Bioinformatics analysis of SARS-CoV-2 RBD mutant variants and insights into antibody and ACE2 receptor binding

Prevailing COVID-19 vaccines are based on the spike protein of earlier SARS-CoV-2 strain that emerged in Wuhan, China. Continuously evolving nature of SARS-CoV-2 resulting emergence of new variant/s raise the risk of immune absconds. Several RBD (receptor-binding domain) variants have been reported to affect the vaccine efficacy considerably. In the present study, we performed in silico structural analysis of spike protein of double mutant (L452R & E484Q), a new variant of SARS-CoV-2 recently reported in India along with K417G variants and earlier reported RBD variants and found structural changes in RBD region after comparing with the wild type. Comparison of the binding affinity of the double mutant and earlier reported RBD variant for ACE2 (angiotensin 2 altered enzymes) receptor and CR3022 antibody with the wild-type strain revealed the lowest binding affinity of the double mutant for CR3022 among all other variants. These findings suggest that the newly emerged double mutant could significantly reduce the impact of the current vaccine which threatens the protective efficacy of current vaccine therapy.

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Structural Analysis And Molecular Characteristics of SARSCoV-2 Spike Protein Following S494P Point Mutation: Molecular Dynamics Study

10.21203/rs.3.rs-625623/v1 ◽

2021 ◽

Author(s):

Mehr Ali Mahmood Janlou ◽

Hassan sahebjamee ◽

Shademan Shokravi

Keyword(s):

Structural Analysis ◽

Binding Affinity ◽

Receptor Binding ◽

Conformational Changes ◽

Spike Protein ◽

Molecular Characteristics ◽

Wild Type ◽

Natural Mutation ◽

The Stability ◽

Different Strains

Abstract The emergence of some mutations in the SARS-CoV-2 receptor binding domain (RBD) can increase the spread and pathogenicity due to the conformational changes and increase the stability of Spike protein. Due to the formation of different strains of SARS-CoV-2 by mutations, and their catastrophic effect on public health, the study of the effect of mutations by scientists and researchers around the world is inevitable. According to available evidence, the S494P variant is observed in several SARS-CoV-2 strains from Michigan, USA. To investigate how the S494P natural mutation alters receptor binding affinity in RBD, we performed structural analysis of wild-type and mutant spike proteins using some bioinformatics and computational tools. The results show that S494P mutation increases the spike protein stability. Also, applying docking by HADDOCK displayed higher binding affinity to hACE2 for mutant spike than wild type possibly due to the increased β-strand and Turn secondary structures which increases surface accessibly surface area (SASA) and chance of interaction. The analysis of S494P as a critical RBD mutation may provide the continuing surveillance of spike mutations to aid in the development of COVID-19 drugs and vaccines.

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Impact of the Double Mutants on Spike Protein of SARS-CoV-2 B.1.617 Lineage to the Human ACE2 Receptor Binding: A Structural Insight

Viruses ◽

10.3390/v13112295 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2295

Author(s):

Mohd Imran Khan ◽

Mohammad Hassan Baig ◽

Tanmoy Mondal ◽

Mohammed Alorabi ◽

Tanuj Sharma ◽

...

Keyword(s):

Binding Affinity ◽

Receptor Binding ◽

Immune Escape ◽

Principal Component ◽

Spike Protein ◽

Human Host ◽

Recent Emergence ◽

Novel Variants ◽

Structural Insight ◽

The Impact

The recent emergence of novel SARS-CoV-2 variants has threatened the efforts to contain the COVID-19 pandemic. The emergence of these “variants of concern” has increased viral transmissibility or immune escape and has supplanted the ancestral strains. The novel variants harbored by the B.1.617 lineage (Kappa and Delta) carry mutations within the receptor-binding domain of spike (S) protein (L452R + E484Q and L452R + T478K), the region binding to the host receptor. The double mutations carried by these novel variants are primarily responsible for an upsurge number of COVID-19 cases in India. In this study, we thoroughly investigated the impact of these double mutations on the binding capability to the human host receptor. We performed several structural analyses and found that the studied double mutations increase the binding affinity of the spike protein to the human host receptor (ACE2). Furthermore, our study showed that these double mutants might be a dominant contributor enhancing the receptor-binding affinity of SARS-CoV-2 and consequently making it more stable. We also investigated the impact of these mutations on the binding affinity of two monoclonal antibodies (Abs) (2-15 and LY-CoV555) and found that the presence of the double mutations also hinders its binding with the studied Abs. The principal component analysis, free energy landscape, intermolecular interaction, and other investigations provided a deeper structural insight to better understand the molecular mechanism responsible for increased viral transmissibility of these variants.

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Structural-bioinformatics analysis of SARS-CoV-2 variants reveals higher hACE2 receptor binding affinity for Omicron B.1.1.529 spike RBD compared to wild-type reference.

