scholarly journals A cell-free assay for rapid screening of inhibitors of hACE2-receptor - SARS-CoV-2-Spike binding

2021 ◽  
Author(s):  
Nanami Kikuchi ◽  
Or Willinger ◽  
Naor Granik ◽  
Noa Navon ◽  
Shanny Ackerman ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Detection Limit ◽  
Angiotensin Converting Enzyme ◽  
Rapid Screening ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Fluorescent Signal ◽  
A Cell ◽  
Particle Preparation

We present a cell-free assay for rapid screening of candidate inhibitors of protein binding, focusing on inhibition of the interaction between the SARS-CoV-2 Spike receptor binding domain (RBD) and human angiotensin-converting enzyme 2 (hACE2). The assay has two components: fluorescent polystyrene particles covalently coated with RBD, termed virion-particles (v-particles), and fluorescently-labeled hACE2 (hACE2F) that binds the v-particles. When incubated with an inhibitor, v-particle - hACE2F binding is diminished, resulting in a reduction in the fluorescent signal of bound hACE2F relative to the non-inhibitor control, which can be measured via flow cytometry or fluorescence microscopy. We determine the amount of RBD needed for v-particle preparation, v-particle incubation time with hACE2F, hACE2F detection limit, and specificity of v-particle binding to hACE2F. We measure the dose response of the v-particles to a known inhibitor. Finally, we demonstrate that RNA-hACE2F granules trap v-particles effectively, providing a basis for potential RNA-hACE2F therapeutics.

scholarly journals Plasma From Recovered COVID-19 Patients Inhibits Spike Protein Binding to ACE2 in a Microsphere-Based Inhibition Assay

2020 ◽  
Vol 222 (12) ◽  
pp. 1965-1973 ◽  
Author(s):  
Edward P Gniffke ◽  
Whitney E Harrington ◽  
Nicholas Dambrauskas ◽  
Yonghou Jiang ◽  
Olesya Trakhimets ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Angiotensin Converting Enzyme ◽  
Protein Binding ◽  
Immunoglobulin G ◽  
Spike Protein ◽  
Converting Enzyme ◽  
Inhibition Assay ◽  
Flow Cytometry Assay ◽  
Angiotensin Converting Enzyme 2 ◽  
A Cell

Abstract We present a microsphere-based flow cytometry assay that quantifies the ability of plasma to inhibit the binding of spike protein to angiotensin-converting enzyme 2. Plasma from 22 patients who had recovered from mild coronavirus disease 2019 (COVID-19) and expressed anti–spike protein trimer immunoglobulin G inhibited angiotensin-converting enzyme 2–spike protein binding to a greater degree than controls. The degree of inhibition was correlated with anti–spike protein immunoglobulin G levels, neutralizing titers in a pseudotyped lentiviral assay, and the presence of fever during illness. This inhibition assay may be broadly useful to quantify the functional antibody response of patients recovered from COVID-19 or vaccine recipients in a cell-free assay system.

scholarly journals Plasma from recovered COVID19 subjects inhibits spike protein binding to ACE2 in a microsphere-based inhibition assay

2020 ◽  
Author(s):  
Edward P. Gniffke ◽  
Whitney E. Harrington ◽  
Nicholas Dambrauskas ◽  
Yonghou Jiang ◽  
Olesya Trakhimets ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Antibody Response ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Inhibition Assay ◽  
Serological Tests ◽  
Angiotensin Converting Enzyme 2 ◽  
A Cell ◽  
Inhibitory Antibodies

AbstractHigh throughput serological tests that can establish the presence and functional activity of anti-SARS-COV2 antibodies are urgently needed. Here we present microsphere-based Flow Cytometry assays that quantify both anti-spike IgGs in plasma, and the ability of plasma to inhibit the binding of spike protein to angiotensin converting enzyme 2 (ACE2). First, we detected anti-spike-trimer IgGs in 22/24 and anti-spike-receptor-binding-domain (RBD) IgGs in 21/24 COVID+ subjects at a median of 36 (range 14-73) days following documented SARS-CoV-2 RNA (+) secretions. Next, we find that plasma from all 22/24 subjects with anti-trimer IgGs inhibited ACE2-trimer binding to a greater degree than controls, and that the degree of inhibition correlated with anti-trimer IgG levels. Depletion of trimer-reactive Igs from plasma reduced ACE2-trimer inhibitory capacity to a greater degree than depletion of RBD-reactive Igs, suggesting that inhibitory antibodies act by binding both within and outside of the RBD. Amongst the 24 subjects, presence of fever was associated with higher levels of anti-trimer IgG and inhibition of binding to human ACE2. This inhibition assay may be broadly useful to quantify the functional antibody response of recovered COVID19 patients or vaccine recipients in a cell-free assay system.

