scholarly journals Deciphering the Binding of Salicylic Acid to Arabidopsis thaliana Chloroplastic GAPDH-A1

2020 ◽  
Vol 21 (13) ◽  
pp. 4678 ◽  
Author(s):  
Igor Pokotylo ◽  
Denis Hellal ◽  
Tahar Bouceba ◽  
Miguel Hernandez-Martinez ◽  
Volodymyr Kravets ◽  
...  

Salicylic acid (SA) has an essential role in the responses of plants to pathogens. SA initiates defence signalling via binding to proteins. NPR1 is a transcriptional co-activator and a key target of SA binding. Many other proteins have recently been shown to bind SA. Amongst these proteins are important enzymes of primary metabolism. This fact could stand behind SA’s ability to control energy fluxes in stressed plants. Nevertheless, only sparse information exists on the role and mechanisms of such binding. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was previously demonstrated to bind SA both in human and plants. Here, we detail that the A1 isomer of chloroplastic glyceraldehyde 3-phosphate dehydrogenase (GAPA1) from Arabidopsis thaliana binds SA with a KD of 16.7 nM, as shown in surface plasmon resonance experiments. Besides, we show that SA inhibits its GAPDH activity in vitro. To gain some insight into the underlying molecular interactions and binding mechanism, we combined in silico molecular docking experiments and molecular dynamics simulations on the free protein and protein–ligand complex. The molecular docking analysis yielded to the identification of two putative binding pockets for SA. A simulation in water of the complex between SA and the protein allowed us to determine that only one pocket—a surface cavity around Asn35—would efficiently bind SA in the presence of solvent. In silico mutagenesis and simulations of the ligand/protein complexes pointed to the importance of Asn35 and Arg81 in the binding of SA to GAPA1. The importance of this is further supported through experimental biochemical assays. Indeed, mutating GAPA1 Asn35 into Gly or Arg81 into Leu strongly diminished the ability of the enzyme to bind SA. The very same cavity is responsible for the NADP+ binding to GAPA1. More precisely, modelling suggests that SA binds to the very site where the pyrimidine group of the cofactor fits. NADH inhibited in a dose-response manner the binding of SA to GAPA1, validating our data.

2017 ◽  
Author(s):  
Ευτυχία Κρίτση

Στην παρούσα διατριβή πραγματοποιήθηκε εκτενής μελέτη για την αναζήτηση πρόδρομων βιοδραστικών ενώσεων (hits) από χημικές βιβλιοθήκες για τρείς βιολογικούς στόχους, μέσω της εφαρμογής εμπορικά διαθέσιμων in silico τεχνικών και μεθοδολογιών.Οι στόχοι που επιλέχθηκαν ανήκουν σε διαφορετικές κατηγορίες πρωτεϊνών με μεγάλο φαρμακευτικό ενδιαφέρον, που όμως παρουσιάζουν διαφορετικό επίπεδο ωριμότητας όσον αφορά την εφαρμογή υπολογιστικών εργαλείωνγια την ανακάλυψη νέων φαρμακευτικών ενώσεων. Συγκεριμένα, οι στόχοι που μελετήθηκαν είναι οι ακόλουθοι:•το ένζυμο της 14-α διμεθυλάσης της λανοστερόλης (CYP51) για την αναζήτηση νέων πρόδρομων βιοδραστικών ενώσεων με αντιμικροβιακές ιδιότητες,•το ένζυμο της HIV τύπου 1 πρωτεάσης (HIV-1 PR) για την αναζήτηση νέων πρόδρομων βιοδραστικών ενώσεων με αντι-HIV δράση,•ο διαμεμβρανικός υποδοχέας της Αγγειοτασίνης ΙΙ (ΑΤ1) για την αναζήτηση νέων πρόδρομων βιοδραστικών με αντιυπερτασική δράσηΟι κυριότερες τεχνικές που χρησιμοποιήθηκαν για την αναζήτηση πρόδρομων βιοδραστικών ενώσεων περιλαμβάνουν την Εικονική Σάρωση (Virtual Screening) με χρήση Φαρμακοφόρων Μοντέλων (Pharmacophore modeling), τη Μοριακή Πρόσδεση (Molecular Docking), την πρόβλεψη μοριακών ιδιοτήτων καθώς και Προσομοιώσεις Μοριακής Δυναμικής (Molecular Dynamics Simulations). Η στρατηγική που ακολουθήθηκε διαφέρει σημαντικά ανά στόχο όσον αφορά τη μεθοδολογική προσέγγιση και την επιλογή των υπολογιστικών εργαλείων-αλγορίθμων, δίνοντας έμφαση στη συμπληρωματικότητα των αποτελεσμάτων τους. Για την ανάδειξη των πρόδρομων βιοδραστικών ενώσεων, πραγματοποιήθηκαν in vitro βιολογικές δοκιμές των ενώσεων που προτάθηκαν μέσω των υπολογιστικών τεχνικών. Οι ενώσεις που επιλέχθηκαν παρουσίασαν ανασταλτική δράση (ή συγγένεια πρόσδεσης) σε ικανοποιητικό εύρος τιμών 102 nM–μΜ για να χαρακτηριστούν πρόδρομες βιοδραστικές. Μείζονος σημασίας είναι και το γεγονός ότι οι δομικοί σκελετοί των προτεινόμενων ενώσεων για κάθε στόχο, είναι διαφορετικοί τόσο μεταξύ τους όσο και συγκρινόμενοι με τα υφιστάμενα φαρμακευτικά μόρια. Ως εκ τούτου, μπορούν να αποτελέσουν κατάλληλα "υποστρώματα" για το επόμενο στάδιο που αφορά τη βελτιστοποίησή τους προς ενώσεις-οδηγούς (hit to lead optimization) και δυνητικά προς νέα φαρμακευτικά προϊόντα.


