scholarly journals Effects of rhodomyrtone on Gram-positive bacterial tubulin homologue FtsZ

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2962 ◽  
Author(s):  
Dennapa Saeloh ◽  
Michaela Wenzel ◽  
Thanyada Rungrotmongkol ◽  
Leendert Willem Hamoen ◽  
Varomyalin Tipmanee ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Pathogenic Bacteria ◽  
Cell Envelope ◽  
Docking Study ◽  
Bacterial Cell Division ◽  
Molecular Docking Study ◽  
Gram Positive ◽  
Ligand Free

Rhodomyrtone, a natural antimicrobial compound, displays potent activity against many Gram-positive pathogenic bacteria, comparable to last-defence antibiotics including vancomycin and daptomycin. Our previous studies pointed towards effects of rhodomyrtone on the bacterial membrane and cell wall. In addition, a recent molecular docking study suggested that the compound could competitively bind to the main bacterial cell division protein FtsZ. In this study, we applied a computational approach (in silico),in vitro, andin vivoexperiments to investigate molecular interactions of rhodomyrtone with FtsZ. Using molecular simulation, FtsZ conformational changes were observed in both (S)- and (R)-rhodomyrtone binding states, compared with the three natural states of FtsZ (ligand-free, GDP-, and GTP-binding states). Calculations of free binding energy showed a higher affinity of FtsZ to (S)-rhodomyrtone (−35.92 ± 0.36 kcal mol−1) than the GDP substrate (−23.47 ± 0.25 kcal mol−1) while less affinity was observed in the case of (R)-rhodomyrtone (−18.11 ± 0.11 kcal mol−1).In vitroexperiments further revealed that rhodomyrtone reduced FtsZ polymerization by 36% and inhibited GTPase activity by up to 45%. However, the compound had no effect on FtsZ localization inBacillus subtilisat inhibitory concentrations and cells also did not elongate after treatment. Higher concentrations of rhodomyrtone did affect localization of FtsZ and also affected localization of its membrane anchor proteins FtsA and SepF, showing that the compound did not specifically inhibit FtsZ but rather impaired multiple divisome proteins. Furthermore, a number of cells adopted a bean-like shape suggesting that rhodomyrtone possibly possesses further targets involved in cell envelope synthesis and/or maintenance.

CarR, a MarR-family regulator from Corynebacterium glutamicum, modulated antibiotic and aromatic compound resistance

2019 ◽  
Vol 476 (21) ◽  
pp. 3141-3159 ◽  
Author(s):  
Meiru Si ◽  
Can Chen ◽  
Zengfan Wei ◽  
Zhijin Gong ◽  
GuiZhi Li ◽  
...  
Keyword(s):  
Stress Response ◽  
Ligand Binding ◽  
Corynebacterium Glutamicum ◽  
Conformational Changes ◽  
Cysteine Oxidation ◽  
Transcriptional Regulatory ◽  
Ligand Free ◽  
Redox Sensing

Abstract MarR (multiple antibiotic resistance regulator) proteins are a family of transcriptional regulators that is prevalent in Corynebacterium glutamicum. Understanding the physiological and biochemical function of MarR homologs in C. glutamicum has focused on cysteine oxidation-based redox-sensing and substrate metabolism-involving regulators. In this study, we characterized the stress-related ligand-binding functions of the C. glutamicum MarR-type regulator CarR (C. glutamicum antibiotic-responding regulator). We demonstrate that CarR negatively regulates the expression of the carR (ncgl2886)–uspA (ncgl2887) operon and the adjacent, oppositely oriented gene ncgl2885, encoding the hypothetical deacylase DecE. We also show that CarR directly activates transcription of the ncgl2882–ncgl2884 operon, encoding the peptidoglycan synthesis operon (PSO) located upstream of carR in the opposite orientation. The addition of stress-associated ligands such as penicillin and streptomycin induced carR, uspA, decE, and PSO expression in vivo, as well as attenuated binding of CarR to operator DNA in vitro. Importantly, stress response-induced up-regulation of carR, uspA, and PSO gene expression correlated with cell resistance to β-lactam antibiotics and aromatic compounds. Six highly conserved residues in CarR were found to strongly influence its ligand binding and transcriptional regulatory properties. Collectively, the results indicate that the ligand binding of CarR induces its dissociation from the carR–uspA promoter to derepress carR and uspA transcription. Ligand-free CarR also activates PSO expression, which in turn contributes to C. glutamicum stress resistance. The outcomes indicate that the stress response mechanism of CarR in C. glutamicum occurs via ligand-induced conformational changes to the protein, not via cysteine oxidation-based thiol modifications.

