scholarly journals Chalcones identify cTXNPx as a potential antileishmanial drug target

2021 ◽  
Vol 15 (11) ◽  
pp. e0009951
Author(s):  
Douglas O. Escrivani ◽  
Rebecca L. Charlton ◽  
Marjolly B. Caruso ◽  
Gabriela A. Burle-Caldas ◽  
Maria Paula G. Borsodi ◽  
...  
Keyword(s):  
Drug Targets ◽  
Homology Model ◽  
Life Forms ◽  
Docking Studies ◽  
Cysteine Residue ◽  
Drug Lead ◽  
Ros Accumulation ◽  
Antileishmanial Drug ◽  
Drug Treatments ◽  
Tryparedoxin Peroxidase

With current drug treatments failing due to toxicity, low efficacy and resistance; leishmaniasis is a major global health challenge that desperately needs new validated drug targets. Inspired by activity of the natural chalcone 2’,6’-dihydroxy-4’-methoxychalcone (DMC), the nitro-analogue, 3-nitro-2’,4’,6’- trimethoxychalcone (NAT22, 1c) was identified as potent broad spectrum antileishmanial drug lead. Structural modification provided an alkyne containing chemical probe that labelled a protein within the parasite that was confirmed as cytosolic tryparedoxin peroxidase (cTXNPx). Crucially, labelling is observed in both promastigote and intramacrophage amastigote life forms, with no evidence of host macrophage toxicity. Incubation of the chalcone in the parasite leads to ROS accumulation and parasite death. Deletion of cTXNPx, by CRISPR-Cas9, dramatically impacts upon the parasite phenotype and reduces the antileishmanial activity of the chalcone analogue. Molecular docking studies with a homology model of in-silico cTXNPx suggest that the chalcone is able to bind in the putative active site hindering access to the crucial cysteine residue. Collectively, this work identifies cTXNPx as an important target for antileishmanial chalcones.

scholarly journals Computational Identification of Drug Lead Compounds for COVID-19 from Moringa Oleifera

2020 ◽  
Author(s):  
Dr. Divya Shaji
Keyword(s):  
Molecular Docking ◽  
Drug Targets ◽  
Moringa Oleifera ◽  
Docking Studies ◽  
World Health ◽  
Lipinski’S Rule ◽  
Lead Compounds ◽  
Global Pandemic ◽  
Drug Lead ◽  
Health Organization

<div>COVID-19 which is caused by the virus SARS-CoV-2, has now been declared a global pandemic by the World Health Organization. At present, no specific vaccines or drugs are available to treat COVID-19. Therefore, there is an urgent need for the identification of novel drug lead compounds</div><div>to treat COVID-19. The SARS-CoV-2 main protease (Mpro also known as 3CLpro) and RNA-dependent RNA polymerase (RdRp also known as nsp12) are the best-characterized drug targets among corona viruses. In order to discover the natural lead compounds for SARS-CoV-2, we</div><div>performed molecular docking with the compounds from <i>Moringa Oleifera</i> that target the Mpro and RdRp. The molecular docking studies were carried out using AutoDock Vina through PyRx. Drug-likeness property of the selected compounds was checked by applying the ‘Lipinski’s rule of five’ using Swiss ADME. The top four compounds with most favourable binding affinity were selected for each of the targets. The results indicated that the compounds kaempferol, pterygospermin, morphine and quercetin exhibited best binding energy towards Mpro and RdRp. This study suggests that these natural compounds could be promising candidates for further evaluation of COVID-19 prevention.</div>

scholarly journals Computational Identification of Drug Lead Compounds for COVID-19 from Moringa Oleifera

2020 ◽  
Author(s):  
Dr. Divya Shaji
Keyword(s):  
Molecular Docking ◽  
Drug Targets ◽  
Moringa Oleifera ◽  
Docking Studies ◽  
World Health ◽  
Lipinski’S Rule ◽  
Lead Compounds ◽  
Global Pandemic ◽  
Drug Lead ◽  
Health Organization

