scholarly journals The ongoing evolution of variants of concern and interest of SARS-CoV-2 in Brazil revealed by convergent indels in the amino (N)-terminal domain of the Spike protein

2021 ◽  
Author(s):  
Paola Cristina Resende ◽  
Felipe Gomes Naveca ◽  
Roberto Dias Lins ◽  
Filipe Zimmer Dezordi ◽  
Matheus V. F. Ferraz ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Immune Escape ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Terminal Domain

Mutations at both the receptor-binding domain (RBD) and the amino (N)-terminal domain (NTD) of the SARS-CoV-2 Spike (S) glycoprotein can alter its antigenicity and promote immune escape. We identified that SARS-CoV-2 lineages circulating in Brazil with mutations of concern in the RBD independently acquired convergent deletions and insertions in the NTD of the S protein, which altered the NTD antigenic-supersite and other predicted epitopes at this region. These findings support that the ongoing widespread transmission of SARS-CoV-2 in Brazil is generating new viral lineages that might be more resistant to neutralization than parental variants of concern.

scholarly journals A neutralizing human antibody binds to the N-terminal domain of the Spike protein of SARS-CoV-2

Science ◽  
2020 ◽  
Vol 369 (6504) ◽  
pp. 650-655 ◽  
Author(s):  
Xiangyang Chi ◽  
Renhong Yan ◽  
Jun Zhang ◽  
Guanying Zhang ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Binding Domain ◽  
Spike Protein ◽  
Human Antibody ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Terminal Domain ◽  
Promising Target

Developing therapeutics against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be guided by the distribution of epitopes, not only on the receptor binding domain (RBD) of the Spike (S) protein but also across the full Spike (S) protein. We isolated and characterized monoclonal antibodies (mAbs) from 10 convalescent COVID-19 patients. Three mAbs showed neutralizing activities against authentic SARS-CoV-2. One mAb, named 4A8, exhibits high neutralization potency against both authentic and pseudotyped SARS-CoV-2 but does not bind the RBD. We defined the epitope of 4A8 as the N-terminal domain (NTD) of the S protein by determining with cryo–eletron microscopy its structure in complex with the S protein to an overall resolution of 3.1 angstroms and local resolution of 3.3 angstroms for the 4A8-NTD interface. This points to the NTD as a promising target for therapeutic mAbs against COVID-19.

scholarly journals A Potential SARS-CoV-2 Variant of Interest (VOI) Harboring Mutation E484K in the Spike Protein Was Identified within Lineage B.1.1.33 Circulating in Brazil

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 724
Author(s):  
Paola Cristina Resende ◽  
Tiago Gräf ◽  
Anna Carolina Dias Paixão ◽  
Luciana Appolinario ◽  
Renata Serrano Lopes ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Binding Domain ◽  
The Other ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Other Hand

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic in Brazil was dominated by two lineages designated as B.1.1.28 and B.1.1.33. The two SARS-CoV-2 variants harboring mutations at the receptor-binding domain of the Spike (S) protein, designated as lineages P.1 and P.2, evolved from lineage B.1.1.28 and are rapidly spreading in Brazil. Lineage P.1 is considered a Variant of Concern (VOC) because of the presence of multiple mutations in the S protein (including K417T, E484K, N501Y), while lineage P.2 only harbors mutation S:E484K and is considered a Variant of Interest (VOI). On the other hand, epidemiologically relevant B.1.1.33 deriving lineages have not been described so far. Here we report the identification of a new SARS-CoV-2 VOI within lineage B.1.1.33 that also harbors mutation S:E484K and was detected in Brazil between November 2020 and February 2021. This VOI displayed four non-synonymous lineage-defining mutations (NSP3:A1711V, NSP6:F36L, S:E484K, and NS7b:E33A) and was designated as lineage N.9. The VOI N.9 probably emerged in August 2020 and has spread across different Brazilian states from the Southeast, South, North, and Northeast regions.

scholarly journals A potential SARS-CoV-2 variant of interest (VOI) harboring mutation E484K in the Spike protein was identified within lineage B.1.1.33 circulating in Brazil