scholarly journals TSPphg Lysin from the Extremophilic Thermus Bacteriophage TSP4 as a Potential Antimicrobial Agent against Both Gram-Negative and Gram-Positive Pathogenic Bacteria

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 192 ◽  
Author(s):  
Feng Wang ◽  
Xinyu Ji ◽  
Qiupeng Li ◽  
Guanling Zhang ◽  
Jiani Peng ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Infection Model ◽  
Bacterial Cells ◽  
Skin Damage ◽  
Gram Positive ◽  
Antibiotic Resistant ◽  
Gram Negative

New strategies against antibiotic-resistant bacterial pathogens are urgently needed but are not within reach. Here, we present in vitro and in vivo antimicrobial activity of TSPphg, a novel phage lysin identified from extremophilic Thermus phage TSP4 by sequencing its whole genome. By breaking down the bacterial cells, TSPphg is able to cause bacteria destruction and has shown bactericidal activity against both Gram-negative and Gram-positive pathogenic bacteria, especially antibiotic-resistant strains of Klebsiella pneumoniae, in which the complete elimination and highest reduction in bacterial counts by greater than 6 logs were observed upon 50 μg/mL TSPphg treatment at 37 °C for 1 h. A murine skin infection model further confirmed the in vivo efficacy of TSPphg in removing a highly dangerous and multidrug-resistant Staphylococcus aureus from skin damage and in accelerating wound closure. Together, our findings may offer a therapeutic alternative to help fight bacterial infections in the current age of mounting antibiotic resistance, and to shed light on bacteriophage-based strategies to develop novel anti-infectives.

scholarly journals Identification of Potent Inhibitors of COVID-19 Main Protease Enzyme by Molecular Docking Study

2020 ◽  
Author(s):  
pooja singh ◽  
Angkita Sharma ◽  
Shoma Paul Nandi
Keyword(s):  
Molecular Docking ◽  
Antiviral Drug ◽  
Cyclopiazonic Acid ◽  
Docking Study ◽  
Molecular Docking Study ◽  
Docking Score ◽  
Protease Enzyme ◽  
Main Protease

<p>Within the span of a few months, the severe acute respiratory syndrome coronavirus, COVID-19 (SARS-CoV-2), has proven to be a pandemic, affecting the world at an exponential rate. It is extremely pathogenic and causes communicable infection in humans. Viral infection causes difficulties in breathing, sore throat, cough, high fever, muscle pain, diarrhea, dyspnea, and may lead to death. Finding a proper drug and vaccines against this virus is the need of the hour. The RNA genome of COVID19 codes for the main protease M<sup>pro</sup>, which is required for viral multiplication. To identify possible antiviral drug(s), we performed molecular docking studies. Our screen identified ten biomolecules naturally present in <i>Aspergillus flavus</i> and <i>Aspergillus oryzae</i> fungi. These molecules include Aspirochlorine, Aflatoxin B1, Alpha-Cyclopiazonic acid, Sporogen, Asperfuran, Aspergillomarasmine A, Maltoryzine, Kojic acid, Aflatrem and Ethyl 3-nitropropionic acid, arranged in the descending order of their docking score. Aspirochlorine exhibited the docking score of – 7.18 Kcal/mole, higher than presently used drug Chloroquine (-6.2930522 Kcal/mol) and out of ten ligands studied four has docking score higher than chloroquine. These natural bioactive compounds could be tested for their ability to inhibit viral growth <i>in- vitro</i> and <i>in-vivo</i>.<b> </b></p>

scholarly journals Antibacterial Activities and Molecular Docking of Novel Sulfone Biscompound Containing Bioactive 1,2,3-Triazole Moiety

