Molecular Dynamics Study of Insulin Mutants

Mean Square ◽

Wild Type ◽

Secondary Structure Content

Human insulin, a small protein hormone consisting of A-chain (21 residues) and B-chain (30 residues) linked by three disulfide bonds, is crucial for controlling the hyperglycemia in type I diabetes. In the present work molecular dynamics simulation (MD) with human insulin and its mutants was used to assess the influence of 10 point mutations (HisA8, ValA10, AspB10, GlnB17, AlaB17, GlnB18, AspB25, ThrB26, GluB27, AspB28), 6 double mutations (GluA13+GluB10, SerA13+GluB27, GluB1+GluB27, SerB2+AspB10, AspB9+GluB27, GluB16+GluB27) and one triple mutation (GluA15+AspA18+AspB3) in the protein sequence on the structure and dynamics of human insulin. A series of thermal unfolding MD simulations with wild type (WT) human insulin and its mutants was performed at 400 K with GROMACS software (version 5.1) using the CHARMM36m force field. The MD results have been analyzed in terms of the parameters characterizing both the global and local protein structure, such as the backbone root mean-square deviation, gyration radius, solvent accessible surface area, the root mean-square fluctuations and the secondary structure content. The MD simulation data showed that depending on time evolution of integral characteristics, the examined mutants can be tentatively divided into three groups: 1) the mutants HisA8, ValA10, AlaB17, AspB25, ThrB26, GluB27, GluA13+GluB10, GluB1+GluB27 and GluB16+GluB27, which exert stabilizing effect on the protein structure in comparison with wild type insulin; 2) the mutants GlnB17, AspB10, SerB2+AspB10 and GluA15+AspA18+AspB3 that did not significantly affect the dynamical properties of human insulin with a minimal stabilizing impact; 3) the mutants AspB28, AspB9+GluB27 and SerA13+GluB27, GlnB18, destabilizing the protein structure. Analysis of the secondary structure content provided evidence for the influence of AspB28, AspB9+GluB27 and SerA13+GluB27, GlnB18 on the insulin unfolding. Our MD results indicate that the replacement of superficial nonpolar residues in the insulin structure by hydrophilic ones gives rise to the increase in protein stability in comparison with the wild type protein.

Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide

Open Chemistry ◽

10.1515/chem-2016-0021 ◽

2016 ◽

Vol 14 (1) ◽

pp. 188-196 ◽

Cited By ~ 1

Author(s):

Syed Lal Badshah ◽

Abdul Naeem Khan ◽

Yahia Nasser Mabkhot

Keyword(s):

Molecular Dynamics ◽

Secondary Structure ◽

Cholera Toxin ◽

Root Mean Square ◽

Host Cells ◽

Dynamics Simulation ◽

Radius Of Gyration ◽

Mean Square ◽

Toxin A

AbstractA molecular dynamics (MD) simulation study of the enzymatic portion of cholera toxin; cholera toxin A-1 polypeptide (CTA1) was performed at 283, 310 and 323 K. From total energy analysis it was observed that this toxin is stable thermodynamically and these outcomes were likewise confirmed by root mean square deviations (RMSD) investigations. The Cα root mean square fluctuation (RMSF) examinations revealed that there are a number of residues inside CTA1, which can be used as target for designing and synthesizing inhibitory drugs, in order to inactivate cholera toxin inside the human body. The fluctuations in the radius of gyration and hydrogen bonding in CTA1 proved that protein unfolding and refolding were normal routine phenomena in its structure at all temperatures. Solvent accessible surface area study identified the hydrophilic nature of the CTA1, and due to this property it can be a potential biological weapon. The structural identification (STRIDE) algorithm for proteins was successfully used to determine the partially disordered secondary structure of CTA1. On account of this partially disordered secondary structure, it can easily deceive the proteolytic enzymes of the endoplasmic reticulum of host cells.

