In Silico study of Rosmarinic Acid Derivatives as Novel Insulin Fibril Inhibitors

2021 ◽  
Vol 20 (06) ◽  
pp. 641-654
Author(s):  
Kaushik Sarkar ◽  
Rajesh Kumar Das

The self-assembly of human insulin (HI) plays a crucial role in regulating amyloid fibrils. Therefore, it is a significant problem for the medical management of diabetes therapy and these findings have led us to investigate the amyloid formation and its inhibition. Few potential inhibitors have been identified to inhibit amyloid fibrils. Rosmarinic acid (RA) is one of the things that inhibits amyloid formation completely by increasing the resistivity of the amyloidogenic insulin (dimer) protein to thermal unfolding. Here, we choose different tested derivative compounds for designing amyloid inhibitors by substituting various functional groups of RA. These derivative compounds were subjected to in silico studies to determine the best drug candidates. In comparison to RA, 14 molecules have higher binding affinity and interactions with the target receptor. After frontier molecular orbitals study, ADME and toxicity analysis, the eight best compounds may act as the best inhibitors. The stability of the docked complexes was visualized by molecular dynamics (MD) simulations. This finding opens a new proposal to explore future studies with these best compounds to increase the thermal stability of the insulin dimers.

2019 ◽  
Vol 16 (4) ◽  
pp. 307-313 ◽  
Author(s):  
Nasrin Zarkar ◽  
Mohammad Ali Nasiri Khalili ◽  
Fathollah Ahmadpour ◽  
Sirus Khodadadi ◽  
Mehdi Zeinoddini

Background: DAB389IL-2 (Denileukin diftitox) as an immunotoxin is a targeted pharmaceutical protein and is the first immunotoxin approved by FDA. It is used for the treatment of various kinds of cancer such as CTCL lymphoma, melanoma, and Leukemia but among all of these, treatment of CTCL has special importance. DAB389IL-2 consists of two distinct parts; the catalytic domain of Diphtheria Toxin (DT) that genetically fused to the whole IL-2. Deamidation is the most important reaction for chemical instability of proteins occurs during manufacture and storage. Deamidation of asparagine residues occurs at a higher rate than glutamine residues. The structure of proteins, temperature and pH are the most important factors that influence the rate of deamidation. Methods: Since there is not any information about deamidation of DAB389IL-2, we studied in silico deamidation by Molecular Dynamic (MD) simulations using GROMACS software. The 3D model of fusion protein DAB389IL-2 was used as a template for deamidation. Then, the stability of deamidated and native form of the drug was calculated. Results: The results of MD simulations were showed that the deamidated form of DAB389IL-2 is more unstable than the normal form. Also, deamidation was carried by incubating DAB389IL-2, 0.3 mg/ml in ammonium hydrogen carbonate for 24 h at 37o C in order to in vitro experiment. Conclusion: The results of in vitro experiment were confirmed outcomes of in silico study. In silico and in vitro experiments were demonstrated that DAB389IL-2 is unstable in deamidated form.


Author(s):  
Hima Vyshnavi ◽  
Gayathri S. S. ◽  
Shahanas Naisam ◽  
Suvanish Kumar ◽  
Nidhin Sreekumar

In this pandemic condition, a drug candidate which is effective against COVID-19 is very much desired. This study initiates an in silico analysis to screen small molecules such as phytochemicals, drug metabolites, and natural metabolites against Nsp12 (a catalytic unit for RNA transcription and replication). Molecular interaction analysis of 6M71 was carried out against 2,860 ligands using Schrodinger Glide software. After docking analysis, the top 10 molecules (Glide score) were subjected to MD simulation for validating the stability. It resulted in top 10 compounds with high binding affinities with the target molecule NSP 12. Out of these, top 3 compounds including PSID_08_LIG3 (HMDB0133544), PSID_08_LIG4 (HMDB0132898), and PSID_08_LIG9 (HMDB0128199) show better Glide scores, better H-bond interaction, better MMGBSA value and stability on dynamic simulation after analysis of the results. The suggested ligands can be postulated as effective antiviral drugs against COVID-19. Further in vivo analysis is needed for validating the drug efficacy.


2019 ◽  
Vol 20 (4) ◽  
pp. 860 ◽  
Author(s):  
Joao Ramos ◽  
Jayaraman Muthukumaran ◽  
Filipe Freire ◽  
João Paquete-Ferreira ◽  
Ana Otrelo-Cardoso ◽  
...  

