Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 138
Filtrar
1.
Mol Neurobiol ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38814535

RESUMO

Bacopa monnieri (L.) Wettst and Centella asiatica (L.) Urb., two nootropics, are recognized in Indian Ayurvedic texts. Studies have attempted to understand their action as memory enhancers and neuroprotectants, but many molecular aspects remain unknown. We propose that Bacopa monnieri (L.) Wettst and Centella asiatica (L.) Urb. share common neuroprotective mechanisms. Mass spectrometry-based untargeted metabolomics and network pharmacology approach were used to identify potential protein targets for the metabolites from each extract. Phytochemical analyses and cell culture validation studies were also used to assess apoptosis and ROS activity using aqueous extracts prepared from both herbal powders. Further, docking studies were also performed using the LibDock protocol. Untargeted metabolomics and network pharmacology approach unveiled 2751 shared metabolites and 3439 and 2928 non-redundant metabolites from Bacopa monnieri and Centella asiatica extracts, respectively, suggesting a potential common neuroprotective mechanism among these extracts. Protein-target prediction highlighted 92.4% similarity among the proteins interacting with metabolites for these extracts. Among them, kinases mapped to MAPK, mTOR, and PI3K-AKT signaling pathways represented a predominant population. Our results highlight a significant similarity in the metabolome of Bacopa monnieri (L.) Wettst and Centella asiatica (L.) Urb., and their potential protein targets may be attributed to their common neuroprotective functions.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38717066

RESUMO

Background: Chikungunya is a zoonotic disease caused by the Chikungunya virus (CHIKV), primarily transmitted to humans through infected Aedes mosquitoes. The infection is characterized by symptoms such as high fever, musculoskeletal pain, polyarthritis, and a rash, which can lead to severe complications such as encephalitis, meningitis, and even fatalities. While many disease manifestations resemble those of other viral infections, chronic arthritis caused by CHIKV is unique, and its molecular mechanisms remain ill-defined. Materials and Methods: Proteomics data from both cellular and patient levels of CHIKV infection were curated from PubMed and screened using inclusion and exclusion criteria. Patient serum proteomics data obtained from PRIDE underwent reanalysis using Proteome Discoverer 2.2. Enrichment and protein-protein interaction network analysis were conducted on differentially expressed proteins from both serum and cellular datasets. Metabolite data from CHIKV-infected patients were further retrieved, and their protein binding partners were identified using BindingDB. The protein-metabolite interaction pathway was further developed using MetaboAnalyst. Results: The proteomics data analysis revealed differential expression of proteins involved in critical host mechanisms, such as cholesterol metabolism and mRNA splicing, during CHIKV infection. Consistent upregulation of two actin cytoskeleton proteins, TAGLN2 and PFN1, was noted in both serum and cellular datasets, and their upregulations are associated with arthritis. Furthermore, alterations in purine metabolism were observed in the integrative proteome-metabolome analysis, correlating with cytoskeletal remodelling. Conclusion: Collectively, this integrative view sheds light on the involvement of actin cytoskeleton remodeling proteins and purine metabolic pathways in the development of arthritis during CHIKV infection.

