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1.
J Mol Graph Model ; 131: 108813, 2024 Jun 13.
Article En | MEDLINE | ID: mdl-38885553

Despite the waning threat of the COVID-19 pandemic, its detrimental impact on global health persists. Regardless of natural immunity or immunity obtained through vaccination, emerging variants of the virus continue to undergo mutations and propagate globally. The persistent mutations in SARS-CoV-2, along with the subsequent formation of recombinant sub-variants has become a challenge for researchers and health professionals, raising concerns about the efficacy of current vaccines. Gaining a better understanding of the biochemical interactions between the Spike Protein (RBD) of SARS-CoV-2 variants and the human ACE2 receptor can prove to be beneficial in designing and developing antiviral therapeutics that are equally effective against all strains and emerging variants. Our objective in this study was to investigate the interfacial binding pattern of the SARS-CoV-2 RBD-ACE2 complex of the Wild Type (WT), Omicron, and the Omicron recombinant sub-variant XBB.1.16. We aimed to examine the atomic level factors and observe how mutations influence the interaction between the virus and its host using Molecular Dynamics simulation, MM/GBSA energy calculations, and Principal Component Analysis. Our findings reveal a higher degree of structural deviation and flexibility in XBB.1.16 compared to WT and Omicron. PCA indicated a wider cluster and significant flexibility in the movements of XBB.1.16 which can also be observed in free energy landscapes, while the normal mode analysis revealed converging motions within the RBD-ACE2 complexes which can facilitate the interaction between them. A pattern of decreased binding affinity was observed in case of XBB.1.16 when compared to the WT and Omicron. These observed deviations in XBB.1.16 when compared to its parent lineage Omicron, and WT can be attributed to the mutations specific to it. Collectively, these results enhance our understanding of the impact of mutations on the interaction between this strain and the host, taking us one step closer to designing effective antiviral therapeutics against the continually mutating strains.

2.
Front Genet ; 15: 1358134, 2024.
Article En | MEDLINE | ID: mdl-38476402

Passion fruit is widely cultivated in tropical, subtropical regions of the world. The attack of bacterial and fungal diseases, and environmental factors heavily affect the yield and productivity of the passion fruit. The CC-NBS-LRR (CNL) gene family being a subclass of R-genes protects the plant against the attack of pathogens and plays a major role in effector-triggered immunity (ETI). However, no information is available regarding this gene family in passion fruit. To address the underlying problem a total of 25 and 21 CNL genes have been identified in the genome of purple (Passiflora edulis Sims.) and yellow (Passiflora edulis f. flavicarpa) passion fruit respectively. Phylogenetic tree was divided into four groups with PeCNLs present in 3 groups only. Gene structure analysis revealed that number of exons ranged from 1 to 9 with 1 being most common. Most of the PeCNL genes were clustered at the chromosome 3 and underwent strong purifying selection, expanded through segmental (17 gene pairs) and tandem duplications (17 gene pairs). PeCNL genes contained cis-elements involved in plant growth, hormones, and stress response. Transcriptome data indicated that PeCNL3, PeCNL13, and PeCNL14 were found to be differentially expressed under Cucumber mosaic virus and cold stress. Three genes were validated to be multi-stress responsive by applying Random Forest model of machine learning. To comprehend the biological functions of PeCNL proteins, their 3D structure and gene ontology (GO) enrichment analysis were done. Our research analyzed the CNL gene family in passion fruit to understand stress regulation and improve resilience. This study lays the groundwork for future investigations aimed at enhancing the genetic composition of passion fruit to ensure robust growth and productivity in challenging environments.