2020 ◽  
Author(s):  
Mark Tristan J. Quimque ◽  
Kin Israel R. Notarte ◽  
arianne letada ◽  
Rey Arturo T. Fernandez ◽  
Kirstin Rhys S. Pueblos ◽  
...  

<div>Aims: To evaluate the in vitro antiproliferative, anticholinesterase and anti-phosphodiesterase activities of the sub-extracts of Uvaria alba (family Annonaceae) and explore putative binding mechanisms of its chemical constituents in silico. <br></div><div><br></div><div>Main methods: U. alba sub-extracts, obtained by solvent-solvent partition, were subjected to antiproliferative and cytotoxicity screening against chronic myelogenous leukemia (K-562) and human cervical cancer (HeLa) cells, respectively. Inhibitory assays against acetylcholinesterase (AChE) and phosphodiesterase (PDE4 B2) enzymes were also performed. The dichloromethane sub-extract (UaD) was chemically profiled using LC-HR-ESIMS-QToF to identify secondary metabolites 1–18. Molecular docking and molecular dynamics simulations were performed to determine the affinity of the putatively annotated metabolites against PDE4 B2B, AChE, ubiquitin specific peptidase 14 (USP14), and Kelch-like ECH-associated protein 1 (Keap1). In addition, DFT calculations were also performed to demonstrate Michael addition reaction between electrophilic cytotoxic metabolites and Cys151 of the Keap1-BTB domain. <br></div><div><br></div><div>Key findings: UaD showed antiproliferative and cytostatic activities against K-562 and HeLa, respectively, and inhibitory activities against AChE and PDE4 B2. Meanwhile, its polyphenolic constituents 3-(3,4-dihydroxybenzyl)-3’,4’,6-trihydroxy-2,4-dimethoxychalcone (8) and grandifloracin (15) showed favorable binding to AChE and Keap1-BTB domain, respectively. The most electrophilic and kinetically stable grandifloracin (15), favorably formed a beta-addition adduct with the Cys151 of Keap1 via Michael addition. The top-ranked ligand-protein complexes attained dynamic stability at 50-ns simulations with high free energy of binding. The top-ranked compounds also conferred favorable in silico pharmacokinetic properties. <br></div><div><br></div><div>Significance: The study highlights the role of U. alba secondary metabolites as potential inhibitors against the aforementioned target proteins in an effort to discover new drug leads for cancer and Alzheimer’s.</div>


2020 ◽  
Author(s):  
Mark Tristan J. Quimque ◽  
Kin Israel R. Notarte ◽  
arianne letada ◽  
Rey Arturo T. Fernandez ◽  
Kirstin Rhys S. Pueblos ◽  
...  

