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1.
J Proteome Res ; 19(4): 1351-1360, 2020 04 03.
Article in English | MEDLINE | ID: covidwho-688546

ABSTRACT

As the infection of 2019-nCoV coronavirus is quickly developing into a global pneumonia epidemic, the careful analysis of its transmission and cellular mechanisms is sorely needed. In this Communication, we first analyzed two recent studies that concluded that snakes are the intermediate hosts of 2019-nCoV and that the 2019-nCoV spike protein insertions share a unique similarity to HIV-1. However, the reimplementation of the analyses, built on larger scale data sets using state-of-the-art bioinformatics methods and databases, presents clear evidence that rebuts these conclusions. Next, using metagenomic samples from Manis javanica, we assembled a draft genome of the 2019-nCoV-like coronavirus, which shows 73% coverage and 91% sequence identity to the 2019-nCoV genome. In particular, the alignments of the spike surface glycoprotein receptor binding domain revealed four times more variations in the bat coronavirus RaTG13 than in the Manis coronavirus compared with 2019-nCoV, suggesting the pangolin as a missing link in the transmission of 2019-nCoV from bats to human.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/virology , Genome, Viral/genetics , Host-Pathogen Interactions , Models, Molecular , Pneumonia, Viral/virology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Animals , Betacoronavirus/classification , Eutheria/virology , HIV-1/genetics , Humans , Metagenome , Pandemics , Protein Structure, Tertiary , Sequence Alignment , Sequence Analysis, Protein , Snakes/virology
2.
J Transl Med ; 18(1): 275, 2020 07 07.
Article in English | MEDLINE | ID: covidwho-655214

ABSTRACT

BACKGROUND: The Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) outbreak originating in Wuhan, China, has raised global health concerns and the pandemic has now been reported on all inhabited continents. Hitherto, no antiviral drug is available to combat this viral outbreak. METHODS: Keeping in mind the urgency of the situation, the current study was designed to devise new strategies for drug discovery and/or repositioning against SARS-CoV-2. In the current study, RNA-dependent RNA polymerase (RdRp), which regulates viral replication, is proposed as a potential therapeutic target to inhibit viral infection. RESULTS: Evolutionary studies of whole-genome sequences of SARS-CoV-2 represent high similarity (> 90%) with other SARS viruses. Targeting the RdRp active sites, ASP760 and ASP761, by antiviral drugs could be a potential therapeutic option for inhibition of coronavirus RdRp, and thus viral replication. Target-based virtual screening and molecular docking results show that the antiviral Galidesivir and its structurally similar compounds have shown promise against SARS-CoV-2. CONCLUSIONS: The anti-polymerase drugs predicted here-CID123624208 and CID11687749-may be considered for in vitro and in vivo clinical trials.


Subject(s)
Betacoronavirus/enzymology , Computational Biology , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Molecular Targeted Therapy , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , RNA Replicase/metabolism , Amino Acid Sequence , Betacoronavirus/isolation & purification , Drug Evaluation, Preclinical , Evolution, Molecular , Humans , Ligands , Molecular Docking Simulation , Pandemics , Phylogeny , RNA Replicase/chemistry , Thermodynamics
3.
J Transl Med ; 18(1): 281, 2020 07 10.
Article in English | MEDLINE | ID: covidwho-639103

ABSTRACT

BACKGROUND: The recent outbreak by SARS-CoV-2 has generated a chaos in global health and economy and claimed/infected a large number of lives. Closely resembling with SARS CoV, the present strain has manifested exceptionally higher degree of spreadability, virulence and stability possibly due to some unidentified mutations. The viral spike glycoprotein is very likely to interact with host Angiotensin-Converting Enzyme 2 (ACE2) and transmits its genetic materials and hijacks host machinery with extreme fidelity for self propagation. Few attempts have been made to develop a suitable vaccine or ACE2 blocker or virus-receptor inhibitor within this short period of time. METHODS: Here, attempt was taken to develop some therapeutic and vaccination strategies with a comparison of spike glycoproteins among SARS-CoV, MERS-CoV and the SARS-CoV-2. We verified their structure quality (SWISS-MODEL, Phyre2, and Pymol) topology (ProFunc), motifs (MEME Suite, GLAM2Scan), gene ontology based conserved domain (InterPro database) and screened several epitopes (SVMTrip) of SARS CoV-2 based on their energetics, IC50 and antigenicity with regard to their possible glycosylation and MHC/paratope binding (Vaxigen v2.0, HawkDock, ZDOCK Server) effects. RESULTS: We screened here few pairs of spike protein epitopic regions and selected their energetic, Inhibitory Concentration50 (IC50), MHC II reactivity and found some of those to be very good target for vaccination. A possible role of glycosylation on epitopic region showed profound effects on epitopic recognition. CONCLUSION: The present work might be helpful for the urgent development of a suitable vaccination regimen against SARS CoV-2.


