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1.
ACS Chem Neurosci ; 11(22): 3701-3703, 2020 11 18.
Article in English | MEDLINE | ID: covidwho-899862

ABSTRACT

Cell entry, the fundamental step in cross-species transmission of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), is initiated by the recognition of the host cell angiotensin-converting enzyme-2 (ACE2) receptor by the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2. To date, several peptides have been proposed against SARS-CoV-2 both as inhibitor agents or as detection tools that can also be attached to the surfaces of nanoparticle carriers. But owing to their natural amino acid sequences, such peptides cannot be considered as efficient therapeutic candidates from a biostability point of view. This discussion demonstrates the design strategy of synthetic nonprotein amino acid substituted peptides with enhanced biostability and binding affinity, the implication of which can make those peptides potential therapeutic agents for inhibition and simple detection tools.


Subject(s)
Antiviral Agents/therapeutic use , Betacoronavirus , Coronavirus Infections/drug therapy , Drug Design , Peptide Fragments/therapeutic use , Pneumonia, Viral/drug therapy , Amino Acid Sequence , Antiviral Agents/metabolism , Betacoronavirus/drug effects , Betacoronavirus/genetics , Coronavirus Infections/genetics , Coronavirus Infections/metabolism , Humans , Pandemics , Peptide Fragments/genetics , Peptide Fragments/metabolism , Pneumonia, Viral/genetics , Pneumonia, Viral/metabolism , Protein Binding/physiology , Sequence Analysis, Protein/methods
2.
mBio ; 11(6)2020 10 30.
Article in English | MEDLINE | ID: covidwho-894829

ABSTRACT

We sequenced the genomes of 5,085 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains causing two coronavirus disease 2019 (COVID-19) disease waves in metropolitan Houston, TX, an ethnically diverse region with 7 million residents. The genomes were from viruses recovered in the earliest recognized phase of the pandemic in Houston and from viruses recovered in an ongoing massive second wave of infections. The virus was originally introduced into Houston many times independently. Virtually all strains in the second wave have a Gly614 amino acid replacement in the spike protein, a polymorphism that has been linked to increased transmission and infectivity. Patients infected with the Gly614 variant strains had significantly higher virus loads in the nasopharynx on initial diagnosis. We found little evidence of a significant relationship between virus genotype and altered virulence, stressing the linkage between disease severity, underlying medical conditions, and host genetics. Some regions of the spike protein-the primary target of global vaccine efforts-are replete with amino acid replacements, perhaps indicating the action of selection. We exploited the genomic data to generate defined single amino acid replacements in the receptor binding domain of spike protein that, importantly, produced decreased recognition by the neutralizing monoclonal antibody CR3022. Our report represents the first analysis of the molecular architecture of SARS-CoV-2 in two infection waves in a major metropolitan region. The findings will help us to understand the origin, composition, and trajectory of future infection waves and the potential effect of the host immune response and therapeutic maneuvers on SARS-CoV-2 evolution.IMPORTANCE There is concern about second and subsequent waves of COVID-19 caused by the SARS-CoV-2 coronavirus occurring in communities globally that had an initial disease wave. Metropolitan Houston, TX, with a population of 7 million, is experiencing a massive second disease wave that began in late May 2020. To understand SARS-CoV-2 molecular population genomic architecture and evolution and the relationship between virus genotypes and patient features, we sequenced the genomes of 5,085 SARS-CoV-2 strains from these two waves. Our report provides the first molecular characterization of SARS-CoV-2 strains causing two distinct COVID-19 disease waves.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/virology , Pneumonia, Viral/virology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Amino Acid Substitution , Antibodies, Neutralizing/immunology , Base Sequence , Betacoronavirus/immunology , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Genome, Viral , Genotype , Humans , Machine Learning , Models, Molecular , Molecular Diagnostic Techniques , Pandemics , Phylogeny , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , /genetics , Sequence Analysis, Protein , Spike Glycoprotein, Coronavirus/immunology , Texas/epidemiology , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics
3.
Biochemistry ; 59(39): 3741-3756, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-765976

