to-noise ratio (SNR) or number of LEDs to obtain a desired accuracy. The calibration and pose estimation are evaluated by means of a Monte Carlo simulation. Computer simulations show that this theoretical bound is close to the RMSE of the proposed estimator and that the proposed pose estimator outperforms the PnP algorithm.

8.
Langmuir ; 37(39): 11646-11656, 2021 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-34569245

RESUMEN

Droplet impinging on the boundary between hydrophilic and hydrophobic regions of a hybrid-wettability surface is studied both experimentally and numerically in the present paper. The interfacial evolution and dynamic feature and the corresponding underlying mechanisms behind are mainly analyzed. Because of the unbalanced surface energy in the vicinity of a boundary, the droplet undergoes spreading-receding in the hydrophobic region before migration toward the hydrophilic region. This results in an increase first but then a decrease in the spreading factor in the hydrophobic region, while it increases continuously in the hydrophilic region. In addition, increasing Weber number leads to the increase in both the spreading factor and migration displacement of the droplet in the hydrophobic region, but the latter decreases in the hydrophilic region, resulting from different momentums of secondary spreading. The experimental determinations are verified in detail by a series of numerical simulations performed based on the single variable method by fixing contact angles in different regions separately and excluding the impact momentum. It is shown that the highly unsymmetrical pressure field is exactly one important reason for droplet migration on the hybrid-wettability surface. Despite the weak dependence of the spreading factor on the hydrophilic contact angle in the hydrophobic region, it has an appreciably positive effect on droplet migration, which is confirmed by the increased pressure gradient with its action area in the hydrophobic region when decreasing the hydrophilic contact angle. This paper advances the fundamental understanding for droplet migration on the hybrid-/gradient-wettability surface.

9.
J Biomol Struct Dyn ; 39(5): 1735-1743, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32193983

RESUMEN

Chitin can be widely found in the fungal cell wall, nematode eggshells, and the exoskeleton of arthropods; however, it is completely absent from higher plants and mammals. The process of chitin degradation is essential for both growth and maturation of insects. Thus, inhibiting chitin degradation is a promising strategy for the control and management of pests. The chitinolytic ß-N-acetyl-D-hexosaminidase OfHex1 of Ostrinia furnacalis (one of the most destructive pests) has been suggested as a potential target for the design of eco-friendly pesticides. This study presents the sequential virtual screening of the ZINC library with 8 million compounds, targeting OfHex1. After confirmation via enzyme inhibition experiments, compound 5 exhibited potential inhibitory activity against OfHex1 with a Ki of 28.9 ± 0.5 µM and significant selectivity (IC50 > 100 µM against HsHexB and hOGA). Molecular dynamics simulations combined with binding free energy and free energy decomposition calculations were conducted to investigate the molecular basis underlying the potency of these inhibitors toward OfHex1. The present work provides useful information for the future rational design of novel and potent OfHex1 inhibitorsCommunicated by Ramaswamy H. Sarma.


Asunto(s)
Mariposas Nocturnas , beta-N-Acetilhexosaminidasas , Animales , Quitina , Inhibidores Enzimáticos/farmacología , Insectos/metabolismo , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , beta-N-Acetilhexosaminidasas/metabolismo
10.
Bioorg Med Chem ; 29: 115846, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33191087

RESUMEN

Succinate dehydrogenase (SDH), a crucial bridge enzyme between the respiratory electron transfer chain and tricarboxylic acid (or Krebs) cycle, has been identified as an ideal target for the development of effective fungicide. In this study, a series of 24 novel SDH inhibitors (SDHIs) were designed, synthesized, and characterized by 1H NMR, 13C NMR, and HRMS. In vitro fungicidal activity experiments, most of the compounds exhibited broad-spectrum antifungal activities against five plant pathogenic fungi. Compounds 9j and 9k showed excellent activities against Pythium aphanidermatum with EC50 values of 9.93 mg/L and 10.50 mg/L, respectively, which were superior to the lead compound Fluopyram with an EC50 value of 19.10 mg/L. Furthermore, the toxicity of these compounds was also tested against Meloidogyne incognita J2 nematodes. The results indicated that compound 9x exhibited moderate nematicidal activity (LC50/48 h = 71.02 mg/L). Molecular docking showed that novel guanidine amide of 9j formed hydrogen bonds with crucial residues, which was crucial to the binding of an inhibitor and SDH. This present work indicates that these derivatives may serve as novel potential fungicides targeting SDH.