3.
Mol Divers ; 2024 Feb 17.
Article En | MEDLINE | ID: mdl-38366102

Given the increasing effectiveness of immune-based therapies, management of their associated toxicities is of utmost importance. Cytokine release syndrome (CRS), characterized by elevated levels of cytokine, poses a significant challenge following the administration of antibodies and CAR-T cell therapies. CRS also contributes to multiple organ dysfunction in severe viral infections, notably in COVID-19. Given the pivotal role of IL-6 cytokine in initiating CRS, it has been considered a most potential therapeutic target to mitigate hyperactivated immune responses. While monoclonal antibodies of IL-6 show promise in mitigating cytokine storm, concerns about immunotoxicity persist, and small molecule IL-6 antagonists remain unavailable. The present study employed sophisticated computational techniques to identify potential hit compounds as IL-6 inhibitors, with the aim of inhibiting IL-6/IL-6R protein-protein interactions. Through ligand-based pharmacophore mapping and shape similarity in combination with docking-based screening, we identified nine hit compounds with diverse chemical scaffolds as potential binders of IL-6. Further, the MD simulation of 300 ns of five virtual hits in a complex with IL-6 was employed to study the dynamic behavior. To provide a more precise prediction, binding free energy was also estimated. The identified compounds persistently interacted with the residues lining the binding site of the IL-6 protein. These compounds displayed low binding energy during MMPBSA calculations, substantiating their strong association with IL-6. This study suggests promising scaffolds as potential inhibitors of IL-6/IL-6R protein-protein interactions and provides direction for lead optimization.

4.
J Biomol Struct Dyn ; 42(7): 3630-3640, 2024 Apr.
Article En | MEDLINE | ID: mdl-37216319

Interleukin-2-inducible T-cell kinase (ITK) is a crucial intracellular signaling mediator in normal and malignant T-cells and natural killer cells. Selective inhibition of ITK might be useful for treating a variety of disorders including; autoimmune, inflammatory, and neoplastic disorders. Over the past two decades, the clinical management of ITK inhibitors has progressed dramatically. So far, specific inhibitor with no off-target effects against ITK is available. Herein, we aim to discover potential virtual hits to fasten the process of drug design and development against ITK. In this regard, the key chemical characteristics of ITK inhibitors were identified using ligand-based pharmacophore modeling. The validated pharmacophore comprises one hydrogen bond donor and three hydrogen bond acceptors and was utilized as a 3D query in virtual screening using ZINC, Covalent, and in-house databases. A total of 12 hit compounds were chosen on the basis of their critical interactions with the significant amino acids of ITK. The orbital energies such as HOMO and LUMO of the hit compounds were calculated to evaluate the inhibitor's potencies. Further, molecular dynamics simulation demonstrated the stability of ITK upon binding of selected virtual hits. Binding energy using the MMGBSA method showed the potential binding affinity of all the hits with ITK. The research identifies key chemical characteristics with geometric restrictions that lead to ITK inhibition.Communicated by Ramaswamy H. Sarma.


Interleukin-2 , Ligands , Molecular Dynamics Simulation , Drug Design , Molecular Docking Simulation
5.
Front Pharmacol ; 14: 1133809, 2023.
Article En | MEDLINE | ID: mdl-36969847

Currently, acetylcholinesterase (AChE) inhibiting drugs in clinical use, such as tacrine, donepezil, rivastigmine, and galanthamine, are associated with serious side effects and short half-lives. In recent years, numerous phytochemicals have been identified as inhibitors of cholinesterases with potential applications in the management of Alzheimer's disease (AD). In this study three natural coumarins, 2'-O-ethylmurrangatin (1), murranganone (2), and paniculatin (3) isolated previously by our group from the leaves of Murraya paniculata, were tested against the two cholinesterases (ChE) enzymes, AChE and butyrylcholinesterase (BChE) using in vitro assay. Molecular docking was performed to highlight the structural properties that contribute to the molecular recognition pattern in the inhibition of ChE and the structural differences resulting in the selectivity of these compounds toward AChE. Classical enzyme inhibition kinetics data suggested that compounds 2 and 3 were potent inhibitors of AChE and BChE, while 1 was found inactive against both enzymes. The findings from molecular docking studies revealed the competitive and non-competitive inhibition mechanisms of compounds 2 and 3 against both enzymes. Molecular docking and simulations have revealed that hydrogen bonding, mediated by ketone and hydroxyl functionalities in various positions, significantly contributes to the binding of the inhibitor to the receptor. According to MD simulation studies, the stability of the ligand-AChE complex for the most active compound (3) is found to be comparable to that of the widely used drug Tacrine. In addition, to evaluate the drug-likeness of compounds, in silico ADME evaluation was performed, and the compounds presented good ADME profiles. Data suggested that the coumarin nucleus having diverse side chains at the C-8 position can serve as a potential inhibitor of cholinesterases and can act as a lead to develop a new semisynthetic drug for the treatment of AD.