<div>COVID-19 which is caused by the virus SARS-CoV-2, has now been declared a global pandemic by the World Health Organization. At present, no specific vaccines or drugs are available to treat COVID-19. Therefore, there is an urgent need for the identification of novel drug lead compounds</div><div>to treat COVID-19. The SARS-CoV-2 main protease (Mpro also known as 3CLpro) and RNA-dependent RNA polymerase (RdRp also known as nsp12) are the best-characterized drug targets among corona viruses. In order to discover the natural lead compounds for SARS-CoV-2, we</div><div>performed molecular docking with the compounds from <i>Moringa Oleifera</i> that target the Mpro and RdRp. The molecular docking studies were carried out using AutoDock Vina through PyRx. Drug-likeness property of the selected compounds was checked by applying the ‘Lipinski’s rule of five’ using Swiss ADME. The top four compounds with most favourable binding affinity were selected for each of the targets. The results indicated that the compounds kaempferol, pterygospermin, morphine and quercetin exhibited best binding energy towards Mpro and RdRp. This study suggests that these natural compounds could be promising candidates for further evaluation of COVID-19 prevention.</div>

Substituted 6,7-dimethoxy-5-oxo-2,3,5,9b-tetrahydrothiazolo[2,3-a]isoindole- 3-1,1-dioxide Derivatives with Antimicrobial Activity and Docking Assisted Prediction of the Mechanism of their Antibacterial and Antifungal Properties

2020 ◽  
Vol 20 (29) ◽  
pp. 2681-2691
Author(s):  
Athina Geronikaki ◽  
Victor Kartsev ◽  
Phaedra Eleftheriou ◽  
Anthi Petrou ◽  
Jasmina Glamočlija ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Drug Targets ◽  
Bacterial Species ◽  
Pharmaceutical Research ◽  
Docking Studies ◽  
Fungal Species ◽  
Docking Analysis ◽  
E Coli ◽  
Antibacterial And Antifungal

Background: Although a great number of the targets of antimicrobial therapy have been achieved, it remains among the first fields of pharmaceutical research, mainly because of the development of resistant strains. Docking analysis may be an important tool in the research for the development of more effective agents against specific drug targets or multi-target agents 1-3. Methods: In the present study, based on docking analysis, ten tetrahydrothiazolo[2,3-a]isoindole derivatives were chosen for the evaluation of the antimicrobial activity. Results: All compounds showed antibacterial activity against eight Gram-positive and Gram-negative bacterial species being, in some cases, more potent than ampicillin and streptomycin against all species. The most sensitive bacteria appeared to be S. aureus and En. Cloacae, while M. flavus, E. coli and P. aeruginosa were the most resistant ones. The compounds were also tested for their antifungal activity against eight fungal species. All compounds exhibited good antifungal activity better than reference drugs bifonazole (1.4 – 41 folds) and ketoconazole (1.1 – 406 folds) against all fungal species. In order to elucidate the mechanism of action, docking studies on different antimicrobial targets were performed. Conclusion: According to docking analysis, the antifungal activity can be explained by the inhibition of the CYP51 enzyme for most compounds with a better correlation of the results obtained for the P.v.c. strain (linear regression between estimated binding Energy and log(1/MIC) with R 2 =0.867 and p=0.000091 or R 2 = 0.924, p= 0.000036, when compound 3 is excluded.

IDENTIFICATION OF SELETIVE CLAUDIN CATION CHANNEL BLOCKERS

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S25-S26
Author(s):  
Jingjing Ma ◽  
Emma Wu ◽  
Ye Li ◽  
William Seibel ◽  
Le Shen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Homology Model ◽  
Docking Studies ◽  
Channel Blockers ◽  
Binding Modes ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Dynamics Simulations ◽  
In Silico Models