Aims: To evaluate the in vitro antiproliferative, anticholinesterase and anti-phosphodiesterase activities of the sub-extracts of Uvaria alba (family Annonaceae) and explore putative binding mechanisms of its chemical constituents in silico. Main methods: U. alba sub-extracts, obtained by solvent-solvent partition, were subjected to antiproliferative and cytotoxicity screening against chronic myelogenous leukemia (K-562) and human cervical cancer (HeLa) cells, respectively. Inhibitory assays against acetylcholinesterase (AChE) and phosphodiesterase (PDE4 B2) enzymes were also performed. The dichloromethane sub-extract (UaD) was chemically profiled using LC-HR-ESIMS-QToF to identify secondary metabolites 1–18. Molecular docking and molecular dynamics simulations were performed to determine the affinity of the putatively annotated metabolites against PDE4 B2B, AChE, ubiquitin specific peptidase 14 (USP14), and Kelch-like ECH-associated protein 1 (Keap1). In addition, DFT calculations were also performed to demonstrate Michael addition reaction between electrophilic cytotoxic metabolites and Cys151 of the Keap1-BTB domain. Key findings: UaD showed antiproliferative and cytostatic activities against K-562 and HeLa, respectively, and inhibitory activities against AChE and PDE4 B2. Meanwhile, its polyphenolic constituents 3-(3,4-dihydroxybenzyl)-3’,4’,6-trihydroxy-2,4-dimethoxychalcone (8) and grandifloracin (15) showed favorable binding to AChE and Keap1-BTB domain, respectively. The most electrophilic and kinetically stable grandifloracin (15), favorably formed a beta-addition adduct with the Cys151 of Keap1 via Michael addition. The top-ranked ligand-protein complexes attained dynamic stability at 50-ns simulations with high free energy of binding. The top-ranked compounds also conferred favorable in silico pharmacokinetic properties. Significance: The study highlights the role of U. alba secondary metabolites as potential inhibitors against the aforementioned target proteins in an effort to discover new drug leads for cancer and Alzheimer’s.


2020 ◽  
Author(s):  
Mark Tristan J. Quimque ◽  
Kin Israel R. Notarte ◽  
arianne letada ◽  
Rey Arturo T. Fernandez ◽  
Kirstin Rhys S. Pueblos ◽  
...  

<div>Aims: To evaluate the in vitro antiproliferative, anticholinesterase and anti-phosphodiesterase activities of the sub-extracts of Uvaria alba (family Annonaceae) and explore putative binding mechanisms of its chemical constituents in silico. <br></div><div><br></div><div>Main methods: U. alba sub-extracts, obtained by solvent-solvent partition, were subjected to antiproliferative and cytotoxicity screening against chronic myelogenous leukemia (K-562) and human cervical cancer (HeLa) cells, respectively. Inhibitory assays against acetylcholinesterase (AChE) and phosphodiesterase (PDE4 B2) enzymes were also performed. The dichloromethane sub-extract (UaD) was chemically profiled using LC-HR-ESIMS-QToF to identify secondary metabolites 1–18. Molecular docking and molecular dynamics simulations were performed to determine the affinity of the putatively annotated metabolites against PDE4 B2B, AChE, ubiquitin specific peptidase 14 (USP14), and Kelch-like ECH-associated protein 1 (Keap1). In addition, DFT calculations were also performed to demonstrate Michael addition reaction between electrophilic cytotoxic metabolites and Cys151 of the Keap1-BTB domain. <br></div><div><br></div><div>Key findings: UaD showed antiproliferative and cytostatic activities against K-562 and HeLa, respectively, and inhibitory activities against AChE and PDE4 B2. Meanwhile, its polyphenolic constituents 3-(3,4-dihydroxybenzyl)-3’,4’,6-trihydroxy-2,4-dimethoxychalcone (8) and grandifloracin (15) showed favorable binding to AChE and Keap1-BTB domain, respectively. The most electrophilic and kinetically stable grandifloracin (15), favorably formed a beta-addition adduct with the Cys151 of Keap1 via Michael addition. The top-ranked ligand-protein complexes attained dynamic stability at 50-ns simulations with high free energy of binding. The top-ranked compounds also conferred favorable in silico pharmacokinetic properties. <br></div><div><br></div><div>Significance: The study highlights the role of U. alba secondary metabolites as potential inhibitors against the aforementioned target proteins in an effort to discover new drug leads for cancer and Alzheimer’s.</div>


