scholarly journals Mechanical activation of spike fosters SARS-CoV-2 viral infection

Cell Research ◽  
2021 ◽  
Author(s):  
Wei Hu ◽  
Yong Zhang ◽  
Panyu Fei ◽  
Tongtong Zhang ◽  
Danmei Yao ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Receptor Binding ◽  
Viral Entry ◽  
Therapeutic Strategy ◽  
Tensile Force ◽  
Spike Protein ◽  
Viral Fusion ◽  
Receptor Binding Domain ◽  
Host Cell Membrane ◽  
Blocking Antibody

AbstractThe outbreak of SARS-CoV-2 (SARS2) has caused a global COVID-19 pandemic. The spike protein of SARS2 (SARS2-S) recognizes host receptors, including ACE2, to initiate viral entry in a complex biomechanical environment. Here, we reveal that tensile force, generated by bending of the host cell membrane, strengthens spike recognition of ACE2 and accelerates the detachment of spike’s S1 subunit from the S2 subunit to rapidly prime the viral fusion machinery. Mechanistically, such mechano-activation is fulfilled by force-induced opening and rotation of spike’s receptor-binding domain to prolong the bond lifetime of spike/ACE2 binding, up to 4 times longer than that of SARS-S binding with ACE2 under 10 pN force application, and subsequently by force-accelerated S1/S2 detachment which is up to ~103 times faster than that in the no-force condition. Interestingly, the SARS2-S D614G mutant, a more infectious variant, shows 3-time stronger force-dependent ACE2 binding and 35-time faster force-induced S1/S2 detachment. We also reveal that an anti-S1/S2 non-RBD-blocking antibody that was derived from convalescent COVID-19 patients with potent neutralizing capability can reduce S1/S2 detachment by 3 × 106 times under force. Our study sheds light on the mechano-chemistry of spike activation and on developing a non-RBD-blocking but S1/S2-locking therapeutic strategy to prevent SARS2 invasion.

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 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 New insights into nCOVID-19 binding domain and its cellular receptors

2020 ◽  
Author(s):  
Ankush Garg ◽  
Gaurav Kumar ◽  
Sharmistha Sinha
Keyword(s):  
Receptor Binding ◽  
Viral Entry ◽  
Binding Domain ◽  
Spike Protein ◽  
Binding Motif ◽  
Receptor Binding Domain ◽  
Angiotensin Converting Enzyme 2 ◽  
Cell Receptors ◽  
High Propensity ◽  
Multiple Receptor

AbstractnCOVID-19 virus makes cellular entry using its spike protein protruding out on its surface. Angiotensin converting enzyme 2 receptor has been identified as a receptor that mediates the viral entry by binding with the receptor binding motif of spike protein. In the present study, we elucidate the significance of N-terminal domain of spike protein in spike-receptor interactions. Recent clinical reports indicate a link between nCOVID-19 infections with patient comorbidities. The underlying reason behind this relationship is not clear. Using molecular docking, we study the affinity of the nCOVID-19 spike protein with cell receptors overexpressed under disease conditions. Our results suggest that certain cell receptors such as DC/L-SIGN, DPP4, IL22R and ephrin receptors could act as potential receptors for the spike protein. The receptor binding domain of nCOVID-19 is more flexible than that of SARS-COV and has a high propensity to undergo phase separation. Higher flexibility of nCOVID-19 receptor binding domain might enable it to bind multiple receptor partners. Further experimental work on the association of these receptors with spike protein may help us to explain the severity of nCOVID-19 infection in patients with comorbidities.

Molecular characterization of COVID-19 therapeutics: Luteolin as an allosteric modulator of the spike protein of SARS-CoV-2

2021 ◽  
Author(s):  
Juan J de Pablo ◽  
Walter Alvarado ◽  
Fabian Bylehn ◽  
Cintia Menendez ◽  
Gustavo Perez
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Molecular Characterization ◽  
Receptor Binding ◽  
Viral Entry ◽  
Spike Protein ◽  
Allosteric Modulator ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2

The interactions between the receptor binding domain (RBD) of SARS-CoV-2 and the angiotensin- converting enzyme 2 (ACE2) are crucial for viral entry and subsequent replication. Given the large and featureless...

scholarly journals In Silico Design of Peptides with Binding to the Receptor Binding Domain (RBD) of the SARS-CoV-2 and Their Utility in Bio-Sensor Development for SARS-CoV-2 Detection

2020 ◽  
Author(s):  
Yogesh Badhe ◽  
Rakesh Gupta ◽  
Beena Rai
Keyword(s):  
Receptor Binding ◽  
Potential Of Mean Force ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Dynamic Simulations ◽  
Host Cell Membrane ◽  
Sensing Platform ◽  
Substrate Peptide ◽  
Force Calculation