Asunto(s)
Antifúngicos/farmacología , Benzamidas/farmacología , Inhibidores Enzimáticos/farmacología , Hongos/efectos de los fármacos , Guanidina/farmacología , Piridinas/farmacología , Succinato Deshidrogenasa/antagonistas & inhibidores , Animales , Antifúngicos/síntesis química , Antifúngicos/química , Benzamidas/síntesis química , Benzamidas/química , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Guanidina/química , Pruebas de Sensibilidad Microbiana , Mitocondrias Cardíacas/enzimología , Simulación del Acoplamiento Molecular , Estructura Molecular , Piridinas/síntesis química , Piridinas/química , Relación Estructura-Actividad , Succinato Deshidrogenasa/metabolismo , Porcinos
11.
ACS Omega ; 5(38): 24467-24476, 2020 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-33015463

RESUMEN

Recycling the phosphorus in sludge by incineration has received great interest at home and abroad. However, heavy metals (HMs) is a restrictive factor for SS thermal treatment. In this study, a comprehensive evaluation method was adopted to evaluate the comprehensive control efficiency of HM emissions during two-step thermal treatment (incineration-calcination). The effects of temperature, calcination time, and additives (CaO and NaCl) on leaching rates, stabilized rates, and comprehensive control efficiency of HM emissions were investigated. Results showed that comprehensive control efficiency increased significantly with an increase of temperature because of the transformation of chemical speciation from a leachable to a more stable combined form. Additives Cao and NaCl promoted the volatilization of HMs and reduced the comprehensive control efficiency. The highest comprehensive control efficiency of HM emissions was 78% when the incineration temperature reached 950 °C. Furthermore, a comparison was made between leaching rates, stabilized rates, and a comprehensive evaluation method. The results were inconsistent when leaching rates and stabilized rates were adopted. In contrast, when the comprehensive evaluation method was used, the results were coordinated and unique. This work can provide a promising approach for the evaluation of control efficiency of HM emissions during the process of thermal treatment of sludge.

12.
R Soc Open Sci ; 7(8): 200079, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32968505

RESUMEN

Boron nitride, also known as white graphene, has attracted extensive attention in the fields of adsorption, catalysis and hydrogen storage due to its excellent chemical properties. In this study, a phosphorus-doped boron nitride (P-BN) material was successfully prepared using red phosphorus as a dopant for the preparation of porous boron nitride precursors. The phosphorus content in the P-BN was adjusted based on the addition rate of phosphorus. The specific surface area of P-BN first increased and then decreased with increasing addition rate of phosphorus. The maximum specific surface area was 837.8 m2 g-1 when the phosphorus addition rate was 0.50. The P-BN prepared in the experiments was used as an adsorbent, and its adsorption capacity for heavy metals from flue gas was investigated. In particular, P-BN presented a stronger adsorption selectivity for zinc compared with other heavy metals, and its adsorption capacity for zinc was 5-38 times higher than for other heavy metals. The maximum adsorption capacity of P-BN for zinc and copper in a single heavy metal atmosphere was 69.45 and 53.80 mg g-1, respectively.

13.
Bioorg Med Chem ; 28(15): 115602, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32631559

RESUMEN

The insect ß-N-acetylhexosaminidase OfHex1 from Ostrinia furnacalis (one of the most destructive agricultural pests) has been considered as a promising pesticide target. In this study, a series of novel and readily available ureido thioglycosides were designed and synthesized based on the catalytic mechanism and the co-crystal structures of OfHex1 with substrates. After evaluation via enzyme inhibition experiments, thioglycosides 11c and 15k were found to have inhibitory activities against OfHex1 with the Ki values of 25.6 µM and 53.8 µM, respectively. In addition, all these ureido thioglycosides exhibited high selectivity toward OfHex1 over hOGA and HsHexB (Ki > 100 µM). Furthermore, to investigate the inhibitory mechanism, the possible binding modes of 11c and 15k with OfHex1 were deduced based on molecular docking analysis. This work may provide useful structural starting points for further rational design of potent inhibitors of OfHex1.