10.21203/rs.3.rs-1153124/v1 ◽

2021 ◽

Author(s):

Vedat Durmaz ◽

Katharina Köchl ◽

Amit Singh ◽

Michael Hetmann ◽

Lena Parigger ◽

...

Keyword(s):

Binding Affinity ◽

Receptor Binding ◽

Bioinformatics Analysis ◽

Structural Bioinformatics ◽

Binding Energies ◽

Large Set ◽

Wild Type ◽

Linear Interaction ◽

Binding Interface ◽

The Impact

Abstract To date, more than 263 million people have been infected with SARS-CoV-2 during the COVID-19 pandemic. In many countries, the global spread came in several pandemic waves characterized by the emergence of new SARS-CoV-2 variants. Here, we report on a sequence- and structural-bioinformatics analysis by which we estimate the impact of amino acid exchanges on the affinity of the SARS-CoV-2 spike receptor-binding domain (RBD) to the human receptor hACE2. This is carried out by qualitative electrostatics and hydrophobicity analysis as well as through molecular dynamics simulations used for the development of a highly accurate linear interaction energy (LIE) binding affinity model that was calibrated on a large set of experimental binding energies. For the newest variant of concern (VOC), B.1.1.529 Omicron, our Halo difference point cloud studies reveal the largest impact on the RBD binding interface compared to any other VOC. Moreover, according to our LIE model, Omicron achieved a substantially higher ACE2 binding affinity than the wild-type and in particular the highest among all VOCs except for Alpha and therefore requires special attention and monitoring. Using this prediction model we provide early structural insight and binding properties before experimentally determined complex structures and binding affinity data become available in the upcoming months.

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Mutations in the B.1.1.7 SARS-CoV-2 spike protein reduce receptor-binding affinity and induce a flexible link to the fusion peptide

10.1101/2021.04.06.438584 ◽

2021 ◽

Author(s):

Eileen Socher ◽

Marcus Conrad ◽

Lukas Heger ◽

Friedrich Paulsen ◽

Heinrich Sticht ◽

...

Keyword(s):

Amino Acid ◽

Binding Affinity ◽

Receptor Binding ◽

Fusion Peptide ◽

Cell Surface Receptor ◽

Spike Protein ◽

Single Amino Acid ◽

Wild Type Virus ◽

Wild Type ◽

Linear Interaction

AbstractThe B.1.1.7 variant of the SARS-CoV-2 virus shows enhanced infectiousness over the wild type virus, leading to increasing patient numbers in affected areas. A number of single amino acid exchanges and deletions within the trimeric viral spike protein characterize this new SARS-CoV-2 variant. Crucial for viral entry into the host cell is the interaction of the spike protein with the cell surface receptor angiotensin-converting enzyme 2 (ACE2) as well as integration of the viral fusion peptide into the host membrane. Respective amino acid exchanges within the SARS-CoV-2 variant B.1.1.7 affect inter-monomeric contact sites within the spike protein (A570D and D614G) as well as the ACE2-receptor interface region (N501Y), which comprises the receptor-binding domain (RBD) of the viral spike protein. However, the molecular consequences of mutations within B.1.1.7 on spike protein dynamics and stability, the fusion peptide, and ACE2 binding are largely unknown. Here, molecular dynamics simulations comparing SARS-CoV-2 wild type with the B.1.1.7 variant revealed inter-trimeric contact rearrangements, altering the structural flexibility within the spike protein trimer. In addition to reduced flexibility in the N-terminal domain of the spike protein, we found increased flexibility in direct spatial proximity of the fusion peptide. This increase in flexibility is due to salt bridge rearrangements induced by the D614G mutation in B.1.1.7 found in pre- and post-cleavage state at the S2’ site. Our results also imply a reduced binding affinity for B.1.1.7 with ACE2, as the N501Y mutation restructures the RBD-ACE2 interface, significantly decreasing the linear interaction energy between the RBD and ACE2.Our results demonstrate how mutations found within B.1.1.7 enlarge the flexibility around the fusion peptide and change the RBD-ACE2 interface, which, in combination, might explain the higher infectivity of B.1.1.7. We anticipate our findings to be starting points for in depth biochemical and cell biological analyses of B.1.1.7, but also other highly contagious SARS-CoV-2 variants, as many of them likewise exhibit a combination of the D614G and N501Y mutation.

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Mutations in the B.1.1.7 SARS-CoV-2 Spike Protein Reduce Receptor-Binding Affinity and Induce a Flexible Link to the Fusion Peptide

Biomedicines ◽

10.3390/biomedicines9050525 ◽

2021 ◽

Vol 9 (5) ◽

pp. 525

Author(s):

Eileen Socher ◽

Marcus Conrad ◽

Lukas Heger ◽

Friedrich Paulsen ◽

Heinrich Sticht ◽

...

