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1.
J Agric Food Chem ; 72(1): 634-646, 2024 Jan 10.
Article in English | MEDLINE | ID: mdl-38131198

ABSTRACT

In this study, novel umami peptides were prepared from oyster (Crassostrea gigas) hydrolysates, and their umami mechanisms were investigated. Umami fractions G2 and G3 were isolated by gel filtration chromatography (GFC) and sensory evaluation. The umami scores of the G2 and G3 fractions were 7.8 ± 0.12 and 7.5 ± 0.18, respectively. 36 potential umami peptides with molecular weights below 1500 Da, E and D accounting for >30% of the peptides and iUmami-SCM > 588 were screened by peptidomics. Peptide source analysis revealed that myosin, paramyosin, and sarcoplasmic were the major precursor proteins for these peptides. The electronic tongue results demonstrated that the synthetic peptides DPNDPDMKY and NARIEELEEE possessed an umami characteristic, whereas SIEDVEESRNK and ISIEDVEESRNK possessed a saltiness characteristic. Additionally, molecular docking results indicated that the umami peptide (DPNDPDMKY, NARIEELEEE, SIEDVEESRNK, and ISIEDVEESRNK) binds to H145, S276, H388, T305, Y218, D216, and Q389 residues in the T1R3 taste receptor via a conventional hydrogen bond and a carbon-hydrogen bond. This research provides a new strategy for the screening of umami peptides.


Subject(s)
Crassostrea , Receptors, G-Protein-Coupled , Animals , Molecular Docking Simulation , Receptors, G-Protein-Coupled/metabolism , Taste , Peptides/chemistry , Proteomics
2.
Food Chem ; 429: 136807, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37450993

ABSTRACT

Yeast extract was separated by using ultrafiltration, gel filtration chromatography, and preparative high-performance liquid chromatography for analyzing the umami mechanism. 13 kinds of umami peptides were screened out from 73 kinds of peptides which were identified in yeast extract using nanoscale ultra-performance liquid chromatography-tandem mass spectrometry and virtual screening. The umami peptides were found to have a threshold range of 0.07-0.61 mM. DWTDDVEAR exhibited a strong umami taste with a pronounced enhancement effect for monosodium glutamate. Molecular docking studies revealed that specific amino acid residues in the T1R1 subunit, including Arg316, Ser401, and Asp315, played a critical role in the umami perception with these peptides. Overall, the study highlights the potential of natural flavor enhancers and provides insights into the mechanism of umami taste perception.


Subject(s)
Peptides , Receptors, G-Protein-Coupled , Receptors, G-Protein-Coupled/metabolism , Molecular Docking Simulation , Peptides/chemistry , Taste , Sodium Glutamate
3.
Molecules ; 28(8)2023 Apr 08.
Article in English | MEDLINE | ID: mdl-37110551

ABSTRACT

Bestrophin 1 (Best1) is a chloride channel that localises to the plasma membrane of retinal pigment epithelium (RPE) cells. Mutations in the BEST1 gene are associated with a group of untreatable inherited retinal dystrophies (IRDs) called bestrophinopathies, caused by protein instability and loss-of-function of the Best1 protein. 4PBA and 2-NOAA have been shown to rescue the function, expression, and localisation of Best1 mutants; however, it is of interest to find more potent analogues as the concentration of the drugs required is too high (2.5 mM) to be given therapeutically. A virtual docking model of the COPII Sec24a site, where 4PBA has been shown to bind, was generated and a library of 1416 FDA-approved compounds was screened at the site. The top binding compounds were tested in vitro in whole-cell patch-clamp experiments of HEK293T cells expressing mutant Best1. The application of 25 µM tadalafil resulted in full rescue of Cl- conductance, comparable to wild type Best1 levels, for p.M325T mutant Best1 but not for p.R141H or p.L234V mutants.


