Polyphenolic Natural Products Active In Silico against SARS-CoV-2 Spike Receptor Binding Domains and Non-Structural Proteins – A Review

2021 ◽  
Vol 25 ◽  
Author(s):  
Mark Tristan Quimque ◽  
Kin Israel Notarte ◽  
Xela Amor Adviento ◽  
Mikhail Harvey Cabunoc ◽  
Von Novi de Leon ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Viral Entry ◽  
Treatment Options ◽  
Polyphenolic Compounds ◽  
Spike Protein ◽  
Structural Proteins ◽  
Cell Recognition ◽  
Post Translational Modifications ◽  
Binding Domains ◽  
Host Cell Recognition

: The ongoing Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has been proven to be more severe than the previous coronavirus outbreaks due to the virus’ high transmissibility. With the emergence of new variants, this global phenomenon took on a more dramatic turn with many countries recently experiencing higher surges of confirmed cases and deaths. On top of this, the inadequacy of effective treatment options for COVID-19 aggravated the problem. As a way to address the unavailability of target-specific viral therapeutics, computational strategies have been employed to hasten and systematize the search. The objective of this review is to provide initial data highlighting the utility of polyphenols as potential prophylaxis or treatment for COVID-19. In particular, presented here are virtually screened polyphenolic compounds which showed potential as either antagonists to viral entry and host cell recognition through binding with various receptor-binding regions of SARS-CoV-2 spike protein or as inhibitors of viral replication and post-translational modifications through binding with essential SARS-CoV-2 non-structural proteins.

scholarly journals Structure, function and antigenicity of the SARS-CoV-2 spike glycoprotein

2020 ◽  
Author(s):  
Alexandra C. Walls ◽  
Young-Jun Park ◽  
M. Alexandra Tortorici ◽  
Abigail Wall ◽  
Andrew T. McGuire ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Target Cells ◽  
Furin Cleavage ◽  
Humoral Immune ◽  
Binding Domains ◽  
Furin Cleavage Site ◽  
Recent Emergence ◽  
Novel Coronavirus

SUMMARYThe recent emergence of a novel coronavirus associated with an ongoing outbreak of pneumonia (Covid-2019) resulted in infections of more than 72,000 people and claimed over 1,800 lives. Coronavirus spike (S) glycoprotein trimers promote entry into cells and are the main target of the humoral immune response. We show here that SARS-CoV-2 S mediates entry in VeroE6 cells and in BHK cells transiently transfected with human ACE2, establishing ACE2 as a functional receptor for this novel coronavirus. We further demonstrate that the receptor-binding domains of SARS-CoV-2 S and SARS-CoV S bind with similar affinities to human ACE2, which correlates with the efficient spread of SARS-CoV-2 among humans. We found that the SARS-CoV-2 S glycoprotein harbors a furin cleavage site at the boundary between the S1/S2 subunits, which is processed during biogenesis and sets this virus apart from SARS-CoV and other SARS-related CoVs. We determined a cryo-electron microscopy structure of the SARS-CoV-2 S ectodomain trimer, demonstrating spontaneous opening of the receptor-binding domain, and providing a blueprint for the design of vaccines and inhibitors of viral entry. Finally, we demonstrate that SARS-CoV S murine polyclonal sera potently inhibited SARS-CoV-2 S-mediated entry into target cells, thereby indicating that cross-neutralizing antibodies targeting conserved S epitopes can be elicited upon vaccination.

scholarly journals Inhibition of SARS-CoV-2 viral entry upon blocking N- and O-glycan elaboration

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Qi Yang ◽  
Thomas A Hughes ◽  
Anju Kelkar ◽  
Xinheng Yu ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Viral Entry ◽  
Multiple Roles ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Mechanistic Studies ◽  
Post Translational Modification ◽  
Minor Contribution ◽  
Chemical Inhibitors ◽  
The Impact

