The Delta Variant Mutations in the Receptor Binding Domain of SARS-CoV-2 Show Enhanced Electrostatic Interactions with the ACE2

Background: SARS-CoV-2 has been shown to bind the host cell ACE2 receptor through its spike protein receptor binding domain (RBD), required for its entry into the host cells. Objective: We have screened phytocompounds from a medicinal herb, Tinospora cordifolia, for their capacities to interrupt the viral RBD and host ACE2 interactions. Method: We employed molecular docking to screen phytocompounds in T. cordifolia against the ACE2-RBD complex, performed molecular dynamics (MD) simulation, and estimated the electrostatic component of binding free energy. Results: ‘Tinocordiside’ docked very well at the center of the interface of ACE2-RBD complex, and was found to be well stabilized during MD simulation. Tinocordiside incorporation significantly decreased electrostatic component of binding free energies of ACE2-RBD complex (23.5 and 17.10 kcal/mol in the trajectories without or with the ligand, respectively). As the basal rate constant of protein association is in the order of 5, (105 to 106 M-1 S-1 ), there might be no big conformational change or loop reorganization, but involves only local conformational change typically observed in diffusion-controlled association. Taken together, the increase in global flexibility of the complex, clearly indicates the start of unbinding process of the complex. Conclusion: It indicates that such an interruption of electrostatic interactions between the RBD and ACE2, and the increase in global flexibility of the complex, would weaken or block SARS-CoV-2 entry and its subsequent infectivity. We postulate that natural phytochemicals like Tinocordiside could be the viable options for controlling SARS-CoV-2 contagion and its entry into host cells.

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Towards an optimal monoclonal antibody with higher binding affinity to the receptor-binding domain of SARS-CoV-2 spike proteins from different variants

10.1101/2022.01.04.474958 ◽

2022 ◽

Author(s):

Andrei Neamtu ◽

Francesca Mocci ◽

Aatto Laaksonen ◽

Fernando Luis Barroso da Silva

Keyword(s):

Monoclonal Antibody ◽

Receptor Binding ◽

Electrostatic Interactions ◽

Multiple Scales ◽

Binding Domain ◽

Binding Motif ◽

Receptor Binding Domain ◽

Structural Determinants ◽

Cancer Multiple ◽

Constant Charge

A highly efficient and robust multiple scales in silico protocol, consisting of atomistic constant charge Molecular Dynamics (MD), constant-charge coarse-grain (CG) MD and constant-pH CG Monte Carlo (MC), has been used to study the binding affinities, the free energy of complexation of selected antigen-binding fragments of the monoclonal antibody (mAbs) CR3022 (originally derived from SARS-CoV-1 patients almost two decades ago) and 11 SARS-CoV-2 variants including the wild type. CR3022 binds strongly to the receptor-binding domain (RBD) of SARS-CoV-2 spike protein, but chooses a different site rather than the receptor-binding motif (RBM) of RBD, allowing its combined use with other mAbs against new emerging virus variants. Totally 235,000 mAbs structures were generated using the RosettaAntibodyDesign software, resulting in top 10 scored CR3022-RBD complexes with critical mutations and compared to the native one, all having the potential to block virus-host cell interaction. Of these 10 finalists, two candidates were further identified in the CG simulations to be clearly best against all virus variants, and surprisingly, all 10 candidates and the native CR3022 did exhibit a higher affinity for the Omicron variant with its highest number of mutations (15) of them all considered in this study. The multiscale protocol gives us a powerful rational tool to design efficient mAbs. The electrostatic interactions play a crucial role and appear to be controlling the affinity and complex building. Clearly, mAbs carrying a lower net charge show a higher affinity. Structural determinants could be identified in atomistic simulations and their roles are discussed in detail to further hint at a strategy towards designing the best RBD binder. Although the SARS-CoV-2 was specifically targeted in this work, our approach is generally suitable for many diseases and viral and bacterial pathogens, leukemia, cancer, multiple sclerosis, rheumatoid, arthritis, lupus, and more.