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4817
Author(s):  
Huda R. M. Rashdan ◽  
Ihsan A. Shehadi ◽  
Mohamad T. Abdelrahman ◽  
Bahaa A. Hemdan
Keyword(s):  
Molecular Docking ◽  
Pathogenic Bacteria ◽  
Analytical Data ◽  
Docking Study ◽  
Antibacterial Activities ◽  
Bactericidal Effect ◽  
Bacterial Strains ◽  
Molecular Docking Study ◽  
Synthetic Compound

In this study, a new synthetic 1,2,3-triazole-containing disulfone compound was derived from dapsone. Its chemical structure was confirmed using microchemical and analytical data, and it was tested for its in vitro antibacterial potential. Six different pathogenic bacteria were selected. MICs values and ATP levels were determined. Further, toxicity performance was measured using MicroTox Analyzer. In addition, a molecular docking study was performed against two vital enzymes: DNA gyrase and Dihydropteroate synthase. The results of antibacterial abilities showed that the studied synthetic compound had a strong bactericidal effect against all tested bacterial strains, as Gram-negative species were more susceptible to the compound than Gram-positive species. Toxicity results showed that the compound is biocompatible and safe without toxic impact. The molecular docking of the compound showed interactions within the pocket of two enzymes, which are able to stabilize the compound and reveal its antimicrobial activity. Hence, from these results, this study recommends that the established compound could be an outstanding candidate for fighting a broad spectrum of pathogenic bacterial strains, and it might therefore be used for biomedical and pharmaceutical applications.

scholarly journals Identification of Novel Thermosensors in Gram-Positive Pathogens

2020 ◽  
Vol 7 ◽  
Author(s):  
Pilar Fernández ◽  
Alejandra Raquel Díaz ◽  
María Florencia Ré ◽  
Lucía Porrini ◽  
Diego de Mendoza ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Response Regulator ◽  
Physiological Mechanism ◽  
Virulence Gene ◽  
Membrane Lipid ◽  
Gram Positive ◽  
Virulence Gene Expression ◽  
Cognate Response Regulator

Temperature is a crucial variable that every living organism, from bacteria to humans, need to sense and respond to in order to adapt and survive. In particular, pathogenic bacteria exploit host-temperature sensing as a cue for triggering virulence gene expression. Here, we have identified and characterized two integral membrane thermosensor histidine kinases (HKs) from Gram-positive pathogens that exhibit high similarity to DesK, the extensively characterized cold sensor histidine kinase from Bacillus subtilis. Through in vivo experiments, we demonstrate that SA1313 from Staphylococcus aureus and BA5598 from Bacillus anthracis, which likely control the expression of putative ATP binding cassette (ABC) transporters, are regulated by environmental temperature. We show here that these HKs can phosphorylate the non-cognate response regulator DesR, partner of DesK, both in vitro and in vivo, inducing in B. subtilis the expression of the des gene upon a cold shock. In addition, we report the characterization of another DesK homolog from B. subtilis, YvfT, also closely associated to an ABC transporter. Although YvfT phosphorylates DesR in vitro, this sensor kinase can only induce des expression in B. subtilis when overexpressed together with its cognate response regulator YvfU. This finding evidences a physiological mechanism to avoid cross talk with DesK after a temperature downshift. Finally, we present data suggesting that the HKs studied in this work appear to monitor different ranges of membrane lipid properties variations to mount adaptive responses upon cooling. Overall, our findings point out that bacteria have evolved sophisticated mechanisms to assure specificity in the response to environmental stimuli. These findings pave the way to understand thermosensing mediated by membrane proteins that could have important roles upon host invasion by bacterial pathogens.

