scholarly journals In Silico Exploration of Small-Molecule α-Helix Mimetics as Inhibitors of SARS-COV-2 Attachment to ACE2

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>

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>


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

2020 ◽  
Author(s):  
Mahdi Ghorbani ◽  
Bernard R. Brooks ◽  
Jeffery B. Klauda

AbstractThe novel coronavirus (nCOV-2019) outbreak has put the world on edge, causing millions of cases and hundreds of thousands of deaths all around the world, as of June 2020, let alone the societal and economic impacts of the crisis. The spike protein of nCOV-2019 resides on the virion’s surface mediating coronavirus entry into host cells by binding its receptor binding domain (RBD) to the host cell surface receptor protein, angiotensin converter enzyme (ACE2). Our goal is to provide a detailed structural mechanism of how nCOV-2019 recognizes and establishes contacts with ACE2 and its difference with an earlier coronavirus SARS-COV in 2002 via extensive molecular dynamics (MD) simulations. Numerous mutations have been identified in the RBD of nCOV-2019 strains isolated from humans in different parts of the world. In this study, we investigated the effect of these mutations as well as other Ala-scanning mutations on the stability of RBD/ACE2 complex. It is found that most of the naturally-occurring mutations to the RBD either strengthen or have the same binding affinity to ACE2 as the wild-type nCOV-2019. This may have implications for high human-to-human transmission of coronavirus in regions where these mutations have been found as well as any vaccine design endeavors since these mutations could act as antibody escape mutants. Furthermore, in-silico Ala-scanning and long-timescale MD simulations, highlight the crucial role of the residues at the interface of RBD and ACE2 that may be used as potential pharmacophores for any drug development endeavors. From an evolutional perspective, this study also identifies how the virus has evolved from its predecessor SARS-COV and how it could further evolve to become more infectious.


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.


2020 ◽  
Vol 23 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Nouman Rasool ◽  
Waqar Hussain

Background: Human Immunodeficiency Virus 1 (HIV-1) is a lentivirus, which causes various HIV-associated infections. The HIV-1 core dissociation is essential for viral cDNA synthesis and phosphorylation of HIV-1 capsid protein (HIV-1 CA) plays an important role in it. Objective: The aim of this study was to explicate the role of three phosphoserine sites i.e. Ser109, Ser149 and Ser178 in the structural stability of HIV-1 CA, and it’s binding with GS-CA1, a novel potent inhibitor. Method: Eight complexes were analyzed and Molecular Dynamics (MD) simulations were performed to observe the stability of HIV-1 CA in the presence and absence of phosphorylation of serine residues at four different temperatures i.e. 300K, 325K, 340K and 350K, along with molecular docking and DFT analysis. Results: The structures showed maximum stability in the presence of phosphorylated serine residue. However, GS-CA1 docked most strongly with the native structure of HIV-1 CA i.e. binding affinity was -8.5 kcal/mol (Ki = 0.579 µM). Conclusion: These results suggest that the phosphorylation of these three serine residues weakens the binding of GS-CA1 with CA and casts derogatory effect on inhibition potential of this inhibitor, but it supports the stability of HIV-1 CA structure that can enhance regulation and replication of HIV-1 in host cells.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Joanna Koziel ◽  
Katarzyna Kmiecik ◽  
Daniela Chmiest ◽  
Katarzyna Maresz ◽  
Danuta Mizgalska ◽  
...  

As a facultative intracellular pathogen,Staphylococcus aureusinvades macrophages and then promotes the cytoprotection of infected cells thus stabilizing safe niche for silent persistence. This process occurs through the upregulation of crucial antiapoptotic genes, in particular,myeloid cell leukemia-1 (MCL-1). Here, we investigated the underlying mechanism and signal transduction pathways leading to increasedMCL-1expression in infected macrophages. LiveS. aureusnot only stimulatedde novosynthesis of Mcl-1, but also prolonged the stability of this antiapoptotic protein. Consistent with this, we proved a crucial role of Mcl-1 inS. aureus-induced cytoprotection, since silencing ofMCL1by siRNA profoundly reversed the cytoprotection of infected cells leading to apoptosis. IncreasedMCL1expression in infected cells was associated with enhanced NFκB activation and subsequent IL-6 secretion, since the inhibition of both NFκB and IL-6 signalling pathways abrogated Mcl-1 induction and cytoprotection. Finally, we confirmed our observationin vivoin murine model of septic arthritis showing the association between the severity of arthritis and Mcl-1 expression. Therefore, we propose thatS. aureusis hijacking the Mcl-1-dependent inhibition of apoptosis to prevent the elimination of infected host cells, thus allowing the intracellular persistence of the pathogen, its dissemination by infected macrophages, and the progression of staphylococci diseases.


2021 ◽  
Vol 68 (3) ◽  
pp. 667-682
Author(s):  
Tahira Naqvi ◽  
Asif Amin ◽  
Shujat Ali ◽  
Mohsin Y. Lone ◽  
Nadeem Bashir ◽  
...  

The activation of caspases is central to apoptotic process in living systems. Defects in apoptosis have been implicated with carcinogenesis. Need to develop smart agents capable of inducing apoptosis in tumor cells is obvious. With this motive, diversity oriented synthesis of 1-benzylpyrrolidin-3-ol analogues was envisaged. The multi component Ugi reaction synthesized library of electronically diverse analogues was explored for cytotoxic propensity towards a panel of human cancer cell lines at 10 μM. The lead compounds exhibit a selective cytotoxicity towards HL-60 cells as compared to cell lines derived from solid tumors. Besides, their milder cytotoxic effect on non-cancerous cell lines reaffirm their selective action towards cancer cells only.The lead molecules were tested for their ability to target caspase-3, as a vital protease triggering apoptosis. The lead compounds were observed to induce apoptosis in HL-60 cells around 10 μM concentration. The lead compounds exhibited various non-covalent supra type interactions with caspase-3 key residues around the active site. The binding ability of lead compounds with caspase-3 was studied via molecular docking and molecular dynamic (MD) simulations. MD simulations indicated the stability of compound-caspase-3 complex throughout the 50 ns simulation run. The stability and bio-availability of the lead compounds under physiological conditions was assessed by their interaction with Bovine Serum Albumin (BSA) as model protein. BSA interactions of lead compounds were studied by various bio-physical methods and further substantiated with in silico MD simulations.


Author(s):  
Elena Susana Barbieri ◽  
Tamara Rubilar ◽  
Ayelén Gázquez ◽  
Marisa Avaro ◽  
Erina Noé Seiler ◽  
...  

Several studies have been published regarding the interaction between the spike protein of the novel coronavirus SARS-CoV-2 and ACE2 receptor in the host cells. In the presente work, we evaluated the in silico properties of two sea urchin pigments, Echinochrome A (EchA) and Spinochromes (SpinA) against the Spike protein (S) towards finding a potential therapeutic drug against the disease caused by the novel coronavirus (COVID-19). The best ensemble docking pose of EchaA and SpinA showed a binding affinity of -5.9 and -6.7 kcal mol-1, respectively. The linked aminoacids (T505, G496 and Y449 for EchA and Y449, Q493 and G496 for SpinA) are in positions involved in ACE2 binding in both RBDs frim SARS-CoV and SARS-CoV-2 suggesting that EchA and SpinA may interact with Spike proteins drom both viruses. The results suggest that these pigments could act as inhibitors of S protein, pointing them as antiviral drugs for SARS-CoV-2.<br>


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