Asunto(s)
Inhibidores Enzimáticos/química , Proteínas de Insectos/antagonistas & inhibidores , Tioglicósidos/química , Urea/análogos & derivados , beta-N-Acetilhexosaminidasas/antagonistas & inhibidores , Animales , Dominio Catalítico , Pruebas de Enzimas , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Humanos , Proteínas de Insectos/metabolismo , Cinética , Simulación del Acoplamiento Molecular , Estructura Molecular , Mariposas Nocturnas/enzimología , Unión Proteica , Relación Estructura-Actividad , Tioglicósidos/síntesis química , Tioglicósidos/metabolismo , Urea/síntesis química , Urea/metabolismo , beta-N-Acetilhexosaminidasas/metabolismo
14.
J Chem Inf Model ; 59(10): 4374-4382, 2019 10 28.
Artículo en Inglés | MEDLINE | ID: mdl-31487462

RESUMEN

ß-N-Acetylhexosaminidases have emerged as promising targets for drug and pesticide discovery due to their critical physiological functions in various cellular processes. In particular, human O-GlcNAcase (hOGA) from the glycoside hydrolase family 84 (GH84) has gained significant attention. This enzyme was found to be linked to various diseases such as diabetes, cancer, and Alzheimer's disease (AD). In this study, to develop novel hOGA inhibitors with suitable pharmaceutical properties, virtual screening of the Drugbank database was performed using a docking-based approach targeting hOGA. Chlorhexidine (4, Ki = 4.0 µM) was identified as a potent hOGA inhibitor with excellent selectivity (Ki > 200 µM against human ß-N-acetylhexosaminidase B) and subjected to structural modifications and SAR studies. Furthermore, molecular dynamics simulations as well as binding free energy and free energy decomposition calculations were carried out to investigate the basis for the efficiency of potent inhibitors against hOGA. This present work revealed the new application of the disinfectant chlorhexidine and provided useful information for the future design of hOGA inhibitors.


Asunto(s)
Descubrimiento de Drogas , beta-N-Acetilhexosaminidasas/antagonistas & inhibidores , beta-N-Acetilhexosaminidasas/metabolismo , Dominio Catalítico , Clorhexidina/farmacología , Humanos , Mitoxantrona/farmacología , Modelos Moleculares , Simulación de Dinámica Molecular , Estructura Molecular , Conformación Proteica , Relación Estructura-Actividad , beta-N-Acetilhexosaminidasas/química
15.
Front Chem ; 7: 533, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31403045

RESUMEN

ß-N-acetylhexosaminidases represent an important class of exoglycosidases and have emerged as the promising targets for drug and pesticide discovery. Among these, human O-GlcNAcase (hOGA) has been reported to be closely linked to several diseases such as Alzheimer's disease, diabetes, and cancer. Potent hOGA inhibitors with high selectivity are therefore of great significance for the regulation of the corresponding physiological processes. In this study, several classes of novel and readily available thioglycosyl-naphthalimides bearing the amide linker were designed and synthesized. To investigate their potency and selectivity, the inhibitory efficiencies toward hOGA and human ß-N-acetylhexosaminidase B (HsHexB) were assayed. Especially, compounds 10a (K i = 0.61 µM) and 16l (K i = 0.72 µM) exhibited excellent inhibitory potency against hOGA and high selectivity (HsHexB, K i > 100 µM). In addition, during the preparation of these thioglycosyl-naphthalimides, a new practical method was developed for the synthesis of ureido glycosides from trichloroethyl carbamates at room temperature and normal pressure without catalyst. Furthermore, the possible binding modes of hOGA with 10a, 10d, and 16j were studied using molecular docking and molecular dynamics simulations to explore the molecular basis for the potency of these thioglycosides. This work present here provides useful clues for the further structural optimization toward hOGA.

16.
J Agric Food Chem ; 67(22): 6387-6396, 2019 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-31090403

RESUMEN

Insect chitinolytic ß- N-acetylhexosaminidase OfHex1, from the agricultural pest Ostrinia furnacalis (Guenée), is considered as a potential target for green pesticide design. In this study, rational molecular design and optimization led to the synthesis of compounds 15r ( Ki = 5.3 µM) and 15y ( Ki = 2.7 µM) that had superior activity against OfHex1 than previously reported lead compounds. Both compounds 15r and 15y had high selectivity toward OfHex1 over human ß- N-acetylhexosaminidase B (HsHexB) and human O-GlcNAcase (hOGA). In addition, to investigate the basis for the potency of glycosylated naphthalimides against OfHex1, molecular docking and molecular dynamics simulations were performed to study possible binding modes. Furthermore, the in vivo biological activity of target compounds with efficient OfHex1 inhibitory potency was assayed against Myzus persicae, Plutella xylostella, and O. furnacalis. This present work indicates that glycosylated naphthalimides can be further developed as potential pest control and management agents targeting OfHex1.


