Complementarity principle in terms of electron density for the study of EGFR complexes

Author(s):  
Shivananda Kandagalla ◽  
Hrvoje Rimac ◽  
Vladimir A Potemkin ◽  
Maria A Grishina

The complementarity principle is a well-established concept in the field of chemistry and biology. This concept is widely studied as the lock-and-key relationship between two structures, such as enzyme and ligand interactions. These interactions are based on the overlap of electron clouds between two structures. In this study, a mathematical relation determining complementarity of intermolecular contacts in terms of overlaps of electron clouds was examined using a quantum orbital-free AlteQ method developed in-house for 64 EGFR–ligand complexes with experimentally measured binding affinity data. A very high correlation was found between the overlap of ligand and enzyme electron clouds and the calculated terms, providing a good basis for prognosis of bioactivity and for molecular docking studies.

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.


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.


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.


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.


2017 ◽  
pp. 727-746
Author(s):  
Kailas Dashrath Sonawane ◽  
Maruti Jayram Dhanavade

Molecular docking has advanced to such an extent that one can rapidly and accurately identify pharmaceutically useful lead compounds. It is being used routinely to understand molecular interactions between enzyme and ligand molecules. Several computational approaches are combined with experimental work to investigate molecular mechanisms in detail at the atomic level. Molecular docking method is also useful to investigate proper orientation and interactions between receptor and ligand. In this chapter we have discussed protein-protein approach to understand interactions between enzyme and amyloid beta (Aß) peptide. The Aß peptide is a causative agent of Alzheimer's disease. The Aß peptides can be cleaved specifically by several enzymes. Their interactions with Aß peptide and specific enzyme can be investigated using molecular docking. Thus, the molecular information obtained from docking studies might be useful to design new therapeutic approaches in treatment of Alzheimer's as well as several other diseases.


Author(s):  
Hemalatha Sattu ◽  
Indira rani Nerella ◽  
Saritha Jyostna Tangeda

Aim: In our earlier research, we have synthesized series of substituted 1-(2, 5-dimethyl thiophene-3yl)-(4-substituted phenyl)-2-propene-1-one derivatives and evaluated them for their anti-bacterial and antifungal activity. In recent years, chalcone derivatives are proved for their varied pharmacological effects ranging from antimicrobial activity to anti-cancer effects. In this study, we have hypothesized the efficiency of our earlier synthesized anti-bacterial and antifungal chalcone derivatives for their potential inhibition of epidermal growth factor receptor protein (EGFR), through molecular docking studies. Methodology: Molecular docking simulation studies are performed using the Glide XP module of Schrodinger Suite and ligand binding energies are also calculated. Results: Molecular docking studies of the selected compounds against EGFR revealed docking scores ranging from -6.746 (compound 5) to -5.681 (compound 3) and also provided insight into binding conformations of the ligands in the EGFR protein environment. Additionally, molecular property and Absorption, Distribution, Metabolism, and Excretion (ADME) predictor analysis is also performed for the dataset ligands, which further provided the probable explanation for the binding potentials. Conclusion: Among all the tested dataset ligands, compound 5 has shown the highest dock score (-6.746) with better ADME profiles. Binding energies in the protein-ligand interactions explain how fit the ligand binds with the target protein. Molecular docking studies of these anti-bacterial, antifungal chalcone derivatives provided deeper insights in understanding the probable conformations of these tested ligands in the EGFR protein environment.


Author(s):  
Kailas Dashrath Sonawane ◽  
Maruti Jayram Dhanavade

Molecular docking has advanced to such an extent that one can rapidly and accurately identify pharmaceutically useful lead compounds. It is being used routinely to understand molecular interactions between enzyme and ligand molecules. Several computational approaches are combined with experimental work to investigate molecular mechanisms in detail at the atomic level. Molecular docking method is also useful to investigate proper orientation and interactions between receptor and ligand. In this chapter we have discussed protein-protein approach to understand interactions between enzyme and amyloid beta (Aß) peptide. The Aß peptide is a causative agent of Alzheimer's disease. The Aß peptides can be cleaved specifically by several enzymes. Their interactions with Aß peptide and specific enzyme can be investigated using molecular docking. Thus, the molecular information obtained from docking studies might be useful to design new therapeutic approaches in treatment of Alzheimer's as well as several other diseases.


2021 ◽  
Vol 6 (2) ◽  
pp. 128-140
Author(s):  
Mukesh Kumar ◽  
Satyavir Singh ◽  
Nazia Siddiqui ◽  
Saleem Javed

In present work, 1-methylnicotinamide (1-MNA) has been investigated theoretically by density functional theory approach and investigated its vibrational spectroscopy. To complete the structure optimization, determination of vibrational frequencies and other valuable parameters, B3LYP method used with the 6-311++G(d,p) basis set. Atoms in molecules theory (AIM) had been used to evaluate ellipticity, isosurface projection by electron localization function and binding energies. The IR and Raman spectra have also been calculated computationally. NBO analysis employed to determine interactions of donor and acceptor. Fukui functions and molecular electrostatic potential (MEP) showed reactive regions of the molecule. UV-vis spectrum calculated using TD-DFT/PCM methods with different solvents. Thermodynamic properties like free energy, enthalpy and entropy with various temperature were calculated. By the use of the electrophilicity index, the probability of the bioactive nature of the molecule was proved theoretically. Protein-ligand interactions calculated and established by molecular docking. The biological investigations for druglikeness also employed for the (1-MNA).


Sign in / Sign up

Export Citation Format

Share Document