6.
Int J Mol Sci ; 23(19)2022 Oct 06.
Article En | MEDLINE | ID: mdl-36233160

The search for an effective anti-viral to inhibit COVID-19 is a challenge for the specialized scientific research community. This work investigated the anti-coronavirus activity for spirooxindole-based phenylsulfone cycloadducts in a single and combination protocols. The newly designed anti-SARS-CoV-2 therapeutics spirooxindoles synthesized by [3 + 2] cycloaddition reactions represent an efficient approach. One-pot multicomponent reactions between phenyl vinyl sulfone, substituted isatins, and amines afforded highly stereoselective anti-SARS-CoV-2 therapeutics spirooxindoles with three stereogenic centers. Herein, the newly synthesized spirooxindoles were assessed individually against the highly pathogenic human coronaviruses and proved to be highly potent and safer. Interestingly, the synergistic effect by combining the potent, tested spirooxindoles resulted in an improved antiviral activity as well as better host-cell safety. Compounds 4i and 4d represented the most potent activity against MERS-CoV with IC50 values of 11 and 23 µM, respectively. Both compounds 4c and 4e showed equipotent activity with the best IC50 against SARS-CoV-2 with values of 17 and 18 µM, respectively, then compounds 4d and 4k with IC50 values of 24 and 27 µM, respectively. Then, our attention oriented to perform a combination protocol as anti-SARS-CoV-2 for the best compounds with a different binding mode and accompanied with different pharmacophores. Combination of compound 4k with 4c and combination of compounds 4k with 4i proved to be more active and safer. Compounds 4k with 4i displayed IC50 = 3.275 µM and half maximal cytotoxic-concentration CC50 = 11832 µM. MD simulation of the most potential compounds as well as in silico ADMET properties were investigated. This study highlights the potential drug-like properties of spirooxindoles as a cocktail anti-coronavirus protocol.


COVID-19 Drug Treatment , Middle East Respiratory Syndrome Coronavirus , Amines/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Humans , Molecular Docking Simulation , SARS-CoV-2
7.
Front Genet ; 13: 1034921, 2022.
Article En | MEDLINE | ID: mdl-36303546

Cyclic nucleotide-gated channels (CNGC) gene family has been found to be involved in physiological processes including signaling pathways, environmental stresses, plant growth, and development. This gene family of non-selective cation channels is known to regulate the uptake of calcium and is reported in several plant species. The pangenome-wide studies enable researchers to understand the genetic diversity comprehensively; as a comparative analysis of multiple plant species or member of a species at once helps to better understand the evolutionary relationships and diversity present among them. In the current study, pangenome-wide analysis of the CNGC gene family has been performed on five Citrus species. As a result, a total of 32 genes in Citrus sinensis, 27 genes in Citrus recticulata, 30 genes in Citrus grandis, 31 genes in Atalantia buxfolia, and 30 genes in Poncirus trifoliata were identified. In addition, two unique genes CNGC13 and CNGC14 were identified, which may have potential roles. All the identified CNGC genes were unevenly distributed on 9 chromosomes except P. trifoliata had genes distributed on 7 chromosomes and were classified into four major groups and two sub-groups namely I, II, III, IV-A, and IV-B. Cyclic nucleotide binding (CNB) motif, calmodulin-binding motif (CaMB), and motif for IQ-domain were conserved in Citrus Spp. Intron exon structures of citrus species were not exactly as same as the gene structures of Arabidopsis. The majority of cis-regulatory elements (CREs) were light responsive and others include growth, development, and stress-related indicating potential roles of the CNGC gene family in these functions. Both segmental and tandem duplication were involved in the expansion of the CNGC gene family in Citrus Spp. The miRNAs are involved in the response of CsCNGC genes towards drought stress along with having regulatory association in the expression of these genes. Protein- Protein interaction (PPI) analysis also showed the interaction of CNGC proteins with other CNGCs which suggested their potential role in pathways regulating different biological processes. GO enrichment revealed that CNGC genes were involved in the transport of ions across membranes. Furthermore, tissue-specific expression patterns of leaves sample of C. sinensis were studied under drought stress. Out of 32 genes of C. sinensis 3 genes i.e., CsCNGC1.4, CsCNGC2.1, and CsCNGC4.2 were highly up-regulated, and only CsCNGC4.6 was highly down-regulated. The qRT-PCR analysis also showed that CNGC genes were highly expressed after treatment with drought stress, while gene expression was lower under controlled conditions. This work includes findings based on multiple genomes instead of one, therefore, this will provide more genomic information rather than single genome-based studies. These findings will serve as a basis for further functional insights into the CNGC gene family.

