scholarly journals Molecular Dynamics Analysis of a Flexible Loop at the Binding Interface of the SARS‐CoV ‐2 Spike Protein Receptor‐Binding Domain

2021 ◽  
Author(s):  
Jonathan K. Williams ◽  
Baifan Wang ◽  
Andrew Sam ◽  
Cody L. Hoop ◽  
David A. Case ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Receptor Binding ◽  
Binding Domain ◽  
Spike Protein ◽  
Dynamics Analysis ◽  
Receptor Binding Domain ◽  
Flexible Loop ◽  
Binding Interface ◽  
Protein Receptor

scholarly journals Molecular Dynamics Analysis of a Flexible Loop at the Binding Interface of the SARS-CoV-2 Spike Protein Receptor-Binding Domain

2021 ◽  
Author(s):  
Jonathan K. Williams ◽  
Baifan Wang ◽  
Andrew Sam ◽  
Cody L. Hoop ◽  
David A. Case ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Receptor Binding ◽  
Binding Domain ◽  
Conformational Space ◽  
Spike Protein ◽  
Conformational Ensemble ◽  
Receptor Binding Domain ◽  
Loop Modeling ◽  
Binding Interface ◽  
Protein Receptor

AbstractSince the identification of the SARS-CoV-2 virus as the causative agent of the current COVID-19 pandemic, considerable effort has been spent characterizing the interaction between the Spike protein receptor-binding domain (RBD) and the human angiotensin converting enzyme 2 (ACE2) receptor. This has provided a detailed picture of the end point structure of the RBD-ACE2 binding event, but what remains to be elucidated is the conformation and dynamics of the RBD prior to its interaction with ACE2. In this work we utilize molecular dynamics simulations to probe the flexibility and conformational ensemble of the unbound state of the receptor-binding domain from SARS-CoV-2 and SARS-CoV. We have found that the unbound RBD has a localized region of dynamic flexibility in Loop 3 and that mutations identified during the COVID-19 pandemic in Loop 3 do not affect this flexibility. We use a loop-modeling protocol to generate and simulate novel conformations of the CoV2-RBD Loop 3 region that sample conformational space beyond the ACE2 bound crystal structure. This has allowed for the identification of interesting substates of the unbound RBD that are lower energy than the ACE2-bound conformation, and that block key residues along the ACE2 binding interface. These novel unbound substates may represent new targets for therapeutic design.

ReaxFF-based molecular dynamics simulation of the interaction between plasma ROS and the receptor-binding domain of the spike protein in the capsid protein of SARS-CoV-2

2021 ◽  
Author(s):  
Huichao Wang ◽  
Tong Zhao ◽  
Shuhui Yang ◽  
Liang Zou ◽  
Xiaolong Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Amino Acid ◽  
Capsid Protein ◽  
Receptor Binding ◽  
Hydrogen Abstraction ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Amino Acid Residues ◽  
Global Epidemic

Abstract Under the severe situation of the current global epidemic, researchers have been working hard to find a reliable way to suppress the infection of the virus and prevent the spread of the epidemic. Studies have shown that the recognition and binding of human angiotensin-converting enzyme 2 (ACE2) by the receptor-binding domain (BRD) of spike protein on the surface of SARS-CoV-2 is a crucial step for SARS-CoV-2 to invade human receptor cells, and blocking this process can inhibit the virus from invading human normal cells. Plasma treatment can disrupt the structure of the RBD and effectively block the binding process. However, the mechanism by which plasma blocks the recognition and binding between the two is not clear. In this study, reaction process between reactive oxygen species (ROS) in plasma and the molecular model of RBD was simulated using a reactive molecular dynamics method. The results showed that the destruction of RBD molecule by ROS was triggered by hydrogen abstraction reactions. O and OH abstracted H atoms from RBD, while the H atoms of H2O2 and HO2 were abstracted by RBD. The hydrogen abstraction resulted in the breakage of C-H, N-H, O-H and C=O bonds and the formation of C=C, C=N bonds. The addition reaction of OH increased the number of O-H bonds and caused the formation of C-O, N-O and O-H bonds. The dissociation of N-H bonds led to the destruction of the original structure of peptide bonds and amino acid residues, change the type of amino acid residues, and caused the conversion of N-C and N=C, C=O and C-O. The simulation partially elucidated the microscopic mechanism of the interaction between ROS in plasma and the capsid protein of SARS-CoV-2, providing theoretical support for the control of SARS-CoV-2 infection by plasma, a contribution to overcoming the global epidemic problem.

scholarly journals Conjugation of Human β-Defensin 2 to Spike Protein Receptor-Binding Domain Induces Antigen-Specific Protective Immunity against Middle East Respiratory Syndrome Coronavirus Infection in Human Dipeptidyl Peptidase 4 Transgenic Mice

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 635
Author(s):  
Ju Kim ◽  
Ye Lin Yang ◽  
Yongsu Jeong ◽  
Yong-Suk Jang
Keyword(s):  
Middle East ◽  
Immune Responses ◽  
Receptor Binding ◽  
Dipeptidyl Peptidase ◽  
Binding Domain ◽  
Middle East Respiratory Syndrome ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Dipeptidyl Peptidase 4 ◽  
Protein Receptor