Identification of the interaction between Angiotensin-converting Enzyme Residues and Severe Acute Respiratory Syndrome Coronavirus 2.

2021 ◽  
Vol 27 ◽  
Author(s):  
Youness Kadil ◽  
Mohammed Mouhcine ◽  
Imane Rahmoune ◽  
Houda Filali
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Methodological Study ◽  
Angiotensin Converting Enzyme 2 ◽  
Enveloped Virus ◽  
Positive Sense ◽  
Contact Residues ◽  
Cell Membrane Protein

Introduction: Coronaviruses are an enveloped virus with a positive-sense single-stranded RNA genome. It has been shown that the viral spike S glycoprotein binds to the cell membrane protein angiotensin-converting enzyme 2 as an invasive process of the virus. The aim of this research is the application of a computational approach in the identification of the interaction residues ACE2 with severe acute respiratory syndrome Coronavirus 2. A methodological study to understand the interactions between SARS CoV2 and ACE2, which is essential for the development of a vaccine and an antiviral. Methods: The S protein is cleaved into two subunits, S1 and S2. S1 contains the receptor-binding domain (RBD) which allows the virus to bind directly to the peptidase domain of ACE2. Results: Our results present the overall differences in contact residues between the different chains, and an alignment between the two SARS Viruses, along with a presentation of similarity between them.Then S2 likely plays a role in membrane fusion. Conclusions : The synthesis of our results appears to provide potentially a rational set of objectives that can help in the development of a SARS-CoV-2 vaccine.

scholarly journals Possible Transmission Flow of SARS-CoV-2 Based on ACE2 Features

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5906
Author(s):  
Sk. Sarif Hassan ◽  
Shinjini Ghosh ◽  
Diksha Attrish ◽  
Pabitra Pal Choudhury ◽  
Alaa A. A. Aljabali ◽  
...  
Keyword(s):  
Amino Acids ◽  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Receptor Binding ◽  
Comprehensive Analysis ◽  
Cellular Receptor ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Protein Receptor

Angiotensin-converting enzyme 2 (ACE2) is the cellular receptor for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is engendering the severe coronavirus disease 2019 (COVID-19) pandemic. The spike (S) protein receptor-binding domain (RBD) of SARS-CoV-2 binds to the three sub-domains viz. amino acids (aa) 22–42, aa 79–84, and aa 330–393 of ACE2 on human cells to initiate entry. It was reported earlier that the receptor utilization capacity of ACE2 proteins from different species, such as cats, chimpanzees, dogs, and cattle, are different. A comprehensive analysis of ACE2 receptors of nineteen species was carried out in this study, and the findings propose a possible SARS-CoV-2 transmission flow across these nineteen species.

scholarly journals Amino acids 484 and 494 of SARS-CoV-2 spike are hotspots of immune evasion affecting antibody but not ACE2 binding

2021 ◽  
Author(s):  
Marta Alenquer ◽  
Filipe Ferreira ◽  
Diana Lousa ◽  
Mariana Valério ◽  
Mónica Medina-Lopes ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Angiotensin Converting Enzyme ◽  
Immune Evasion ◽  
Neutralizing Antibodies ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Antibody Neutralization ◽  
Angiotensin Converting Enzyme 2 ◽  
The Core

AbstractUnderstanding SARS-CoV-2 evolution and host immunity is critical to control COVID-19 pandemics. At the core is an arms-race between SARS-CoV-2 antibody and angiotensin-converting enzyme 2 (ACE2) recognition, a function of the viral protein spike and, predominantly, of its receptor-binding-domain (RBD). Mutations in spike impacting antibody or ACE2 binding are known, but the effect of mutation synergy is less explored. We engineered 22 spike-pseudotyped lentiviruses containing individual and combined mutations, and confirmed that E484K evades antibody neutralization elicited by infection or vaccination, a capacity augmented when complemented by K417N and N501Y mutations. In silico analysis provided an explanation for E484K immune evasion. E484 frequently engages in interactions with antibodies but not with ACE2. Importantly, we identified a novel amino acid of concern, S494, which shares a similar pattern. Using the already circulating mutation S494P, we found that it reduces antibody neutralization of convalescent sera. This amino acid emerges as an additional hotspot for immune evasion and a target for therapies, vaccines and diagnostics.One-Sentence SummaryAmino acids in SARS-CoV-2 spike protein implicated in immune evasion are biased for binding to neutralizing antibodies but dispensable for binding the host receptor angiotensin-converting enzyme 2.

scholarly journals A Multifunctional Peptide From Bacillus Fermented Soybean for Effective Inhibition of SARS-CoV-2 S1 Receptor Binding Domain and Modulation of Toll Like Receptor 4: A Molecular Docking Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Srichandan Padhi ◽  
Samurailatpam Sanjukta ◽  
Rounak Chourasia ◽  
Rajendra K. Labala ◽  
Sudhir P. Singh ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Angiotensin Converting Enzyme ◽  
Receptor Binding ◽  
In Silico ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Angiotensin Converting Enzyme 2 ◽  
Fermented Soybean