3.
Mol Divers ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743308

RESUMO

Alcoholic liver injury resulting from excessive alcohol consumption is a significant social concern. Alcohol dehydrogenase (ADH) plays a critical role in the conversion of alcohol to acetaldehyde, leading to tissue damage. The management of alcoholic liver injury encompasses nutritional support and, in severe cases liver transplantation, but potential adverse effects exist, and effective medications are currently unavailable. Natural products with their potential benefits and historical use in traditional medicine emerge as promising alternatives. Triphala, a traditional polyherbal formula demonstrates beneficial effects in addressing diverse health concerns, with a notable impact on treating alcoholic liver damage through enhanced liver metabolism. The present study aims to identify potential active phytocompounds in Triphala targeting ADH to prevent alcoholic liver injury. Screening 119 phytocompounds from the Triphala formulation revealed 62 of them showing binding affinity to the active site of the ADH1B protein. Promising lipid-like molecule from Terminalia bellirica, (4aS, 6aR, 6aR, 6bR, 7R, 8aR, 9R, 10R, 11R, 12aR, 14bS)-7, 10, 11-trihydroxy-9-(hydroxymethyl)-2, 2, 6a, 6b, 9, 12a-hexamethyl-1, 3, 4, 5, 6, 6a, 7, 8, 8a, 10, 11, 12, 13, 14b-tetradecahydropicene-4a-carboxylic acid showed high binding efficiency to a competitive ADH inhibitor, 4-Methylpyrazole. Pharmacokinetic analysis further confirmed the drug-likeness and non-hepatotoxicity of the top-ranked compound. Molecular dynamics simulation and MM-PBSA studies revealed the stability of the docked complexes with minimal fluctuation and consistency of the hydrogen bonds throughout the simulation. Together, computational investigations suggest that (4aS, 6aR, 6aR, 6bR, 7R, 8aR, 9R, 10R, 11R, 12aR, 14bS)-7, 10, 11-trihydroxy-9-(hydroxymethyl)-2, 2, 6a, 6b, 9, 12a-hexamethyl-1, 3, 4, 5, 6, 6a, 7, 8, 8a, 10, 11, 12, 13, 14b-tetradecahydropicene-4a-carboxylic acid from the Triphala formulation holds promise as an ADH inhibitor, suggesting an alternative therapy for alcoholic liver injury.

4.
Int J Biochem Cell Biol ; 170: 106558, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479581

RESUMO

Thousand and one amino acid kinase 1 (TAOK1) is a sterile 20 family Serine/Threonine kinase linked to microtubule dynamics, checkpoint signaling, DNA damage response, and neurological functions. Molecular-level alterations of TAOK1 have been associated with neurodevelopment disorders and cancers. Despite their known involvement in physiological and pathophysiological processes, and as a core member of the hippo signaling pathway, the phosphoregulatory network of TAOK1 has not been visualized. Aimed to explore this network, we first analyzed the predominantly detected and differentially regulated TAOK1 phosphosites in global phosphoproteome datasets across diverse experimental conditions. Based on 709 qualitative and 210 quantitative differential cellular phosphoproteome datasets that were systematically assembled, we identified that phosphorylation at Ser421, Ser9, Ser965, and Ser445 predominantly represented TAOK1 in almost 75% of these datasets. Surprisingly, the functional role of all these phosphosites in TAOK1 remains unexplored. Hence, we employed a robust strategy to extract the phosphosites in proteins that significantly correlated in expression with predominant TAOK1 phosphosites. This led to the first categorization of the phosphosites including those in the currently known and predicted interactors, kinases, and substrates, that positively/negatively correlated with the expression status of each predominant TAOK1 phosphosites. Subsequently, we also analyzed the phosphosites in core proteins of the hippo signaling pathway. Based on the TAOK1 phosphoregulatory network analysis, we inferred the potential role of the predominant TAOK1 phosphosites. Especially, we propose pSer9 as an autophosphorylation and TAOK1 kinase activity-associated phosphosite and pS421, the most frequently detected phosphosite in TAOK1, as a significant regulatory phosphosite involved in the maintenance of genome integrity. Considering that the impact of all phosphosites that predominantly represent each kinase is essential for the efficient interpretation of global phosphoproteome datasets, we believe that the approach undertaken in this study is suitable to be extended to other kinases for accelerated research.


