Design and Synthesis of De Novo Boomerang Shaped Molecules and their In Silico & SERS-based Interactions with SARS-CoV-2 Spike Protein and ACE2

2021 ◽  
Author(s):  
Amrutham Linet ◽  
Manu M Joseph ◽  
Haritha Mambatta ◽  
Shamna k ◽  
Sunil varughese ◽  
...  

The recent outbreak of the COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which infects human epithelial tissue by interaction of the receptor-binding domain of its spike...

2021 ◽  
pp. eabd6990
Author(s):  
Sang Il Kim ◽  
Jinsung Noh ◽  
Sujeong Kim ◽  
Younggeun Choi ◽  
Duck Kyun Yoo ◽  
...  

Stereotypic antibody clonotypes exist in healthy individuals and may provide protective immunity against viral infections by neutralization. We observed that 13 out of 17 patients with COVID-19 had stereotypic variable heavy chain (VH) antibody clonotypes directed against the receptor-binding domain (RBD) of SARS-CoV-2 spike protein. These antibody clonotypes were comprised of immunoglobulin heavy variable (IGHV)3-53 or IGHV3-66 and immunoglobulin heavy joining (IGHJ)6 genes. These clonotypes included IgM, IgG3, IgG1, IgA1, IgG2, and IgA2 subtypes and had minimal somatic mutations, which suggested swift class switching after SARS-CoV-2 infection. The different immunoglobulin heavy variable chains were paired with diverse light chains resulting in binding to the RBD of SARS-CoV-2 spike protein. Human antibodies specific for the RBD can neutralize SARS-CoV-2 by inhibiting entry into host cells. We observed that one of these stereotypic neutralizing antibodies could inhibit viral replication in vitro using a clinical isolate of SARS-CoV-2. We also found that these VH clonotypes existed in six out of 10 healthy individuals, with IgM isotypes predominating. These findings suggest that stereotypic clonotypes can develop de novo from naïve B cells and not from memory B cells established from prior exposure to similar viruses. The expeditious and stereotypic expansion of these clonotypes may have occurred in patients infected with SARS-CoV-2 because they were already present.


2020 ◽  
Author(s):  
Harshawardhan Pande

The COVID-19 pandemic caused by the SARS-CoV-2 virus is posing a major global challenge due to its rapid infectivity and lethality. Despite a global effort towards creating a vaccine, no viable vaccine currently exists. While multiple bioinformatic studies have attempted to predict epitopes, they have focused on the whole spike protein without considering antibody mediated enhancement or Th-2 immunopathology and have missed some important but less antigenic epitopes in the receptor binding domain. Therefore, this study used in silico methods to design and evaluate a potential multiepitope vaccine that specifically targets the receptor binding domain due to its critical function in viral entry. Immunoinformatic tools were used to specifically examine the receptor binding domain of the surface glycoprotein for suitable T cell and B cell epitopes. The selected 5 B cell and 8 T cell epitopes were then constructed into a subunit vaccine and appropriate adjuvants along with the universal immunogenic PADRE sequence were added to boost efficacy. The structure of the vaccine construct was predicted through a de novo approach and molecular docking simulations were performed which demonstrated high affinity binding to TLR 5 receptor and appropriate HLA proteins. Finally, the vaccine candidate was cloned into an expression vector for use as a recombinant vaccine. Similarities to some recent epitope mapping studies suggest a high potential for eliciting neutralizing antibodies and generating a favorable overall immune response.


2021 ◽  
Vol 17 (8) ◽  
pp. e1009857
Author(s):  
Michelle N. Vu ◽  
Vineet D. Menachery

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) emerged as a virus with a pathogenicity closer to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and a transmissibility similar to common cold coronaviruses (CoVs). In this review, we briefly discuss the features of the receptor-binding domain (RBD) and protease cleavage of the SARS-CoV-2 spike protein that enable SARS-CoV-2 to be a pandemic virus.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 724
Author(s):  
Paola Cristina Resende ◽  
Tiago Gräf ◽  
Anna Carolina Dias Paixão ◽  
Luciana Appolinario ◽  
Renata Serrano Lopes ◽  
...  

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.


2021 ◽  
Author(s):  
Laura VanBlargan ◽  
John Errico ◽  
Peter Halfmann ◽  
Seth Zost ◽  
James Crowe ◽  
...  

Abstract The emergence of the highly-transmissible B.1.1.529 Omicron variant of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is concerning for antibody countermeasure efficacy because of the number of mutations in the spike protein. Here, we tested a panel of anti-receptor binding domain monoclonal antibodies (mAbs) corresponding to those in clinical use by Vir Biotechnology (S309, the parent mAb of VIR-7831 [Sotrovimab]), AstraZeneca (COV2-2196 and COV2-2130, the parent mAbs of AZD8895 and AZD1061), Regeneron (REGN10933 and REGN10987), Lilly (LY-CoV555 and LY-CoV016), and Celltrion (CT-P59) for their ability to neutralize an infectious B.1.1.529 Omicron isolate. Several mAbs (LY-CoV555, LY-CoV016, REGN10933, REGN10987, and CT-P59) completely lost neutralizing activity against B.1.1.529 virus in both Vero-TMPRSS2 and Vero-hACE2-TMPRSS2 cells, whereas others were reduced (COV2-2196 and COV2-2130 combination, ~12-fold decrease) or minimally affected (S309). Our results suggest that several, but not all, of the antibodies in clinical use may lose efficacy against the B.1.1.529 Omicron variant.


Science ◽  
2020 ◽  
Vol 369 (6504) ◽  
pp. 650-655 ◽  
Author(s):  
Xiangyang Chi ◽  
Renhong Yan ◽  
Jun Zhang ◽  
Guanying Zhang ◽  
Yuanyuan Zhang ◽  
...  

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.


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