Keyword(s):

Binding Affinity ◽

Receptor Binding ◽

Salt Bridge ◽

Fusion Peptide ◽

Spike Protein ◽

Spatial Proximity ◽

Wild Type Virus ◽

Wild Type ◽

Protein Variant ◽

Linear Interaction

The B.1.1.7 variant of the SARS-CoV-2 virus shows enhanced infectiousness over the wild type virus, leading to increasing patient numbers in affected areas. Amino acid exchanges within the SARS-CoV-2 spike protein variant of B.1.1.7 affect inter-monomeric contact sites within the trimer (A570D and D614G) as well as the ACE2-receptor interface region (N501Y), which comprises the receptor-binding domain (RBD) of the spike protein. However, the molecular consequences of mutations within B.1.1.7 on spike protein dynamics and stability or ACE2 binding are largely unknown. Here, molecular dynamics simulations comparing SARS-CoV-2 wild type with the B.1.1.7 variant revealed inter-trimeric contact rearrangements, altering the structural flexibility within the spike protein trimer. Furthermore, we found increased flexibility in direct spatial proximity of the fusion peptide due to salt bridge rearrangements induced by the D614G mutation in B.1.1.7. This study also implies a reduced binding affinity for B.1.1.7 with ACE2, as the N501Y mutation restructures the RBD–ACE2 interface, significantly decreasing the linear interaction energy between the RBD and ACE2. Our results demonstrate how mutations found within B.1.1.7 enlarge the flexibility around the fusion peptide and change the RBD–ACE2 interface. We anticipate our findings to be starting points for in depth biochemical and cell biological analyses of B.1.1.7.

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Design of a companion bioinformatic tool to detect the emergence and geographical distribution of SARS-CoV-2 Spike protein genetic variants

Journal of Translational Medicine ◽

10.1186/s12967-020-02675-4 ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Alice Massacci ◽

Eleonora Sperandio ◽

Lorenzo D’Ambrosio ◽

Mariano Maffei ◽

Fabio Palombo ◽

...

Keyword(s):

Receptor Binding ◽

Consensus Sequence ◽

Cell Epitope ◽

Vaccine Design ◽

Binding Domain ◽

Spike Protein ◽

Antibody Activity ◽

Binding Motif ◽

Receptor Binding Domain ◽

The Impact

Abstract Background Tracking the genetic variability of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) is a crucial challenge. Mainly to identify target sequences in order to generate robust vaccines and neutralizing monoclonal antibodies, but also to track viral genetic temporal and geographic evolution and to mine for variants associated with reduced or increased disease severity. Several online tools and bioinformatic phylogenetic analyses have been released, but the main interest lies in the Spike protein, which is the pivotal element of current vaccine design, and in the Receptor Binding Domain, that accounts for most of the neutralizing the antibody activity. Methods Here, we present an open-source bioinformatic protocol, and a web portal focused on SARS-CoV-2 single mutations and minimal consensus sequence building as a companion vaccine design tool. Furthermore, we provide immunogenomic analyses to understand the impact of the most frequent RBD variations. Results Results on the whole GISAID sequence dataset at the time of the writing (October 2020) reveals an emerging mutation, S477N, located on the central part of the Spike protein Receptor Binding Domain, the Receptor Binding Motif. Immunogenomic analyses revealed some variation in mutated epitope MHC compatibility, T-cell recognition, and B-cell epitope probability for most frequent human HLAs. Conclusions This work provides a framework able to track down SARS-CoV-2 genomic variability.

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The Impact on Infectivity and Neutralization Efficiency of SARS-CoV-2 Lineage B.1.351 Pseudovirus

Viruses ◽

10.3390/v13040633 ◽

2021 ◽

Vol 13 (4) ◽

pp. 633

Author(s):

Yeong Jun Kim ◽

Ui Soon Jang ◽

Sandrine M. Soh ◽

Joo-Youn Lee ◽

Hye-Ra Lee

Keyword(s):

South Africa ◽

Monoclonal Antibodies ◽

Cell Fusion ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Receptor Binding Domain ◽