ABSTRACT

The SARS-CoV-2 main protease (Mpro) is essential to viral replication and cleaves highly specific substrate sequences, making it an obvious target for inhibitor design. However, as for any virus, SARS-CoV-2 is subject to constant neutral drift and selection pressure, with new Mpro mutations arising over time. Identification and structural characterization of Mpro variants is thus critical for robust inhibitor design. Here we report sequence analysis, structure predictions, and molecular modeling for seventy-nine Mpro variants, constituting all clinically observed mutations in this protein as of April 29, 2020. Residue substitution is widely distributed, with some tendency toward larger and more hydrophobic residues. Modeling and protein structure network analysis suggest differences in cohesion and active site flexibility, revealing patterns in viral evolution that have relevance for drug discovery.


Subject(s)
Betacoronavirus/enzymology , Betacoronavirus/genetics , Models, Molecular , Mutation , Viral Nonstructural Proteins/genetics , Catalytic Domain , Drug Discovery , Evolution, Molecular , Humans , Molecular Structure , Phylogeny , Protease Inhibitors/chemistry , Sequence Analysis, Protein , Viral Nonstructural Proteins/antagonists & inhibitors
4.
Infect Dis Poverty ; 9(1): 132, 2020 Sep 16.
Article in English | MEDLINE | ID: covidwho-768657

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) linked with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause severe illness and life-threatening pneumonia in humans. The current COVID-19 pandemic demands an effective vaccine to acquire protection against the infection. Therefore, the present study was aimed to design a multiepitope-based subunit vaccine (MESV) against COVID-19. METHODS: Structural proteins (Surface glycoprotein, Envelope protein, and Membrane glycoprotein) of SARS-CoV-2 are responsible for its prime functions. Sequences of proteins were downloaded from GenBank and several immunoinformatics coupled with computational approaches were employed to forecast B- and T- cell epitopes from the SARS-CoV-2 highly antigenic structural proteins to design an effective MESV. RESULTS: Predicted epitopes suggested high antigenicity, conserveness, substantial interactions with the human leukocyte antigen (HLA) binding alleles, and collective global population coverage of 88.40%. Taken together, 276 amino acids long MESV was designed by connecting 3 cytotoxic T lymphocytes (CTL), 6 helper T lymphocyte (HTL) and 4 B-cell epitopes with suitable adjuvant and linkers. The MESV construct was non-allergenic, stable, and highly antigenic. Molecular docking showed a stable and high binding affinity of MESV with human pathogenic toll-like receptors-3 (TLR3). Furthermore, in silico immune simulation revealed significant immunogenic response of MESV. Finally, MEV codons were optimized for its in silico cloning into the Escherichia coli K-12 system, to ensure its increased expression. CONCLUSION: The MESV developed in this study is capable of generating immune response against COVID-19. Therefore, if designed MESV further investigated experimentally, it would be an effective vaccine candidate against SARS-CoV-2 to control and prevent COVID-19.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/immunology , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/immunology , Coronavirus Infections/genetics , Coronavirus Infections/immunology , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/genetics , Epitopes, T-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/genetics , Humans , Immunogenicity, Vaccine/immunology , Molecular Docking Simulation , Pneumonia, Viral/immunology , Sequence Analysis, Protein , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Toll-Like Receptor 3/chemistry , Toll-Like Receptor 3/genetics , Toll-Like Receptor 3/immunology , Vaccines, Subunit/chemistry , Vaccines, Subunit/genetics , Vaccines, Subunit/immunology , Vaccinology/methods , Viral Matrix Proteins/chemistry , Viral Matrix Proteins/genetics , Viral Matrix Proteins/immunology , Viral Vaccines/chemistry , Viral Vaccines/genetics
5.
Int J Biol Macromol ; 162: 820-837, 2020 Nov 01.
Article in English | MEDLINE | ID: covidwho-618504