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe acute respiratory symptoms. Due to the lack of medical countermeasures, effective and safe vaccines against MERS-CoV infection are urgently required. Although different types of candidate vaccines have been developed, their immunogenicity is limited, and the dose and administration route need optimization to achieve optimal protection. We here investigated the potential use of human β-defensin 2 (HBD 2) as an adjuvant to enhance the protection provided by MERS-CoV vaccination. We found that immunization of human dipeptidyl peptidase 4 (hDPP4)-transgenic (hDPP4-Tg) mice with spike protein receptor-binding domain (S RBD) conjugated with HBD 2 (S RBD-HBD 2) induced potent antigen (Ag)-specific adaptive immune responses and protected against MERS-CoV infection. In addition, immunization with S RBD-HBD 2 alleviated progressive pulmonary fibrosis in the lungs of MERS-CoV-infected hDPP4-Tg mice and suppressed endoplasmic reticulum stress signaling activation upon viral infection. Compared to intramuscular administration, intranasal administration of S RBD-HBD 2 induced more potent mucosal IgA responses and was more effective for protecting against intranasal MERS-CoV infection. In conclusion, our findings suggest that HBD 2 potentiates Ag-specific immune responses against viral Ag and can be used as an adjuvant enhancing the immunogenicity of subunit vaccine candidates against MERS-CoV.

scholarly journals Combining a Fusion Inhibitory Peptide Targeting the MERS-CoV S2 Protein HR1 Domain and a Neutralizing Antibody Specific for the S1 Protein Receptor-Binding Domain (RBD) Showed Potent Synergism against Pseudotyped MERS-CoV with or without Mutations in RBD

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 31 ◽  
Author(s):  
Cong Wang ◽  
Chen Hua ◽  
Shuai Xia ◽  
Weihua Li ◽  
Lu Lu ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Inhibitory Peptide ◽  
Protein Receptor ◽  
Neutralizing Monoclonal Antibody ◽  
Peptide Targeting ◽  
Combinatorial Strategy

Middle East respiratory syndrome coronavirus (MERS-CoV) has continuously posed a threat to public health worldwide, yet no therapeutics or vaccines are currently available to prevent or treat MERS-CoV infection. We previously identified a fusion inhibitory peptide (HR2P-M2) targeting the MERS-CoV S2 protein HR1 domain and a highly potent neutralizing monoclonal antibody (m336) specific to the S1 spike protein receptor-binding domain (RBD). However, m336 was found to have reduced efficacy against MERS-CoV strains with mutations in RBD, and HR2P-M2 showed low potency, thus limiting the clinical application of each when administered separately. However, we herein report that the combination of m336 and HR2P-M2 exhibited potent synergism in inhibiting MERS-CoV S protein-mediated cell–cell fusion and infection by MERS-CoV pseudoviruses with or without mutations in the RBD, resulting in the enhancement of antiviral activity in contrast to either one administered alone. Thus, this combinatorial strategy could be used in clinics for the urgent treatment of MERS-CoV-infected patients.

scholarly journals Can the SARS-CoV-2 Spike Protein Bind Integrins Independent of the RGD Sequence?

2021 ◽  
Vol 11 ◽  
Author(s):  
Christopher A. Beaudoin ◽  
Samir W. Hamaia ◽  
Christopher L.-H. Huang ◽  
Tom L. Blundell ◽  
Antony P. Jackson
Keyword(s):  
Receptor Binding ◽  
Conformational Changes ◽  
Sequence Similarity ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Binding Motifs ◽  
Rgd Motif ◽  
Rgd Sequence ◽  
Protein Receptor

The RGD motif in the Severe Acute Syndrome Coronavirus 2 (SARS-CoV-2) spike protein has been predicted to bind RGD-recognizing integrins. Recent studies have shown that the spike protein does, indeed, interact with αVβ3 and α5β1 integrins, both of which bind to RGD-containing ligands. However, computational studies have suggested that binding between the spike RGD motif and integrins is not favourable, even when unfolding occurs after conformational changes induced by binding to the canonical host entry receptor, angiotensin-converting enzyme 2 (ACE2). Furthermore, non-RGD-binding integrins, such as αx, have been suggested to interact with the SARS-CoV-2 spike protein. Other viral pathogens, such as rotaviruses, have been recorded to bind integrins in an RGD-independent manner to initiate host cell entry. Thus, in order to consider the potential for the SARS-CoV-2 spike protein to bind integrins independent of the RGD sequence, we investigate several factors related to the involvement of integrins in SARS-CoV-2 infection. First, we review changes in integrin expression during SARS-CoV-2 infection to identify which integrins might be of interest. Then, all known non-RGD integrin-binding motifs are collected and mapped to the spike protein receptor-binding domain and analyzed for their 3D availability. Several integrin-binding motifs are shown to exhibit high sequence similarity with solvent accessible regions of the spike receptor-binding domain. Comparisons of these motifs with other betacoronavirus spike proteins, such as SARS-CoV and RaTG13, reveal that some have recently evolved while others are more conserved throughout phylogenetically similar betacoronaviruses. Interestingly, all of the potential integrin-binding motifs, including the RGD sequence, are conserved in one of the known pangolin coronavirus strains. Of note, the most recently recorded mutations in the spike protein receptor-binding domain were found outside of the putative integrin-binding sequences, although several mutations formed inside and close to one motif, in particular, may potentially enhance binding. These data suggest that the SARS-CoV-2 spike protein may interact with integrins independent of the RGD sequence and may help further explain how SARS-CoV-2 and other viruses can evolve to bind to integrins.

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