The Spike protein of SARS-CoV-2, its receptor-binding domain (RBD), and its primary receptor ACE2 are extensively glycosylated. The impact of this post-translational modification on viral entry is yet unestablished. We expressed different glycoforms of the Spike-protein and ACE2 in CRISPR-Cas9 glycoengineered cells, and developed corresponding SARS-CoV-2 pseudovirus. We observed that N- and O-glycans had only minor contribution to Spike-ACE2 binding. However, these carbohydrates played a major role in regulating viral entry. Blocking N-glycan biosynthesis at the oligomannose stage using both genetic approaches and the small molecule kifunensine dramatically reduced viral entry into ACE2 expressing HEK293T cells. Blocking O-glycan elaboration also partially blocked viral entry. Mechanistic studies suggest multiple roles for glycans during viral entry. Among them, inhibition of N-glycan biosynthesis enhanced Spike-protein proteolysis. This could reduce RBD presentation on virus, lowering binding to host ACE2 and decreasing viral entry. Overall, chemical inhibitors of glycosylation may be evaluated for COVID-19.

scholarly journals Conformational States of the Severe Acute Respiratory Syndrome Coronavirus Spike Protein Ectodomain

2006 ◽  
Vol 80 (14) ◽  
pp. 6794-6800 ◽  
Author(s):  
Fang Li ◽  
Marcelo Berardi ◽  
Wenhui Li ◽  
Michael Farzan ◽  
Philip R. Dormitzer ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Membrane Fusion ◽  
Receptor Binding ◽  
Conformational Changes ◽  
Viral Entry ◽  
Protein S ◽  
Spike Protein ◽  
Fusion Peptides ◽  
Conformational States ◽  
Protease Cleavage

ABSTRACT The severe acute respiratory syndrome coronavirus enters cells through the activities of a spike protein (S) which has receptor-binding (S1) and membrane fusion (S2) regions. We have characterized four sequential states of a purified recombinant S ectodomain (S-e) comprising S1 and the ectodomain of S2. They are S-e monomers, uncleaved S-e trimers, cleaved S-e trimers, and dissociated S1 monomers and S2 trimer rosettes. Lowered pH induces an irreversible transition from flexible, L-shaped S-e monomers to clove-shaped trimers. Protease cleavage of the trimer occurs at the S1-S2 boundary; an ensuing S1 dissociation leads to a major rearrangement of the trimeric S2 and to formation of rosettes likely to represent clusters of elongated, postfusion trimers of S2 associated through their fusion peptides. The states and transitions of S suggest conformational changes that mediate viral entry into cells.

scholarly journals Host-cell recognition through GRP78 is enhanced in the new UK variant of SARS-CoV-2, in silico 

2021 ◽  
Author(s):  
Abdo A Elfiky ◽  
Ibrahim M Ibrahim
Keyword(s):  
Host Cell ◽  
Cell Receptor ◽  
Spike Protein ◽  
Cell Recognition ◽  
Receptor Binding Domain ◽  
Host Cell Receptor ◽  
Mutant Variant ◽  
New Variant ◽  
The Uk ◽  
Host Cell Recognition

Abstract New SARS-CoV-2 variant VUI 202012/01 started in the UK and currently spreading in Europe and Australia during the last few days. The new variant bears about nine mutations in the spike protein (Δ69-70, Δ145, N501Y, A570D, D614G, P681H, T716I, S982A, and D1118H). The N501Y lies in the receptor-binding domain (RBD) of the spike and interacts with the host-cell receptor ACE2 responsible for viral recognition and entry. We tried to simulate the system of ACE2-SARS-CoV-2 spike RBD in the wildtype and mutated isoform of the RBD (N501Y). Additionally, the GRP78 association with the ACE2-SARS-CoV-2 spike RBD is modeled at the presence of this mutant variant of the viral spike.

scholarly journals Mutations in the Spike Protein of Middle East Respiratory Syndrome Coronavirus Transmitted in Korea Increase Resistance to Antibody-Mediated Neutralization

2018 ◽  
Vol 93 (2) ◽  
Author(s):  
Hannah Kleine-Weber ◽  
Mahmoud Tarek Elzayat ◽  
Lingshu Wang ◽  
Barney S. Graham ◽  
Marcel A. Müller ◽  
...  
Keyword(s):  
Middle East ◽  
Protein Binding ◽  
Receptor Binding ◽  
Viral Entry ◽  
Middle East Respiratory Syndrome ◽  
Spike Protein ◽  
Target Cells ◽  
S Protein ◽  
Hospital Outbreak ◽  
The Republic