ABSTRACT

SARS-CoV-2 is the deadly virus behind COVID-19, the disease that went on to ravage the world and caused the biggest pandemic 21st century has witnessed so far. On the face of ongoing death and destruction, the urgent need for the discovery of a vaccine against the virus is paramount. This study resorted to the emerging discipline of immunoinformatics in order to design a multi-epitope mRNA vaccine against the spike glycoprotein of SARS-CoV-2. Various immunoinformatics tools were utilized to predict T and B lymphocyte epitopes. The epitopes were channeled through a filtering pipeline comprised of antigenicity, toxicity, allergenicity, and cytokine inducibility evaluation with the goal of selecting epitopes capable of generating both T and B cell-mediated immune responses. Molecular docking simulation between the epitopes and their corresponding MHC molecules was carried out. 13 epitopes, a highly immunogenic adjuvant, elements for proper sub-cellular trafficking, a secretion booster, and appropriate linkers were combined for constructing the vaccine. The vaccine was found to be antigenic, almost neutral at physiological pH, non-toxic, non-allergenic, capable of generating a robust immune response and had a decent worldwide population coverage. Based on these parameters, this design can be considered a promising choice for a vaccine against SARS-CoV-2.


Subject(s)
Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , RNA, Messenger/immunology , Viral Vaccines/immunology , Betacoronavirus/immunology , Coronavirus Infections/genetics , Coronavirus Infections/immunology , Coronavirus Infections/virology , Drug Design , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/immunology , Humans , Immunogenicity, Vaccine , Molecular Docking Simulation , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Sequence Analysis, Protein , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/chemistry , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Viral Vaccines/chemistry , Viral Vaccines/genetics
6.
J Proteome Res ; 19(11): 4718-4729, 2020 11 06.
Article in English | MEDLINE | ID: covidwho-748160

ABSTRACT

We present METATRYP version 2 software that identifies shared peptides across the predicted proteomes of organisms within environmental metaproteomics studies to enable accurate taxonomic attribution of peptides during protein inference. Improvements include ingestion of complex sequence assembly data categories (metagenomic and metatranscriptomic assemblies, single cell amplified genomes, and metagenome assembled genomes), prediction of the least common ancestor (LCA) for a peptide shared across multiple organisms, increased performance through updates to the backend architecture, and development of a web portal (https://metatryp.whoi.edu). Major expansion of the marine METATRYP database with predicted proteomes from environmental sequencing confirms a low occurrence of shared tryptic peptides among disparate marine microorganisms, implying tractability for targeted metaproteomics. METATRYP was designed to facilitate ocean metaproteomics and has been integrated into the Ocean Protein Portal (https://oceanproteinportal.org); however, it can be readily applied to other domains. We describe the rapid deployment of a coronavirus-specific web portal (https://metatryp-coronavirus.whoi.edu/) to aid in use of proteomics on coronavirus research during the ongoing pandemic. A coronavirus-focused METATRYP database identified potential SARS-CoV-2 peptide biomarkers and indicated very few shared tryptic peptides between SARS-CoV-2 and other disparate taxa analyzed, sharing <1% peptides with taxa outside of the betacoronavirus group, establishing that taxonomic specificity is achievable using tryptic peptide-based proteomic diagnostic approaches.