Subject(s)
Betacoronavirus/immunology , Computational Biology/methods , Coronavirus Infections/immunology , Coronavirus Infections/virology , Epitopes/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/immunology , Amino Acid Motifs , Amino Acid Sequence , Conserved Sequence , Coronavirus Infections/prevention & control , Glycosylation , Histocompatibility Antigens Class II/metabolism , Humans , Inhibitory Concentration 50 , Molecular Sequence Annotation , Pandemics , Protein Structure, Secondary , Spike Glycoprotein, Coronavirus/chemistry
4.
Chaos ; 30(6): 061102, 2020 Jun.
Article in English | MEDLINE | ID: covidwho-628595

ABSTRACT

There is an urgent necessity of effective medication against severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), which is producing the COVID-19 pandemic across the world. Its main protease (Mpro) represents an attractive pharmacological target due to its involvement in essential viral functions. The crystal structure of free Mpro shows a large structural resemblance with the main protease of SARS CoV (nowadays known as SARS CoV-1). Here, we report that average SARS CoV-2 Mpro is 1900% more sensitive than SARS CoV-1 Mpro in transmitting tiny structural changes across the whole protein through long-range interactions. The largest sensitivity of Mpro to structural perturbations is located exactly around the catalytic site Cys-145 and coincides with the binding site of strong inhibitors. These findings, based on a simplified representation of the protein as a residue network, may help in designing potent inhibitors of SARS CoV-2 Mpro.


Subject(s)
Betacoronavirus/metabolism , Catalytic Domain/drug effects , Coronavirus Infections/drug therapy , Cysteine Endopeptidases/metabolism , Pneumonia, Viral/drug therapy , Protease Inhibitors/pharmacology , Viral Nonstructural Proteins/metabolism , Amino Acid Sequence , Binding Sites/drug effects , Crystallography, X-Ray , Cysteine Endopeptidases/drug effects , Drug Design , Humans , Pandemics , SARS Virus/metabolism , Viral Nonstructural Proteins/drug effects
5.
Microbes Infect ; 22(4-5): 221-225, 2020.
Article in English | MEDLINE | ID: covidwho-627037

ABSTRACT

SARS-CoV-2, the newly identified human coronavirus causing severe pneumonia pandemic, was probably originated from Chinese horseshoe bats. However, direct transmission of the virus from bats to humans is unlikely due to lack of direct contact, implying the existence of unknown intermediate hosts. Angiotensin converting enzyme 2 (ACE2) is the receptor of SARS-CoV-2, but only ACE2s of certain species can be utilized by SARS-CoV-2. Here, we evaluated and ranked the receptor-utilizing capability of ACE2s from various species by phylogenetic clustering and sequence alignment with the currently known ACE2s utilized by SARS-CoV-2. As a result, we predicted that SARS-CoV-2 tends to utilize ACE2s of various mammals, except murines, and some birds, such as pigeon. This prediction may help to screen the intermediate hosts of SARS-CoV-2.


Subject(s)
Betacoronavirus/metabolism , Birds/metabolism , Coronavirus Infections/virology , Mammals/metabolism , Peptidyl-Dipeptidase A/genetics , Pneumonia, Viral/virology , Amino Acid Sequence , Animals , Humans , Pandemics , Phylogeny , Protein Conformation , Species Specificity
6.
J Virol ; 94(13)2020 06 16.
Article in English | MEDLINE | ID: covidwho-603623