Assuntos
Fosfotransferases , Proteínas Serina-Treonina Quinases , Fosfotransferases/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais
5.
Comput Biol Med ; 171: 108164, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38412690

RESUMO

Inflammation plays a pivotal role in various pathological processes, ranging from routine injuries and infections to cancer. Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) are two major enzymes involved in the formation of lipid mediators of inflammation, such as prostaglandins and leukotrienes, through the arachidonic acid pathway. Despite the frequent use of nonsteroidal anti-inflammatory drugs for managing inflammatory disorders by inhibiting these enzymes, there is a wide spectrum of adverse effects linked to their usage. Jeevaneeya Rasayana (JR), a polyherbal formulation traditionally used in India, is renowned for its anti-inflammatory properties. The present study aimed to identify the potential phytocompounds in JR plants against COX-2 and 5-LOX, utilizing molecular docking and dynamic simulations. Among the 429 identified phytocompounds retrieved from publicly available data sources, Terrestribisamide and 1-(9Z-octadecenoyl)-sn-glycero-3-phosphoethanolamine have shown potential binding affinity and favorable interactions with COX-2 and 5-LOX arachidonic acid binding sites. The physicochemical properties and ADMET profiles of these compounds determined their drug-likeness and pharmacokinetics features. Additional validation using molecular dynamics simulations, SASA, Rg, and MM-PBSA binding energy calculations affirmed the stability of the complex formed between those compounds with target proteins. Together, the study identified the effectual binding potential of those bioactive compounds against COX-2 and 5-LOX, providing a viable approach for the development of effective anti-inflammatory medications.


Assuntos
Anti-Inflamatórios , Inflamação , Extratos Vegetais , Humanos , Ciclo-Oxigenase 2/química , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/uso terapêutico , Simulação de Acoplamento Molecular , Ácido Araquidônico/uso terapêutico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/uso terapêutico
6.
Heliyon ; 10(3): e24853, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38322877

RESUMO

The first observation of the ν1+3ν3 combination band of the nitrogen dioxide isotopologue 16O14N18O is presented. The band was measured using Fourier-Transform Incoherent Broad-Band Cavity Enhanced Absorption Spectroscopy (FT-IBBCEAS) in the region between 5870 cm-1 and 5940 cm-1. To confirm the assignment, the band was simulated using a standard asymmetric top Watson Hamiltonian using extrapolated rotational and centrifugal distortion constants. Furthermore, the first experimental observation of the ν1+3ν3 band of the 18O14N18O isotopologue is also reported. The positions of ro-vibrational lines of the ν1+3ν3 band of the naturally most abundant isotopologue 16O14N16O were used for wavenumber calibration of line positions.

7.
J Neurovirol ; 30(1): 57-70, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167982

RESUMO

In recent years, we have seen the widespread devastations and serious health complications manifested by COVID-19 globally. Although we have effectively controlled the pandemic, uncertainties persist regarding its potential long-term effects, including prolonged neurological issues. To gain comprehensive insights, we conducted a meta-analysis of mass spectrometry-based proteomics data retrieved from different studies with a total of 538 COVID-19 patients and 523 healthy controls. The meta-analysis revealed that top-enriched pathways were associated with neurological disorders, including Alzheimer's (AD) and Parkinson's disease (PD). Further analysis confirmed a direct correlation in the expression patterns of 24 proteins involved in Alzheimer's and 23 proteins in Parkinson's disease with COVID-19. Protein-protein interaction network and cluster analysis identified SNCA as a hub protein, a known biomarker for Parkinson's disease, in both AD and PD. To the best of our knowledge, this is the first meta-analysis study providing proteomic profiling evidence linking COVID-19 to neurological complications.


Assuntos
Doença de Alzheimer , Biomarcadores , COVID-19 , Doença de Parkinson , Mapas de Interação de Proteínas , Proteoma , SARS-CoV-2 , COVID-19/sangue , COVID-19/virologia , COVID-19/metabolismo , Humanos , Doença de Parkinson/virologia , Doença de Parkinson/sangue , Doença de Parkinson/metabolismo , Doença de Parkinson/genética , Doença de Alzheimer/sangue , Doença de Alzheimer/virologia , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Biomarcadores/sangue , Biomarcadores/metabolismo , alfa-Sinucleína/sangue , alfa-Sinucleína/metabolismo , Proteômica/métodos
8.
OMICS ; 28(1): 32-44, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38190109