Subject(s)
Aquatic Organisms/genetics , Coronavirus/genetics , Metagenomics/methods , Proteome , Software , Bacterial Proteins/classification , Bacterial Proteins/genetics , Betacoronavirus/genetics , Cluster Analysis , Coronavirus Infections/virology , Humans , Molecular Sequence Annotation , Pandemics , Peptides/classification , Peptides/genetics , Pneumonia, Viral/virology , Proteome/classification , Proteome/genetics , Sequence Analysis, Protein , Transcriptome/genetics , Viral Proteins/classification , Viral Proteins/genetics
7.
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
8.
J Virol ; 94(15)2020 07 16.
Article in English | MEDLINE | ID: covidwho-661225

ABSTRACT

The emergence of a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulted in a pandemic. Here, we used X-ray structures of human ACE2 bound to the receptor-binding domain (RBD) of the spike protein (S) from SARS-CoV-2 to predict its binding to ACE2 proteins from different animals, including pets, farm animals, and putative intermediate hosts of SARS-CoV-2. Comparing the interaction sites of ACE2 proteins known to serve or not serve as receptors allows the definition of residues important for binding. From the 20 amino acids in ACE2 that contact S, up to 7 can be replaced and ACE2 can still function as the SARS-CoV-2 receptor. These variable amino acids are clustered at certain positions, mostly at the periphery of the binding site, while changes of the invariable residues prevent S binding or infection of the respective animal. Some ACE2 proteins even tolerate the loss or acquisition of N-glycosylation sites located near the S interface. Of note, pigs and dogs, which are not infected or are not effectively infected and have only a few changes in the binding site, exhibit relatively low levels of ACE2 in the respiratory tract. Comparison of the RBD of S of SARS-CoV-2 with that from bat coronavirus strain RaTG13 (Bat-CoV-RaTG13) and pangolin coronavirus (Pangolin-CoV) strain hCoV-19/pangolin/Guangdong/1/2019 revealed that the latter contains only one substitution, whereas Bat-CoV-RaTG13 exhibits five. However, ACE2 of pangolin exhibits seven changes relative to human ACE2, and a similar number of substitutions is present in ACE2 of bats, raccoon dogs, and civets, suggesting that SARS-CoV-2 may not be especially adapted to ACE2 of any of its putative intermediate hosts. These analyses provide new insight into the receptor usage and animal source/origin of SARS-CoV-2.IMPORTANCE SARS-CoV-2 is threatening people worldwide, and there are no drugs or vaccines available to mitigate its spread. The origin of the virus is still unclear, and whether pets and livestock can be infected and transmit SARS-CoV-2 are important and unknown scientific questions. Effective binding to the host receptor ACE2 is the first prerequisite for infection of cells and determines the host range. Our analysis provides a framework for the prediction of potential hosts of SARS-CoV-2. We found that ACE2 from species known to support SARS-CoV-2 infection tolerate many amino acid changes, indicating that the species barrier might be low. Exceptions are dogs and especially pigs, which revealed relatively low ACE2 expression levels in the respiratory tract. Monitoring of animals is necessary to prevent the generation of a new coronavirus reservoir. Finally, our analysis also showed that SARS-CoV-2 may not be specifically adapted to any of its putative intermediate hosts.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/virology , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/virology , Spike Glycoprotein, Coronavirus/metabolism , Virus Attachment , Animals , Animals, Domestic , Betacoronavirus/metabolism , Chiroptera/virology , Coronavirus Infections/metabolism , Dogs , Glycosylation , Host-Pathogen Interactions , Humans , Models, Animal , Pandemics , Pets , Pneumonia, Viral/metabolism , Protein Binding , Protein Conformation , Protein Interaction Domains and Motifs , Raccoons/virology , Sequence Alignment , Sequence Analysis, Protein , Swine , Viverridae/virology
9.
Microbes Infect ; 22(4-5): 182-187, 2020.
Article in English | MEDLINE | ID: covidwho-626674