Subject(s)
Chloride Channels , Retinal Pigment Epithelium , Humans , Bestrophins/metabolism , Chloride Channels/genetics , Chloride Channels/metabolism , Tadalafil , HEK293 Cells , Mutation , Retinal Pigment Epithelium/metabolism , Vesicular Transport Proteins/genetics
4.
Molecules ; 28(1)2023 Jan 03.
Article in English | MEDLINE | ID: mdl-36615638

ABSTRACT

Inhibitor of Apoptosis Proteins (IAPs) are validated targets for cancer therapy, and the deregulation of their activities within the NF-κB pathway correlates with chemoresistance events, even after treatment with IAPs-antagonists in the clinic (Smac-mimetics). The molecule FC2 was identified as a NF-κB pathway modulator in MDA-MB-231 adenocarcinoma cancer cells after virtual screening of the Chembridge library against the Baculoviral IAP Repeat 1 (BIR1) domain of cIAP2 and XIAP. An improved cytotoxic effect is observed when FC2 is combined with Smac-mimetics or with the cytokine Tumor Necrosis Factor (TNF). Here, we propose a library of 22 derivatives of FC2, whose scaffold was rationally modified starting from the position identified as R1. The cytotoxic effect of FC2 derivatives was evaluated in MDA-MB-231 and binding to the cIAP2- and XIAP-BIR1 domains was assessed in fluorescence-based techniques and virtual docking. Among 22 derivatives, 4m and 4p display improved efficacy/potency in MDA-MB-231 cells and low micromolar binding affinity vs the target proteins. Two additional candidates (4b and 4u) display promising cytotoxic effects in combination with TNF, suggesting the connection between this class of molecules and the NF-κB pathway. These results provide the rationale for further FC2 modifications and the design of novel IAP-targeting candidates supporting known therapies.


Subject(s)
Antineoplastic Agents , Neoplasms , NF-kappa B/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Protein Binding , Inhibitor of Apoptosis Proteins/metabolism , Antineoplastic Agents/pharmacology , Benzodiazepinones/pharmacology , Apoptosis , Mitochondrial Proteins/metabolism
5.
Front Chem ; 10: 948553, 2022.
Article in English | MEDLINE | ID: mdl-36353143

ABSTRACT

Considering the significant impact of the recent COVID-19 outbreak, development of broad-spectrum antivirals is a high priority goal to prevent future global pandemics. Antiviral development processes generally emphasize targeting a specific protein from a particular virus. However, some antiviral agents developed for specific viral protein targets may exhibit broad spectrum antiviral activity, or at least provide useful lead molecules for broad spectrum drug development. There is significant potential for repurposing a wide range of existing viral protease inhibitors to inhibit the SARS-CoV2 3C-like protease (3CLpro). If effective even as relatively weak inhibitors of 3CLpro, these molecules can provide a diverse and novel set of scaffolds for new drug discovery campaigns. In this study, we compared the sequence- and structure-based similarity of SARS-CoV2 3CLpro with proteases from other viruses, and identified 22 proteases with similar active-site structures. This structural similarity, characterized by secondary-structure topology diagrams, is evolutionarily divergent within taxonomically related viruses, but appears to result from evolutionary convergence of protease enzymes between virus families. Inhibitors of these proteases that are structurally similar to the SARS-CoV2 3CLpro protease were identified and assessed as potential inhibitors of SARS-CoV2 3CLpro protease by virtual docking. Several of these molecules have docking scores that are significantly better than known SARS-CoV2 3CLpro inhibitors, suggesting that these molecules are also potential inhibitors of the SARS-CoV2 3CLpro protease. Some have been previously reported to inhibit SARS-CoV2 3CLpro. The results also suggest that established inhibitors of SARS-CoV2 3CLpro may be considered as potential inhibitors of other viral 3C-like proteases.

6.
J Agric Food Chem ; 70(47): 14898-14906, 2022 Nov 30.
Article in English | MEDLINE | ID: mdl-36325587

ABSTRACT

The development of saltiness or saltiness enhancement peptides is important to decrease the dietary risk factor of high sodium. Taste peptides in the yeast extract were separated by ultrafiltration and subsequently identified by UPLC-Q-TOF-MS/MS. The 377 identified peptides were placed into the umami receptor T1R1/T1R3. The results showed that eight taste peptides with higher binding energies were screened by molecular virtual docking, and the results revealed that Asp218, Ser276, and Asn150 of T1R1 play key roles in umami docking of peptides. The taste characteristic description and saltiness enhancement effect results suggested that PKLLLLPKP (sourness and umami, 0.18 mM), GGISTGNLN (sourness, 0.59 mM), LVKGGLIP (umami, 0.28 mM), and SSAVK (umami, 0.35 mM) had higher saltiness enhancement effects. The sigmoid curve analysis further confirmed that the taste detection threshold of the GGISTGNLN in the peptide and salt model (157.47 mg/L) was lower than 320.99 mg/L and exhibited a synergistic effect on saltiness perception, whereas SSAVK, PKLLLLPKP, and LVKGGLIP exhibited additive effects on the saltiness perception. This work also corroborated previous research, which indicated that the sourness and umami taste attributes could enhance the saltiness perception.