Abstract Compromised epithelial barrier function is known to be associated with inflammatory bowel disease (IBD) and may contribute to disease development. One mechanism of barrier dysfunction is increased expression of paracellular tight junction ion and water channels formed by claudins. Claudin-2 and -15 are two such channels. We hypothesize that blocking these channels could be a viable therapeutic approach to treat diarrhea. In an effort to develop blockers of these channels, we turn to our previously developed and validated in silico models of claudin-15 (Samanta et al. 2018). We reasoned that compounds that can bind with the interior of claudin pores can limit paracellular water and ion flux. Thus, we used docking algorithms to search for putative small molecules that bind in the claudin-15 pore. AutoDock Vina was initially used to assess rigid docking using small compound databases. The small molecules were analyzed based on binding affinity to the pore and visualized using VMD for their potential blockage of the channel. Clusters of binding modes were identified based on the prominent interacting residues of the protein with the small molecules. We initially screened 10,500 compounds from within the UIC Centre for Drug Discovery and a cross-section of 10,000 compounds from the NCI open compound repository. This initial screen allowed us to identify 2 first-in-class selective claudin-15 blockers with efficacy in MDCK monolayers induced to express claudin-15 and in wildtype duodenum. Next, we screened the entire NCI open compound repository for additional molecules structurally related to our best initially identified molecule and this has allowed us to identify 13 additional molecules that increase TER of claudin-15 expressing MDCK monolayers by 90–160%. Additionally, these molecules possess similar structural components that will be collected in a fragment library and explored through molecular dynamics simulations. We also developed a claudin-2 homology model on which we are performing docking studies and in vitro measurements, which we expect will result in similar candidate ligands for blocking claudin-2. Our study will provide important insight into the role of claudin-dependent cation permeability in fundamental physiology, which we believe will lead to the utility of claudin blockers as a novel and much needed approach to treat diseases such as IBD.

scholarly journals New chemical tools for probing activity and inhibition of the NAD + -dependent lysine deacylase sirtuin 2

2018 ◽  
Vol 373 (1748) ◽  
pp. 20170083 ◽  
Author(s):  
Sören Swyter ◽  
Matthias Schiedel ◽  
Daria Monaldi ◽  
Sándor Szunyogh ◽  
Attila Lehotzky ◽  
...  
Keyword(s):  
Drug Targets ◽  
Docking Studies ◽  
Molecular Tools ◽  
Molecule Inhibitor ◽  
Cellular Target ◽  
Library Screen ◽  
Dependent Protein ◽  
Chemical Tools ◽  
Substrate Proteins ◽  
Potential Therapeutics

Sirtuins are NAD + -dependent protein deacylases capable of cleaving off acetyl as well as other acyl groups from the ɛ-amino group of lysines in histones and other substrate proteins. They have been reported as promising drug targets, and thus modulators of their activity are needed as molecular tools to uncover their biological function and as potential therapeutics. Here, we present new assay formats that complement existing assays for sirtuin biochemistry and cellular target engagement. Firstly, we report the development of a homogeneous fluorescence-based activity assay using unlabelled acylated peptides. Upon deacylation, the free lysine residue reacts with fluorescamine to form a fluorophore. Secondly, using click chemistry with a TAMRA-azide on a propargylated sirtuin inhibitor, we prepared the first fluorescently labelled small-molecule inhibitor of Sirt2. This is used in a binding assay, which is based on fluorescence polarization. We used it successfully to map potential inhibitor-binding sites and also to show cellular Sirt2 engagement. By means of these new assays, we were able to identify and characterize novel Sirt2 inhibitors out of a focused library screen. The binding of the identified Sirt2 inhibitors was rationalized by molecular docking studies. These new chemical tools thus can enhance further sirtuin research. This article is part of a discussion meeting issue ‘Frontiers in epigenetic chemical biology'.

P144 IN SILICO IDENTIFICATION OF PUTATITVE CLAUDIN CHANNEL BLOCKERS

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S30-S30
Author(s):  
Emma Wu ◽  
Priyanka Samanta ◽  
Ye Li ◽  
Le Shen ◽  
Fatemeh Khalili ◽  
...  
Keyword(s):  
In Silico ◽  
Homology Model ◽  
Docking Studies ◽  
Channel Blockers ◽  
Barrier Dysfunction ◽  
Dynamic Simulations ◽  
Epithelial Barrier Function ◽  
In Vitro Measurements ◽  
Potential Ligand