Mollusc-Derived Brominated Indoles for the Selective Inhibition of Cyclooxygenase: A Computational Expedition

Molecules ◽

10.3390/molecules26216538 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6538

Author(s):

Md. Mominur Rahman ◽

Md. Junaid ◽

S. M. Zahid Hosen ◽

Mohammad Mostafa ◽

Lei Liu ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Docking ◽

Surface Area ◽

Root Mean Square ◽

Selective Inhibition ◽

Dynamics Simulation ◽

Mean Square ◽

Cox 1

Inflammation plays an important role in different chronic diseases. Brominated indoles derived from the Australian marine mollusk Dicathais orbita (D. orbita) are of interest for their anti-inflammatory properties. This study evaluates the binding mechanism and potentiality of several brominated indoles (tyrindoxyl sulfate, tyrindoleninone, 6-bromoisatin, and 6,6′-dibromoindirubin) against inflammatory mediators cyclooxygenases-1/2 (COX-1/2) using molecular docking, followed by molecular dynamics simulation, along with physicochemical, drug-likeness, pharmacokinetic (pk), and toxicokinetic (tk) properties. Molecular docking identified that these indole compounds are anchored, with the main amino acid residues, positioned in the binding pocket of the COX-1/2, required for selective inhibition. Moreover, the molecular dynamics simulation based on root mean square deviation (RMSD), radius of gyration (Rg), solvent accessible surface area (SASA), and root mean square fluctuation (RMSF) analyses showed that these natural brominated molecules transit rapidly to a progressive constant configuration during binding with COX-1/2 and seem to accomplish a consistent dynamic behavior by maintaining conformational stability and compactness. The results were comparable to the Food and Drug Administration (FDA)-approved selective COX inhibitor, aspirin. Furthermore, the free energy of binding for the compounds assessed by molecular mechanics–Poisson–Boltzmann surface area (MM–PBSA) confirmed the binding capacity of indoles towards COX-1/2, with suitable binding energy values except for the polar precursor tyrindoxyl sulfate (with COX-1). The physicochemical and drug-likeness analysis showed zero violations of Lipinski’s rule, and the compounds are predicted to have excellent pharmacokinetic profiles. These indoles are projected to be non-mutagenic and free from hepatotoxicity, with no inhibition of human ether-a-go–go gene (hERG) I inhibitors, and the oral acute toxicity LD50 in rats is predicted to be similar or lower than aspirin. Overall, this work has identified a plausible mechanism for selective COX inhibition by natural marine indoles as potential therapeutic candidates for the mitigation of inflammation.

Molecular Dynamics Study of Amyloidogenic Mutants of Human Lysozyme

East European Journal of Physics ◽

10.26565/2312-4334-2018-4-04 ◽

2018 ◽

Keyword(s):

Molecular Dynamics ◽

Secondary Structure ◽

Root Mean Square ◽

Fibril Formation ◽

Structure Evolution ◽

Gyration Radius ◽

Renal Amyloidosis ◽

Mean Square ◽

Human Lysozyme

The mutants of human lysozyme are capable of fibril formation implicated in the etiology of familial systemic or renal amyloidosis. A series of 100 ns thermal unfolding molecular dynamics (MD) simulations with WT human lysozyme and its seven amyloidogenic variants (I56T, D67H, F57I, W64R, Y54N, F57I/T70N and T70N/W112R) have been performed at 500 K. The molecular dynamics simulations were performed with GROMACS software (version 5.1) using the CHARMM36m force field. The MD results have been analysed in terms of the parameters characterizing both the global and local protein structure, such as the backbone root mean-square deviation, gyration radius, solvent accessible surface area, the root mean-square fluctuations and the secondary structure content. Depending on the observed effects, the examined variants of human lysozyme have been roughly divided into three groups comprising of mutants with faster (Y54N and F57I/T70N), similar (D67H and I56T) or slower (W64, F57I and T70N/W112R) unfolding rate compared to the wild-type counterpart. The analysis of the protein fluctuational behavior revealed that in most mutants the β-domain displays stronger fluctuations (except the W64R and F57I) and higher flexibility of the C- and D-helices relative to the native lysozyme with the exception of W64R and Y54N which show marked decrease (W64R) or increase (Y54N) in mobility of almost all residues. The analysis of secondary structure evolution provided evidence for higher stability of α-domain compared to β-domain. The results obtained reinforce the idea that mutation-induced global structural destabilization is not the only factor contributing to protein misfolding, the modifications in conformation and dynamics of selected protein regions may also play significant role in amyloid fibril formation.