ABSTRACT

Genetic variability across the three major histocompatibility complex (MHC) class I genes (human leukocyte antigen A [HLA-A], -B, and -C genes) may affect susceptibility to and severity of the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19). We performed a comprehensive in silico analysis of viral peptide-MHC class I binding affinity across 145 HLA-A, -B, and -C genotypes for all SARS-CoV-2 peptides. We further explored the potential for cross-protective immunity conferred by prior exposure to four common human coronaviruses. The SARS-CoV-2 proteome was successfully sampled and was represented by a diversity of HLA alleles. However, we found that HLA-B*46:01 had the fewest predicted binding peptides for SARS-CoV-2, suggesting that individuals with this allele may be particularly vulnerable to COVID-19, as they were previously shown to be for SARS (M. Lin, H.-T. Tseng, J. A. Trejaut, H.-L. Lee, et al., BMC Med Genet 4:9, 2003, https://bmcmedgenet.biomedcentral.com/articles/10.1186/1471-2350-4-9). Conversely, we found that HLA-B*15:03 showed the greatest capacity to present highly conserved SARS-CoV-2 peptides that are shared among common human coronaviruses, suggesting that it could enable cross-protective T-cell-based immunity. Finally, we reported global distributions of HLA types with potential epidemiological ramifications in the setting of the current pandemic.IMPORTANCE Individual genetic variation may help to explain different immune responses to a virus across a population. In particular, understanding how variation in HLA may affect the course of COVID-19 could help identify individuals at higher risk from the disease. HLA typing can be fast and inexpensive. Pairing HLA typing with COVID-19 testing where feasible could improve assessment of severity of viral disease in the population. Following the development of a vaccine against SARS-CoV-2, the virus that causes COVID-19, individuals with high-risk HLA types could be prioritized for vaccination.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/virology , Histocompatibility Testing/methods , Pneumonia, Viral/virology , Amino Acid Sequence , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Epitopes, T-Lymphocyte/immunology , Genetic Variation , Genotype , Haplotypes , Histocompatibility Antigens Class I/genetics , Histocompatibility Antigens Class I/immunology , Humans , Immunity, Innate/immunology , Pandemics , Pneumonia, Viral/immunology , T-Lymphocytes/immunology
7.
J Chin Med Assoc ; 83(6): 537-543, 2020 06.
Article in English | MEDLINE | ID: covidwho-601886

ABSTRACT

BACKGROUND: China announced an outbreak of new coronavirus in the city of Wuhan on December 31, 2019; lash to now, the virus transmission has become pandemic worldwide. Severe cases from the Huanan Seafood Wholesale market in Wuhan were confirmed pneumonia with a novel coronavirus (2019-nCoV). Understanding the molecular mechanisms of genome selection and packaging is critical for developing antiviral strategies. Thus, we defined the correlation in 10 severe acute respiratory syndrome coronavirus (SARS-CoV2) sequences from different countries to analyze the genomic patterns of disease origin and evolution aiming for developing new control pandemic processes. METHODS: We apply genomic analysis to observe SARS-CoV2 sequences from GenBank (http://www.ncbi.nim.nih.gov/genebank/): MN 908947 (China, C1), MN985325 (USA: WA, UW), MN996527 (China, C2), MT007544 (Australia: Victoria, A1), MT027064 (USA: CA, UC), MT039890 (South Korea, K1), MT066175 (Taiwan, T1), MT066176 (Taiwan, T2), LC528232 (Japan, J1), and LC528233 (Japan, J2) for genomic sequence alignment analysis. Multiple Sequence Alignment by Clustalw (https://www.genome.jp/tools-bin/clustalw) web service is applied as our alignment tool. RESULTS: We analyzed 10 sequences from the National Center for Biotechnology Information (NCBI) database by genome alignment and found no difference in amino acid sequences within M and N proteins. There are two amino acid variances in the spike (S) protein region. One mutation found from the South Korea sequence is verified. Two possible "L" and "S" SNPs found in ORF1ab and ORF8 regions are detected. CONCLUSION: We performed genomic analysis and comparative multiple sequences of SARS-CoV2. Studies about the biological symptoms of SARS-CoV2 in clinic animals and humans will manipulate an understanding on the origin of pandemic crisis.


Subject(s)
Betacoronavirus/genetics , Genome, Viral , Amino Acid Sequence , Polymorphism, Single Nucleotide , Sequence Alignment , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics
8.
Aging (Albany NY) ; 12(12): 11263-11276, 2020 06 16.
Article in English | MEDLINE | ID: covidwho-601536