ABSTRACT Middle East respiratory syndrome coronavirus (MERS-CoV) poses a threat to public health. The virus is endemic in the Middle East but can be transmitted to other countries by travel activity. The introduction of MERS-CoV into the Republic of Korea by an infected traveler resulted in a hospital outbreak of MERS that entailed 186 cases and 38 deaths. The MERS-CoV spike (S) protein binds to the cellular protein DPP4 via its receptor binding domain (RBD) and mediates viral entry into target cells. During the MERS outbreak in Korea, emergence and spread of viral variants that harbored mutations in the RBD, D510G and I529T, was observed. Counterintuitively, these mutations were found to reduce DPP4 binding and viral entry into target cells. In this study, we investigated whether they also exerted proviral effects. We confirm that changes D510G and I529T reduce S protein binding to DPP4 but show that this reduction only translates into diminished viral entry when expression of DPP4 on target cells is low. Neither mutation modulated S protein binding to sialic acids, S protein activation by host cell proteases, or inhibition of S protein-driven entry by interferon-induced transmembrane proteins. In contrast, changes D510G and I529T increased resistance of S protein-driven entry to neutralization by monoclonal antibodies and sera from MERS patients. These findings indicate that MERS-CoV variants with reduced neutralization sensitivity were transmitted during the Korean outbreak and that the responsible mutations were compatible with robust infection of cells expressing high levels of DPP4. IMPORTANCE MERS-CoV has pandemic potential, and it is important to identify mutations in viral proteins that might augment viral spread. In the course of a large hospital outbreak of MERS in the Republic of Korea in 2015, the spread of a viral variant that contained mutations in the viral spike protein was observed. These mutations were found to reduce receptor binding and viral infectivity. However, it remained unclear whether they also exerted proviral effects. We demonstrate that these mutations reduce sensitivity to antibody-mediated neutralization and are compatible with robust infection of target cells expressing large amounts of the viral receptor DPP4.

scholarly journals Competitive SARS-CoV-2 Serology Reveals Most Antibodies Targeting the Spike Receptor-Binding Domain Compete for ACE2 Binding

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
James R. Byrnes ◽  
Xin X. Zhou ◽  
Irene Lui ◽  
Susanna K. Elledge ◽  
Jeff E. Glasgow ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Receptor Binding ◽  
Viral Entry ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Block Interaction ◽  
Angiotensin Converting Enzyme 2 ◽  
Protein Receptor

ABSTRACT As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread around the world, there is an urgent need for new assay formats to characterize the humoral response to infection. Here, we present an efficient, competitive serological assay that can simultaneously determine an individual’s seroreactivity against the SARS-CoV-2 Spike protein and determine the proportion of anti-Spike antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. In this approach based on the use of enzyme-linked immunosorbent assays (ELISA), we present natively folded viral Spike protein receptor-binding domain (RBD)-containing antigens via avidin-biotin interactions. Sera are then competed with soluble ACE2-Fc, or with a higher-affinity variant thereof, to determine the proportion of ACE2 blocking anti-RBD antibodies. Assessment of sera from 144 SARS-CoV-2 patients ultimately revealed that a remarkably consistent and high proportion of antibodies in the anti-RBD pool targeted the epitope responsible for ACE2 engagement (83% ± 11%; 50% to 107% signal inhibition in our largest cohort), further underscoring the importance of tailoring vaccines to promote the development of such antibodies. IMPORTANCE With the emergence and continued spread of the SARS-CoV-2 virus, and of the associated disease, coronavirus disease 2019 (COVID-19), there is an urgent need for improved understanding of how the body mounts an immune response to the virus. Here, we developed a competitive SARS-CoV-2 serological assay that can simultaneously determine whether an individual has developed antibodies against the SARS-CoV-2 Spike protein receptor-binding domain (RBD) and measure the proportion of these antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. Using this assay and 144 SARS-CoV-2 patient serum samples, we found that a majority of anti-RBD antibodies compete for ACE2 binding. These results not only highlight the need to design vaccines to generate such blocking antibodies but also demonstrate the utility of this assay to rapidly screen patient sera for potentially neutralizing antibodies.

scholarly journals Structural impact on SARS-CoV-2 spike protein by D614G substitution

Science ◽  
2021 ◽  
pp. eabf2303
Author(s):  
Jun Zhang ◽  
Yongfei Cai ◽  
Tianshu Xiao ◽  
Jianming Lu ◽  
Hanqin Peng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Membrane Fusion ◽  
Receptor Binding ◽  
Viral Entry ◽  
Vaccine Development ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Structural Rearrangements ◽  
Viral Spread ◽  
Structural Impact