Abstract Compromised epithelial barrier function is known to be associated with inflammatory bowel disease (IBD) and may contribute to disease development. One mechanism of barrier dysfunction is increased expression of paracellular tight junction ion and water channels formed by claudins. Claudin-2 and -15 are two such channels. We hypothesize that blocking these channels could be a viable therapeutic approach to treat diarrhea in IBD. In an effort to develop blockers of these channels, we turn to our previously developed and validated in silico models of claudin-15 (Samanta et al. 2018). We reasoned that molecules that can bind with the interior of claudin pores can limit paracellular water and ion flux. Thus, we used docking algorithms to search for putative drugs that bind in the claudin-15 pore. AutoDock Vina (Scripps Research Institute) was initially used to assess rigid docking using small molecule ligand databases. The ligands were analyzed based on binding affinity to the pore and visualized using VMD (University of Illinois at Urbana-Champaign) for their potential blockage of the channel. Overall, a total of eight candidate ligands from the databases were identified: three from the UICentre database of 10000 ligands, one chemically similar structure identified in another online database (Chemspider), and four which are modifications on the chemical structure generated using ChemDraw. The analysis revealed that the eight ligands were docked in two predominant positions. In the first position, the ligands with more rings docked in an almost linear fashion and interacted with both D55 and D64 pore residues. In the second position of binding, the ligands were more flexible and could hence fold to interact only with D55 residues, thus biding predominantly in the center of the pores. To further evaluate these ligands, we will now turn to 1) flexible claudin-15 docking studies, 2) molecular dynamic simulations and, 3) in vitro measurements using monolayers induced to express claudin -15 and claudin-15 mutants. We also developed a claudin-2 homology model on which we will perform docking studies and in vitro measurements, which we expect will result in similar candidate ligands for blocking claudin-2. Finally, other databases will be analyzed for potential ligand blockers of claudin-2 and -15.

scholarly journals A Potential Peptide From Soy Cheese Produced Using Lactobacillus delbrueckii WS4 for Effective Inhibition of SARS-CoV-2 Main Protease and S1 Glycoprotein

2020 ◽  
Vol 7 ◽  
Author(s):  
Rounak Chourasia ◽  
Srichandan Padhi ◽  
Loreni Chiring Phukon ◽  
Md Minhajul Abedin ◽  
Sudhir P. Singh ◽  
...  
Keyword(s):  
Drug Targets ◽  
Docking Studies ◽  
Lactobacillus Delbrueckii ◽  
Amino Acid Residues ◽  
Main Protease ◽  
Effective Inhibition ◽  
Cheese Peptides ◽  
Potential Inhibitors

The COVID-19 pandemic caused by novel SARS-CoV-2 has resulted in an unprecedented loss of lives and economy around the world. In this study, search for potential inhibitors against two of the best characterized SARS-CoV-2 drug targets: S1 glycoprotein receptor-binding domain (RBD) and main protease (3CLPro), was carried out using the soy cheese peptides. A total of 1,420 peptides identified from the cheese peptidome produced using Lactobacillus delbrueckii WS4 were screened for antiviral activity by employing the web tools, AVPpred, and meta-iAVP. Molecular docking studies of the selected peptides revealed one potential peptide “KFVPKQPNMIL” that demonstrated strong affinity toward significant amino acid residues responsible for the host cell entry (RBD) and multiplication (3CLpro) of SARS-CoV-2. The peptide was also assessed for its ability to interact with the critical residues of S1 RBD and 3CLpro of other β-coronaviruses. High binding affinity was observed toward critical amino acids of both the targeted proteins in SARS-CoV, MERS-CoV, and HCoV-HKU1. The binding energy of KFVPKQPNMIL against RBD and 3CLpro of the four viruses ranged from −8.45 to −26.8 kcal/mol and −15.22 to −22.85 kcal/mol, respectively. The findings conclude that cheese, produced by using Lb. delbrueckii WS4, could be explored as a prophylactic food for SARS-CoV-2 and related viruses. In addition, the multi-target inhibitor peptide, which effectively inhibited both the viral proteins, could further be used as a terminus a quo for the in vitro and in vivo function against SARS-CoV-2.

scholarly journals Peroxiredoxins play a major role in protecting Trypanosoma cruzi against macrophage- and endogenously-derived peroxynitrite

2008 ◽  
Vol 410 (2) ◽  
pp. 359-368 ◽  
Author(s):  
Lucía Piacenza ◽  
Gonzalo Peluffo ◽  
María Noel Alvarez ◽  
John M. Kelly ◽  
Shane R. Wilkinson ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Trypanosoma Cruzi ◽  
Fluorescence Probe ◽  
Reactive Oxygen ◽  
Cysteine Residue ◽  
Protective Effects ◽  
Nitrogen Species ◽  
Intact Cells ◽  
Tryparedoxin Peroxidase