ABSTRACT

The outbreak of COVID-19 has now become a global pandemic that has severely impacted lives and economic stability. There is, however, no effective antiviral drug that can be used to treat COVID-19 to date. Built on the fact that SARS-CoV-2 initiates its entry into human cells by the receptor binding domain (RBD) of its spike protein binding to the angiotensin-converting enzyme 2 (hACE2), we extended a recently developed approach, EvoDesign, to design multiple peptide sequences that can competitively bind to the SARS-CoV-2 RBD to inhibit the virus from entering human cells. The protocol starts with the construction of a hybrid peptidic scaffold by linking two fragments grafted from the interface of the hACE2 protein (a.a. 22-44 and 351-357) with a linker glycine, which is followed by the redesign and refinement simulations of the peptide sequence to optimize its binding affinity to the interface of the SARS-CoV-2 RBD. The binding experiment analyses showed that the designed peptides exhibited a significantly stronger binding potency to hACE2 than the wild-type hACE2 receptor (with -53.35 vs. -46.46 EvoEF2 energy unit scores for the top designed and wild-type peptides, respectively). This study demonstrates a new avenue to utilize computationally designed peptide motifs to treat the COVID-19 disease by blocking the critical spike-RBD and hACE2 interactions.


Subject(s)
Coronavirus Infections/drug therapy , Peptides/chemical synthesis , Peptides/pharmacology , Peptidyl-Dipeptidase A/physiology , Pneumonia, Viral/drug therapy , Spike Glycoprotein, Coronavirus/physiology , Amino Acid Sequence , Antiviral Agents , Binding Sites , Drug Design , Evolution, Molecular , Humans , Models, Molecular , Pandemics , Protein Binding , Protein Conformation , Virus Internalization/drug effects
9.
Viruses ; 12(6)2020 06 15.
Article in English | MEDLINE | ID: covidwho-598456

ABSTRACT

As more cases of COVID-19 are studied and treated worldwide, it had become apparent that the lethal and most severe cases of pneumonia are due to an out-of-control inflammatory response to the SARS-CoV-2 virus. I explored the putative causes of this specific feature through a detailed genomic comparison with the closest SARS-CoV-2 relatives isolated from bats, as well as previous coronavirus strains responsible for the previous epidemics (SARS-CoV and MERS-CoV). The high variability region of the nsp3 protein was confirmed to exhibit the most variations between closest strains. It was then studied in the context of physiological and molecular data available in the literature. A number of convergent findings suggest de-mono-ADP-ribosylation (de-MARylation) of STAT1 by the SARS-CoV-2 nsp3 as a putative cause of the cytokine storm observed in the most severe cases of COVID-19. This may suggest new therapeutic approaches and help in designing assays to predict the virulence of naturally circulating SARS-like animal coronaviruses.


Subject(s)
ADP-Ribosylation/physiology , Betacoronavirus/genetics , Cytokine Release Syndrome/pathology , STAT1 Transcription Factor/metabolism , Viral Nonstructural Proteins/metabolism , Amino Acid Sequence/genetics , Coronavirus Infections/pathology , Humans , Inflammation/pathology , Inflammation/virology , Middle East Respiratory Syndrome Coronavirus/genetics , Pandemics , Peptidyl-Dipeptidase A/biosynthesis , Peptidyl-Dipeptidase A/genetics , Pneumonia, Viral/pathology , SARS Virus/genetics , Sequence Homology , Viral Nonstructural Proteins/genetics
12.
Vaccine ; 38(32): 5071-5075, 2020 07 06.
Article in English | MEDLINE | ID: covidwho-592568

ABSTRACT

SARS-CoV-2 is the cause of the worldwide outbreak of COVID-19 that has been characterized as a pandemic by the WHO. Since the first report of COVID-19 on December 31, 2019, 179,111 cases were confirmed in 160 countries/regions with 7426 deaths as of March 17, 2020. However, there have been no vaccines approved in the world to date. In this study, we analyzed the biological characteristics of the SARS-CoV-2 Spike protein, Pro330-Leu650 (SARS-CoV-2-SPL), using biostatistical methods. SARS-CoV-2-SPL possesses a receptor-binding region (RBD) and important B (Ser438-Gln506, Thr553-Glu583, Gly404-Aps427, Thr345-Ala352, and Lys529-Lys535) and T (9 CD4 and 11 CD8 T cell antigenic determinants) cell epitopes. High homology in this region between SARS-CoV-2 and SARS-CoV amounted to 87.7%, after taking the biological similarity of the amino acids into account and eliminating the receptor-binding motif (RBM). The overall topology indicated that the complete structure of SARS-CoV-2-SPL was with RBM as the head, and RBD as the trunk and the tail region. SARS-CoV-2-SPL was found to have the potential to elicit effective B and T cell responses. Our findings may provide meaningful guidance for SARS-CoV-2 vaccine design.