Fermented soybean products are traditionally consumed and popular in many Asian countries and the northeastern part of India. To search for potential agents for the interruption of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike glycoprotein 1 (S1) and human angiotensin-converting enzyme 2 (ACE2) receptor interactions, the in silico antiviral prospective of peptides identified from the proteome of kinema was investigated. Soybean was fermented using Bacillus licheniformis KN1G, Bacillus amyloliquefaciens KN2G and two different strains of Bacillus subtilis (KN2B and KN2M). The peptides were screened in silico for possible antiviral activity using two different web servers (AVPpred and meta-iAVP), and binding interactions of selected 44 peptides were further explored against the receptor-binding domain (RBD) of the S1 protein (PDB ID: 6M0J) by molecular docking using ZDOCK. The results showed that a peptide ALPEEVIQHTFNLKSQ (P13) belonging to B. licheniformis KN1G fermented kinema was able to make contacts with the binding motif of RBD by blocking specific residues designated as critical (GLN493, ASN501) in the binding of human angiotensin-converting enzyme 2 (ACE2) cell receptor. The selected peptide was also observed to have a significant affinity towards human toll like receptor 4 (TLR4)/Myeloid Differentiation factor 2 (MD2) (PDB ID: 3FXI) complex known for its essential role in cytokine storm. The energy properties of the docked complexes were analyzed through the Generalized Born model and Solvent Accessibility method (MM/GBSA) using HawkDock server. The results showed peptidyl amino acids GLU5, GLN8, PHE11, and LEU13 contributed most to P13-RBD binding. Similarly, ARG90, PHE121, LEU61, PHE126, and ILE94 were appeared to be significant in P13-TLR4/MD2 complex. The findings of the study suggest that the peptides from fermented soy prepared using B. licheniformis KN1G have better potential to be used as antiviral agents. The specific peptide ALPEEVIQHTFNLKSQ could be synthesized and used in combination with experimental studies to validate its effect on SARS-CoV-2-hACE2 interaction and modulation of TLR4 activity. Subsequently, the protein hydrolysate comprising these peptides could be used as prophylaxis against viral diseases, including COVID-19.

scholarly journals Structural Dissection of Viral Spike-Protein Binding of SARS-CoV-2 and SARS-CoV-1 to the Human Angiotensin-Converting Enzyme 2 (ACE2) as Cellular Receptor

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1038
Author(s):  
Deborah Giordano ◽  
Luigi De Masi ◽  
Maria Antonia Argenio ◽  
Angelo Facchiano
Keyword(s):  
Angiotensin Converting Enzyme ◽  
In Silico Analysis ◽  
Host Cells ◽  
Spike Protein ◽  
Cellular Receptor ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
The World ◽  
Silico Analysis

An outbreak by a new severe acute respiratory syndrome betacoronavirus (SARS-CoV-2) has spread CoronaVirus Disease 2019 (COVID-19) all over the world. Immediately, following studies have confirmed the human Angiotensin-Converting Enzyme 2 (ACE2) as a cellular receptor of viral Spike-Protein (Sp) that mediates the CoV-2 invasion into the pulmonary host cells. Here, we compared the molecular interactions of the viral Sp from previous SARS-CoV-1 of 2002 and SARS-CoV-2 with the host ACE2 protein by in silico analysis of the available experimental structures of Sp-ACE2 complexes. The K417 amino acid residue, located in the region of Sp Receptor-Binding Domain (RBD) of the new coronavirus SARS-CoV-2, showed to have a key role for the binding to the ACE2 N-terminal region. The R426 residue of SARS-CoV-1 Sp-RBD also plays a key role, although by interacting with the central region of the ACE2 sequence. Therefore, our study evidenced peculiarities in the interactions of the two Sp-ACE2 complexes. Our outcomes were consistent with previously reported mutagenesis studies on SARS-CoV-1 and support the idea that a new and different RBD was acquired by SARS-CoV-2. These results have interesting implications and suggest further investigations.

Effective ACE2 Peptide-Nanoparticle Conjugation and Its Binding with SARS-Cov-2 RBD Quantified by Dynamic Light Scattering

2021 ◽  
Author(s):  
Vince St. Dollente Mesias ◽  
Hongni Zhu ◽  
Xiao Tang ◽  
Xin Dai ◽  
Yusong Guo ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Angiotensin Converting Enzyme ◽  
Receptor Binding ◽  
Spike Protein ◽  
Cellular Receptor ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Protein Receptor

The infection of coronavirus initiates with the binding between its spike protein receptor binding domain (RBD) and a human cellular receptor called angiotensin-converting enzyme 2 (ACE2). Here, we construct truncated...

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.

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