8.
Comput Biol Chem ; 101: 107774, 2022 Dec.
Article En | MEDLINE | ID: mdl-36162184

Interleukin-1ß (IL1ß) is a keynote mediator of inflammation with diverse physiological functions, playing a fundamental role in memory and mood regulation. The pleiotropic effects of IL-1ß have been proposed to be implicated in the pathogenesis and etiology of depression. Thus, targeting IL-1ß offers an inimitable opportunity to develop new strategies for an alternative therapy to treat depression. The focus of this study is to find out the potential inhibitors against IL-1ß. Since, there is no oral specific drug reported yet thus, demanding an urgent need to develop new immunomodulatory drugs to combat chronic diseases. In this study, ligand-based pharmacophore modeling integrated with virtual screening and molecular docking strategy was designed to identify novel compounds capable of inhibiting the interactions towards cognitive receptor IL-1RI. In this connection, a set of 30,000 compounds were screened by a developed pharmacophore model that led to the retrieval of 2043 molecules from the in-house library and ZINC Database. Primarily, specific binding regions for IL-1ß inhibitors have been explored by blind docking studies. After the selection of the binding site, the hits identified as actives based on the 3D-pharmacophore model were assessed by molecular docking studies. In a stepwise screening, six potential virtual hits were shortlisted for molecular dynamic simulation to acquire insights into their dynamic behavior. The obtained results highlighted that these compounds are stabilized in the targeted pocket of IL-1ß and possibly block the formation of an active heterocomplex, subsequently locking the associated signaling cascade. Further in vitro experiments confirmed the inhibitory potential of Compound-157 and compound-283 with the IC50 of 1.6 ± 0.1 and 9.1 ± 1.7 µg/mL respectively.


Depression , Quantitative Structure-Activity Relationship , Molecular Docking Simulation , Interleukin-1beta , Molecular Dynamics Simulation , Ligands , Anti-Inflammatory Agents/pharmacology
9.
Int J Mol Sci ; 23(18)2022 Sep 07.
Article En | MEDLINE | ID: mdl-36142242

During the past two decades, the world has witnessed the emergence of various SARS-CoV-2 variants with distinct mutational profiles influencing the global health, economy, and clinical aspects of the COVID-19 pandemic. These variants or mutants have raised major concerns regarding the protection provided by neutralizing monoclonal antibodies and vaccination, rates of virus transmission, and/or the risk of reinfection. The newly emerged Omicron, a genetically distinct lineage of SARS-CoV-2, continues its spread in the face of rising vaccine-induced immunity while maintaining its replication fitness. Efforts have been made to improve the therapeutic interventions and the FDA has issued Emergency Use Authorization for a few monoclonal antibodies and drug treatments for COVID-19. However, the current situation of rapidly spreading Omicron and its lineages demands the need for effective therapeutic interventions to reduce the COVID-19 pandemic. Several experimental studies have indicated that the FDA-approved monoclonal antibodies are less effective than antiviral drugs against the Omicron variant. Thus, in this study, we aim to identify antiviral compounds against the Spike protein of Omicron, which binds to the human angiotensin-converting enzyme 2 (ACE2) receptor and facilitates virus invasion. Initially, docking-based virtual screening of the in-house database was performed to extract the potential hit compounds against the Spike protein. The obtained hits were optimized by DFT calculations to determine the electronic properties and molecular reactivity of the compounds. Further, MD simulation studies were carried out to evaluate the dynamics of protein-ligand interactions at an atomistic level in a time-dependent manner. Collectively, five compounds (AKS-01, AKS-02, AKS-03, AKS-04, and AKS-05) with diverse scaffolds were identified as potential hits against the Spike protein of Omicron. Our study paves the way for further in vitro and in vivo studies.