Subject(s)
Betacoronavirus/chemistry , Drug Design , Models, Immunological , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/chemistry , Viral Vaccines/immunology , Amino Acid Sequence , Antigens, Viral/chemistry , Antigens, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/immunology , Humans , Models, Molecular , Pandemics/prevention & control , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Pneumonia, Viral/prevention & control , Pneumonia, Viral/virology , Sequence Alignment , Vaccines, Subunit/chemistry , Vaccines, Subunit/immunology
13.
Viruses ; 12(6)2020 06 03.
Article in English | MEDLINE | ID: covidwho-532726

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory illness in humans; the second-largest and most deadly outbreak to date occurred in Saudi Arabia. The dromedary camel is considered a possible host of the virus and also to act as a reservoir, transmitting the virus to humans. Here, we studied evolutionary relationships for 31 complete genomes of betacoronaviruses, including eight newly sequenced MERS-CoV genomes isolated from dromedary camels in Saudi Arabia. Through bioinformatics tools, we also used available sequences and 3D structure of MERS-CoV spike glycoprotein to predict MERS-CoV epitopes and assess antibody binding affinity. Phylogenetic analysis showed the eight new sequences have close relationships with existing strains detected in camels and humans in Arabian Gulf countries. The 2019-nCov strain appears to have higher homology to both bat coronavirus and SARS-CoV than to MERS-CoV strains. The spike protein tree exhibited clustering of MERS-CoV sequences similar to the complete genome tree, except for one sequence from Qatar (KF961222). B cell epitope analysis determined that the MERS-CoV spike protein has 24 total discontinuous regions from which just six epitopes were selected with score values of >80%. Our results suggest that the virus circulates by way of camels crossing the borders of Arabian Gulf countries. This study contributes to finding more effective vaccines in order to provide long-term protection against MERS-CoV and identifying neutralizing antibodies.


Subject(s)
Camelus/virology , Coronavirus Infections/virology , Middle East Respiratory Syndrome Coronavirus/genetics , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Animals , Betacoronavirus/classification , Betacoronavirus/genetics , Betacoronavirus/isolation & purification , Biological Evolution , DNA, Complementary/chemistry , DNA, Viral/chemistry , Epitopes/analysis , Epitopes/chemistry , Epitopes/genetics , Gene Library , Humans , Middle East Respiratory Syndrome Coronavirus/classification , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Phylogeny , RNA, Viral/analysis , RNA, Viral/chemistry , RNA, Viral/isolation & purification , Saudi Arabia
14.
J Virol ; 94(12)2020 06 01.
Article in English | MEDLINE | ID: covidwho-459315

ABSTRACT

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that recently emerged in China is thought to have a bat origin, as its closest known relative (BatCoV RaTG13) was described previously in horseshoe bats. We analyzed the selective events that accompanied the divergence of SARS-CoV-2 from BatCoV RaTG13. To this end, we applied a population genetics-phylogenetics approach, which leverages within-population variation and divergence from an outgroup. Results indicated that most sites in the viral open reading frames (ORFs) evolved under conditions of strong to moderate purifying selection. The most highly constrained sequences corresponded to some nonstructural proteins (nsps) and to the M protein. Conversely, nsp1 and accessory ORFs, particularly ORF8, had a nonnegligible proportion of codons evolving under conditions of very weak purifying selection or close to selective neutrality. Overall, limited evidence of positive selection was detected. The 6 bona fide positively selected sites were located in the N protein, in ORF8, and in nsp1. A signal of positive selection was also detected in the receptor-binding motif (RBM) of the spike protein but most likely resulted from a recombination event that involved the BatCoV RaTG13 sequence. In line with previous data, we suggest that the common ancestor of SARS-CoV-2 and BatCoV RaTG13 encoded/encodes an RBM similar to that observed in SARS-CoV-2 itself and in some pangolin viruses. It is presently unknown whether the common ancestor still exists and, if so, which animals it infects. Our data, however, indicate that divergence of SARS-CoV-2 from BatCoV RaTG13 was accompanied by limited episodes of positive selection, suggesting that the common ancestor of the two viruses was poised for human infection.IMPORTANCE Coronaviruses are dangerous zoonotic pathogens; in the last 2 decades, three coronaviruses have crossed the species barrier and caused human epidemics. One of these is the recently emerged SARS-CoV-2. We investigated how, since its divergence from a closely related bat virus, natural selection shaped the genome of SARS-CoV-2. We found that distinct coding regions in the SARS-CoV-2 genome evolved under conditions of different degrees of constraint and are consequently more or less prone to tolerate amino acid substitutions. In practical terms, the level of constraint provides indications about which proteins/protein regions are better suited as possible targets for the development of antivirals or vaccines. We also detected limited signals of positive selection in three viral ORFs. However, we warn that, in the absence of knowledge about the chain of events that determined the human spillover, these signals should not be necessarily interpreted as evidence of an adaptation to our species.