2021 ◽  
Author(s):  
Paola Cristina Resende ◽  
Tiago Gräf ◽  
Anna Carolina Dias Paixão ◽  
Luciana Appolinario ◽  
Renata Serrano Lopes ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
S Protein

SummaryThe SARS-CoV-2 epidemic in Brazil was dominated by two lineages designated as B.1.1.28 and B.1.1.33. Two SARS-CoV-2 variants harboring mutations at the receptor-binding domain of the Spike (S) protein, designated as lineages P.1 and P.2, evolved within lineage B.1.1.28 and are rapidly spreading in Brazil. Lineage P.1 is considered a Variant of Concern (VOC) because of the presence of multiple mutations in the S protein (including K417T, E484K, N501Y), while lineage P.2 only harbors mutation S:E484K and is considered a Variant of Interest (VOI). Here we report the identification of a new SARS-CoV-2 VOI within lineage B.1.1.33 that also harbors mutation S:E484K and was detected in Brazil between November 2020 and February 2021. This VOI displayed four non-synonymous lineage-defining mutations (NSP3:A1711V, NSP6:F36L, S:E484K, and NS7b:E33A) and was designated as lineage N.9. The VOI N.9 probably emerged in August 2020 and has spread across different Brazilian states from the Southeast, South, North and Northeast regions.

scholarly journals Rotavirus as an Expression Platform of the SARS-CoV-2 Spike Protein

2021 ◽  
Author(s):  
Asha A. Philip ◽  
John T. Patton
Keyword(s):  
Receptor Binding ◽  
Rna Virus ◽  
Serial Passage ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Double Stranded Rna ◽  
S Protein ◽  
Rotavirus A ◽  
Rotavirus Vaccines

AbstractRotavirus, a segmented double-stranded RNA virus, is a major cause of acute gastroenteritis in young children. The introduction of live oral rotavirus vaccines has reduced the incidence of rotavirus disease in many countries. To explore the possibility of establishing a combined rotavirus-SARS-CoV-2 vaccine, we generated recombinant (r)SA11 rotaviruses with modified segment 7 RNAs that contained coding sequences for NSP3 and FLAG-tagged portions of the SARS-CoV-2 spike (S) protein. A 2A translational element was used to drive separate expression of NSP3 and the S product. rSA11 viruses were recovered that encoded the S-protein S1 fragment, N-terminal domain (NTD), receptor-binding domain (RBD), extended receptor-binding domain (ExRBD), and S2 core (CR) domain (rSA11/NSP3-fS1, -fNTD, -fRBD, -fExRBD, and -fCR, respectively). Generation of rSA11/fS1 required a foreign-sequence insertion of 2.2-kbp, the largest such insertion yet made into the rotavirus genome. Based on isopycnic centrifugation, rSA11 containing S sequences were denser than wildtype virus, confirming the capacity of the rotavirus to accommodate larger genomes. Immunoblotting showed that rSA11/-fNTD, -fRBD, -fExRBD, and -fCR viruses expressed S products of expected size, with fExRBD expressed at highest levels. These rSA11 viruses were genetically stable during serial passage. In contrast, rSA11/NSP3-fS1 failed to express its expected 80-kDa fS1 product, for unexplained reasons. Moreover, rSA11/NSP3-fS1 was genetically unstable, with variants lacking the S1 insertion appearing during serial passage. Nonetheless, these results emphasize the potential usefulness of rotavirus vaccines as expression vectors of portions of the SARS-CoV-2 S protein (e.g., NTD, RBD, ExRBD, and CR) with sizes smaller than the S1 fragment.ImportanceAmong the vaccines administered to children in the US and many other countries are those targeting rotavirus, a segmented double-stranded RNA virus that is a major cause of severe gastroenteritis. In this study, we have examined the feasibility of modifying the rotavirus genome by reverse genetics, such that the virus could serve as an expression vector of the SARS-CoV-2 spike protein. Results were obtained showing that recombinant rotaviruses can be generated that express domains of the SARS CoV-2 spike protein, including the receptor-binding domain (RBD), a common target of neutralizing antibodies produced in individuals infected by the virus. Our findings raise the possibility of creating a combined rotavirus-COVID-19 vaccine that could be used in place of current rotavirus vaccines.