Angiotensin-Converting Enzyme 2 , COVID-19 Drug Treatment , Antibodies, Monoclonal , Antibodies, Viral , Antiviral Agents/pharmacology , Cheminformatics , Humans , Ligands , Pandemics , Peptidyl-Dipeptidase A/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
10.
Biomed Res Int ; 2022: 6865472, 2022.
Article En | MEDLINE | ID: mdl-35865666

Betamethasone is an important glucocorticoids (GCs), frequently used to cure allergies (such as asthma and angioedema), Crohn's disease, skin diseases (such as dermatitis and psoriasis), systemic lupus erythematosus, rheumatic disorders, and leukemia. Present investigation deals to find potential agonist of glucocorticoid receptors after biotransformation of betamethasone dipropionate (1) and to carry out the molecular docking and ADME analyses. Biotransformation of 1 was carried out with Launaea capitata (dandy) roots and Musa acuminate (banana) leaves. M. acuminate furnished low-cost value-added products such as Sananone dipropionate (2) in 5% yields. Further, biocatalysis of Sananone dipropionate (2) with M. acuminate gave Sananone propionate (3) and Sananone (4) in 12% and 7% yields, respectively. However, Sananone (4) was obtained in 37% yields from Launaea capitata. Compound 5 was obtained in 11% yield after ß-elimination of propionic acid at C-17 during oxidation of compound 1. The structure elucidation of new compounds 2-5 was accomplished through combined use of X-ray diffraction and NMR (1D and 2D) studies. In addition to this, molecular docking and ADME analyses of all transformed products of 1 were also done. Compounds 1-5 showed -12.53 to -10.11 kcal/mol potential binding affinity with glucocorticoid receptor (GR) and good ADME profile. Moreover, all the compounds showed good oral bioavailability with the octanol/water partition coefficient in the range of 2.23 to 3.65, which indicated that compounds 1-5 were in significant agreement with the given criteria to be considered as drug-like.


Dermatologic Agents , Psoriasis , Betamethasone/analogs & derivatives , Biotransformation , Dermatologic Agents/therapeutic use , Humans , Molecular Docking Simulation , Psoriasis/drug therapy , Receptors, Glucocorticoid
11.
Front Chem ; 10: 892093, 2022.
Article En | MEDLINE | ID: mdl-35755247

The pandemic of COVID-19, caused by SARS-CoV-2, has globally affected the human health and economy. Since the emergence of the novel coronavirus SARS-CoV-2, the life-threatening virus continues to mutate and evolve. Irrespective of acquired natural immunity and vaccine-induced immunity, the emerging multiple variants are growing exponentially, crossing the territorial barriers of the modern world. The rapid emergence of SARS-CoV-2 multiple variants challenges global researchers regarding the efficacy of available vaccines and variant transmissibility. SARS-CoV-2 surface-anchored S-protein recognizes and interacts with the host-cell ACE2, facilitating viral adherence and entrance into the cell. Understanding the interfacial interactions between the spike protein of SARS-CoV-2 variants and human ACE2 receptor is important for the design and development of antiviral therapeutics against SARS-CoV-2 emerging variants. Despite extensive research, the crucial determinants related to the molecular interactions between the spike protein of SARS-CoV-2 variants and host receptors are poorly understood. Thus, in this study, we explore the comparative interfacial binding pattern of SARS-CoV-2 spike RBD of wild type, Delta, and Omicron with the human ACE2 receptor to determine the crucial determinants at the atomistic level, using MD simulation and MM/GBSA energy calculations. Based on our findings, the substitution of Q493R, G496S, Q498R, and Y505H induced internal conformational changes in Omicron spike RBD, which leads to higher binding affinity than Delta spike RBD with the human ACE2 receptor, eventually contributing to higher transmission and infectivity. Taken together, these results could be used for the structure-based design of effective antiviral therapeutics against SARS-CoV-2 variants.