ABSTRACT

Envelope protein of coronaviruses is a structural protein existing in both monomeric and homo-pentameric form. It has been related to a multitude of roles including virus infection, replication, dissemination and immune response stimulation. In the present study, we employed an immunoinformatic approach to investigate the major immunogenic domains of the SARS-CoV-2 envelope protein and map them among the homologue proteins of coronaviruses with tropism for animal species that are closely inter-related with the human beings population all over the world. Also, when not available, we predicted the envelope protein structural folding and mapped SARS-CoV-2 epitopes. Envelope sequences alignment provides evidence of high sequence homology for some of the investigated virus specimens; while the structural mapping of epitopes resulted in the interesting maintenance of the structural folding and epitope sequence localization also in the envelope proteins scoring a lower alignment score. In line with the One-Health approach, our evidences provide a molecular structural rationale for a potential role of taxonomically related coronaviruses in conferring protection from SARS-CoV-2 infection and identifying potential candidates for the development of diagnostic tools and prophylactic-oriented strategies.


Subject(s)
Betacoronavirus/metabolism , Computational Biology/methods , Coronavirus Infections/immunology , Coronavirus Infections/virology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Viral Envelope Proteins/immunology , Animals , Betacoronavirus/classification , Betacoronavirus/genetics , Betacoronavirus/immunology , Epitope Mapping , Gene Expression Regulation, Viral , Humans , Models, Molecular , One Health , Pandemics , Phylogeny , Protein Conformation , Sequence Alignment , Sequence Analysis, Protein
10.
J Med Microbiol ; 69(6): 864-873, 2020 Jun.
Article in English | MEDLINE | ID: covidwho-436403

ABSTRACT

Introduction. The emergence of SARS-CoV-2 has taken humanity off guard. Following an outbreak of SARS-CoV in 2002, and MERS-CoV about 10 years later, SARS-CoV-2 is the third coronavirus in less than 20 years to cross the species barrier and start spreading by human-to-human transmission. It is the most infectious of the three, currently causing the COVID-19 pandemic. No treatment has been approved for COVID-19. We previously proposed targets that can serve as binding sites for antiviral drugs for multiple coronaviruses, and here we set out to find current drugs that can be repurposed as COVID-19 therapeutics.Aim. To identify drugs against COVID-19, we performed an in silico virtual screen with the US Food and Drug Administration (FDA)-approved drugs targeting the RNA-dependent RNA polymerase (RdRP), a critical enzyme for coronavirus replication.Methodology. Initially, no RdRP structure of SARS-CoV-2 was available. We performed basic sequence and structural analysis to determine if RdRP from SARS-CoV was a suitable replacement. We performed molecular dynamics simulations to generate multiple starting conformations that were used for the in silico virtual screen. During this work, a structure of RdRP from SARS-CoV-2 became available and was also included in the in silico virtual screen.Results. The virtual screen identified several drugs predicted to bind in the conserved RNA tunnel of RdRP, where many of the proposed targets were located. Among these candidates, quinupristin is particularly interesting because it is expected to bind across the RNA tunnel, blocking access from both sides and suggesting that it has the potential to arrest viral replication by preventing viral RNA synthesis. Quinupristin is an antibiotic that has been in clinical use for two decades and is known to cause relatively minor side effects.Conclusion. Quinupristin represents a potential anti-SARS-CoV-2 therapeutic. At present, we have no evidence that this drug is effective against SARS-CoV-2 but expect that the biomedical community will expeditiously follow up on our in silico findings.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Pneumonia, Viral/drug therapy , /antagonists & inhibitors , Animals , Antiviral Agents/therapeutic use , Betacoronavirus/enzymology , Betacoronavirus/genetics , Betacoronavirus/physiology , Coronavirus Infections/virology , Drug Evaluation, Preclinical/methods , Drug Synergism , Humans , Molecular Conformation , Pandemics , Phylogeny , Pneumonia, Viral/virology , Rifampin/pharmacology , Sequence Alignment , Sequence Analysis, Protein , Virginiamycin/analogs & derivatives , Virginiamycin/pharmacology , Virus Replication/drug effects
11.
Microbes Infect ; 22(4-5): 182-187, 2020.
Article in English | MEDLINE | ID: covidwho-346567