<p>The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions of people across the globe and created not only a health emergency but also a financial crisis. This virus attacks on the angiotensin-converting enzyme 2 (ACE2) receptor situated on the surface of the host cell membrane. The spike protein of the virus binds to this receptor which is a critical step of infection. </p> <p>A molecule which can specifically stop this binding could be a potential therapeutic. In this study, we have tested 12 potential peptides which can bind to the receptor binding domain (RBD) of the spike protein of the virus and thus can potentially inhibit the binding of the latter on ACE2 receptor. These peptides are screened based on their binding with RBD of the spike protein and aqueous stability, obtained using several atomistic molecular dynamic simulations. The potential of mean force calculation of two most promising peptides confirmed their binding to the RBD of the spike protein. </p> <p>Furthermore, these two potential peptides were tested for their use in a biosensing application for SARS-CoV-2 detection. Two types of biosensing platforms, a graphene sheet and a carbon nano tube (CNT), were tested. The peptides were modified in order to functionalize the graphene and CNT. Based on the interaction between the substrate, peptide and spike protein, the utility of screened peptide for a given bio sensing platform is discussed and recommended. </p>

scholarly journals Proteolytic Transformation and Stimulation of SARSCov-2 Spike Protein with Human ACE-2 Receptor

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Sohail S ◽  
◽  
Rana H ◽  
Awan DS ◽  
Sohail F ◽  
...  
Keyword(s):  
Amino Acid ◽  
Receptor Binding ◽  
Viral Entry ◽  
Attachment Site ◽  
Binding Domain ◽  
Host Cells ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Major Pathway ◽  
Important Relationship

Severe acute respiratory syndrome coronavirus has a great role in causing respiratory illness in humans and has the most important relationship of its spike proteins with host ACE-2 receptors. After entry into the human body, the viral S protein receptor-binding domain binds to human ACE-2 receptor. Two modes explained in this paper of an ACE-2 shedding. The shedding induces the process of viral entry to host cells by binding SARS-CoV-2 proteins. The residues of arginine and lysine in the ACE-2 receptor from 652 to 659 amino acid cleavage by ADAM17 but in TMPRSS2 the residues can be seen on amino acid from 697 to 716. Corona virus genome shows some structural proteins that are responsible for the cellular entry and facilitate the attachment of a virus to the host cell. Virus recognizes the attachment site and binds with it and enter into the cell. Spike protein is split from the cleavage site along its two subunits S1 and S2 then during this process. S2 subunit release RBD (Receptor- Binding Domain) of S1 mediated to the ACE-2. The RBD of S1 consists of 200 amino acid domains. The unknown protein B6ATI which is a neutral amino acid transporter located in ileum is the basic cause for formation of ACE-2 homodimer. In this way S1 domain provides site for another S2 domain. This leads to concealing of the ACE-2 ectodomain cleavage-sites, shedding. It prevents endocytosis of the receptor blocking a major pathway in the viral entry.

scholarly journals In Silico Design of Peptides with Binding to the Receptor Binding Domain (RBD) of the SARS-CoV-2 and Their Utility in Bio-Sensor Development for SARS-CoV-2 Detection

2020 ◽  
Author(s):  
Yogesh Badhe ◽  
Rakesh Gupta ◽  
Beena Rai
Keyword(s):  
Receptor Binding ◽  
Potential Of Mean Force ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Dynamic Simulations ◽  
Host Cell Membrane ◽  
Sensing Platform ◽  
Substrate Peptide ◽  
Force Calculation

<p>The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions of people across the globe and created not only a health emergency but also a financial crisis. This virus attacks on the angiotensin-converting enzyme 2 (ACE2) receptor situated on the surface of the host cell membrane. The spike protein of the virus binds to this receptor which is a critical step of infection. </p> <p>A molecule which can specifically stop this binding could be a potential therapeutic. In this study, we have tested 12 potential peptides which can bind to the receptor binding domain (RBD) of the spike protein of the virus and thus can potentially inhibit the binding of the latter on ACE2 receptor. These peptides are screened based on their binding with RBD of the spike protein and aqueous stability, obtained using several atomistic molecular dynamic simulations. The potential of mean force calculation of two most promising peptides confirmed their binding to the RBD of the spike protein. </p> <p>Furthermore, these two potential peptides were tested for their use in a biosensing application for SARS-CoV-2 detection. Two types of biosensing platforms, a graphene sheet and a carbon nano tube (CNT), were tested. The peptides were modified in order to functionalize the graphene and CNT. Based on the interaction between the substrate, peptide and spike protein, the utility of screened peptide for a given bio sensing platform is discussed and recommended. </p>

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