Bcl-2 protein is involved in cell apoptosis and is considered an interesting target for anti-cancer therapy. The present study aims to understand the stability and conformational changes of Bcl-2 upon interaction with the inhibitor venetoclax, and to explore other drug-target regions. We combined biophysical and in silico approaches to understand the mechanism of ligand binding to Bcl-2. Thermal shift assay (TSA) and urea electrophoresis showed a significant increase in protein stability upon venetoclax incubation, which is corroborated by molecular docking and molecular dynamics simulations. An 18 °C shift in Bcl-2 melting temperature was observed in the TSA, corresponding to a binding affinity multiple times higher than that of any other reported Bcl-2 inhibitor. This protein-ligand interaction does not implicate alternations in protein conformation, as suggested by SAXS. Additionally, bioinformatics approaches were used to identify deleterious non-synonymous single nucleotide polymorphisms (nsSNPs) of Bcl-2 and their impact on venetoclax binding, suggesting that venetoclax interaction is generally favored against these deleterious nsSNPs. Apart from the BH3 binding groove of Bcl-2, the flexible loop domain (FLD) also plays an important role in regulating the apoptotic process. High-throughput virtual screening (HTVS) identified 5 putative FLD inhibitors from the Zinc database, showing nanomolar affinity toward the FLD of Bcl-2.


2020 ◽  
Author(s):  
Rameez Jabeer Khan ◽  
Rajat Kumar Jha ◽  
Ekampreet Singh ◽  
Monika Jain ◽  
Gizachew Muluneh Amera ◽  
...  

<div>The recent COVID-19 pandemic caused by SARS-CoV-2 has recorded a high number of infected people across the globe. The notorious nature of the virus makes it necessary for us to identify promising therapeutic agents in a time-sensitive manner. The current study utilises an <i>in silico</i> based drug repurposing approach to identify potential drug candidates targeting non-structural protein 15 (NSP15), i.e. a uridylate specific endoribonuclease of SARS-CoV-2</div><div>which plays an indispensable role in RNA processing and viral immune evasion from the host immune system. NSP15 was screened against an in-house library of 123 antiviral drugs obtained from the DrugBank database from which three promising drug candidates were identified based on their estimated free energy of binding (<i>ΔG</i>), estimated inhibition constant (<i>Ki</i>), the orientation of drug molecules in the active site and the key interacting residues of</div><div>NSP15. The MD simulations were performed for the selected NSP15-drug complexes along with free protein to mimic on their physiological state. The binding free energies of the selected NSP15-drug complexes were also calculated using the trajectories of MD simulations of NSP15-drug complexes through MM/PBSA (Molecular Mechanics with Poisson-Boltzmann and surface area solvation) approach where NSP15-Simeprevir (-242.559 kJ/mol) and NSP15-Paritaprevir (-149.557 kJ/mol) exhibited the strongest binding affinities. Together with the results of molecular docking, global dynamics, essential dynamics and binding free energy analysis, we propose that Simeprevir and Paritaprevir are promising drug candidates for the inhibition of NSP15 and could act as potential therapeutic agents against SARS-CoV-2.</div>


2020 ◽  
Vol 17 (12) ◽  
pp. 1552-1565
Author(s):  
Sonia Verma ◽  
Akashdeep Singh Pathania ◽  
Somesh Baranwal ◽  
Pradeep Kumar

Background: Cancer is a leading cause of deaths worldwide, accounting for 9.6 million deaths in 2018. According to the WHO, the most common causes of cancer deaths are lung, colorectal, stomach liver and breast cancer. Introduction: PARP-1 has a crucial role in cell proliferation, survival and death due to its role in the regulation of multiple biological processes. Quinazolinone and its derivatives represent a large class of biologically active compounds that exhibit a broad spectrum of biological activities such as anti-HIV, anticancer, antifungal, antibacterial, anticonvulsant, anti-inflammatory, antidepressant, antimalarial, antioxidant and antileishmanial activities. Methods: In this study, we have synthesized quinazolinone derivatives by reaction of 2- aminobenzamide and substituted benzaldehydes. The synthesized compounds were also screened in silico for their PARP-1 binding affinities by molecular docking studies using Schrodinger 2016 software. In silico ADME studies were also performed for the synthesized compounds by using QikProp tool of Schrodinger software. Results: Results of in silico studies indicated that quinazolinone derivatives exhibited a good affinity towards the active site of PARP-1. Out of all synthesized compounds, SVA-11 exhibited a maximum dock score (-10.421). Results of ADME studies indicated the suitability of synthesized compounds as drug candidates. Conclusion: The synthesized compounds showed better docking scores than reference drug valiparib. Furthermore, they exhibited favorable ADME profile. Therefore, they may serve as lead compounds in the discovery of PARP-1 inhibitors.