RESUMO

Host-virus Protein-Protein Interactions (PPIs) play pivotal roles in biological processes crucial for viral pathogenesis and by extension, inform antiviral drug discovery and therapeutics innovations. Despite efforts to develop the Epstein-Barr virus (EBV)-host PPI network, there remain significant knowledge gaps and a limited number of interacting human proteins deciphered. Furthermore, understanding the dynamics of the EBV-host PPI network in the distinct lytic and latent viral stages remains elusive. In this study, we report a comprehensive map of the EBV-human protein interactions, encompassing 1752 human and 61 EBV proteins by integrating data from the public repository HPIDB (v3.0) as well as curated high-throughput proteomic data from the literature. To address the stage-specific nature of EBV infection, we generated two detailed subset networks representing the latent and lytic stages, comprising 747 and 481 human proteins, respectively. Functional and pathway enrichment analysis of these subsets uncovered the profound impact of EBV proteins on cancer. The identification of highly connected proteins and the characterization of intrinsically disordered and cancer-related proteins provide valuable insights into potential therapeutic targets. Moreover, the exploration of drug-protein interactions revealed notable associations between hub proteins and anticancer drugs, offering novel perspectives for controlling EBV pathogenesis. This study represents, to the best of our knowledge, the first comprehensive investigation of the two distinct stages of EBV infection using high-throughput datasets. This makes a contribution to our understanding of EBV-host interactions and provides a foundation for future drug discovery and therapeutic interventions.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias , Humanos , Herpesvirus Humano 4/genética , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Infecções por Vírus Epstein-Barr/patologia , Proteômica , Interações Hospedeiro-Patógeno , Antivirais/farmacologia , Antivirais/uso terapêutico , Descoberta de Drogas
9.
J Biomol Struct Dyn ; 42(4): 1956-1965, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37097921

RESUMO

Quorum sensing plays a major role in the expression of virulence and development of biofilm in the human pathogen Pseudomonas aeruginosa. Natural compounds are well-known for their antibacterial characteristics by blocking various metabolic pathways. The goal of this study is to find natural compounds that mimic AHL (Acyl homoserine lactone) and suppress virulence in P. aeruginosa, which is triggered by quorum sensing-dependent pathways as an alternative drug development strategy. To support this rationale, functional network analysis and in silico investigations were carried out to find natural AHL analogues, followed by molecular docking studies. Out of the 16 top-hit AHL analogues derived from phytochemicals, seven ligands were found to bind to the quorum sensing activator proteins. Cassialactone, an AHL analogue, exhibited the highest binding affinity for RhlI, RhlR, and PqsE of P. aeruginosa, with a docking score of -9.4, -8.9, and -8.7 kcal/mol, respectively. 2(5H)-Furanone, a well-known inhibitor, was also docked to compare the docking score and intermolecular interactions between the ligand and the target protein. Furthermore, molecular dynamics simulations and binding free energy calculations were performed to determine the stability of the docked complexes. Additionally, the ADME properties of the analogues were also analyzed to evaluate the pharmacological parameters. Functional network analysis further showed that the interconnectedness of proteins such as RhlI, RhlR, LasI, and PqsE with the virulence and biofilm phenotype of the pathogen could offer potential as a therapeutic target.Communicated by Ramaswamy H. Sarma.


Assuntos
Pseudomonas aeruginosa , Percepção de Quorum , Humanos , Pseudomonas aeruginosa/genética , Fatores de Virulência/metabolismo , Simulação de Acoplamento Molecular , Proteínas de Bactérias/metabolismo , Biofilmes
10.
J Biomol Struct Dyn ; : 1-9, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38147402