ABSTRACT

Envelope protein of coronaviruses is a structural protein existing in both monomeric and homo-pentameric form. It has been related to a multitude of roles including virus infection, replication, dissemination and immune response stimulation. In the present study, we employed an immunoinformatic approach to investigate the major immunogenic domains of the SARS-CoV-2 envelope protein and map them among the homologue proteins of coronaviruses with tropism for animal species that are closely inter-related with the human beings population all over the world. Also, when not available, we predicted the envelope protein structural folding and mapped SARS-CoV-2 epitopes. Envelope sequences alignment provides evidence of high sequence homology for some of the investigated virus specimens; while the structural mapping of epitopes resulted in the interesting maintenance of the structural folding and epitope sequence localization also in the envelope proteins scoring a lower alignment score. In line with the One-Health approach, our evidences provide a molecular structural rationale for a potential role of taxonomically related coronaviruses in conferring protection from SARS-CoV-2 infection and identifying potential candidates for the development of diagnostic tools and prophylactic-oriented strategies.


Subject(s)
Betacoronavirus/metabolism , Computational Biology/methods , Coronavirus Infections/immunology , Coronavirus Infections/virology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Viral Envelope Proteins/immunology , Animals , Betacoronavirus/classification , Betacoronavirus/genetics , Betacoronavirus/immunology , Epitope Mapping , Gene Expression Regulation, Viral , Humans , Models, Molecular , One Health , Pandemics , Phylogeny , Protein Conformation , Sequence Alignment , Sequence Analysis, Protein
12.
Int J Antimicrob Agents ; 55(5): 105960, 2020 May.
Article in English | MEDLINE | ID: covidwho-65372

ABSTRACT

The recent emergence of the novel pathogenic SARS-coronavirus 2 (SARS-CoV-2) is responsible for a worldwide pandemic. Given the global health emergency, drug repositioning is the most reliable option to design an efficient therapy for infected patients without delay. The first step of the viral replication cycle [i.e. attachment to the surface of respiratory cells, mediated by the spike (S) viral protein] offers several potential therapeutic targets. The S protein uses the angiotension-converting enzyme-2 (ACE-2) receptor for entry, but also sialic acids linked to host cell surface gangliosides. Using a combination of structural and molecular modelling approaches, this study showed that chloroquine (CLQ), one of the drugs currently under investigation for SARS-CoV-2 treatment, binds sialic acids and gangliosides with high affinity. A new type of ganglioside-binding domain at the tip of the N-terminal domain of the SARS-CoV-2 S protein was identified. This domain (111-158), which is fully conserved among clinical isolates worldwide, may improve attachment of the virus to lipid rafts and facilitate contact with the ACE-2 receptor. This study showed that, in the presence of CLQ [or its more active derivative, hydroxychloroquine (CLQ-OH)], the viral S protein is no longer able to bind gangliosides. The identification of this new mechanism of action of CLQ and CLQ-OH supports the use of these repositioned drugs to cure patients infected with SARS-CoV-2. The in-silico approaches used in this study might also be used to assess the efficiency of a broad range of repositioned and/or innovative drug candidates before clinical evaluation.


Subject(s)
Betacoronavirus/drug effects , Chloroquine/pharmacology , Coronavirus Infections/drug therapy , Hydroxychloroquine/pharmacology , Pneumonia, Viral/drug therapy , Amino Acid Sequence , Betacoronavirus/chemistry , Chloroquine/chemistry , Chloroquine/therapeutic use , Humans , Hydroxychloroquine/chemistry , Hydroxychloroquine/therapeutic use , Models, Molecular , Molecular Targeted Therapy , Pandemics , Protein Structure, Quaternary , Protein Structure, Tertiary , Sequence Analysis, Protein , Spike Glycoprotein, Coronavirus/chemistry
13.
J Infect Dev Ctries ; 14(1): 3-17, 2020 01 31.
Article in English | MEDLINE | ID: covidwho-1512