scholarly journals Structural remodeling of SARS-CoV-2 spike protein glycans reveals the regulatory roles in receptor binding affinity

2021 ◽  
Author(s):  
Yen-Pang Hsu ◽  
Debopreeti Mukherjee ◽  
Vladimir Shchurik ◽  
Alexey Makarov ◽  
Benjamin F. Mann
Keyword(s):  
Binding Affinity ◽  
Receptor Binding ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Receptor Binding Affinity ◽  
Protein Receptor ◽  
Regulatory Effects

AbstractGlycans of the SARS-CoV-2 spike protein are speculated to play functional roles in the infection processes as they extensively cover the protein surface and are highly conserved across the variants. To date, the spike protein has become the principal target for vaccine and therapeutic development while the exact effects of its glycosylation remain elusive. Experimental reports have described the heterogeneity of the spike protein glycosylation profile. Subsequent molecular simulation studies provided a knowledge basis of the glycan functions. However, there are no studies to date on the role of discrete glycoforms on the spike protein pathobiology. Building an understanding of its role in SARS-CoV-2 is important as we continue to develop effective medicines and vaccines to combat the disease. Herein, we used designed combinations of glycoengineering enzymes to simplify and control the glycosylation profile of the spike protein receptor-binding domain (RBD). Measurements of the receptor binding affinity revealed the regulatory effects of the RBD glycans. Remarkably, opposite effects were observed from differently remodeled glycans, which presents a potential strategy for modulating the spike protein behaviors through glycoengineering. Moreover, we found that the reported anti-SARS-CoV-(2) antibody, S309, neutralizes the impact of different RBD glycoforms on the receptor binding affinity. Overall, this work reports the regulatory roles that glycosylation plays in the interaction between the viral spike protein and host receptor, providing new insights into the nature of SARS-CoV-2. Beyond this study, enzymatic remodeling of glycosylation offers the opportunity to understand the fundamental role of specific glycoforms on glycoconjugates across molecular biology.Covert art LegendsThe glycosylation of the SARS-CoV-2 spike protein receptor-binding domain has regulatory effects on the receptor binding affinity. Sialylation or not determines the “stabilizing” or “destabilizing” effect of the glycans. (Protein structure model is adapted from Protein Data Bank: 6moj. The original model does not contain the glycan structure.)SignificanceGlycans extensively cover the surface of SARS-CoV-2 spike (S) protein but the relationships between the glycan structures and the protein pathological behaviors remain elusive. Herein, we simplified and harmonized the glycan structures in the S protein receptor-binding domain and reported their regulatory roles in human receptor interaction. Opposite regulatory effects were observed and were determined by discrete glycan structures, which can be neutralized by the reported S309 antibody binding to the S protein. This report provides new insight into the mechanism of SARS-CoV-2 S protein infection as well as S309 neutralization.

scholarly journals Structure-activity relationships of B.1.617 and other SARS-CoV-2 spike variants

2021 ◽  
Author(s):  
Tzu-Jing Yang ◽  
Pei-Yu Yu ◽  
Yuan-Chih Chang ◽  
Ning-En Chang ◽  
Yu-Xi Tsai ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Host Immunity ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Structure Activity Relationships ◽  
Terminal Domain ◽  
Structure Activity ◽  
Functional States ◽  
Binding Interfaces

The surge of COVID-19 infection cases is spurred by emerging SARS-CoV-2 variants such as B.1.617. Here we report 38 cryo-EM structures, corresponding to the spike protein of the Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2) and Kappa (B.1.617.1) variants in different functional states with and without its receptor, ACE2. Mutations on the N-terminal domain not only alter the conformation of the highly antigenic supersite of the Delta variant, but also remodel the glycan shield by deleting or adding N-glycans of the Delta and Gamma variants, respectively. Substantially enhanced ACE2 binding was observed for all variants, whose mutations on the receptor binding domain modulate the electrostatics of the binding interfaces. Despite their abilities to escape host immunity, all variants can be potently neutralized by three unique antibodies.

scholarly journals Identification of the Receptor-Binding Domain of the Spike Glycoprotein of Human Betacoronavirus HKU1