Effects of the Temperature and the pH on the Main Protease of SARS-CoV-2: A Molecular Dynamics Simulation Study

Biointerface Research in Applied Chemistry ◽

10.33263/briac126.72397248 ◽

2021 ◽

Vol 12 (6) ◽

pp. 7239-7248

Keyword(s):

Molecular Dynamics ◽

Root Mean Square ◽

Dynamics Simulation ◽

Effect Of Temperature ◽

Water Molecules ◽

Mean Square ◽

Main Protease ◽

Decreasing Ph ◽

Increasing Temperature

The novel coronavirus, recognized as COVID-19, is the cause of an infection outbreak in December 2019. The effect of temperature and pH changes on the main protease of SARS-CoV-2 were investigated using all-atom molecular dynamics simulation. The obtained results from the root mean square deviation (RMSD) and root mean square fluctuations (RMSF) analyses showed that at a constant temperature of 25℃ and pH=5, the conformational change of the main protease is more significant than that of pH=6 and 7. Also, by increasing temperature from 25℃ to 55℃ at constant pH=7, a remarkable change in protein structure was observed. The radial probability of water molecules around the main protease was decreased by increasing temperature and decreasing pH. The weakening of the binding energy between the main protease and water molecules due to the increasing temperature and decreasing pH has reduced the number of hydrogen bonds between the main protease and water molecules. Finding conditions that alter the conformation of the main protease could be fundamental because this change could affect the virus’s functionality and its ability to impose illness.

Molecular Dynamics Simulation of Barnase: Contribution of Noncovalent Intramolecular Interaction to Thermostability

Mathematical Problems in Engineering ◽

10.1155/2013/504183 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Zhiguo Chen ◽

Yi Fu ◽

Wenbo Xu ◽

Ming Li

Keyword(s):

Molecular Dynamics ◽

Thermal Stability ◽

Root Mean Square ◽

Clinical Medicine ◽

Intramolecular Interaction ◽

Salt Bridge ◽

Dynamics Simulation ◽

Mean Square ◽

Thermal Stability Of

Bacillus amyloliquefaciensribonuclease Barnase (RNase Ba) is a 12 kD (kilodalton) small extracellular ribonuclease. It has broad application prospects in agriculture, clinical medicine, pharmaceutical, and so forth. In this work, the thermal stability of Barnase has been studied using molecular dynamics simulation at different temperatures. The present study focuses on the contribution of noncovalent intramolecular interaction to protein stability and how they affect the thermal stability of the enzyme. Profiles of root mean square deviation and root mean square fluctuation identify thermostable and thermosensitive regions of Barnase. Analyses of trajectories in terms of secondary structure content, intramolecular hydrogen bonds and salt bridge interactions indicate distinct differences in different temperature simulations. In the simulations, Four three-member salt bridge networks (Asp8-Arg110-Asp12, Arg83-Asp75-Arg87, Lys66-Asp93-Arg69, and Asp54-Lys27-Glu73) have been identified as critical salt bridges for thermostability which are maintained stably at higher temperature enhancing stability of three hydrophobic cores. The study may help enlighten our knowledge of protein structural properties, noncovalent interactions which can stabilize secondary peptide structures or promote folding, and also help understand their actions better. Such an understanding is required for designing efficient enzymes with characteristics for particular applications at desired working temperatures.

Screening of Potent Phytochemical Inhibitors Against SARS-CoV-2 Main Protease: An Integrative Computational Approach

Frontiers in Bioinformatics ◽

10.3389/fbinf.2021.717141 ◽

2021 ◽

Vol 1 ◽

Author(s):

Shafi Mahmud ◽

Md. Robiul Hasan ◽

Suvro Biswas ◽

Gobindo Kumar Paul ◽

Shamima Afrose ◽

...

Keyword(s):