12.
J Biomol Struct Dyn ; 40(23): 12964-12974, 2022.
Article En | MEDLINE | ID: mdl-34632940

The Galaninergic system consist of Galanin and its receptors, involved in neuromodulation and neurotransmission. Galanin regulate its physiologic and pathologic functions by interacting with three G-protein coupled receptors; GalR1, GalR2 and GalR3. The widespread distribution of Galanin and its receptor subtypes in central and peripheral nervous system makes them an attractive drug target for the treatment of neurological diseases. However, subtypes selective ligands paucity and little structural information related to either Galanin receptors and Galanin receptor-ligand complexes hampered the structure-based drug design. Thus computational modeling characterization strategy was utilized for Galanin receptor 3D structure prediction and subtypes ligands binding selectivity. Reported ligands with experimental activity were docked against the homology model of Galanin receptors. Further, the MD simulation and binding free energy calculation were carried out to determine the binding interactions pattern consistency and selectivity towards receptor subtype. Results of binding free energy of per residue indicate key contribution of GalR1 Phe115 and His267 in the selective binding of ligands while Tyr103, Tyr270 and His277 play major role in the selective binding of GalR3 ligands. Our study provide rationale for further in silico virtual screening of small molecules for the development of selective ligands against Galanin receptor subtypes.Communicated by Ramaswamy H. Sarma.


Galanin , Receptor, Galanin, Type 2 , Receptors, Galanin/metabolism , Galanin/chemistry , Galanin/metabolism , Ligands , Receptor, Galanin, Type 2/chemistry , Receptor, Galanin, Type 2/metabolism , Protein Binding
13.
J Biomol Struct Dyn ; 40(8): 3777-3788, 2022 05.
Article En | MEDLINE | ID: mdl-33251983

The COVID-19 pandemic has claimed more than a million lives worldwide within a short time span. Due to the unavailability of specific antiviral drugs or vaccine, the infections are causing panic both in general public and among healthcare providers. Therefore, an urgent discovery and development of effective antiviral drug for the treatment of COVID-19 is highly desired. Targeting the main protease (Mpro) of the causative agent, SARS-CoV-2 has great potential for drug discovery and drug repurposing efforts. Published crystal structures of SARS-CoV-2 Mpro further facilitated in silico investigations for discovering new inhibitors against Mpro. The present study aimed to screen several libraries of synthetic flavonoids and benzisothiazolinones as potential SARS-CoV-2 Mpro inhibitors using in silico methods. The short-listed compounds after virtual screening were filtered through SwissADME modeling tool to remove molecules with unfavorable pharmacokinetics and medicinal properties. The drug-like molecules were further subjected to iterative docking for the identification of top binders of SARS-CoV-2 Mpro. Finally, molecular dynamic (MD) simulations and binding free energy calculations were performed for the evaluation of the dynamic behavior, stability of protein-ligand complex, and binding affinity, resulting in the identification of thioflavonol, TF-9 as a potential inhibitor of Mpro. The computational studies further revealed the binding of TF-9 close to catalytic dyad and interactions with conserved residues in the S1 subsite of the substrate binding site. Our in-silico study demonstrated that synthetic analogs of flavonoids, particularly thioflavonols, have a strong tendency to inhibit the main protease Mpro, and thereby inhibit the reproduction of SARS-CoV-2. Communicated by Ramaswamy H. Sarma.


Antiviral Agents , COVID-19 Drug Treatment , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Coronavirus 3C Proteases , Flavonoids/pharmacology , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Pandemics , Peptide Hydrolases , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , SARS-CoV-2
14.
J Mol Struct ; 1231: 129953, 2021 May 05.
Article En | MEDLINE | ID: mdl-33500591

The pandemic of COVID-19 has an unprecedented impact on global health and economy. The novel SARS-CoV-2 is recognized as the etiological agent of current outbreak. Because of its contagious human-to-human transmission, it is an utmost global health emergency at present. To mitigate this threat many scientists and researchers are racing to develop antiviral therapy against the virus. Unfortunately, to date no vaccine or antiviral therapeutic is approved thus there is an urgent need to discover antiviral agent to help the individual who are at high risk. Virus main protease or chymotrypsin-like protease plays a pivotal role in virus replication and transcription; thus, it is considered as an attractive drug target to combat the COVID-19. In this study, multistep structure based virtual screening of CAS antiviral database is performed for the identification of potent and effective small molecule inhibitors against chymotrypsin-like protease of SARS-CoV-2. Consensus scoring strategy combine with flexible docking is used to extract potential hits. As a result of extensive virtual screening, 4 hits were shortlisted for MD simulation to study their stability and dynamic behavior. Insight binding modes demonstrated that the selected hits stabilized inside the binding pocket of the target protein and exhibit complementarity with the active site residues. Our study provides compounds for further in vitro and in vivo studies against SARS-CoV-2.