scholarly journals Comparative Study of Piper sylvaticum Roxb. Leaves and Stems for Anxiolytic and Antioxidant Properties Through In Vivo, In Vitro, and In Silico Approaches

Biomedicines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 68 ◽  
Author(s):  
Md. Adnan ◽  
Md. Nazim Uddin Chy ◽  
A.T.M. Mostafa Kamal ◽  
Md Obyedul Kalam Azad ◽  
Kazi Asfak Ahmed Chowdhury ◽  
...  
Keyword(s):  
Molecular Docking ◽  
In Silico ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Reducing Power ◽  
Docking Study ◽  
Molecular Docking Study ◽  
Dose Dependent

Piper sylvaticum Roxb. is traditionally used by the indigenous people of tropical and subtropical countries like Bangladesh, India, and China for relieving the common cold or a variety of chronic diseases, such as asthma, chronic coughing, piles, rheumatic pain, headaches, wounds, tuberculosis, indigestion, and dyspepsia. This study tested anxiolytic and antioxidant activities by in vivo, in vitro, and in silico experiments for the metabolites extracted (methanol) from the leaves and stems of P. sylvaticum (MEPSL and MEPSS). During the anxiolytic evaluation analyzed by elevated plus maze and hole board tests, MEPSL and MEPSS (200 and 400 mg/kg, body weight) exhibited a significant and dose-dependent reduction of anxiety-like behavior in mice. Similarly, mice treated with MEPSL and MEPSS demonstrated dose-dependent increases in locomotion and CNS simulative effects in open field test. In addition, both extracts (MEPSL and MEPSS) also showed moderate antioxidant activities in DPPH scavenging and ferric reducing power assays compared to the standard, ascorbic acid. In parallel, previously isolated bioactive compounds from this plant were documented and subjected to a molecular docking study to correlate them with the pharmacological outcomes. The selected four major phytocompounds displayed favorable binding affinities to potassium channel and xanthine oxidoreductase enzyme targets in molecular docking experiments. Overall, P. sylvaticum is bioactive, as is evident through experimental and computational analysis. Further experiments are necessary to evaluate purified novel compounds for the clinical evaluation.

scholarly journals MOLECULAR DOCKING STUDY ON 1H-(3,4d) PYRAZOLO-PYRIMIDINES AS CYCLIN DEPENDANT KINASE (CDK2) INHIBITORS

2016 ◽  
Vol 9 (1) ◽  
pp. 94
Author(s):  
Manisha S. Phoujdar ◽  
Gourishankar R. Aland
Keyword(s):  
Data Bank ◽  
Docking Study ◽  
Docking Studies ◽  
Van Der Waals Interactions ◽  
Binding Modes ◽  
Molecular Docking Study ◽  
Discovery Studio ◽  
Receptor Assays

Objective: CDK2 inhibitors are implicated in several carcinomas viz. Carcinoma of lung, bladder, sarcomas and retinoblastoma. Pyrazolopyrimidines, being purine bioisosters inhibit more than one type of kinase. In this study, we are studying some novel derivatives of 1H-pyrazolo [3,4d] pyrimidines not reported earlier. The objective of the present study is an attempt towards design and development of 1H-[3,4-] pyrazolo-pyrimidines as CDK2 inhibitors through rational drug design.Methods: The present study has been done on CDK2 structure, PDB ID, 3WBL, co-crystallized with ligand PDY from RCSB protein data bank. A series of seventeen 1H-Pyrazolo [3,4-d] pyrimidines feasible for synthesis was docked on the said CDK2 receptor using Auto Dock 4 version, 1.5.6. Outputs were exported to discovery studio 3.5 client for visual inspection of the binding modes and interactions of the compounds with amino acid residues in the active sites.Results: The results of docking studies revealed that the present series of 1H-Pyrazolo[3,4-d] pyrimidines is showing significant binding through hydrogen bonding, hydrophobic, pi and Van der waals interactions, similar to the ligand PDY. Some conserved H-bond interactions comparable to bioisosters and compounds presently under human trials were noted. Ki values predicted in silico also suggest that the series will show promising CDK2 inhibitory activity.Conclusion: The series designed and docked can be further developed by synthesis and in vitro and in vivo activity. The receptor inhibitory activity can also be checked by specific receptor assays.