Root Mean Square ◽

Global Economy ◽

Transmission Rate ◽

Accessible Surface Area ◽

Dynamics Simulation ◽

Radius Of Gyration ◽

Mean Square ◽

Protease Inhibition ◽

Main Protease

Coronavirus disease 2019 (COVID-19) is a potentially lethal and devastating disease that has quickly become a public health threat worldwide. Due to its high transmission rate, many countries were forced to implement lockdown protocols, wreaking havoc on the global economy and the medical crisis. The main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus for COVID-19, represent an effective target for the development of a new drug/vaccine because it is well-conserved and plays a vital role in viral replication. Mpro inhibition can stop the replication, transcription as well as recombination of SARS-CoV-2 after the infection and thus can halt the formation of virus particles, making Mpro a viable therapeutic target. Here, we constructed a phytochemical dataset based on a rigorous literature review and explored the probability that various phytochemicals will bind with the main protease using a molecular docking approach. The top three hit compounds, medicagol, faradiol, and flavanthrin, had binding scores of −8.3, −8.6, and −8.8 kcal/mol, respectively, in the docking analysis. These three compounds bind to the active groove, consisting of His41, Cys45, Met165, Met49, Gln189, Thr24, and Thr190, resulting in main protease inhibition. Moreover, the multiple descriptors from the molecular dynamics simulation, including the root-mean-square deviation, root-mean-square fluctuation, solvent-accessible surface area, radius of gyration, and hydrogen bond analysis, confirmed the stable nature of the docked complexes. In addition, absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis confirmed a lack of toxicity or carcinogenicity for the screened compounds. Our computational analysis may contribute toward the design of an effective drug against the main protease of SARS-CoV-2.

Use of multiple picosecond high-mass molecular dynamics simulations to predict crystallographic B-factors of folded globular proteins

10.1101/052126 ◽

2016 ◽

Author(s):

Yuan-Ping Pang

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Root Mean Square ◽

A Priori ◽

Model Systems ◽

Dynamics Simulation ◽

High Mass ◽

Mean Square ◽

Dynamics Simulations

ABSTRACTPredicting crystallographic B-factors of a protein from a conventional molecular dynamics simulation is challenging in part because the B-factors calculated through sampling the atomic positional fluctuations in a picosecond molecular dynamics simulation are unreliable and the sampling of a longer simulation yields overly large root mean square deviations between calculated and experimental B-factors. This article reports improved B-factor prediction achieved by sampling the atomic positional fluctuations in multiple picosecond molecular dynamics simulations that use uniformly increased atomic masses by 100-fold to increase time resolution. Using the third immunoglobulin-binding domain of protein G, bovine pancreatic trypsin inhibitor, ubiquitin, and lysozyme as model systems, the B-factor root mean square deviations (mean ± standard error) of these proteins were 3.1 ± 0.2–9 ± 1 Å2for Cα and 7.3 ± 0.9–9.6 ± 0.2 Å2for Cγ, when the sampling was done, for each of these proteins, over 20 distinct, independent, and 50-picosecond high-mass molecular dynamics simulations using AMBER forcefield FF12MC or FF14SB. These results suggest that sampling the atomic positional fluctuations in multiple picosecond high-mass molecular dynamics simulations may be conducive toa prioriprediction of crystallographic B-factors of a folded globular protein.

Luteolin and abyssinone II as potential inhibitors of SARS-CoV-2: an in silico molecular modeling approach in battling the COVID-19 outbreak

Bulletin of the National Research Centre ◽

10.1186/s42269-020-00479-6 ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Mohammad Mahfuz Ali Khan Shawan ◽

Sajal Kumar Halder ◽

Md. Ashraful Hasan

Keyword(s):

Molecular Dynamics ◽

Root Mean Square ◽

In Silico ◽

Binding Free Energy ◽

Biologically Active ◽

Dynamics Simulation ◽

Mean Square ◽

Efficient Treatment ◽

Target Proteins

Abstract Background At present, the entire world is in a war against COVID-19 pandemic which has gradually led us toward a more compromised “new normal” life. SARS-CoV-2, the pathogenic microorganism liable for the recent COVID-19 outbreak, is extremely contagious in nature resulting in an unusual number of infections and death globally. The lack of clinically proven therapeutic intervention for COVID-19 has dragged the world’s healthcare system into the biggest challenge. Therefore, development of an efficient treatment scheme is now in great demand. Screening of different biologically active plant-based natural compounds could be a useful strategy for combating this pandemic. In the present research, a collection of 43 flavonoids of 7 different classes with previously recorded antiviral activity was evaluated via computational and bioinformatics tools for their impeding capacity against SARS-CoV-2. In silico drug likeness, pharmacophore and Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) profile analysis of the finest ligands were carried out using DataWarrior, DruLiTo and admetSAR programs, respectively. Molecular docking was executed by AutoDock Vina, while molecular dynamics simulation of the target protein–ligand bound complexes was done using nanoscalable molecular dynamics and visual molecular dynamics software package. Finally, the molecular target analysis of the selected ligands within Homo sapiens was conducted with SwissTargetPredcition web server. Results Out of the forty-three flavonoids, luteolin and abyssinone II were found to develop successful docked complex within the binding sites of target proteins in terms of lowest binding free energy and inhibition constant. The root mean square deviation and root mean square fluctuation values of the docked complex displayed stable interaction and efficient binding between the ligands and target proteins. Both of the flavonoids were found to be safe for human use and possessed good drug likeness properties and target accuracy. Conclusions Conclusively, the current study proposes that luteolin and abyssinone II might act as potential therapeutic candidates for SARS-CoV-2 infection. In vivo and in vitro experiments, however, should be taken under consideration to determine the efficiency and to demonstrate the mechanism of action.

