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1.
Zhongguo Yufang Shouyi Xuebao / Chinese Journal of Preventive Veterinary Medicine ; 44(11):1135-1141, 2023.
Article in Chinese | CAB Abstracts | ID: covidwho-20238997

ABSTRACT

Previous studies have revealed that developmental regulated brain protein (Drebrin) is involved in cell- to-cell communication, nerve transmission, tumor metastasis, spermatogenesis and other life activities, but there are few studies on viruses. The aim of the current research was therefore, to study the function of Drebrin and its effect on the proliferation of porcine epidemic diarrhea virus (PEDV). The Drebrin gene was cloned according to the Drebrin gene sequence (XM_008015438.2) of Chlorocebus sabaeus registered by GenBank, and the phylogenetic tree was constructed to analyze its homology. The results showed that the CDS region of Vero cells Drebrin gene was 2088 bp long, encoding 695 amino acids, and was relatively conserved and had high homology with all species. To investigate the effect of Drebrin on the proliferation of PEDV in Vero cells, the eukaryotic expression vector pcDNA3.1-Drebrin-Flag was constructed. After transfection of Vero cells with different concentrations of pcDNA3.1-Drebrin-Flag, cells were infected with PEDV. Our results showed that overexpression of Drebrin in Vero cells could significantly inhibit the intracellular PEDV mRNA level and N protein expression, reduce the extracellular virus titer and inhibit the proliferation of PEDV. Further study on the interaction between Drebrin and PEDV S proteins by laser confocal technique was also performed. The results showed that Drebrin and S protein were co-located in the cytoplasm, suggesting that the two proteins may interact with each other. This study demonstrated for the first time that Drebrin can inhibit PEDV proliferation in Vero cells, laying a foundation for further research in to Drebrin function and provides a valuable information for anti-PEDV research.

2.
Koomesh ; 24(6), 2022.
Article in Persian | CAB Abstracts | ID: covidwho-20231716

ABSTRACT

Introduction: Covid-19 epidemic results from an infection caused by SARS-CoV2. Evolution-based analyses on the nucleotide sequences show that SARS-CoV2 is a member of the genus Beta-coronaviruses and its genome consists of a single-stranded RNA, encoding 16 proteins. Among the structural proteins, the nucleocapsid is the most abundant protein in virus structure, highly immunogenic, with sequence conservatory. Due to a large number of mutations in the spike protein, the aim of this study was to investigate bioinformatics, expression of nucleocapsid protein and evaluate its immunogenicity as an immunogenic candidate. Materials and Methods: B and T cell epitopes of nucleocapsid protein were examined in the IEDB database. The PET28a-N plasmid was transferred to E. coli BL21(DE3) expression host, and IPTG induced recombinant protein expression. The protein was purified using Ni-NTA column affinity chromatography, and the Western blotting method was utilized to confirm it. Finally, mice were immunized with three routes of purified protein. Statistical analysis of the control group injection and test results was carried out by t-test from SPSS software. Results: The optimized gene had a Codon adaptation index (CAI) of 0/97 Percentage of codons having high- frequency distribution was improved to 85%. Expression of recombinant protein in E. coli led to the production of BoNT/B-HCC with a molecular weight of 45 kDa. The total yield of purified protein was 43 mg/L. Immunization of mice induced serum antibody response. Statistical analysis showed that the antibody titer ratio was significantly different compared to the control sample and the antibody titer was acceptable up to a dilution of 1.256000. Conclusion: According to the present study results, the protein can be used as an immunogenic candidate for developing vaccines against SARS-CoV2 in future research.

3.
Science ; 380(6645):564-564, 2023.
Article in English | Academic Search Complete | ID: covidwho-2321270

ABSTRACT

In January, a federal audit found that EcoHealth had misreported nearly $90,000 in expenses for several grants dating to 2014 and that NIH had erred by not justifying its termination (later changed to a suspension) of the 2019 grant. Three years after then-President Donald Trump pressured the U.S. National Institutes of Health (NIH) to shut down a research grant to a group studying how bat coronaviruses jump to people, the agency has restarted the award. [Extracted from the article] Copyright of Science is the property of American Association for the Advancement of Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

4.
Journal of Southern Agriculture ; 53(9):2674-2682, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2316622

ABSTRACT

[Objective] To prepare broad-spectrum monoclonal antibody against N protein of avian infectious bronchitis virus (IBV), so as to lay a foundation for identifying conservative domain epitope of N protein and establish a universal IBV detection method. [Method] N protein of GX-YL5, a representative strain of IBV dominant serotype in Guangxi, was expressed in prokaryote. BALB/c mice were immunized with the purified protein. After the serum titer of the immunized mice reached 104 or more, the splenocytes were fused with SP2/0 myeloma cells. After screening by indirect ELISA, monoclonal antibody was prepared by ascites-induced method. Western blotting, IFA and indirect ELISA were used to identify the titer, subtype, reaction specificity and cross-reaction spectrum. And the prepared monoclonal antibody was used for immunohistochemical detection. And the prepared monoclonal antibody was used to detect the IBV in the trachea and kidney tissues of SPF chickens artificially infected with 4 representative IBV variants (GX-N130048, GX-N160421, GX-QZ171023 and GX-QZ170728). [Result] The prepared monoclonal antibody N2D5 had a titer greater than 217 and its subtype was IgG2b. The Western blotting and IFA results showed that the monoclonal antibody N2D5 only reacted with IBV, and were negative with Newcastle disease virus (NDV), infectious laryngotracheitis virus (ILTV), avian metapneumovirus (aMPV), infectious bursal disease virus (IBDV), avian leukosis virus (ALV) and Marek's disease virus (MDV). Monoclonal antibody N2D5 reacted with many genotypes in China and all 7 serotypes of IBV currently prevalent in Guangxi, including commonly used standard strains, vaccine strains and field strains. Immunohistochemistry showed that the virus signals could be detected in the trachea and kidney tissues of SPF chickens at different time after artificial infection of 3 representative IBV strains from chicken and 1 isolated strain from duck, which further proved its broad spectrum. [Conclusion] The monoclonal antibody N2D5 of IBV prepared based on hybridoma technology belongs to the IgG2b subtype. It has the characteristics of high specificity, wide response spectrum and strong binding ability with IBV. It can be used as a specific diagnostic antibody for clinical diagnosis of IBV and the study of virus distribution.