Subject(s)
Betacoronavirus/genetics , Evolution, Molecular , Selection, Genetic , Amino Acid Sequence , Animals , Betacoronavirus/classification , Chiroptera/virology , Coronavirus Infections/virology , Genome, Viral/genetics , Humans , Models, Molecular , Open Reading Frames/genetics , Pandemics , Phylogeny , Pneumonia, Viral/virology , Viral Proteins/chemistry , Viral Proteins/genetics
15.
Nat Commun ; 11(1): 2806, 2020 06 01.
Article in English | MEDLINE | ID: covidwho-459009

ABSTRACT

Given the ongoing SARS-CoV-2 pandemic, identification of immunogenic targets against the coronavirus spike glycoprotein will provide crucial advances towards the development of sensitive diagnostic tools and potential vaccine candidate targets. In this study, using pools of overlapping linear B-cell peptides, we report two IgG immunodominant regions on SARS-CoV-2 spike glycoprotein that are recognised by sera from COVID-19 convalescent patients. Notably, one is specific to SARS-CoV-2, which is located in close proximity to the receptor binding domain. The other region, which is localised at the fusion peptide, could potentially function as a pan-SARS target. Functionally, antibody depletion assays demonstrate that antibodies targeting these immunodominant regions significantly alter virus neutralisation capacities. Taken together, identification and validation of these neutralising B-cell epitopes will provide insights towards the design of diagnostics and vaccine candidates against this high priority coronavirus.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/immunology , Amino Acid Sequence , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Coronavirus Infections/blood , Epitopes, B-Lymphocyte , Humans , Immunodominant Epitopes , Immunoglobulin G/blood , Pandemics , Pneumonia, Viral/blood , Spike Glycoprotein, Coronavirus/chemistry
16.
BMC Mol Cell Biol ; 21(1): 49, 2020 Jul 01.
Article in English | MEDLINE | ID: covidwho-619133

ABSTRACT

BACKGROUND: Following the recent outbreak of the new coronavirus pandemic (Covid-19), the rapid determination of the structure of the homo-trimeric spike glycoprotein has prompted the study reported here. The aims were to identify potential "druggable" binding pockets in the protein and, if located, to virtual screen pharmaceutical agents currently in use for predicted affinity to these pockets which might be useful to restrict, reduce, or inhibit the infectivity of the virion. RESULTS: Our analyses of this structure have revealed a key potentially druggable pocket where it might be viable to bind pharmaceutical agents to inhibit its ability to infect human cells. This pocket is found at the inter-chain interface that exists between two domains prior to the virion binding to human Angiotensin Converting Enzyme 2 (ACE2) protein. One of these domains is the highly mobile receptor binding domain, which must move into position to interact with ACE2, which is an essential feature for viral entry to the host cell. Virtual screening with a library of purchasable drug molecules has identified pharmaceuticals currently in use as prescription and over the counter medications that, in silico, readily bind into this pocket. CONCLUSIONS: This study highlights possible drugs already in use as pharmaceuticals that may act as agents to interfere with the movements of the domains within this protein essential for the infectivity processes and hence might slow, or even halt, the infection of host cells by this new coronavirus. As these are existing pharmaceuticals already approved for use in humans, this knowledge could accelerate their roll-out, through repurposing, for affected individuals and help guide the efforts of other researchers in finding effective treatments for the disease.


Subject(s)
Antiviral Agents/pharmacology , Binding Sites/drug effects , Coronavirus Infections/drug therapy , Drug Repositioning , Pneumonia, Viral/drug therapy , Spike Glycoprotein, Coronavirus/metabolism , Amino Acid Sequence , Betacoronavirus/drug effects , Humans , Pandemics , Peptidyl-Dipeptidase A/metabolism , Protein Domains/drug effects , Spike Glycoprotein, Coronavirus/chemistry , Virus Internalization/drug effects
17.
Biomed Res Int ; 2020: 4389089, 2020.
Article in English | MEDLINE | ID: covidwho-618728