Identification of Potential SARS-CoV-2 Main Protease and Spike Protein Inhibitors from the Genus Aloe: An In Silico Study for Drug Development

Molecules ◽

10.3390/molecules26061767 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1767

Author(s):

Mohamed E. Abouelela ◽

Hamdy K. Assaf ◽

Reda A. Abdelhamid ◽

Ehab S. Elkhyat ◽

Ahmed M. Sayed ◽

...

Keyword(s):

Molecular Dynamics ◽

Drug Development ◽

Root Mean Square ◽

In Silico ◽

Dynamics Simulation ◽

Spike Protein ◽

Energy Calculation ◽

Mean Square ◽

Main Protease

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) disease is a global rapidly spreading virus showing very high rates of complications and mortality. Till now, there is no effective specific treatment for the disease. Aloe is a rich source of isolated phytoconstituents that have an enormous range of biological activities. Since there are no available experimental techniques to examine these compounds for antiviral activity against SARS-CoV-2, we employed an in silico approach involving molecular docking, dynamics simulation, and binding free energy calculation using SARS-CoV-2 essential proteins as main protease and spike protein to identify lead compounds from Aloe that may help in novel drug discovery. Results retrieved from docking and molecular dynamics simulation suggested a number of promising inhibitors from Aloe. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) calculations indicated that compounds 132, 134, and 159 were the best scoring compounds against main protease, while compounds 115, 120, and 131 were the best scoring ones against spike glycoprotein. Compounds 120 and 131 were able to achieve significant stability and binding free energies during molecular dynamics simulation. In addition, the highest scoring compounds were investigated for their pharmacokinetic properties and drug-likeness. The Aloe compounds are promising active phytoconstituents for drug development for SARS-CoV-2.

Reappraisal of Trifluperidol against NSP-3 protein: Potential therapeutic for COVID-19

10.21203/rs.3.rs-52706/v1 ◽

2020 ◽

Author(s):

Ajita Pandey

Keyword(s):

Root Mean Square ◽

Dynamics Simulation ◽

Radius Of Gyration ◽

Scoring Functions ◽

Mean Square ◽

Structural Protein ◽

Approved Drugs ◽

Fda Approved Drugs

Abstract Novel coronavirus disease 2019 (COVID-19) is a highly infectious disease that is caused by the recently discovered severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Because there are no specific vaccines or drugs for SARS-CoV-2, drug repurposing may be a promising approach. SARS-CoV-2 has a positive-sense RNA genome that encodes non-structural proteins (Nsps), which are essential for viral replication in the host cell. Non-structural protein 3 (Nsp3) is a multidomain protein and is the largest protein of the replicase complex. Nsp3 contains an ADP-ribose phosphatase (ADRP) domain, also called the macrodomain, which interferes with the host immune response. In the present study, we used computational regression methods to target the ADRP domain of Nsp3, using FDA-approved drugs. We virtually screened 2,892 FDA-approved drugs, using a combination of molecular docking and scoring functions. Saquinavir and trifluperidol were identified as potential leads and were further investigated using molecular dynamics simulation (MDS) to predict the stability and behavior of the ADRP-drug complexes. Analysis of root mean square deviation, root mean square fluctuation, radius of gyration, solvent accessible surface area and number of hydrogen bonds showed that the ADRP-trifluperidol complex is more stable than the ADRP-saquinavir complex. The screening and the MDS results suggest that trifluperidol is a novel inhibitor of the ADRP domain of Nsp3. Trifluperidol could, therefore, potentially be used to help control the spread of COVID-19, either alone or in combination with antiviral agents. Further in-vitro and in-vivo experiments are necessary to confirm our in silico results.