Asunto(s)
Inhibidores Enzimáticos/síntesis química , Proteínas de Insectos/antagonistas & inhibidores , Insecticidas/síntesis química , Mariposas Nocturnas/enzimología , Naftalimidas/síntesis química , beta-N-Acetilhexosaminidasas/antagonistas & inhibidores , Animales , Evaluación de Medicamentos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Glicosilación , Humanos , Proteínas de Insectos/química , Insecticidas/química , Insecticidas/farmacología , Cinética , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Mariposas Nocturnas/efectos de los fármacos , Naftalimidas/química , Naftalimidas/farmacología , beta-N-Acetilhexosaminidasas/química
17.
Front Chem ; 7: 235, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31111026

RESUMEN

ß-N-acetyl-D-hexosaminidases have attracted significant attention due to their crucial role in diverse physiological functions including antibacterial synergists, pathogen defense, virus infection, lysosomal storage, and protein glycosylation. In particular, the GH3 ß-N-acetyl-D-hexosaminidase of V. cholerae (VcNagZ), human GH20 ß-N-acetyl-D-hexosaminidase B (HsHexB), and human GH84 ß-N-acetyl-D-hexosaminidase (hOGA) are three important representative glycosidases. These have been found to be implicated in ß-lactam resistance (VcNagZ), lysosomal storage disorders (HsHexB) and Alzheimer's disease (hOGA). Considering the profound effects of these three enzymes, many small molecule inhibitors with good potency and selectivity have been reported to regulate the corresponding physiological functions. In this paper, the best-known inhibitors PUGNAc and two of its derivatives (N-valeryl-PUGNAc and EtBuPUG) were selected as model compounds and docked into the active pockets of VcNagZ, HsHexB, and hOGA, respectively. Subsequently, molecular dynamics simulations of the nine systems were performed to systematically compare their binding modes from active pocket architecture and individual interactions. Furthermore, the binding free energy and free energy decomposition are calculated using the MM/GBSA methods to predict the binding affinities of enzyme-inhibitor systems and to quantitatively analyze the contribution of each residue. The results show that PUGNAc is deeply-buried in the active pockets of all three enzymes, which indicates its potency (but not selectivity) against VcNagZ, HsHexB, and hOGA. However, EtBuPUG, bearing branched 2-isobutamido, adopted strained conformations and was only located in the active pocket of VcNagZ. It has completely moved out of the pocket of HsHexB and lacks interactions with HsHexB. This indicates why the selectivity of EtBuPUG to VcNagZ/HsHexB is the largest, reaching 968-fold. In addition, the contributions of the catalytic residue Asp253 (VcNagZ), Asp254 (VcNagZ), Asp175 (hOGA), and Asp354 (HsHexB) are important to distinguish the activity and selectivity of these inhibitors. The results of this study provide a helpful structural guideline to promote the development of novel and selective inhibitors against specific ß-N-acetyl-D-hexosaminidases.

18.
ACS Sens ; 4(5): 1222-1229, 2019 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-31001975

RESUMEN

The development of effective detection methods for hexosaminidase is of great importance for the rapid screening of potential inhibitors in vitro and for the early diagnosis of related diseases ex vivo. In this study, the activatable fluorescent probes that are based on naphthalimide decorated with ethylene glycol units were synthesized using N-acetyl-ß-d-glucosaminide as a hexosaminidase-responsive group. When exposed to this enzyme, the glucoside-linked naphthalimide moiety of 1c can be cleaved quickly with significant changes in both color (from colorless to yellow) and fluorescence (from blue to green). Probe 1c shows better water-solubility and fluorescence properties than common substrate 4-methylumbelliferyl N-acetyl-ß-d-glucosaminide. Furthermore, the response mechanism of 1c to hexosaminidase was evaluated using HPLC analysis and TD-DFT calculations. Molecular docking was performed to investigate the interaction mode. In addition, 1c has successfully achieved the straightforward rapid discovery of effective hexosaminidase inhibitors. Fluorescence imaging experiments indicate that 1c has good cell safety and can be employed as a useful tool for detecting intracellular hexosaminidase activity.