2020 ◽  
Author(s):  
Sahar Qazi ◽  
Mustafa Alhaji Isa ◽  
Adam Mustapha ◽  
Khalid Raza ◽  
Ibrahim Alkali Allamin ◽  
...  

<p>The Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) is an infectious virus that causes mild to severe life-threatening upper respiratory tract infection. The virus emerged in Wuhan, China in 2019, and later spread across the globe. Its genome has been completely sequenced and based on the genomic information, the virus possessed 3C-Like Main Protease (3CLpro), an essential multifunctional enzyme that plays a vital role in the replication and transcription of the virus by cleaving polyprotein at eleven various sites to produce different non-structural proteins. This makes the protein an important target for drug design and discovery. Herein, we analyzed the interaction between the 3CLpro and potential inhibitory compounds identified from the extracts of <i>Zingiber offinale</i> and <i>Anacardium occidentale</i> using in silico docking and Molecular Dynamics (MD) Simulation. The crystal structure of SARS-CoV-2 main protease in complex with 02J (5-Methylisoxazole-3-carboxylic acid) and PEJ (composite ligand) (PDB Code: 6LU7,2.16Å) retrieved from Protein Data Bank (PDB) and subject to structure optimization and energy minimization. A total of twenty-nine compounds were obtained from the extracts of <i>Zingiber offinale </i>and the leaves of <i>Anacardium occidentale. </i>These compounds were screened for physicochemical (Lipinski rule of five, Veber rule, and Egan filter), <i>Pan</i>-Assay Interference Structure (PAINS), and pharmacokinetic properties to determine the Pharmaceutical Active Ingredients (PAIs). Of the 29 compounds, only nineteen (19) possessed drug-likeness properties with efficient oral bioavailability and less toxicity. These compounds subjected to molecular docking analysis to determine their binding energies with the 3CLpro. The result of the analysis indicated that the free binding energies of the compounds ranged between ˗5.08 and -10.24kcal/mol, better than the binding energies of 02j (-4.10kcal/mol) and PJE (-5.07kcal.mol). Six compounds (CID_99615 = -10.24kcal/mol, CID_3981360 = 9.75kcal/mol, CID_9910474 = -9.14kcal/mol, CID_11697907 = -9.10kcal/mol, CID_10503282 = -9.09kcal/mol and CID_620012 = -8.53kcal/mol) with good binding energies further selected and subjected to MD Simulation to determine the stability of the protein-ligand complex. The results of the analysis indicated that all the ligands form stable complexes with the protein, although, CID_9910474 and CID_10503282 had a better stability when compared to other selected phytochemicals (CID_99615, CID_3981360, CID_620012, and CID_11697907). </p>


2020 ◽  
Author(s):  
Sahar Qazi ◽  
Mustafa Alhaji Isa ◽  
Adam Mustapha ◽  
Khalid Raza ◽  
Ibrahim Alkali Allamin ◽  
...  