Subject(s)
Tandem Mass Spectrometry , Taste , Molecular Docking Simulation , Receptors, G-Protein-Coupled/metabolism , Peptides/chemistry
7.
Beilstein J Org Chem ; 18: 1355-1378, 2022.
Article in English | MEDLINE | ID: mdl-36247982

ABSTRACT

This perspective is an attempt to document the problems that medicinal chemists are facing in drug discovery. It is also trying to identify relevant/possible, research areas in which academics can have an impact and should thus be the subject of grant calls. Accordingly, it describes how hit discovery happens, how compounds to be screened are selected from available chemicals and the possible reasons for the recurrent paucity of useful/exploitable results reported. This is followed by the successful hit to lead stories leading to recent and original antibacterials which are, or about to be, used in human medicine. Then, illustrated considerations and suggestions are made on the possible inputs of academic medicinal chemists. This starts with the observation that discovering a "good" hit in the course of a screening campaign still rely on a lot of luck - which is within the reach of academics -, that the hit to lead process requires a lot of chemistry and that if public-private partnerships can be important throughout these stages, they are absolute requirements for clinical trials. Concerning suggestions to improve the current hit success rate, one academic input in organic chemistry would be to identify new and pertinent chemical space, design synthetic accesses to reach these and prepare the corresponding chemical libraries. Concerning hit to lead programs on a given target, if no new hits are available, previously reported leads along with new structural data can be pertinent starting points to design, prepare and assay original analogues. In conclusion, this text is an actual plea illustrating that, in many countries, academic research in medicinal chemistry should be more funded, especially in the therapeutic area neglected by the industry. At the least, such funds would provide the intensive to secure series of hopefully relevant chemical entities which appears to often lack when considering the results of academic as well as industrial screening campaigns.

8.
Metabolites ; 12(9)2022 Aug 25.
Article in English | MEDLINE | ID: mdl-36144197

ABSTRACT

Olea europaea L. Cv. Arbequina (OEA) (Oleaceae) is an olive variety species that has received little attention. Besides our previous work for the chemical profiling of OEA leaves using LC−HRESIMS, an additional 23 compounds are identified. An excision wound model is used to measure wound healing action. Wounds are provided with OEA (2% w/v) or MEBO® cream (marketed treatment). The wound closure rate related to vehicle-treated wounds is significantly increased by OEA. Comparing to vehicle wound tissues, significant levels of TGF-ß in OEA and MEBO® (p < 0.05) are displayed by gene expression patterns, with the most significant levels in OEA-treated wounds. Proinflammatory TNF-α and IL-1ß levels are substantially reduced in OEA-treated wounds. The capability of several lignan-related compounds to interact with MMP-1 is revealed by extensive in silico investigation of the major OEA compounds (i.e., inverse docking, molecular dynamics simulation, and ΔG calculation), and their role in the wound-healing process is also characterized. The potential of OEA as a potent MMP-1 inhibitor is shown in subsequent in vitro testing (IC50 = 88.0 ± 0.1 nM). In conclusion, OEA is introduced as an interesting therapeutic candidate that can effectively manage wound healing because of its anti-inflammatory and antioxidant properties.