Asunto(s)
Pruebas de Enzimas/métodos , Hexosaminidasas/química , Hexosaminidasas/metabolismo , Espacio Intracelular/metabolismo , Naftalimidas/química , Imagen Óptica/métodos , Benceno/química , Dominio Catalítico , Línea Celular Tumoral , Inhibidores Enzimáticos/farmacología , Glicosilación , Hexosaminidasas/antagonistas & inhibidores , Humanos , Cinética , Simulación del Acoplamiento Molecular , Polietilenglicoles/química
19.
Bioorg Med Chem ; 27(12): 2315-2322, 2019 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-30528165

RESUMEN

The insect enzyme GH20 ß-N-acetyl-d-hexosaminidase OfHex1 represents an important chitinolytic enzyme found in the agricultural pest Ostrinia furnacalis (Guenée) and inhibition of this enzyme has been considered a promising strategy for the development of eco-friendly pesticides. In this article, based on the structure of the catalytic domains of OfHex1, a series of novel glycosyl triazoles were designed and synthesized via Cu-catalyzed azide-alkyne [3+2] cycloaddition reaction. To investigate the potency and selectivity of these glycosyl triazoles, the inhibition activities towards OfHex1 and HsHexB (human ß-N-acetylhexosaminidase B) were studied. Particularly compound 17c (OfHex1, Ki = 28.68 µM; HsHexB, Ki > 100 µM) exhibited a suitable activity and selectivity against OfHex1. Furthermore, the possible inhibitory mechanisms of 17c with OfHex1 were studied using molecular docking and MD simulations. The structure-activity relationship results as well as the formed binding patterns may provide promising insights into the further development of novel OfHex1 inhibitors.


Asunto(s)
Inhibidores Enzimáticos/química , Glicósidos/química , Insecticidas/química , Triazoles/química , beta-N-Acetilhexosaminidasas/antagonistas & inhibidores , Animales , Dominio Catalítico , Reacción de Cicloadición , Diseño de Fármacos , Pruebas de Enzimas , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Glicósidos/síntesis química , Glicósidos/metabolismo , Humanos , Proteínas de Insectos/antagonistas & inhibidores , Insecticidas/síntesis química , Insecticidas/metabolismo , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Estructura Molecular , Mariposas Nocturnas/enzimología , Pichia/genética , Unión Proteica , Relación Estructura-Actividad , Triazoles/síntesis química , Triazoles/metabolismo , beta-N-Acetilhexosaminidasas/química , beta-N-Acetilhexosaminidasas/metabolismo
20.
J Mol Model ; 24(4): 86, 2018 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-29511885

RESUMEN

Human sodium-dependent glucose co-transporter 2 (hSGLT2) is a crucial therapeutic target in the treatment of type 2 diabetes. In this study, both comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were applied to generate three-dimensional quantitative structure-activity relationship (3D-QSAR) models. In the most accurate CoMFA-based and CoMSIA-based QSAR models, the cross-validated coefficients (r2cv) were 0.646 and 0.577, respectively, while the non-cross-validated coefficients (r2) were 0.997 and 0.991, respectively, indicating that both models were reliable. In addition, we constructed a homology model of hSGLT2 in the absence of a crystal structure. Molecular docking was performed to explore the bonding mode of inhibitors to the active site of hSGLT2. Molecular dynamics (MD) simulations and binding free energy calculations using MM-PBSA and MM-GBSA were carried out to further elucidate the interaction mechanism. With regards to binding affinity, we found that hydrogen-bond interactions of Asn51 and Glu75, located in the active site of hSGLT2, with compound 40 were critical. Hydrophobic and electrostatic interactions were shown to enhance activity, in agreement with the results obtained from docking and 3D-QSAR analysis. Our study results shed light on the interaction mode between inhibitors and hSGLT2 and may aid in the development of C-aryl glucoside SGLT2 inhibitors.


Asunto(s)
Descubrimiento de Drogas , Ligandos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Transportador 2 de Sodio-Glucosa/química , Sitios de Unión , Dominio Catalítico , Descubrimiento de Drogas/métodos , Humanos , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Concentración 50 Inhibidora , Conformación Molecular , Unión Proteica , Relación Estructura-Actividad Cuantitativa , Reproducibilidad de los Resultados , Inhibidores del Cotransportador de Sodio-Glucosa 2
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