scholarly journals Structure Based Design and Molecular Docking Studies for Phosphorylated Tau Inhibitors in Alzheimer’s Disease

Cells ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 260 ◽  
Author(s):  
Jangampalli Pradeepkiran ◽  
P. Reddy

The purpose of our study is to identify phosphorylated tau (p-tau) inhibitors. P-tau has recently received great interest as a potential drug target in Alzheimer’s disease (AD). The continuous failure of Aβ-targeted therapeutics recommends an alternative drug target to treat AD. There is increasing evidence and growing awareness of tau, which plays a central role in AD pathophysiology, including tangles formation, abnormal activation of phosphatases/kinases, leading p-tau aggregation in AD neurons. In the present study, we performed computational pharmacophore models, molecular docking, and simulation studies for p-tau in order to identify hyperphosphorylated sites. We found multiple serine sites that altered the R1/R2 repeats flanking sequences in the tau protein, affecting the microtubule binding ability of tau. The ligand molecules exhibited the p-O ester scaffolds with inhibitory and/or blocking actions against serine residues of p-tau. Our molecular docking results revealed five ligands that showed high docking scores and optimal protein-ligand interactions of p-tau. These five ligands showed the best pharmacokinetic and physicochemical properties, including good absorption, distribution, metabolism, and excretion (ADME) and admetSAR toxicity tests. The p-tau pharmacophore based drug discovery models provide the comprehensive and rapid drug interventions in AD, and tauopathies are expected to be the prospective future therapeutic approach in AD.

2020 ◽  
Vol 17 (2) ◽  
pp. 233-247
Author(s):  
Krishna A. Gajjar ◽  
Anuradha K. Gajjar

Background: Pharmacophore mapping and molecular docking can be synergistically integrated to improve the drug design and discovery process. A rational strategy, combiphore approach, derived from the combined study of Structure and Ligand based pharmacophore has been described to identify novel GPR40 modulators. Methods: DISCOtech module from Discovery studio was used for the generation of the Structure and Ligand based pharmacophore models which gave hydrophobic aromatic, ring aromatic and negative ionizable as essential pharmacophoric features. The generated models were validated by screening active and inactive datasets, GH scoring and ROC curve analysis. The best model was exposed as a 3D query to screen the hits from databases like GLASS (GPCR-Ligand Association), GPCR SARfari and Mini-Maybridge. Various filters were applied to retrieve the hit molecules having good drug-like properties. A known protein structure of hGPR40 (pdb: 4PHU) having TAK-875 as ligand complex was used to perform the molecular docking studies; using SYBYL-X 1.2 software. Results and Conclusion: Clustering both the models gave RMSD of 0.89. Therefore, the present approach explored the maximum features by combining both ligand and structure based pharmacophore models. A common structural motif as identified in combiphore for GPR40 modulation consists of the para-substituted phenyl propionic acid scaffold. Therefore, the combiphore approach, whereby maximum structural information (from both ligand and biological protein) is explored, gives maximum insights into the plausible protein-ligand interactions and provides potential lead candidates as exemplified in this study.


Author(s):  
Punabaka Jyothi ◽  
Kuna Yellamma

Objective: Alzheimer’s disease (AD), a progressive neurodegenerative disorder with many cognitive and neuropsychiatric symptoms, is biochemically characterized by a significant decrease in the brain neurotransmitter Acetylcholine (ACh).Methods: In the present insilico study, six plant bioactive compounds namely Harmol, Vasicine, Harmaline, Harmine, Harmane and Harmalol (from P. Nigellastrum Bunge) were analyzed for their inhibitory role on AChE (Acetylcholinesterase) and BChE (Butyrylcholinesterase) activity by applying the molecular docking studies. Other parameters viz. determination of molecular interaction-based binding affinity values, protein-ligand interactions, Lipinski rule of five, functional properties and biological activities for the above compounds were also calculated by employing the appropriate bioinformatics tools.Results: The results of docking analysis clearly showed that Harmalol has highest binding affinity with AChE (-8.6 kcal/mole) and BChE (-8.0 kcal/mole) but it does not qualified the enzyme inhibitory activity, since it was exerted, and also has least percentage activity on AD and neurodegenerative disease. Whereas, the Harmine has been second qualified binding affinity (-8.4 kcal/mol) and first in other parameters when compared with Harmalol.Conclusion: Based on docking results and other parameters conducted, we are concluding that Harmine is the best compound for further studies to treat AD.Keywords: Alzheimer's disease (AD), Acetylcholinesterase, Butyrylcholinesterase, Lead Molecules


2020 ◽  
Vol 45 (2) ◽  
Author(s):  
Eda Özturan Özer ◽  
Oya Unsal Tan ◽  
Suna Turkoglu