Viral Spread ◽

New Variant ◽

Global Concern ◽

The Impact

A new variant of SARS-CoV-2 B.1.351 lineage (first found in South Africa) has been raising global concern due to its harboring of multiple mutations in the spike that potentially increase transmissibility and yield resistance to neutralizing antibodies. We here tested infectivity and neutralization efficiency of SARS-CoV-2 spike pseudoviruses bearing particular mutations of the receptor-binding domain (RBD) derived either from the Wuhan strains (referred to as D614G or with other sites) or the B.1.351 lineage (referred to as N501Y, K417N, and E484K). The three different pseudoviruses B.1.351 lineage related significantly increased infectivity compared with other mutants that indicated Wuhan strains. Interestingly, K417N and E484K mutations dramatically enhanced cell–cell fusion than N501Y even though their infectivity were similar, suggesting that K417N and E484K mutations harboring SARS-CoV-2 variant might be more transmissible than N501Y mutation containing SARS-CoV-2 variant. We also investigated the efficacy of two different monoclonal antibodies, Casirivimab and Imdevimab that neutralized SARS-CoV-2, against several kinds of pseudoviruses which indicated Wuhan or B.1.351 lineage. Remarkably, Imdevimab effectively neutralized B.1.351 lineage pseudoviruses containing N501Y, K417N, and E484K mutations, while Casirivimab partially affected them. Overall, our results underscore the importance of B.1.351 lineage SARS-CoV-2 in the viral spread and its implication for antibody efficacy.

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Phycobilins as Potent Food Bioactive Broad-Spectrum Inhibitors Against Proteases of SARS-CoV-2 and Other Coronaviruses: A Preliminary Study

Frontiers in Microbiology ◽

10.3389/fmicb.2021.645713 ◽

2021 ◽

Vol 12 ◽

Author(s):

Brahmaiah Pendyala ◽

Ankit Patras ◽

Chandravanu Dash

Keyword(s):

Binding Affinity ◽

Broad Spectrum ◽

In Silico ◽

Research Area ◽

Therapeutic Drug ◽

Inhibitor Activity ◽

Current Vaccine ◽

Mutant Strains ◽

The Impact

In the 21st century, we have witnessed three coronavirus outbreaks: SARS in 2003, MERS in 2012, and the ongoing pandemic coronavirus disease 2019 (COVID-19). The search for efficient vaccines and development and repurposing of therapeutic drugs are the major approaches in the COVID-19 pandemic research area. There are concerns about the evolution of mutant strains (e.g., VUI – 202012/01, a mutant coronavirus in the United Kingdom), which can potentially reduce the impact of the current vaccine and therapeutic drug development trials. One promising approach to counter the mutant strains is the “development of effective broad-spectrum antiviral drugs” against coronaviruses. This study scientifically investigates potent food bioactive broad-spectrum antiviral compounds by targeting main protease (Mpro) and papain-like protease (PLpro) proteases of coronaviruses (CoVs) using in silico and in vitro approaches. The results reveal that phycocyanobilin (PCB) shows potential inhibitor activity against both proteases. PCB had the best binding affinity to Mpro and PLpro with IC50 values of 71 and 62 μm, respectively. Also, in silico studies with Mpro and PLpro enzymes of other human and animal CoVs indicate broad-spectrum inhibitor activity of the PCB. As with PCB, other phycobilins, such as phycourobilin (PUB), phycoerythrobilin (PEB), and phycoviolobilin (PVB) show similar binding affinity to SARS-CoV-2 Mpro and PLpro.

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

eLife ◽

10.7554/elife.61552 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 1

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.

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P219L substitution in human D-amino acid oxidase impacts the ligand binding and catalytic efficiency

The Journal of Biochemistry ◽

10.1093/jb/mvaa083 ◽

2020 ◽

Vol 168 (5) ◽

pp. 557-567

Author(s):

Wanitcha Rachadech ◽

Yusuke Kato ◽

Rabab M Abou El-Magd ◽

Yuji Shishido ◽

Soo Hyeon Kim ◽

...

Keyword(s):

Amino Acid ◽

Conformational Changes ◽

Active Site ◽

Structural Changes ◽

Catalytic Efficiency ◽

Acid Oxidase ◽

Wild Type ◽

Amino Acid Oxidase ◽

Adenine Ring ◽

The Impact

Abstract Human D-amino acid oxidase (DAO) is a flavoenzyme that is implicated in neurodegenerative diseases. We investigated the impact of replacement of proline with leucine at Position 219 (P219L) in the active site lid of human DAO on the structural and enzymatic properties, because porcine DAO contains leucine at the corresponding position. The turnover numbers (kcat) of P219L were unchanged, but its Km values decreased compared with wild-type, leading to an increase in the catalytic efficiency (kcat/Km). Moreover, benzoate inhibits P219L with lower Ki value (0.7–0.9 µM) compared with wild-type (1.2–2.0 µM). Crystal structure of P219L in complex with flavin adenine dinucleotide (FAD) and benzoate at 2.25 Å resolution displayed conformational changes of the active site and lid. The distances between the H-bond-forming atoms of arginine 283 and benzoate and the relative position between the aromatic rings of tyrosine 224 and benzoate were changed in the P219L complex. Taken together, the P219L substitution leads to an increase in the catalytic efficiency and binding affinity for substrates/inhibitors due to these structural changes. Furthermore, an acetic acid was located near the adenine ring of FAD in the P219L complex. This study provides new insights into the structure–function relationship of human DAO.

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