2021 ◽  
Vol 116 ◽  
pp. 105347
Author(s):  
Esraa Z. Mohammed ◽  
Walaa R. Mahmoud ◽  
Riham F. George ◽  
Ghaneya S. Hassan ◽  
Farghaly A. Omar ◽  
...  

2000 ◽  
Vol 348 (1) ◽  
pp. 167-172 ◽  
Author(s):  
Clara REDONDO ◽  
Ana M. DAMAS ◽  
Maria João M. SARAIVA

The molecular mechanisms that convert soluble transthyretin (TTR) tetramers into insoluble amyloid fibrils are still unknown; dissociation of the TTR tetramer is a pre-requisite for amyloid formation in vitro and involvement of monomers and/or dimers in fibril formation has been suggested by structural studies. We have designed four mutated proteins with the purpose of stabilizing [Ser117 → Cys (S117C) and Glu92 → Cys (E92C)] or destabilizing [Asp18 → Asn (D18N) and Leu110 → Ala (D110A)] the dimer/tetramer interactions in TTR, aiming at elucidating structural determinants in amyloidogenesis. The resistance of the mutated proteins to dissociation was analysed by HPLC studies of diluted TTR preparations. Both ‘stabilized’ mutants migrated as tetramers and, upon dilution, no other TTR species was observed, confirming the increased resistance to dissociation. For the ‘destabilized’ mutants, a mixture of tetrameric and monomeric forms co-existed at low dilution and the latter increased upon 10-fold dilution. Both of the destabilizing mutants formed amyloid in vitro when acidified. This result indicated that both the AB loop of TTR, destabilized in D18N, and the hydrophobic interactions affecting the dimer-dimer interfaces in L110A are implicated in the stability of the tetrameric structure. The stabilized mutants, which were dimeric in nature through disulphide bonding, were unable to polymerize into amyloid, even at pH 3.2. When the amyloid formation assay was repeated in the presence of 2-mercaptoethanol, upon disruption of the S-S bridges of these stable dimers, amyloid fibril formation was observed. This experimental evidence suggests that monomers, rather than dimers, are the repeating structural subunit comprising the amyloid fibrils.


2020 ◽  
Author(s):  
Mohammed Hakmi ◽  
El Mehdi Bouricha ◽  
Jihane Akachar ◽  
Badreddine Lmimouni ◽  
Jaouad EL Harti ◽  
...  

The novel coronavirus, SARS-CoV-2, has infected more than 10 million people and caused more than 502,539 deaths worldwide as of June 2020. The explosive spread of the virus and the rapid increase in the number of cases require the immediate development of effective therapies and vaccines as well as accurate diagnosis tools. The pathogenesis of the disease is triggered by the entry of SARS-CoV-2 via its spike protein into ACE2-bearing host cells, particularly pneumocytes, resulting in overactivation of the immune system, which attacks the infected cells and damages the lung tissue. The interaction of the SARS-CoV-2 receptor binding domain (RBD) with host cells is primarily mediated by the N-terminal helix of the ACE2; thus, inhibition of the spike-ACE2 interaction may be a promising therapeutic strategy for blocking the entry of the virus into host cells. In this paper, we used an in-silico approach to explore small-molecule α-helix mimetics as inhibitors that may disrupt the attachment of SARS-CoV-2 to ACE2. First, the RBD-ACE2 interface in the 6M0J structure was studied by the MM-GBSA decomposition module of the HawkDock server, which led to the identification of two critical target regions in the RBD. Next, two virtual screening experiments of 7236 α-helix mimetics from ASINEX were conducted on the above regions using the iDock tool, which resulted in 10 candidates with favorable binding affinities. Finally, the stability of RBD complexes with the top-two ranked compounds was further validated by 40 ns MD simulations using Desmond package of Schrodinger.<br>


Sign in / Sign up

Export Citation Format

Share Document