RESUMO

Post-translational modifications (PTMs) are crucial covalent processes that alter protein properties, achieved through proteolytic cleavage or addition of modifying groups like acetyl, phosphoryl, glycosyl, or methyl to amino acids. ADP-ribosylation is a reversible post-translational modification, where ADP-ribose units are covalently attached to target protein side chains. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that plays a key role in physiological and pathological conditions. Studies have reported that ADP-ribosylation affects VEGF's ability to bind to VEGF receptors, impacting angiogenesis signalling. However, the specific amino acid undergoing ADP-ribosylation on VEGF remained unknown. To understand the mechanism of ADP-ribose addition to VEGF, an in silico study was designed. The study initially checked for the presence of any conserved motif where ADP-ribosylation could potentially occur and identified the presence of the EIE motif in VEGF, a probable site for ADP-ribosylation for many proteins. Subsequently, the amino acids near this motif were selected and their structural properties were analyzed. Surface-exposed amino acids were chosen, and ADP-ribose was then added to their side chains. The results revealed that the amino acids ASP (67) and GLU (70) underwent glycosidic linkage with ADP-ribose, indicating that they are the most probable modification sites. Subsequently, Molecular dynamic simulation analysis such as RMSD, RMSF, Rg, PCA, and FEL, along with MM-PBSA binding free energy calculations were performed to understand the stability of the VEGF-ADP-ribose complexes. The analysis revealed that amino acid at position 67 (ASP67) is the most probable site for ADP-ribosylation in VEGF.Communicated by Ramaswamy H. Sarma.

11.
Cureus ; 15(6): e41130, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37519619

RESUMO

Background Infections can spread within the dental clinic through many routes. Interrupting this transmission of infection within the dental office is an important part of the dental practice. This study aimed to assess the knowledge, attitude, and practice regarding precautions against droplet and airborne infections among dental students in South India. Methodology A cross-sectional, questionnaire-based survey was conducted among 236 undergraduate dental students in Chennai. The questionnaire consisted of 11 questions in three categories of knowledge, attitude, and practice regarding airborne and droplet isolation precautions. The collected data were compiled and analyzed using SPSS version 13 software (SPSS Inc., Chicago, IL, USA). Results The frequency scores of knowledge, attitude, and practice regarding droplet and airborne isolation precautions showed that dental students were very much aware of the precautions and the guidelines. The mean scores for knowledge, attitude, and practice were 7.70 ± 2.48, 37.22 ± 6.98, and 7.1 ± 1.64, respectively. There were no significant differences among subgroups (third-year students, fourth-year students, and interns) regarding knowledge, attitude, and practice. A positive linear correlation was observed between knowledge and attitude, knowledge and practice, and attitude and practice (p < 0.05). Conclusions According to the results of this study, dental students had adequate knowledge, positive attitudes, and compliance. Training programs on isolation precautions are needed to sustain and update the knowledge according to the changing trends in infectious diseases.

12.
J Cell Commun Signal ; 17(3): 1067-1079, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36881336

RESUMO

Vascular endothelial growth factor-A (VEGF-A) is one of the primary factors promoting angiogenesis in endothelial cells. Although defects in VEGF-A signaling are linked to diverse pathophysiological conditions, the early phosphorylation-dependent signaling events pertinent to VEGF-A signaling remain poorly defined. Hence, a temporal quantitative phosphoproteomic analysis was performed in human umbilical vein endothelial cells (HUVECs) treated with VEGF-A-165 for 1, 5 and 10 min. This led to the identification and quantification of 1971 unique phosphopeptides corresponding to 961 phosphoproteins and 2771 phosphorylation sites in total. Specifically, 69, 153, and 133 phosphopeptides corresponding to 62, 125, and 110 phosphoproteins respectively, were temporally phosphorylated at 1, 5, and 10 min upon addition of VEGF-A. These phosphopeptides included 14 kinases, among others. This study also captured the phosphosignaling events directed through RAC, FAK, PI3K-AKT-MTOR, ERK, and P38 MAPK modules with reference to our previously assembled VEGF-A/VEGFR2 signaling pathway map in HUVECs. Apart from a significant enrichment of biological processes such as cytoskeleton organization and actin filament binding, our results also suggest a role of AAK1-AP2M1 in the regulation of VEGFR endocytosis. Taken together, the temporal quantitative phosphoproteomics analysis of VEGF signaling in HUVECs revealed early signaling events and we believe that this analysis will serve as a starting point for the analysis of differential signaling across VEGF members toward the full elucidation of their role in the angiogenesis processes. Workflow for the identification of early phosphorylation events induced by VEGF-A-165 in HUVEC cells.