9.
Front Mol Biosci ; 9: 867241, 2022.
Article in English | MEDLINE | ID: mdl-35392534

ABSTRACT

Virtual screening is a cost- and time-effective alternative to traditional high-throughput screening in the drug discovery process. Both virtual screening approaches, structure-based molecular docking and ligand-based cheminformatics, suffer from computational cost, low accuracy, and/or reliance on prior knowledge of a ligand that binds to a given target. Here, we propose a neural network framework, NeuralDock, which accelerates the process of high-quality computational docking by a factor of 106, and does not require prior knowledge of a ligand that binds to a given target. By approximating both protein-small molecule conformational sampling and energy-based scoring, NeuralDock accurately predicts the binding energy, and affinity of a protein-small molecule pair, based on protein pocket 3D structure and small molecule topology. We use NeuralDock and 25 GPUs to dock 937 million molecules from the ZINC database against superoxide dismutase-1 in 21 h, which we validate with physical docking using MedusaDock. Due to its speed and accuracy, NeuralDock may be useful in brute-force virtual screening of massive chemical libraries and training of generative drug models.

10.
Microbiol Spectr ; 10(2): e0231521, 2022 04 27.
Article in English | MEDLINE | ID: mdl-35352998

ABSTRACT

The highly adaptive cellular response of Mycobacterium tuberculosis to various antibiotics and the high costs for clinical trials, hampers the development of novel antimicrobial agents with improved efficacy and safety. Subsequently, in silico drug screening methods are more commonly being used for the discovery and development of drugs, and have been proven useful for predicting the pharmacokinetics, toxicities, and targets, of prospective new antimicrobial agents. In this investigation we used a reversed target fishing approach to determine potential hit targets and their possible interactions between M. tuberculosis and decoquinate RMB041, a propitious new antituberculosis compound. Two of the 13 identified targets, Cyp130 and BlaI, were strongly proposed as optimal drug-targets for dormant M. tuberculosis, of which the first showed the highest comparative binding affinity to decoquinate RMB041. The metabolic pathways associated with the selected target proteins were compared to previously published molecular mechanisms of decoquinate RMB041 against M. tuberculosis, whereby we confirmed disrupted metabolism of proteins, cell wall components, and DNA. We also described the steps within these pathways that are inhibited and elaborated on decoquinate RMB041's activity against dormant M. tuberculosis. This compound has previously showed promising in vitro safety and good oral bioavailability, which were both supported by this in silico study. The pharmacokinetic properties and toxicity of this compound were predicted and investigated using the online tools pkCSM and SwissADME, and Discovery Studio software, which furthermore supports previous safety and bioavailability characteristics of decoquinate RMB041 for use as an antimycobacterial medication. IMPORTANCE This article elaborates on the mechanism of action of a novel antibiotic compound against both, active and dormant Mycobacterium tuberculosis and describes its pharmacokinetics (including oral bioavailability and toxicity). Information provided in this article serves useful during the search for drugs that shorten the treatment regimen for Tuberculosis and cause minimal adverse effects.


Subject(s)
Decoquinate , Mycobacterium tuberculosis , Tuberculosis, Lymph Node , Antitubercular Agents/chemistry , Antitubercular Agents/pharmacology , Decoquinate/metabolism , Decoquinate/pharmacology , Drug Discovery , Humans , Mycobacterium tuberculosis/metabolism , Prospective Studies
11.
BMC Pharmacol Toxicol ; 22(1): 68, 2021 11 02.
Article in English | MEDLINE | ID: mdl-34727985

ABSTRACT

BACKGROUND: Ovarian cancer is the world's dreaded disease and its prevalence is expanding globally. The study of integrated molecular networks is crucial for the basic mechanism of cancer cells and their progression. During the present investigation, we have examined different flavonoids that target protein kinases B (AKT1) protein which exerts their anticancer efficiency intriguing the role in cross-talk cell signalling, by metabolic processes through in-silico approaches. METHOD: Molecular dynamics simulation (MDS) was performed to analyze and evaluate the stability of the complexes under physiological conditions and the results were congruent with molecular docking. This investigation revealed the effect of a point mutation (W80R), considered based on their frequency of occurrence, with AKT1 protein. RESULTS: The ligand with high docking scores and favourable behaviour on dynamic simulations are proposed as potential W80R inhibitors. A virtual screening analysis was performed with 12,000 flavonoids satisfying Lipinski's rule of five according to which drug-likeness is predicted based on its pharmacological and biological properties to be active and taken orally. The pharmacokinetic ADME (adsorption, digestion, metabolism, and excretion) studies featured drug-likeness. Subsequently, a statistically significant 3D-QSAR model of high correlation coefficient (R2) with 0.822 and cross-validation coefficient (Q2) with 0.6132 at 4 component PLS (partial least square) were used to verify the accuracy of the models. Taxifolin holds good interactions with the binding domain of W80R, highest Glide score of - 9.63 kcal/mol with OH of GLU234 and H bond ASP274 and LEU156 amino acid residues and one pi-cation interaction and one hydrophobic bond with LYS276. CONCLUSION: Natural compounds have always been a richest source of active compounds with a wide variety of structures, therefore, these compounds showed a special inspiration for medical chemists. The present study has aimed molecular docking and molecular dynamics simulation studies on taxifolin targeting W80R mutant protein of protein kinase B/serine- threonine kinase/AKT1 (EC:2.7.11.1) protein of ovarian cancer for designing therapeutic intervention. The expected result supported the molecular cause in a mutant form which resulted in a gain of ovarian cancer. Here we discussed validations computationally and yet experimental evaluation or in vivo studies are endorsed for further study. Several of these compounds should become the next marvels for early detection of ovarian cancer.