2015 ◽  
Vol 89 (17) ◽  
pp. 8816-8827 ◽  
Author(s):  
Zhaohui Qian ◽  
Xiuyuan Ou ◽  
Luiz Gustavo Bentim Góes ◽  
Christina Osborne ◽  
Anna Castano ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein ◽  
S Protein ◽  
Receptor Proteins ◽  
Group A

ABSTRACTCoronavirus spike (S) glycoproteins mediate receptor binding, membrane fusion, and virus entry and determine host range. Murine betacoronavirus (β-CoV) in group A uses the N-terminal domain (NTD) of S protein to bind to its receptor, whereas the β-CoVs severe acute respiratory syndrome CoV in group B and Middle East respiratory syndrome CoV in group C and several α-CoVs use the downstream C domain in their S proteins to recognize their receptor proteins. To identify the receptor-binding domain in the spike of human β-CoV HKU1 in group A, we generated and mapped a panel of monoclonal antibodies (MAbs) to the ectodomain of HKU1 spike protein. They did not cross-react with S proteins of any other CoV tested. Most of the HKU1 spike MAbs recognized epitopes in the C domain between amino acids 535 and 673, indicating that this region is immunodominant. Two of the MAbs blocked HKU1 virus infection of primary human tracheal-bronchial epithelial (HTBE) cells. Preincubation of HTBE cells with a truncated HKU1 S protein that includes the C domain blocked infection with HKU1 virus, but preincubation of cells with truncated S protein containing only the NTD did not block infection. These data suggest that the receptor-binding domain (RBD) of HKU1 spike protein is located in the C domain, where the spike proteins of α-CoVs and β-CoVs in groups B and C bind to their specific receptor proteins. Thus, two β-CoVs in group A, HKU1 and murine CoV, have evolved to use different regions of their spike glycoproteins to recognize their respective receptor proteins.IMPORTANCEMouse hepatitis virus, a β-CoV in group A, uses the galectin-like NTD in its spike protein to bind its receptor protein, while HCoV-OC43, another β-CoV in group A, uses the NTD to bind to its sialic-acid containing receptor. In marked contrast, the NTD of the spike glycoprotein of human respiratory β-CoV HKU1, which is also in group A, does not bind sugar. In this study, we showed that for the spike protein of HKU1, the purified C domain, downstream of the NTD, could block HKU1 virus infection of human respiratory epithelial cells, and that several monoclonal antibodies that mapped to the C domain neutralized virus infectivity. Thus, the receptor-binding domain of HKU1 spike glycoprotein is located in the C domain. Surprisingly, two β-CoVs in group A, mouse hepatitis virus and HKU1, have evolved to use different regions of their spike glycoproteins to recognize their respective receptors.

scholarly journals SARS-CoV-2 Spike Protein and Its Receptor Binding Domain Promote a Proinflammatory Activation Profile on Human Dendritic Cells

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3279
Author(s):  
Dante Barreda ◽  
César Santiago ◽  
Juan R. Rodríguez ◽  
José F. Rodríguez ◽  
José M. Casasnovas ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Receptor Binding ◽  
Cell Receptor ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Mhc Molecules ◽  
Activation Profile ◽  
Human Dendritic Cells

Dendritic cells (DCs) are the most potent antigen-presenting cells, and their function is essential to configure adaptative immunity and avoid excessive inflammation. DCs are predicted to play a crucial role in the clinical evolution of the infection by the severe acute respiratory syndrome (SARS) coronavirus (CoV)-2. DCs interaction with the SARS-CoV-2 Spike protein, which mediates cell receptor binding and subsequent fusion of the viral particle with host cell, is a key step to induce effective immunity against this virus and in the S protein-based vaccination protocols. Here we evaluated human DCs in response to SARS-CoV-2 S protein, or to a fragment encompassing the receptor binding domain (RBD) challenge. Both proteins increased the expression of maturation markers, including MHC molecules and costimulatory receptors. DCs interaction with the SARS-CoV-2 S protein promotes activation of key signaling molecules involved in inflammation, including MAPK, AKT, STAT1, and NFκB, which correlates with the expression and secretion of distinctive proinflammatory cytokines. Differences in the expression of ACE2 along the differentiation of human monocytes to mature DCs and inter-donor were found. Our results show that SARS-CoV-2 S protein promotes inflammatory response and provides molecular links between individual variations and the degree of response against this virus.