ABSTRACT

The Coronavirus Disease 2019 (COVID-19) is a new viral infection caused by the severe acute respiratory coronavirus 2 (SARS-CoV-2). Genomic analyses have revealed that SARS-CoV-2 is related to Pangolin and Bat coronaviruses. In this report, a structural comparison between the Sars-CoV-2 Envelope and Membrane proteins from different human isolates with homologous proteins from closely related viruses is described. The analyses here reported show the high structural similarity of Envelope and Membrane proteins to the counterparts from Pangolin and Bat coronavirus isolates. However, the comparisons have also highlighted structural differences specific of Sars-CoV-2 proteins which may be correlated to the cross-species transmission and/or to the properties of the virus. Structural modelling has been applied to map the variant sites onto the predicted three-dimensional structure of the Envelope and Membrane proteins.


Subject(s)
Betacoronavirus/chemistry , Coronavirus Infections/virology , Pneumonia, Viral/virology , Viral Envelope Proteins/chemistry , Viral Matrix Proteins/chemistry , Alphacoronavirus/chemistry , Alphacoronavirus/classification , Alphacoronavirus/genetics , Amino Acid Sequence , Animals , Betacoronavirus/classification , Betacoronavirus/genetics , Chiroptera/virology , Coronaviridae/chemistry , Coronaviridae/classification , Coronaviridae/genetics , Eutheria/virology , Humans , Models, Molecular , Pandemics , Protein Conformation , Sequence Homology, Amino Acid , Species Specificity , Structural Homology, Protein , Viral Envelope Proteins/genetics , Viral Matrix Proteins/genetics
18.
Molecules ; 25(11)2020 May 29.
Article in English | MEDLINE | ID: covidwho-436971

ABSTRACT

The coronavirus disease, COVID-19, caused by the novel coronavirus SARS-CoV-2, which first emerged in Wuhan, China and was made known to the World in December 2019 turned into a pandemic causing more than 126,124 deaths worldwide up to April 16th, 2020. It has 79.5% sequence identity with SARS-CoV-1 and the same strategy for host cell invasion through the ACE-2 surface protein. Since the development of novel drugs is a long-lasting process, researchers look for effective substances among drugs already approved or developed for other purposes. The 3D structure of the SARS-CoV-2 main protease was compared with the 3D structures of seven proteases, which are drug targets, and docking analysis to the SARS-CoV-2 protease structure of thirty four approved and on-trial protease inhibitors was performed. Increased 3D structural similarity between the SARS-CoV-2 main protease, the HCV protease and α-thrombin was found. According to docking analysis the most promising results were found for HCV protease, DPP-4, α-thrombin and coagulation Factor Xa known inhibitors, with several of them exhibiting estimated free binding energy lower than -8.00 kcal/mol and better prediction results than reference compounds. Since some of the compounds are well-tolerated drugs, the promising in silico results may warrant further evaluation for viral anticipation. DPP-4 inhibitors with anti-viral action may be more useful for infected patients with diabetes, while anti-coagulant treatment is proposed in severe SARS-CoV-2 induced pneumonia.


Subject(s)
Anticoagulants/chemistry , Antiviral Agents/chemistry , Betacoronavirus/drug effects , Dipeptidyl-Peptidase IV Inhibitors/chemistry , Protease Inhibitors/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Amino Acid Sequence , Anticoagulants/pharmacology , Antiviral Agents/pharmacology , Betacoronavirus/chemistry , Betacoronavirus/enzymology , Betacoronavirus/genetics , Binding Sites , Coronavirus Infections/drug therapy , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Dipeptidyl Peptidase 4/chemistry , Dipeptidyl Peptidase 4/genetics , Dipeptidyl Peptidase 4/metabolism , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Factor Xa/chemistry , Factor Xa/genetics , Factor Xa/metabolism , Hepacivirus/chemistry , Hepacivirus/enzymology , Hepacivirus/genetics , Humans , Molecular Docking Simulation , Pandemics , Pneumonia, Viral/drug therapy , Protease Inhibitors/pharmacology , Protein Binding , Protein Conformation , Protein Interaction Domains and Motifs , Sequence Alignment , Structural Homology, Protein , Substrate Specificity , Thermodynamics , Thrombin/antagonists & inhibitors , Thrombin/chemistry , Thrombin/genetics , Thrombin/metabolism , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
19.
mBio ; 11(3)2020 05 29.
Article in English | MEDLINE | ID: covidwho-432175