Potential Bioactive glycosylated flavonoids as SARS-CoV-2 Main protease Inhibitors: A molecular Docking Study

2020 ◽  
Author(s):  
sabri ahmed cherrak ◽  
merzouk hafida ◽  
mokhtari soulimane nassima
Keyword(s):  
Molecular Docking ◽  
Data Bank ◽  
Docking Study ◽  
Docking Studies ◽  
Molecular Docking Study ◽  
Chemical Structures ◽  
In Vivo Experiments ◽  
Main Protease

A novel (COVID-19) responsible of acute respiratory infection closely related to SARS-CoV has recently emerged. So far there is no consensus for drug treatment to stop the spread of the virus. Discovery of a drug that would limit the virus expansion is one of the biggest challenges faced by the humanity in the last decades. In this perspective, testing existing drugs as inhibitors of the main COVID-19 protease is a good approach.Among natural phenolic compounds found in plants, fruit, and vegetables; flavonoids are the most abundant. Flavonoids, especially in their glycosylated forms, display a number of physiological activities, which makes them interesting to investigate as antiviral molecules.The flavonoids chemical structures were downloaded from PubChem and protease structure 6lu7 was from the Protein Data Bank site. Molecular docking study was performed using AutoDock Vina. Among the tested molecules Quercetin-3-O-rhamnoside showed the highest binding affinity (-9,7 kcal/mol). Docking studies showed that glycosylated flavonoids are good inhibitors for the covid-19 protease and could be further investigated by in vitro and in vivo experiments for further validation.

scholarly journals Thymus algeriensis and Thymus fontanesii: Chemical Composition, In Vivo Antiinflammatory, Pain Killing and Antipyretic Activities: A Comprehensive Comparison

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 599 ◽  
Author(s):  
Mansour Sobeh ◽  
Samar Rezq ◽  
Mohammed Cheurfa ◽  
Mohamed A.O. Abdelfattah ◽  
Rasha M.H. Rashied ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Secondary Metabolites ◽  
Docking Study ◽  
Molecular Docking Study ◽  
Thymus Algeriensis ◽  
Comprehensive Comparison ◽  
Cox 2 ◽  
Anti Inflammatory

This study aimed to investigate the chemical composition, and evaluate the antioxidant, anti-inflammatory, anti-pyretic, and the analgesic properties of methanol extracts from the leaves of Thymus algeriensis and Thymus fontanesii (Lamiaceae). Thirty-five secondary metabolites were characterized in both extracts using HPLC-PDA-ESI-MS/MS. Phenolic acids, mainly rosmarinic acid and its derivatives, dominated the T. algeriensis extract, while the phenolic diterpene carnosol and the methylated flavonoid salvigenin, prevailed in T. fontanesii extract. Molecular docking study was carried out to estimate the anti-inflammatory potential and the binding affinities of some individual secondary metabolites from both extracts to the main enzymes involved in the inflammation pathway. In vitro enzyme inhibitory assays and in vivo assays were used to investigate the antioxidant and anti-inflammatory activities of the extracts. Results revealed that both studied Thymus species exhibited antioxidant, anti-inflammatory, analgesic, and antipyretic effects. They showed to be a more potent antioxidant than ascorbic acid and more selective against cyclooxygenase (COX-2) than diclofenac and indomethacin. Relatively, the T. fontanesii extract was more potent as COX-2 inhibitor than T. algeriensis. In conclusion, Thymus algeriensis and Thymus fontanesii may be interesting candidates for the treatment of inflammation and oxidative stress-related disorders.

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