Substitution for aspartic acid by glycine at position 614 in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 appears to facilitate rapid viral spread. The G614 strain and its recent variants are now the dominant circulating forms. We report here cryo-EM structures of a full-length G614 S trimer, which adopts three distinct prefusion conformations differing primarily by the position of one receptor-binding domain. A loop disordered in the D614 S trimer wedges between domains within a protomer in the G614 spike. This added interaction appears to prevent premature dissociation of the G614 trimer, effectively increasing the number of functional spikes and enhancing infectivity, and to modulate structural rearrangements for membrane fusion. These findings extend our understanding of viral entry and suggest an improved immunogen for vaccine development.

scholarly journals Monoclonal Antibodies Capable of Binding SARS-CoV-2 Spike Protein Receptor Binding Motif Specifically Prevent GM-CSF Induction

2020 ◽  
Author(s):  
Xiaoling Qiang ◽  
Shu Zhu ◽  
Jianhua Li ◽  
Ping Wang ◽  
Kevin J. Tracey ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Receptor Binding ◽  
Viral Entry ◽  
Protein Targeting ◽  
Inflammatory Responses ◽  
Human Monocyte ◽  
Spike Protein ◽  
Binding Motif ◽  
Gm Csf ◽  
Future Assessment

AbstractA severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2) has recently caused a pandemic COVID-19 disease that infected more than 25.6 million and killed 852,000 people worldwide. Like the SARS-CoV, SARS-CoV-2 also employs a receptor-binding motif (RBM) of its envelope spike protein for binding the host angiotensin-converting enzyme 2 (ACE2) to gain viral entry. Currently, extensive efforts are being made to produce vaccines against a surface fragment of a SARS-CoV-2, such as the spike protein, in order to boost protective antibody responses. It was previously unknown how spike protein-targeting antibodies would affect innate inflammatory responses to SARS-CoV-2 infections. Here we generated a highly purified recombinant protein corresponding to the RBM of SARS-CoV-2, and used it to screen for cross-reactive monoclonal antibodies (mAbs). We found two RBM-binding mAbs that competitively inhibited its interaction with human ACE2, and specifically blocked the RBM-induced GM-CSF secretion in both human monocyte and murine macrophage cultures. Our findings have suggested a possible strategy to prevent SARS-CoV-2-elicited “cytokine storm”, and provided a potentially useful criteria for future assessment of innate immune-modulating properties of various SARS-CoV-2 vaccines.One Sentence SummaryRBM-binding Antibodies Inhibit GM-CSF Induction.

scholarly journals Sequence variation of SARS-CoV-2 spike protein may facilitate stronger interaction with ACE2 promoting high infectivity

2020 ◽  
Author(s):  
Masaud Shah ◽  
Bilal Ahmad ◽  
Sangdun Choi ◽  
Hyun Goo Woo
Keyword(s):  
Monoclonal Antibodies ◽  
Severe Acute Respiratory Syndrome ◽  
Sequence Variation ◽  
Spike Protein ◽  
Cell Recognition ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Binding Domains ◽  
Conformational Epitopes ◽  
High Infectivity

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease (COVID-19), is a novel beta coronavirus emerged in China in 2019. Coronavirus uses spike glycoprotein to interact with host angiotensin-converting enzyme 2 (ACE2) and ensure cell recognition. High infectivity of SARS-CoV-2 raises questions on spike-ACE2 binding affinity and its neutralization by anti-SARS-CoV monoclonal antibodies (mAbs). Here, we observed Val-to-Lys417 mutation in the receptor-binding domains (RBD) of SARS-CoV-2, which established a Lys-Asp electrostatic interaction enhancing its ACE2-binding. Pro-to-Ala475 substitution and Gly482 insertion in the AGSTPCNGV-loop of RBD hindered neutralization of SARS-CoV-2 by anti-SARS-CoV mAbs. In addition, we identified unique and structurally conserved conformational-epitopes on RBDs, which can be potential therapeutic targets. Collectively, we provide new insights into the mechanisms underlying the high infectivity of SARS-CoV-2 and development of new effective neutralizing agents.

Sign in / Sign up

Export Citation Format

Share Document