ABSTRACT

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was recently identified as the causative agent for the coronavirus disease 2019 (COVID-19) outbreak that has generated a global health crisis. We use a combination of genomic analysis and sensitive profile-based sequence and structure analysis to understand the potential pathogenesis determinants of this virus. As a result, we identify several fast-evolving genomic regions that might be at the interface of virus-host interactions, corresponding to the receptor binding domain of the Spike protein, the three tandem Macro fold domains in ORF1a, and the uncharacterized protein ORF8. Further, we show that ORF8 and several other proteins from alpha- and beta-CoVs belong to novel families of immunoglobulin (Ig) proteins. Among them, ORF8 is distinguished by being rapidly evolving, possessing a unique insert, and having a hypervariable position among SARS-CoV-2 genomes in its predicted ligand-binding groove. We also uncover numerous Ig domain proteins from several unrelated metazoan viruses, which are distinct in sequence and structure but share comparable architectures to those of the CoV Ig domain proteins. Hence, we propose that SARS-CoV-2 ORF8 and other previously unidentified CoV Ig domain proteins fall under the umbrella of a widespread strategy of deployment of Ig domain proteins in animal viruses as pathogenicity factors that modulate host immunity. The rapid evolution of the ORF8 Ig domain proteins points to a potential evolutionary arms race between viruses and hosts, likely arising from immune pressure, and suggests a role in transmission between distinct host species.IMPORTANCE The ongoing COVID-19 pandemic strongly emphasizes the need for a more complete understanding of the biology and pathogenesis of its causative agent SARS-CoV-2. Despite intense scrutiny, several proteins encoded by the genomes of SARS-CoV-2 and other SARS-like coronaviruses remain enigmatic. Moreover, the high infectivity and severity of SARS-CoV-2 in certain individuals make wet-lab studies currently challenging. In this study, we used a series of computational strategies to identify several fast-evolving regions of SARS-CoV-2 proteins which are potentially under host immune pressure. Most notably, the hitherto-uncharacterized protein encoded by ORF8 is one of them. Using sensitive sequence and structural analysis methods, we show that ORF8 and several other proteins from alpha- and beta-coronavirus comprise novel families of immunoglobulin domain proteins, which might function as potential immune modulators to delay or attenuate the host immune response against the viruses.


Subject(s)
Coronavirus/genetics , Coronavirus/pathogenicity , Evolution, Molecular , Viral Proteins/genetics , Virulence Factors/genetics , Amino Acid Sequence , Animals , Betacoronavirus/chemistry , Betacoronavirus/classification , Betacoronavirus/genetics , Betacoronavirus/pathogenicity , Coronavirus/chemistry , Coronavirus/classification , Genome, Viral/genetics , Host Specificity , Humans , Immunoglobulin Domains/genetics , Models, Molecular , Open Reading Frames , Phylogeny , Viral Proteins/chemistry , Virulence Factors/chemistry
20.
Front Biosci (Landmark Ed) ; 25: 1894-1900, 2020 06 01.
Article in English | MEDLINE | ID: covidwho-422434

ABSTRACT

We analyzed the nucleocapsid and surface proteins from several Coronaviridae viruses using an alignment-free computer program. Three isolates of novel, human coronavirus (SARS0CoV-2) (2019) that are responsible for the current pandemic and older SARS strains of human and animal coronaviruses were examined. The nucleocapsid and glycoprotein sequences are identical for the three novel 2019 human isolates and they are closely related to these sequences in six bat and human SARS coronaviruses. This strongly supports the bat origin of the pandemic, novel coronavirus. One surface glycoprotein fragment of 111 amino acids is the largest, conserved, common permutation in the examined bat SARS-like and human SARS viruses, including the Covid-19 virus. BLAST analysis confirmed that this fragment is conserved only in the human and bat SARS strains. This fragment likely is involved in infectivity and is of interest for vaccine development. Surface glycoprotein and nucleocapsid protein sequence homologies of 58.9% and 82.5%, respectively, between the novel SARS0CoV-2 strains and the human SARS (2018) virus suggest that existing anti-SARS vaccines may provide some protection against the novel coronavirus.


Subject(s)
Betacoronavirus/genetics , Coronaviridae/genetics , Coronavirus Infections , Nucleocapsid Proteins/genetics , Pandemics , Pneumonia, Viral , Spike Glycoprotein, Coronavirus/genetics , Algorithms , Amino Acid Sequence , Animals , Chiroptera/virology , Coronaviridae/classification , Genome, Viral/genetics , Humans , Software , Species Specificity , Viral Envelope Proteins/genetics
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