scholarly journals Efficacy of ancestral receptor-binding domain, S1 and trimeric spike protein vaccines against SARS-CoV-2 variants B.1.1.7, B.1.351, and B.1.617.1

2021 ◽  
Author(s):  
Yong Yang ◽  
Jinkai Zang ◽  
Shiqi Xu ◽  
Xueyang Zhang ◽  
Sule Yuan ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Immune Escape ◽  
Neutralizing Antibody ◽  
Prototype Strain ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Antibody Titers ◽  
Continued Use

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current SARS-CoV-2 vaccines are based on spike (S) protein, S1 subunit, or receptor-binding domain (RBD) of prototype strain. Emergence of several novel SARS-CoV-2 variants has raised concern about potential immune escape. In this study, we performed an immunogenicity comparison of ancestral RBD, S1, and S ectodomain trimer (S-trimer) antigens and tested the efficacy of these prototype vaccines against the circulating variants, especially B.1.617 that has been linked to India's current COVID-19 surge. We found that RBD and S-trimer proteins could induce significantly higher neutralizing antibody titers than S1 protein. For the three vaccines, the neutralizing titers decreased over time, but still remained high for at least five months after immunization. Importantly, the three prototype vaccines were still effective in neutralizing the variants of concern, although B.1.351 and B.1.617.1 lineages showed varying degrees of reduction in neutralization by the immune sera. The vaccines-induced sera were shown to block receptor binding and inhibit S protein-mediated membrane fusion. In addition, the immune sera did not promote antibody-dependent enhancement (ADE) in vitro. Our work provides valuable information for development of SARS-CoV-2 subunit vaccines and also supports the continued use of ancestral RBD or S-based vaccines to fight the COVID-19 epidemic.

scholarly journals Catechin and curcumin interact with S protein of SARS-CoV2 and ACE2 of human cell membrane: insights from computational studies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atala B. Jena ◽  
Namrata Kanungo ◽  
Vinayak Nayak ◽  
G. B. N. Chainy ◽  
Jagneshwar Dandapat
Keyword(s):  
Amino Acid ◽  
Binding Affinity ◽  
Receptor Binding ◽  
Computational Study ◽  
Cell Receptor ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Amino Acid Residues ◽  
S Protein

AbstractThe recent outbreak of the coronavirus (SARS-CoV2) is an unprecedented threat to human health and society across the globe. In this context, development of suitable interventions is the need of the hour. The viral spike protein (S Protein) and the cognate host cell receptor ACE2 can be considered as effective and appropriate targets for interventions. It is evident from the present computational study, that catechin and curcumin, not only exhibit strong binding affinity to viral S Protein and host receptor ACE2 but also to their complex (receptor-binding domain (RBD) of the spike protein of SARS-CoV2 and ACE2; RBD/ACE2-complex). The binding affinity values of catechin and curcumin for the S protein, ACE2 and RBD/ACE2-complex are − 10.5 and − 7.9 kcal/mol; − 8.9 and − 7.8 kcal/mol; and − 9.1 and − 7.6 kcal/mol, respectively. Curcumin directly binds to the receptor binding domain (RBD) of viral S Protein. Molecular simulation study over a period of 100 ns further substantiates that such interaction within RBD site of S Protein occurs during 40–100 ns out of 100 ns simulation trajectory. Contrary to this, catechin binds with amino acid residues present near the RBD site of S Protein and causes fluctuation in the amino acid residues of the RBD and its near proximity. Both catechin and curcumin bind the interface of ‘RBD/ACE2-complex’ and intervene in causing fluctuation of the alpha helices and beta-strands of the protein complex. Protein–protein interaction studies in presence of curcumin or catechin also corroborate the above findings suggesting the efficacy of these two polyphenols in hindering the formation of S Protein-ACE2 complex. In conclusion, this computational study for the first time predicts the possibility of above two polyphenols for therapeutic strategy against SARS-CoV2.

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