Subject(s)
Ovarian Neoplasms/genetics , Proto-Oncogene Proteins c-akt/genetics , Female , Flavonoids/chemistry , Flavonoids/pharmacokinetics , Flavonoids/pharmacology , Humans , Molecular Docking Simulation , Ovarian Neoplasms/drug therapy , Point Mutation , Proto-Oncogene Proteins c-akt/chemistry , Quantitative Structure-Activity Relationship
12.
Int J Mol Sci ; 22(19)2021 Sep 28.
Article in English | MEDLINE | ID: mdl-34638829

ABSTRACT

A new series of 4-(1H-benzo[d]imidazol-1-yl)pyrimidin-2-amine linked sulfonamide derivatives 12a-n was designed and synthesized according to the structure of well-established V600EBRAF inhibitors. The terminal sulfonamide moiety was linked to the pyrimidine ring via either ethylamine or propylamine bridge. The designed series was tested at fixed concentration (1 µM) against V600EBRAF, finding that 12e, 12i and 12l exhibited the strongest inhibitory activity among all target compounds and 12l had the lowest IC50 of 0.49 µM. They were further screened on NCI 60 cancer cell lines to reveal that 12e showed the most significant growth inhibition against multiple cancer cell lines. Therefore, cell cycle analysis of 12e was conducted to investigate the effect on cell cycle progression. Finally, virtual docking studies was performed to gain insights for the plausible binding modes of vemurafenib, 12i, 12e and 12l.


Subject(s)
Antineoplastic Agents , Cell Proliferation/drug effects , Molecular Docking Simulation , Mutation, Missense , Neoplasms , Proto-Oncogene Proteins B-raf , Sulfonamides , Amino Acid Substitution , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Neoplasms/drug therapy , Neoplasms/enzymology , Neoplasms/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/metabolism , Sulfonamides/chemical synthesis , Sulfonamides/chemistry , Sulfonamides/pharmacology
13.
Eur J Med Chem ; 209: 112935, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33097301

ABSTRACT

Salidroside [(2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-(4-hydroxyphenethoxy)tetrahy-dro-2H-pyran-3,4,5-triol] is an antioxidant, anti-inflammatory and neuroprotective agent, but its drug-like properties are unoptimized and its mechanism of actions is uncertain. We synthesized twenty-six novel derivatives of salidroside and examined them in CoCl2-treated PC12 cells using MTT assay. pOBz, synthesized by esterifying the phenolic hydroxyl group of salidroside with benzoyl chloride, was one of five derivatives that were more cytoprotective than salidroside, with an EC50 of 0.038 µM versus 0.30 µM for salidroside. pOBz was also more lipophilic, with log P of 1.44 versus -0.89 for salidroside. Reverse virtual docking predicted that pOBz would bind strongly with monoamine oxidase (MAO) B by occupying its entrance and substrate cavities, and by interacting with the inter-cavity gating residue Ile199 and Tyr435 of the substrate cavity. Enzymatic studies confirmed that pOBz competitively inhibited the activity of purified human MAO-B (Ki = 0.041 µM versus Ki = 0.92 µM for salidroside), and pOBz was highly selective for MAO-B over MAO-A. In vivo, pOBz inhibited cerebral MAO activity after middle cerebral artery occlusion with reperfusion in rats, and it reduced cerebral infarct volume, improved neurological function and NeuN expression, and inhibited complement C3 expression and apoptosis. Our results suggest that pOBz is a structurally novel type of competitive and selective MAO-B inhibitor, with potent neuroprotective properties after cerebral ischemia-reperfusion injury in rats.