13.
Biomater Adv ; 146: 213305, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36709630

RESUMO

Thymol (2-isopropyl-5-methylphenol; Thy) is a monoterpene phenolic phytocompound with medicinal properties; however, its impact on osteogenesis is yet to be thoroughly investigated. Its distribution is often hampered because of its intricate hydrophobic structure, which reduces its bioavailability. In this study, we synthesized a drug delivery vehicle using semi-interpenetrating polymer network (SIPN) hydrogels containing sodium alginate and poly(2-ethyl-2-oxazoline) (SA/Pox) loaded with Thy at varying concentrations (100, 150, and 200 µM). Subsequently, they were coated with chitosan (CS) to increase bioactivity and for sustained and prolonged release of Thy. Thy-loaded CS-coated SIPN hydrogels (SA/Pox/CS-Thy) were developed using ionic gelation and polyelectrolyte-complexation techniques. The addition of CS to hydrogels enhanced their physicochemical and material properties. These hydrogels were cytofriendly toward mouse mesenchymal stem cells (mMSCs). When mMSCs were cultured on hydrogels, Thy stimulated osteoblastic differentiation, as evidenced by calcium deposits at the cellular level. The expression of RUNX2, a key bone transcriptional factor, and other differentiation biomarkers was significantly enhanced in mMSCs cultured on SA/Pox/CS-Thy hydrogels. Notably, Thy in the SA/Pox/CS hydrogels significantly activated the TGF-ß/BMP signaling pathway, which is involved in osteogenesis. A rat tibial bone defect model system revealed that the incorporation of Thy into SA/Pox/CS hydrogels augmented bone regeneration. Thus, sustained and prolonged release of Thy from the SA/Pox/CS hydrogels promoted osteoblast differentiation in vitro and bone formation in vivo. These findings shed light on the effect of Thy bioavailability in fostering osteoblast differentiation and its prospective application in bone rejuvenation.


Assuntos
Quitosana , Ratos , Camundongos , Animais , Quitosana/química , Quitosana/farmacologia , Hidrogéis/farmacologia , Timol/farmacologia , Regeneração Óssea , Osteogênese
14.
J Biomol Struct Dyn ; 41(19): 9211-9218, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-36473711

RESUMO

The infection by Nipah Virus (NiV), a zoonotic paramyxovirus, is fatal and several outbreaks have been reported in humans in various countries. No effective vaccines or drugs are developed till date to control this infection. The NiV-Glycoprotein (NiV-G) is one of the essential proteins for viral entry by binding to the Ephrin-B receptors. The present study screens the potential phytocompounds that can target NiV-G and thereby inhibit the viral entry to human. Computer-aided virtual screening of 1426 phytocompounds from various medicinal plants was carried out to investigate their efficacy as potential therapeutics. Ribavirin, the currently used drug, was also docked to compare the docking score and intermolecular interactions between ligand and target protein. Further, molecular dynamics simulations and MM-PBSA binding free energy calculations were performed to understand the stability of the docked complexes. Radius of gyrations and Solvent Accessible Surface Area were also performed to evaluate the compactness and solvent behaviour of ligand-receptor complexes during the 100 ns simulation. Our analysis revealed that the alkaloid, Serpentinine, has the highest potency to block NiV-G with favourable binding.Communicated by Ramaswamy H. Sarma.