ABSTRACT

On 31 December 2019 the Wuhan Health Commission reported a cluster of atypical pneumonia cases that was linked to a wet market in the city of Wuhan, China. The first patients began experiencing symptoms of illness in mid-December 2019. Clinical isolates were found to contain a novel coronavirus with similarity to bat coronaviruses. As of 28 January 2020, there are in excess of 4,500 laboratory-confirmed cases, with > 100 known deaths. As with the SARS-CoV, infections in children appear to be rare. Travel-related cases have been confirmed in multiple countries and regions outside mainland China including Germany, France, Thailand, Japan, South Korea, Vietnam, Canada, and the United States, as well as Hong Kong and Taiwan. Domestically in China, the virus has also been noted in several cities and provinces with cases in all but one provinence. While zoonotic transmission appears to be the original source of infections, the most alarming development is that human-to-human transmission is now prevelant. Of particular concern is that many healthcare workers have been infected in the current epidemic. There are several critical clinical questions that need to be resolved, including how efficient is human-to-human transmission? What is the animal reservoir? Is there an intermediate animal reservoir? Do the vaccines generated to the SARS-CoV or MERS-CoV or their proteins offer protection against 2019-nCoV? We offer a research perspective on the next steps for the generation of vaccines. We also present data on the use of in silico docking in gaining insight into 2019-nCoV Spike-receptor binding to aid in therapeutic development. Diagnostic PCR protocols can be found at https://www.who.int/health-topics/coronavirus/laboratory-diagnostics-for-novel-coronavirus.


Subject(s)
Betacoronavirus , Coronavirus Infections/transmission , Disease Reservoirs/veterinary , Disease Transmission, Infectious , Pneumonia, Viral/transmission , Animals , Betacoronavirus/genetics , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Disease Reservoirs/virology , Humans , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Sequence Analysis, Protein , Travel , Vaccination , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Vaccines , Zoonoses
14.
Pathog Glob Health ; 114(2): 64-67, 2020 03.
Article in English | MEDLINE | ID: covidwho-795

ABSTRACT

The global spread of the 2019-nCoV is continuing and is fast moving, as indicated by the WHO raising the risk assessment to high. In this article, we provide a preliminary phylodynamic and phylogeographic analysis of this new virus. A Maximum Clade Credibility tree has been built using the 29 available whole genome sequences of 2019-nCoV and two whole genome sequences that are highly similar sequences from Bat SARS-like Coronavirus available in GeneBank. We are able to clarify the mechanism of transmission among the countries which have provided the 2019-nCoV sequence isolates from their patients. The Bayesian phylogeographic reconstruction shows that the 2019-2020 nCoV most probably originated from the Bat SARS-like Coronavirus circulating in the Rhinolophus bat family. In agreement with epidemiological observations, the most likely geographic origin of the new outbreak was the city of Wuhan, China, where 2019-nCoV time of the most recent common ancestor emerged, according to molecular clock analysis, around November 25th, 2019. These results, together with previously recorded epidemics, suggest a recurring pattern of periodical epizootic outbreaks due to Betacoronavirus. Moreover, our study describes the same population genetic dynamic underlying the SARS 2003 epidemic, and suggests the urgent need for the development of effective molecular surveillance strategies of Betacoronavirus among animals and Rhinolophus of the bat family.


Subject(s)
Betacoronavirus/genetics , Chiroptera/virology , Coronavirus Infections/genetics , Coronavirus/genetics , Evolution, Molecular , Genome, Viral , Phylogeny , Pneumonia, Viral/genetics , Animals , Bayes Theorem , China/epidemiology , Coronavirus/isolation & purification , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , DNA, Viral/genetics , Disease Outbreaks , Disease Reservoirs/virology , Global Health , Humans , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Sequence Analysis, Protein , Zoonoses/epidemiology , Zoonoses/genetics
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