There is increasing evidence that Trypanosoma cruzi antioxidant enzymes play a key immune evasion role by protecting the parasite against macrophage-derived reactive oxygen and nitrogen species. Using T. cruzi transformed to overexpress the peroxiredoxins TcCPX (T. cruzi cytosolic tryparedoxin peroxidase) and TcMPX (T. cruzi mitochondrial tryparedoxin peroxidase), we found that both cell lines readily detoxify cytotoxic and diffusible reactive oxygen and nitrogen species generated in vitro or released by activated macrophages. Parasites transformed to overexpress TcAPX (T. cruzi ascorbate-dependent haemoperoxidase) were also more resistant to H2O2 challenge, but unlike TcMPX and TcCPX overexpressing lines, the TcAPX overexpressing parasites were not resistant to peroxynitrite. Whereas isolated tryparedoxin peroxidases react rapidly (k=7.2×105 M−1·s−1) and reduce peroxynitrite to nitrite, our results demonstrate that both TcMPX and TcCPX peroxiredoxins also efficiently decompose exogenous- and endogenously-generated peroxynitrite in intact cells. The degree of protection provided by TcCPX against peroxynitrite challenge results in higher parasite proliferation rates, and is demonstrated by inhibition of intracellular redox-sensitive fluorescence probe oxidation, protein 3-nitrotyrosine and protein–DMPO (5,5-dimethylpyrroline-N-oxide) adduct formation. Additionally, peroxynitrite-mediated over-oxidation of the peroxidatic cysteine residue of peroxiredoxins was greatly decreased in TcCPX overexpressing cells. The protective effects generated by TcCPX and TcMPX after oxidant challenge were lost by mutation of the peroxidatic cysteine residue in both enzymes. We also observed that there is less peroxynitrite-dependent 3-nitrotyrosine formation in infective metacyclic trypomastigotes than in non-infective epimastigotes. Together with recent reports of up-regulation of antioxidant enzymes during metacyclogenesis, our results identify components of the antioxidant enzyme network of T. cruzi as virulence factors of emerging importance.

scholarly journals Aryl-4,5-dihydro-1H-pyrazole-1-carboxamide Derivatives Bearing a Sulfonamide Moiety Show Single-digit Nanomolar-to-Subnanomolar Inhibition Constants against the Tumor-associated Human Carbonic Anhydrases IX and XII

2020 ◽  
Vol 21 (7) ◽  
pp. 2621
Author(s):  
Priya Hargunani ◽  
Nikhil Tadge ◽  
Mariangela Ceruso ◽  
Janis Leitans ◽  
Andris Kazaks ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Inhibitory Activity ◽  
Phenyl Ring ◽  
Drug Targets ◽  
Binding Mode ◽  
Docking Studies ◽  
Carbonic Anhydrases ◽  
Single Digit ◽  
Ca Ix ◽  
Shed Light

A series of new 3-phenyl-5-aryl-N-(4-sulfamoylphenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide derivatives was designed here, synthesized, and studied for carbonic anhydrase (CAs, EC 4.2.1.1) inhibitory activity against the human (h) isozymes I, II, and VII (cytosolic, off-target isoforms), and IX and XII (anticancer drug targets). Generally, CA I was not effectively inhibited, whereas effective inhibitors were identified against both CAs II (KIs in the range of 5.2–233 nM) and VII (KIs in the range of 2.3–350 nM). Nonetheless, CAs IX and XII were the most susceptible isoforms to this class of inhibitors. In particular, compounds bearing an unsubstituted phenyl ring at the pyrazoline 3 position showed 1.3–1.5 nM KIs against CA IX. In contrast, a subset of derivatives having a 4-halo-phenyl at the same position of the aromatic scaffold even reached subnanomolar KIs against CA XII (0.62–0.99 nM). Docking studies with CA IX and XII were used to shed light on the derivative binding mode driving the preferential inhibition of the tumor-associated CAs. The identified potent and selective CA IX/XII inhibitors are of interest as leads for the development of new anticancer strategies.

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