Assuntos
Vírus Nipah , Plantas Medicinais , Humanos , Vírus Nipah/metabolismo , Simulação de Acoplamento Molecular , Ligantes , Glicoproteínas/química , Solventes , Simulação de Dinâmica Molecular
15.
J Biomol Struct Dyn ; 41(20): 11166-11177, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36572420

RESUMO

The outbreak of severe acute respiratory coronavirus 2 (SARS-CoV-2) has created a public health emergency globally. SARS-CoV-2 enters the human cell through the binding of the spike protein to human angiotensin converting enzyme 2 (ACE2) receptor. Significant changes have been reported in the mutational landscape of SARS-CoV-2 in the receptor binding domain (RBD) of S protein, subsequent to evolution of the pandemic. The present study examines the correlation between the binding affinity of mutated S-proteins and the rate of viral infectivity. For this, the binding affinity of SARS-CoV and variants of SARS-CoV-2 towards ACE2 was computationally determined. Subsequently, the RBD mutations were classified on the basis of the number of strains identified with respect to each mutation and the resulting variation in the binding affinity was computationally examined. The molecular docking studies indicated a significant correlation between the Z-Rank score of mutated S proteins and the rate of infectivity, suitable for predicting SARS-CoV-2 infectivity. Accordingly, a 30-mer peptide was designed and the inhibitory properties were computationally analyzed. Single amino acid-wise mutation was performed subsequently to identify the peptide with the highest binding affinity. Molecular dynamics and free energy calculations were then performed to examine the stability of the peptide-protein complexes. Additionally, selected peptides were synthesized and screened using a colorimetric assay. Together, this study developed a model to predict the rate of infectivity of SARS-CoV-2 variants and propose a potential peptide that can be used as an inhibitor for the viral entry to human.Communicated by Ramaswamy H. Sarma.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Enzima de Conversão de Angiotensina 2/genética , Simulação de Acoplamento Molecular , Peptídeos , Mutação , Ligação Proteica , Simulação de Dinâmica Molecular
16.
J Biomol Struct Dyn ; 40(2): 903-917, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32924827

RESUMO

COVID-19, which has emerged recently as a pandemic viral infection caused by SARS-coronavirus 2 has spread rapidly around the world, creating a public health emergency. The current situation demands an effective therapeutic strategy to control the disease using drugs that are approved, or by inventing new ones. The present study examines the possible repurposing of existing anti-viral protease inhibitor drugs. For this, the structural features of the viral spike protein, the substrate for host cell protease and main protease of the available SARS CoV-2 isolates were established by comparing with related viruses for which antiviral drugs are effective. The results showed 97% sequence similarity among SARS and SARS-CoV-2 main protease and has same cleavage site positions and ACE2 receptor binding region as in the SARS-CoV spike protein. Though both are N-glycosylated, unlike SARS-CoV, human SARS-CoV-2 S-protein was O-glycosylated as well. Molecular docking studies were done to explore the role of FDA approved protease inhibitors to control SARS-CoV-2 replication. The results indicated that, Ritonavir has the highest potency to block SARS-CoV-2 main protease and human TMPRSS2, a host cell factor that aids viral infection. Other drugs such as Indinavir and Atazanavir also showed favourable binding with Cathepsin B/L that helped viral fusion with the host cell membrane. Further molecular dynamics simulation and MM-PBSA binding free energy calculations confirmed the stability of protein-drug complexes. These results suggest that protease inhibitors particularly Ritonavir, either alone or in combination with other drugs such as Atazanavir, have the potential to treat COVID 19.Communicated by Ramaswamy H. Sarma.


Assuntos
COVID-19 , Inibidores de Proteases , Humanos , Simulação de Acoplamento Molecular , Pandemias , SARS-CoV-2
18.
Environ Geochem Health ; 44(6): 1713-1737, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34767150