<p>The Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) is an infectious virus that causes mild to severe life-threatening upper respiratory tract infection. The virus emerged in Wuhan, China in 2019, and later spread across the globe. Its genome has been completely sequenced and based on the genomic information, the virus possessed 3C-Like Main Protease (3CLpro), an essential multifunctional enzyme that plays a vital role in the replication and transcription of the virus by cleaving polyprotein at eleven various sites to produce different non-structural proteins. This makes the protein an important target for drug design and discovery. Herein, we analyzed the interaction between the 3CLpro and potential inhibitory compounds identified from the extracts of <i>Zingiber offinale</i> and <i>Anacardium occidentale</i> using in silico docking and Molecular Dynamics (MD) Simulation. The crystal structure of SARS-CoV-2 main protease in complex with 02J (5-Methylisoxazole-3-carboxylic acid) and PEJ (composite ligand) (PDB Code: 6LU7,2.16Å) retrieved from Protein Data Bank (PDB) and subject to structure optimization and energy minimization. A total of twenty-nine compounds were obtained from the extracts of <i>Zingiber offinale </i>and the leaves of <i>Anacardium occidentale. </i>These compounds were screened for physicochemical (Lipinski rule of five, Veber rule, and Egan filter), <i>Pan</i>-Assay Interference Structure (PAINS), and pharmacokinetic properties to determine the Pharmaceutical Active Ingredients (PAIs). Of the 29 compounds, only nineteen (19) possessed drug-likeness properties with efficient oral bioavailability and less toxicity. These compounds subjected to molecular docking analysis to determine their binding energies with the 3CLpro. The result of the analysis indicated that the free binding energies of the compounds ranged between ˗5.08 and -10.24kcal/mol, better than the binding energies of 02j (-4.10kcal/mol) and PJE (-5.07kcal.mol). Six compounds (CID_99615 = -10.24kcal/mol, CID_3981360 = 9.75kcal/mol, CID_9910474 = -9.14kcal/mol, CID_11697907 = -9.10kcal/mol, CID_10503282 = -9.09kcal/mol and CID_620012 = -8.53kcal/mol) with good binding energies further selected and subjected to MD Simulation to determine the stability of the protein-ligand complex. The results of the analysis indicated that all the ligands form stable complexes with the protein, although, CID_9910474 and CID_10503282 had a better stability when compared to other selected phytochemicals (CID_99615, CID_3981360, CID_620012, and CID_11697907). </p>


Author(s):  
Sisir Nandi ◽  
Mohit Kumar ◽  
Mridula Saxena ◽  
Anil Kumar Saxena

Background: The novel coronavirus disease (COVID-19) is caused by a new strain (SARS-CoV-2) erupted in 2019. Nowadays, it is a great threat that claims uncountable lives worldwide. There is no specific chemotherapeutics developed yet to combat COVID-19. Therefore, scientists have been devoted in the quest of the medicine that can cure COVID- 19. Objective: Existing antivirals such as ASC09/ritonavir, lopinavir/ritonavir with or without umifenovir in combination with antimalarial chloroquine or hydroxychloroquine have been repurposed to fight the current coronavirus epidemic. But exact biochemical mechanisms of these drugs towards COVID-19 have not been discovered to date. Method: In-silico molecular docking can predict the mode of binding to sort out the existing chemotherapeutics having a potential affinity towards inhibition of the COVID-19 target. An attempt has been made in the present work to carry out docking analyses of 34 drugs including antivirals and antimalarials to explain explicitly the mode of interactions of these ligands towards the COVID-19protease target. Results: 13 compounds having good binding affinity have been predicted towards protease binding inhibition of COVID-19. Conclusion: Our in silico docking results have been confirmed by current reports from clinical settings through the citation of suitable experimental in vitro data available in the published literature.


2019 ◽  
Vol 15 (5) ◽  
pp. 445-455 ◽  
Author(s):  
Suraj N. Mali ◽  
Sudhir Sawant ◽  
Hemchandra K. Chaudhari ◽  
Mustapha C. Mandewale

Background: : Thiadiazole not only acts as “hydrogen binding domain” and “two-electron donor system” but also as constrained pharmacophore. Methods:: The maleate salt of 2-((2-hydroxy-3-((4-morpholino-1, 2,5-thiadiazol-3-yl) oxy) propyl) amino)- 2-methylpropan-1-ol (TML-Hydroxy)(4) has been synthesized. This methodology involves preparation of 4-morpholino-1, 2,5-thiadiazol-3-ol by hydroxylation of 4-(4-chloro-1, 2,5-thiadiazol-3-yl) morpholine followed by condensation with 2-(chloromethyl) oxirane to afford 4-(4-(oxiran-2-ylmethoxy)-1,2,5-thiadiazol- 3-yl) morpholine. Oxirane ring of this compound was opened by treating with 2-amino-2-methyl propan-1- ol to afford the target compound TML-Hydroxy. Structures of the synthesized compounds have been elucidated by NMR, MASS, FTIR spectroscopy. Results: : The DSC study clearly showed that the compound 4-maleate salt is crystalline in nature. In vitro antibacterial inhibition and little potential for DNA cleavage of the compound 4 were explored. We extended our study to explore the inhibition mechanism by conducting molecular docking, ADMET and molecular dynamics analysis by using Schrödinger. The molecular docking for compound 4 showed better interactions with target 3IVX with docking score of -8.508 kcal/mol with respect to standard ciprofloxacin (docking score= -3.879 kcal/mol). TML-Hydroxy was obtained in silico as non-carcinogenic and non-AMES toxic with good percent human oral absorption profile (69.639%). TML-Hydroxy showed the moderate inhibition against Mycobacteria tuberculosis with MIC 25.00 μg/mL as well as moderate inhibition against S. aureus, Bacillus sps, K. Pneumoniae and E. coli species. Conclusion: : In view of the importance of the 1,2,5-thiadiazole moiety involved, this study would pave the way for future development of more effective analogs for applications in medicinal field.