Subject(s)
Glucosides/chemical synthesis , Monoamine Oxidase Inhibitors/chemical synthesis , Monoamine Oxidase/metabolism , Neuroprotective Agents/chemical synthesis , Phenols/chemical synthesis , Reperfusion Injury/drug therapy , Amino Acid Sequence , Animals , Apoptosis/drug effects , Biological Transport , Blood-Brain Barrier/metabolism , Complement C3/metabolism , Drug Evaluation, Preclinical , Gene Expression Regulation/drug effects , Glucosides/pharmacology , Humans , Male , Molecular Docking Simulation , Monoamine Oxidase Inhibitors/pharmacology , Neuroprotective Agents/pharmacology , PC12 Cells , Phenols/pharmacology , Protein Binding , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship
14.
Drug Des Devel Ther ; 14: 1779-1798, 2020.
Article in English | MEDLINE | ID: mdl-32440103

ABSTRACT

BACKGROUND: Radiotherapy has an ameliorative effect on a wide variety of tumors, but hepatocellular carcinoma (HCC) is insensitive to this treatment. Overactivated mammalian target of rapamycin (mTOR) plays an important part in the resistance of HCC to radiotherapy; thus, mTOR inhibitors have potential as novel radiosensitizers to enhance the efficacy of radiotherapy for HCC. METHODS: A lead compound was found based on pharmacophore modeling and molecular docking, and optimized according to the differences between the ATP-binding pockets of mTOR and PI3K. The radiosensitizing effect of the optimized compound (2a) was confirmed by colony formation assays and DNA double-strand break assays in vitro. The discovery and preclinical characteristics of this compound are described. RESULTS: The key amino acid residues in mTOR were identified, and a precise virtual screening model was constructed. Compound 2a, with a 4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine scaffold, exhibited promising potency against mTOR (mTOR IC50=7.1 nmol/L (nM)) with 126-fold selectivity over PI3Kα. Moreover, 2a significantly enhanced the sensitivity of HCC to radiotherapy in vitro in a dose-dependent manner. CONCLUSION: A new class of selective mTOR inhibitors was developed and their radiosensitization effects were confirmed. This study also provides a basis for developing mTOR-specific inhibitors for use as radiosensitizers for HCC radiotherapy.


Subject(s)
Carcinoma, Hepatocellular/therapy , Liver Neoplasms/therapy , Pyrimidinones/pharmacology , Radiation-Sensitizing Agents/pharmacology , TOR Serine-Threonine Kinases/antagonists & inhibitors , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Models, Molecular , Molecular Structure , Pyrimidinones/chemical synthesis , Pyrimidinones/chemistry , Radiation-Sensitizing Agents/chemical synthesis , Radiation-Sensitizing Agents/chemistry , Structure-Activity Relationship , TOR Serine-Threonine Kinases/metabolism
15.
Neuroscience ; 439: 62-79, 2020 07 15.
Article in English | MEDLINE | ID: mdl-31158437

ABSTRACT

Most local anesthetics (LAs) are amine compounds bearing one or several phenolic rings. Many of them are protonated at physiological pH, but benzocaine (Bzc) is permanently uncharged, which is relevant because the effects of LAs on nicotinic acetylcholine (ACh) receptors (nAChRs) depend on their presence as uncharged or protonated species. The aims of this study were to assess the effects of Bzc on nAChRs and to correlate them with its binding to putative interacting sites on this receptor. nAChRs from Torpedo electroplaques were microtransplanted to Xenopus oocytes and currents elicited by ACh (IAChs), either alone or together with Bzc, were recorded at different potentials. Co-application of ACh with increasing concentrations of Bzc showed that Bzc reversibly blocked nAChRs. IACh inhibition by Bzc was voltage-independent, but the IACh rebound elicited when rinsing Bzc suggests an open-channel blockade. Besides, ACh and Bzc co-application enhanced nAChR desensitization. When Bzc was just pre-applied it also inhibited IACh, by blocking closed (resting) nAChRs. This blockade slowed down the kinetics of both the IACh activation and the recovery from blockade. The electrophysiological results indicate that Bzc effects on nAChRs are similar to those of 2,6-dimethylaniline, an analogue of the hydrophobic moiety of lidocaine. Furthermore, docking assays on models of the nAChR revealed that Bzc and DMA binding sites on nAChRs overlap fairly well. These results demonstrate that Bzc inhibits nAChRs by multiple mechanisms and contribute to better understanding both the modulation of nAChRs and how LAs elicit some of their clinical side effects. This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.