15.
J Biomol Struct Dyn ; 39(7): 2607-2616, 2021 04.
Article En | MEDLINE | ID: mdl-32238094

Recently, the world has witnessed outbreak of a novel Coronavirus (SARS-CoV-2), the virus which initially emerged in Wuhan, China has now made its way to a large part of the world, resulting in a public emergency of international concern. The functional importance of Chymotrypsin-like protease (3CLpro) in viral replication and maturation turns it into an attractive target for the development of effective antiviral drugs against SARS and other coronaviruses. At present, there is no standard drug regime nor any vaccine available against the infection. The rapid development and identification of efficient interventions against SARS-CoV-2 remains a major challenge. Based on the available knowledge of closely related coronavirus and their safety profiles, repurposing of existing antiviral drugs and screening of available databases is considered a near term strategic and economic way to contain the SARS-CoV-2 pandemic. Herein, we applied computational drug design methods to identify Chymotrypsin-like protease inhibitors from FDA approved antiviral drugs and our in-house database of natural and drug-like compounds of synthetic origin. As a result three FDA approved drugs (Remdesivir, Saquinavir and Darunavir) and two natural compounds (. flavone and coumarine derivatives) were identified as promising hits. Further, MD simulation and binding free energy calculations were performed to evaluate the dynamic behavior, stability of protein-ligand contact, and binding affinity of the hit compounds. Our results indicate that the identified compounds can inhibit the function of Chymotrypsin-like protease (3CLpro) of Coronavirus. Considering the severity of the spread of coronavirus, the current study is in-line with the concept of finding the new inhibitors against the vital pathway of the corona virus to expedite the process of drug discovery.Communicated by Ramaswamy H. Sarma.


COVID-19 , SARS-CoV-2 , Chymases , Humans , Molecular Docking Simulation , Pandemics , Protease Inhibitors/pharmacology
16.
Sci Rep ; 10(1): 20974, 2020 12 01.
Article En | MEDLINE | ID: mdl-33262408

Tumor Necrosis Factor Alpha (TNF-α) is a pleiotropic pro-inflammatory cytokine. It act as central biological regulator in critical immune functions, but its dysregulation has been linked with a number of diseases. Inhibition of TNF-α has considerable therapeutic potential for diseases such as cancer, diabetes, and especially autoimmune diseases. Despite the fact that many small molecule inhibitors have been identified against TNF-α, no orally active drug has been reported yet which demand an urgent need of a small molecule drug against TNF-α. This study focuses on the development of ligand-based selective pharmacophore model to perform virtual screening of plant origin natural product database for the identification of potential inhibitors against TNF-α. The resultant hits, identified as actives were evaluated by molecular docking studies to get insight into their potential binding interaction with the target protein. Based on pharmacophore matching, interacting residues, docking score, more affinity towards TNF-α with diverse scaffolds five compounds were selected for in vitro activity study. Experimental validation led to the identification of three chemically diverse potential compounds with the IC50 32.5 ± 4.5 µM, 6.5 ± 0.8 µM and 27.4 ± 1.7 µM, respectively.


Computer Simulation , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Biological Assay , Drug Evaluation, Preclinical , Humans , Inhibitory Concentration 50 , Molecular Docking Simulation , Reproducibility of Results , THP-1 Cells
17.
Eur J Dent ; 13(1): 124-128, 2019 Feb.
Article En | MEDLINE | ID: mdl-31170770

Nuclear magnetic resonance (NMR) spectroscopy is one of the most significant analytical techniques that has been developed in the past few decades. A broad range of biological and nonbiological applications ranging from an individual cell to organs and tissues has been investigated through NMR. Various aspects of this technique are still under research, and many functions of the NMR are still pending a better understanding and acknowledgment. Therefore, this review is aimed at providing a general overview of the main principles, types of this technique, and the advantages and disadvantages of NMR spectroscopy. In addition, an insight into the current uses of NMR in the field of medicine and dentistry and ongoing developments of NMR spectroscopy for future applications has been discussed.

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