2020 ◽  
Vol 18 ◽  
Author(s):  
Debadash Panigrahi ◽  
Ganesh Prasad Mishra

Objective:: Recent pandemic caused by SARS-CoV-2 described in Wuhan China in December-2019 spread widely almost all the countries of the world. Corona virus (COVID-19) is causing the unexpected death of many peoples and severe economic loss in several countries. Virtual screening based on molecular docking, drug-likeness prediction, and in silico ADMET study has become an effective tool for the identification of small molecules as novel antiviral drugs to treat diseases. Methods:: In the current study, virtual screening was performed through molecular docking for identifying potent inhibitors against Mpro enzyme from the ZINC library for the possible treatment of COVID-19 pandemic. Interestingly, some compounds are identified as possible anti-covid-19 agents for future research. 350 compounds were screened based on their similarity score with reference compound X77 from ZINC data bank and were subjected to docking with crystal structure available of Mpro enzyme. These compounds were then filtered by their in silico ADME-Tox and drug-likeness prediction values. Result:: Out of these 350 screened compounds, 10 compounds were selected based on their docking score and best docked pose in comparison to the reference compound X77. In silico ADME-Tox and drug likeliness predictions of the top compounds were performed and found to be excellent results. All the 10 screened compounds showed significant binding pose with the target enzyme main protease (Mpro) enzyme and satisfactory pharmacokinetic and toxicological properties. Conclusion:: Based on results we can suggest that the identified compounds may be considered for therapeutic development against the COVID-19 virus and can be further evaluated for in vitro activity, preclinical, clinical studies and formulated in a suitable dosage form to maximize their bioavailability.


2021 ◽  
Vol 22 (15) ◽  
pp. 7811
Author(s):  
Olufunmilayo Olukemi Akapo ◽  
Joanna M. Macnar ◽  
Justyna D. Kryś ◽  
Puleng Rosinah Syed ◽  
Khajamohiddin Syed ◽  
...  

Cytochrome P450 monooxygenase CYP51 (sterol 14α-demethylase) is a well-known target of the azole drug fluconazole for treating cryptococcosis, a life-threatening fungal infection in immune-compromised patients in poor countries. Studies indicate that mutations in CYP51 confer fluconazole resistance on cryptococcal species. Despite the importance of CYP51 in these species, few studies on the structural analysis of CYP51 and its interactions with different azole drugs have been reported. We therefore performed in silico structural analysis of 11 CYP51s from cryptococcal species and other Tremellomycetes. Interactions of 11 CYP51s with nine ligands (three substrates and six azoles) performed by Rosetta docking using 10,000 combinations for each of the CYP51-ligand complex (11 CYP51s × 9 ligands = 99 complexes) and hierarchical agglomerative clustering were used for selecting the complexes. A web application for visualization of CYP51s’ interactions with ligands was developed (http://bioshell.pl/azoledocking/). The study results indicated that Tremellomycetes CYP51s have a high preference for itraconazole, corroborating the in vitro effectiveness of itraconazole compared to fluconazole. Amino acids interacting with different ligands were found to be conserved across CYP51s, indicating that the procedure employed in this study is accurate and can be automated for studying P450-ligand interactions to cater for the growing number of P450s.


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