Subject(s)
Receptors, Nicotinic , Acetylcholine , Anesthetics, Local/pharmacology , Animals , Benzocaine/pharmacology , Muscles , Oocytes
16.
J Biomol Struct Dyn ; 37(7): 1843-1856, 2019 Apr.
Article in English | MEDLINE | ID: mdl-29697300

ABSTRACT

Galantamine (Gnt) is a natural alkaloid inhibitor of acetylcholinesterase and is presently one of the most used drugs in the treatment against Alzheimer's disease during both the initial and intermediate stages. Among several natural Gnt derivatives, sanguinine (Sng) and lycoramine (Lyc) attract attention because of the way their subtle chemical differences from Gnt lead to drastic and opposite distinctions in inhibitory effects. However, to date, there is no solved structure for these natural derivatives. In the present study, we applied computational modeling and free energy calculation methods to better elucidate the molecular basis of the subtle distinctions between these derivatives and Gnt. The results showed that differences in the mobility of the non-aromatic ring carried by the Lyc-like sp2-sp3 modification display drastic conformational, vibrational, and entropic penalties at binding compared to Gnt. Additionally, the establishment of a stronger hydrogen bond network added enthalpic advantages for the linkage of the Sng-like methoxy-hydroxy substituted ligands. These results, which suggest an affinity ranking in agreement with that found in the literature, provided insights that are helpful for future planning and development of new anti-Alzheimer's disease drugs.


Subject(s)
Acetylcholinesterase/chemistry , Cholinesterase Inhibitors/chemistry , Molecular Conformation , Molecular Docking Simulation , Molecular Dynamics Simulation , Alzheimer Disease/drug therapy , Binding Sites , Catalytic Domain , Cholinesterase Inhibitors/pharmacology , Humans , Hydrogen Bonding , Ligands , Molecular Structure , Protein Binding
17.
Curr Med Chem ; 26(21): 3874-3889, 2019.
Article in English | MEDLINE | ID: mdl-28707592

ABSTRACT

BACKGROUND: Computer-Aided Drug Design has strongly accelerated the development of novel antineoplastic agents by helping in the hit identification, optimization, and evaluation. RESULTS: Computational approaches such as cheminformatic search, virtual screening, pharmacophore modeling, molecular docking and dynamics have been developed and applied to explain the activity of bioactive molecules, design novel agents, increase the success rate of drug research, and decrease the total costs of drug discovery. Similarity, searches and virtual screening are used to identify molecules with an increased probability to interact with drug targets of interest, while the other computational approaches are applied for the design and evaluation of molecules with enhanced activity and improved safety profile. CONCLUSION: In this review are described the main in silico techniques used in rational drug design of antineoplastic agents and presented optimal combinations of computational methods for design of more efficient antineoplastic drugs.


Subject(s)
Antineoplastic Agents/chemical synthesis , Computer-Aided Design , Drug Design , Drug Evaluation, Preclinical/methods , Quantitative Structure-Activity Relationship , Antineoplastic Agents/chemistry , Humans , Models, Molecular
18.
FEBS J ; 285(17): 3286-3298, 2018 09.
Article in English | MEDLINE | ID: mdl-30055105