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Destabilizing the Structural Integrity of SARS-CoV2 Receptor Proteins by Curcumin Along with Hydroxychloroquine: An Insilco Approach for a Combination Therapy

10.26434/chemrxiv.12090438.v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Akhileshwar Srivastava ◽

Divya Singh

Keyword(s):

Binding Energy ◽

Combination Therapy ◽

Receptor Binding ◽

Structural Integrity ◽

Binding Domain ◽

Receptor Binding Domain ◽

Receptor Proteins ◽

Main Protease ◽

The Stability ◽

Therapeutic Activities

Presently, an emerging disease (COVID-19) has been spreading across the world due to coronavirus (SARS-CoV2). For treatment of SARS-CoV2 infection, currently hydroxychloroquine has been suggested by researchers, but it has not been found enough effective against this virus. The present study based on in silico approaches was designed to enhance the therapeutic activities of hydroxychloroquine by using curcumin as an adjunct drug against SARS-CoV2 receptor proteins: main-protease and S1 receptor binding domain (RBD). The webserver (ANCHOR) showed the higher protein stability for both receptors with disordered score (<0.5). The molecular docking analysis revealed that the binding energy (-24.58 kcal/mol) of hydroxychloroquine was higher than curcumin (-20.47 kcal/mol) for receptor main-protease, whereas binding energy of curcumin (<a>-38.84</a> kcal/mol) had greater than hydroxychloroquine<a> (-35.87</a> kcal/mol) in case of S1 receptor binding domain. Therefore, this study suggested that the curcumin could be used as combination therapy along with hydroxychloroquine for disrupting the stability of SARS-CoV2 receptor proteins

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Amoxicillin Trihydrate-Clavulanate Potassium As Potential Inhibitor of 2019 Novel Coronavirus Main Protease with Strong Receptor-Binding Domain (RBD), Molecular Docking and SAR Study

SSRN Electronic Journal ◽

10.2139/ssrn.3580230 ◽

2020 ◽

Author(s):

Khedidja benarous ◽

Talia Serseg ◽

Mohamed Yousfi

Keyword(s):

Molecular Docking ◽

Receptor Binding ◽

Binding Domain ◽

Receptor Binding Domain ◽

Potential Inhibitor ◽

Main Protease ◽

Amoxicillin Trihydrate ◽

Novel Coronavirus ◽

Sar Study

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Amoxicillin and Clavulanate as Potential Multiple Effect Inhibitors of 2019 Novel Coronavirus Main Protease and RNA-Dependent RNA Polymerase with Strong Receptor-Binding Domain (RBD), Molecular Docking and SAR Study

SSRN Electronic Journal ◽

10.2139/ssrn.3618303 ◽

2020 ◽

Author(s):

Khedidja benarous ◽

Talia Serseg ◽

Mohamed Yousfi

Keyword(s):

Molecular Docking ◽

Rna Polymerase ◽

Receptor Binding ◽

Binding Domain ◽

Receptor Binding Domain ◽

Rna Dependent Rna Polymerase ◽

Multiple Effect ◽

Main Protease ◽

Novel Coronavirus ◽

Sar Study

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Role of key point Mutations in Receptor Binding Domain of SARS-CoV-2 Spike Glycoprotein

Infectious Disorders - Drug Targets ◽

10.2174/1871526520666200804161650 ◽

2020 ◽

Vol 20 ◽

Author(s):

Bipin Singh

Keyword(s):

Receptor Binding ◽

Point Mutations ◽

Binding Domain ◽

Receptor Binding Domain ◽

Spike Glycoprotein ◽

Angiotensin Converting Enzyme 2 ◽

Recent Outbreak ◽

Novel Coronavirus ◽

Genomic Similarity

: The recent outbreak of novel coronavirus (SARS-CoV-2 or 2019-nCoV) and its worldwide spread is posing one of the major threats to human health and the world economy. It has been suggested that SARS-CoV-2 is similar to SARSCoV based on the comparison of the genome sequence. Despite the genomic similarity between SARS-CoV-2 and SARSCoV, the spike glycoprotein and receptor binding domain in SARS-CoV-2 shows the considerable difference compared to SARS-CoV, due to the presence of several point mutations. The analysis of receptor binding domain (RBD) from recently published 3D structures of spike glycoprotein of SARS-CoV-2 (Yan, R., et al. (2020); Wrapp, D., et al. (2020); Walls, A. C., et al. (2020)) highlights the contribution of a few key point mutations in RBD of spike glycoprotein and molecular basis of its efficient binding with human angiotensin-converting enzyme 2 (ACE2).

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