RESUMO

The Suruliyar sub basin in Tamil Nadu, India, was monitored for the assessment of water and soil quality. Surface water, groundwater, and soil samples were collected during the pre-monsoon (June 2016) and post-monsoon (December 2016) seasons within the sub basin area and analyzed for various physical, chemical, and biological properties, namely, pH, electrical conductivity, total dissolved solids (TDS), calcium, magnesium, sodium, nitrate, sulfate, fluoride, chloride, biological oxygen demand, chemical oxygen demand, and total and fecal coliform. All the values were compared with Indian and global standards, and the values for each parameter were within the permissible limits. However, some samples were edging toward the upward limit. Fecal coliforms (14 to 36 counts per 100 ml) were present in the river water, thus indicating anthropogenic contamination. Correlation analysis confirmed that TDS was significantly positively correlated with most of the cations and anions. Groundwater was assessed using several indices, such as the Piper diagram, United States Salinity Laboratory diagram, sodium adsorption ratio, and sodium percentage. Results showed that all the groundwater samples could be used for irrigation purposes; however, the chloride contents exceeded the permissible limit. Soil analysis results showed that all nutrients were within the permissible limits. Drought assessment showed the existence of both dry and wet years occurring most frequently, which might have a strong influence on the quality of water and soil parameters. This study suggests that the monitoring of surface, groundwater, and soil parameters is essential to maintain the sub basin area for ensuring sustainable development in the future.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Agricultura , Cloretos/análise , Monitoramento Ambiental/métodos , Água Subterrânea/química , Humanos , Índia , Sódio/análise , Solo , Água/análise , Poluentes Químicos da Água/análise , Qualidade da Água , Abastecimento de Água
19.
Int J Biol Macromol ; 183: 1925-1938, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34097956

RESUMO

Despite the spontaneous regenerative properties of autologous bone grafts, this technique remains dilatory and restricted to fractures and injuries. Conventional grafting strategies used to treat bone tissue damage have several limitations. This highlights the need for novel approaches to overcome the persisting challenges. Tissue-like constructs that can mimic natural bone structurally and functionally represent a promising strategy. Bone tissue engineering (BTE) is an approach used to develop bioengineered bone with subtle architecture. BTE utilizes biomaterials to accommodate cells and deliver signaling molecules required for bone rejuvenation. Among the various techniques available for scaffold creation, 3D-printing technology is considered to be a superior technique as it enables the design of functional scaffolds with well-defined customizable properties. Among the biomaterials obtained from natural, synthetic, or ceramic origins, naturally derived chitosan (CS) polymers are promising candidates for fabricating reliable tissue constructs. In this review, the physicochemical-biological properties and applications of CS-based 3D-printed scaffolds and their future perspectives in BTE are summarized.


Assuntos
Quitosana/química , Alicerces Teciduais/química , Regeneração Óssea , Humanos , Impressão Tridimensional , Engenharia Tecidual
20.
Int J Tuberc Lung Dis ; 25(5): 358-366, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33977903

RESUMO

BACKGROUND: Barts Health National Health Service Trust (BHNHST) serves a diverse population of 2.5 million people in London, UK. We undertook a health services assessment of factors used to evaluate the risk of severe acute respiratory coronavirus 2 (SARS-CoV-2) infection.METHODS: Patients with confirmed polymerase chain reaction (PCR) test results admitted between 1 March and 1 August 2020 were included, alongwith clinician-diagnosed suspected cases. Prognostic factors from the 4C Mortality score and 4C Deterioration scores were extracted from electronic health records and logistic regression was used to quantify the strength of association with 28-day mortality and clinical deterioration using national death registry linkage.RESULTS: Of 2783 patients, 1621 had a confirmed diagnosis, of whom 61% were male and 54% were from Black and Minority Ethnic groups; 26% died within 28 days of admission. Mortality was strongly associated with older age. The 4C mortality score had good stratification of risk with a calibration slope of 1.14 (95% CI 1.01-1.27). It may have under-estimated mortality risk in those with a high respiratory rate or requiring oxygen.CONCLUSION: Patients in this diverse patient cohort had similar mortality associated with prognostic factors to the 4C score derivation sample, but survival might be poorer in those with respiratory failure.


Assuntos
COVID-19 , Medicina Estatal , Idoso , Feminino , Hospitalização , Humanos , Londres/epidemiologia , Masculino , Fatores de Risco , SARS-CoV-2
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...