ABSTRACT

Inhibitor of Apoptosis Proteins (IAPs) is highly conserved negative regulators of apoptosis overexpressed in many cancer cells. Based on their endogenous antagonist, Smac/DIABLO, mimic compounds (Smac-mimetics, SMs) have been developed to inhibit IAPs prosurvival activity, showing promising effects in advanced phases of clinical trials. Since different IAP homologs play distinctive roles in cancer cell survival and immunomodulation, SM-induced apoptosis proceeds through diverse mechanisms. After binding to their BIR3 domain, SMs have been shown to rapidly induce auto-ubiquitylation and degradation of cellular IAPs (cIAPs), thus leading to cell death mainly by activation of the noncanonical NF-κB pathway. For this reason, we started the BIR3-driven design of compounds selective for cIAP1 and with reduced affinity for X-linked IAP (XIAP), in order to focus SMs antitumor activity on cIAPs degradation. In this work, we describe the crystal structures of the BIR3 domains of cIAP1 and XIAP, each in complex with a cIAP1-selective SM (SM130 and SM114, respectively). The two SMs displayed 23- and 32-fold higher affinity for cIAP1-BIR3 over XIAP-BIR3 in molecular displacement experiments based on fluorescence polarization. In vitro cell-based assays confirmed that both selective SMs triggered apoptosis in cancer cells with different efficiencies by inducing caspases-3, -8, and -9-independent cIAP1 degradation. The design of cIAPs-selective compounds represents an innovative approach in the field of anticancer drugs development, being useful to elucidate different prosurvival mechanisms and to reduce the adverse effects of pan-IAPs compounds in cancer therapy. DATABASE: Structural data are available in the Protein Data Bank database under the accession codes 6EXW (cIAP1-BIR3/SM130 complex) and 6EY2 (XIAP-BIR3/SM114 complex).


Subject(s)
Antineoplastic Agents/pharmacology , Biomimetic Materials/pharmacology , Breast Neoplasms/pathology , Drug Design , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Intracellular Signaling Peptides and Proteins , Mitochondrial Proteins , Amino Acid Sequence , Antineoplastic Agents/chemistry , Apoptosis , Apoptosis Regulatory Proteins , Biomimetic Materials/chemistry , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Caspases/metabolism , Cell Survival , Crystallography, X-Ray , Female , Humans , Inhibitor of Apoptosis Proteins/chemistry , Inhibitor of Apoptosis Proteins/metabolism , Models, Molecular , Protein Binding , Protein Conformation , Protein Domains , Sequence Homology , Tumor Cells, Cultured
19.
Front Chem ; 6: 105, 2018.
Article in English | MEDLINE | ID: mdl-29713626

ABSTRACT

In this work a peptide based gas sensor array based of ZnO nanoparticles (ZnONPs) has been realized. Four different pentapeptides molecularly modeled for alcohols and esters having cysteine as a common spacer have been immobilized onto ZnONPs. ZnONPs have been morphologically and spectroscopically characterized. Modified nanoparticles have been then deposited onto quartz crystal microbalances (QCMs) and used as gas sensors with nitrogen as carrier gas. Analysis of the pure compounds modeled demonstrated a nice fitting of modeling with real data. The peptide based ZnONPs had very low sensitivity to water, compared to previously studied AuNPs peptide based gas sensors allowing the use of the array on samples with high water content. Real samples of fruit juices have been assayed; stability of the signal, good repeatability, and discrimination ability of the array was achieved.

20.
Curr Top Med Chem ; 18(32): 2743-2773, 2018.
Article in English | MEDLINE | ID: mdl-30663568

ABSTRACT

Computer-aided drug discovery (CADD) tools have provided an effective way in the drug discovery pipeline for expediting of this long process and economizing the cost of research and development. Due to the dramatic increase in the availability of human proteins as drug targets and small molecule information due to the advances in bioinformatics, cheminformatics, genomics, proteomics, and structural information, the applicability of in silico drug discovery has been extended. Computational approaches have been used at almost all stages in the drug discovery pipeline including target identification and validation, lead discovery and optimization, and pharmacokinetic and toxicity profiles prediction. As each area covers a variety of computational methods, it is unmanageable to assess comprehensively all areas of CADD applications or every aspect of an area in one review article. However, in this article, we tried to present an overview of computational methods used in almost all the areas concerned with drug design and highlight some of the recent successes.


Subject(s)
Communicable Diseases/drug therapy , Computer Simulation , Computer-Aided Design , Drug Discovery , Computational Biology , Humans , Ligands , Proteins/antagonists & inhibitors , Proteins/chemistry
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