AbstractBackground/ObjectiveGinsenosides, the major active components of the ginseng, are known to have various effects on nervous systems. The present study aimed to clarify the inhibition potentials of ginsenosides Rb1, Rc, Re and Rg1 on acetylcholinesterase (AChE) and butrylcholinesterase (BChE) activities, and to evaluate the underlying mechanisms of inhibitions provided by protein-ligand interactions considering their probable candidates of prodrug.Materials and methodsThe inhibitory mechanisms of ginsenosides related with their structural diversity were analyzed kinetically and protein-ligand interactions for both enzymes were evaluated with most potent ginsenosides, by molecular docking studies.ResultsGinsenosides Re and Rg1, with sugar moieties attached to the C-6 and C-20 positions of core structure were found to possess the most powerful inhibitory effect on AChE and BChE activities. Molecular docking studies have been confirmed by kinetic studies. Ginsenosides having a direct interaction with amino acid residues belonging to the catalytic triad revealed the most powerful inhibition with lowest enzyme-inhibitor dissociation constant (Ki) values.ConclusionsGinsenosides Re and Rg1, either alone or in a specific combination, may provide beneficial effects on neurodegenerative pathologies in therapeutic terms.


Author(s):  
AKILA S. ◽  
MALAR VIZHI S. ◽  
VIJAYALAKSHMI P. ◽  
CLARA MARY A. ◽  
RAJALAKSHMI M.

Objective: Alzheimer's disease (AD) is a progressive, fatal brain disorder that would be putting a growing strain on health and social care systems. Present anti-AD agents are limited in their application due to their adverse effects, toxicity, and limited targets in AD pathology. As a result, it is important to develop an AD-fighting compound. Some flavonoids (such as kaempferol, myricetin, quercetin, and syringetin) have been shown to be effective in the treatment of Alzheimer's disease. Methods: We chose 284 flavonoids from the NPACT database for molecular docking studies in order to examine their binding interactions with the Alzheimer target protein CD33. Results: These compounds exhibited significant docking interactions with a variety of targets implicated in the pathogenesis of AD. We chose the top three compounds (Rutin, Morin, and,4,4'-Trihydroxydihydrochalcone) based on the scoring parameter. Conclusion: These compounds exhibited favorable pharmacokinetic properties, indicating that they could be attractive drug candidates for the treatment of Alzheimer's disease.


Author(s):  
Kavita Pandey ◽  
Gursimran Kaur Uppal ◽  
Ratna Upadhyay

The bark of the tree Terminalia arjuna commonly referred as Arjuna is widely used in Ayurveda as a therapeutic agent for heart disease. More recently, a proprietary botanical extract of T. arjuna with tradename, Oxyjun®, demonstrated cardiotonic and ergogenic benefits for the first time in a younger and healthier population. However, the mechanism of action and biological actives of this novel sports ingredient were not clear. A molecular docking approach was adopted to understand the protein-ligand interactions and establish the most probable mechanism(s) of cardio vascular actions of the phytoconstituents of the T. arjuna standardized extract (TASE). Twenty-one phytochemicals (ligands) were chosen from Arjuna and their binding affinities against eight proteins serving cardiovascular functions (target proteins) were investigated. Autodock Vina was used to carry out the molecular docking studies. Potential efficacy in humans was assessed on the basis of ADMET properties and Lipinski’s Rule of 5. We found that arjunic acid, arjungenin, arjunetin, arjunglucoside1, chrysin, kaempferol, luteolin, rhamnetin and taxifolin demonstrated good docking scores and bioactivity.


2020 ◽  
Author(s):  
Vikas Kumar ◽  
Nitin Sharma ◽  
Anuradha Sourirajan ◽  
Prem Kumar Khosla ◽  
Kamal Dev

AbstractTerminalia arjuna (Roxb.) Wight and Arnot (T. arjuna) commonly known as Arjuna has been known for its cardiotonic nature in heart failure, ischemic, cardiomyopathy, atherosclerosis, myocardium necrosis and also has been used in the treatment of different human disorders such as blood diseases, anaemia and viral diseases. Our focus has been on phytochemicals which do not exhibit any cytotoxicity and have significant cardioprotective activity. Since Protein-Ligand interactions play a key role in structure-based drug design, therefore with the help of molecular docking, we screened 19 phytochemicals present in T. arjuna and investigated their binding affinity against different cardiovascular target proteins. The three-dimensional (3D) structure of target cardiovascular proteins were retrieved from Protein Data Bank, and docked with 3D Pubchem structures of 19 phytochemicals using Autodock vina. Molecular docking and drug-likeness studies were made using ADMET properties while Lipinski’s rule of five was performed for the phytochemicals to evaluate their cardio protective activity. Among all selected phytocompounds, arjunic acid, arjungenin, and terminic acid were found to fulfill all ADMET rules, drug likeness, and are less toxic in nature. Our studies, therefore revealed that these three phytochemicals from T. arjuna can be used as promising candidates for developing broad spectrum drugs against cardiovascular diseases.


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