5.
Southwest China Journal of Agricultural Sciences ; 36(2):427-434, 2023.
Article in Chinese | CAB Abstracts | ID: covidwho-2316572

ABSTRACT

[Objective] Using the bimolecular fluorescence complementation (BiFC) technology, the present experiment aimed to study the interaction relationship and localization of the target peptide and the complementary peptide based on the porcine epidemic diarrhea virus (PEDV) S protein receptor binding site peptide in living cells, so as to provide the foundation and theoretical support for the further use of the peptide in the detection of porcine epidemic diarrhea virus. [Method] The target peptide was designed according to the physical and chemical characteristics of the target protein, such as the amino acid composition, the type of charge, the ability to form intennolecular hydrogen bonds, the strength of polarity, and hydrophobicity;According to the amino acid composition of the target protein, a complementary peptide that interacted with it in theory was designed, and the target peptide and complementary peptide were predicted and analyzed by using bioinfonnatics tools;The target peptide and complementary peptide were inserted into the pBiFC-VC155 and pBiFC-VN173 vector, which was double digested by the EcoRI/XhoI and NotI/SalI, respectively, verified by enzyme digestion and sequencing, and then transfected into Vero cells to study the interaction between the target peptide and the complementary peptide, and the precise localization of BiFC complex in cells. [Result] Bioinfonnatics analysis showed that the target peptide and complementary peptide had hydrophilic and hydrophobic domains, respectively, and the hydrophilic domains were both positively and negatively charged, which could generate electrostatic attraction. The results of enzyme digestion and sequencing showed that the pBiFC-VC155-target peptide and pBiFC-VNI73-complementary peptide plasmids were successfully constructed;Cell transfection experiments showed that the target peptide and complementary peptide could form BiFC complexes in Vcro cells after co-transfection of recombinant plasmids, indicating that they could interact with each other;Indirect immuttolluorescence assay confirmed that the BiFC complex was mainly distributed in the nucleus. [Conclusion] It was confirmed that the peptide designed based on the PEW/ S protein receptor binding site can interact with each other in living cells, demonstrating the feasibility of the peptide for detection.

6.
Indonesian Journal of Cancer Chemoprevention ; 13(3):166-174, 2022.
Article in English | CAB Abstracts | ID: covidwho-2315348

ABSTRACT

SARS-CoV-2 genome encodes two large polyproteins (pp), pp1a and pp1ab which are cleaved and transformed into a mature form by a protease, non-structural protein 3 (NSP3). NSP3 is encoded by open reading frame (ORF) 1a/b. Curcuma longa (C. longa) or turmeric has been documented to have antiviral effects. The aim of this study was to assess the viral activities of C. longa against SARS-CoV-2 focusing on its potency to inhibit viral replication by targeting NSP3. PubChem databases were used to obtain the metabolic profile of C. longa. The compound's interaction with nucleocapsid was analyzed using molecular docking with Molegro Virtual Docker. Bioinformatics analysis based on rerank score presents all compounds of C. longa have higher binding affinity than the native ligand with cyclocurcumin as the lowest score (-128.38 kcal/mol). This anti-viral activity was hypothesized from the similarity of hydrogen bonds with amino acid residues Ser 128 and Asn 40 as key residues present in Ribavirin. This study reveals that C. longa is the potential to be developed as an antiviral agent through replication inhibition in SARS-CoV-2 targeting its replication mediated by NSP3.

7.
Acta Medica Iranica ; 61(2):97-104, 2023.
Article in English | EMBASE | ID: covidwho-2315060

ABSTRACT

COVID-19 is caused by SARS-CoV-2 which has structural and non-structural proteins (NSP) essential for infection and viral replication. There is a possible binding of SARS-CoV-2 to the beta-1 chain of hemoglobin in red blood cells and thus, decreasing the oxygen transport capacity. Since hydroxychloroquine (HCQ) can accumulate in red cells, there is a chance of interaction of this drug with the virus. To analyze possible interactions between SARS-CoV-2 NSP and hemoglobin with the HCQ using molecular docking and implications for the infected host. This research consisted of a study using bioinformatics tools. The files of the protein structures and HCQ were prepared using the AutoDock Tools software. These files were used to perform molecular docking simulations by AutoDock Vina. The binding affinity report of the generated conformers was analyzed using PyMol software, as well as the chemical bonds formed. The results showed that HCQ is capable of interacting with both SARS-CoV-2 NSP and human hemoglobin. The HCQ/NSP3 conformer, HCQ/NSP5, HCQ/NSP7-NSP8-NSP12, HCQ/NSP9, HCQ/NSP10-NSP16 showed binding affinity. In addition, the interaction between HCQ and hemoglobin resulted in polar bonds. Interaction between SARS-CoV-2 NSP and HCQ indicates that this drug possibly acts by preventing the continuity of infection.Copyright © 2023 Tehran University of Medical Sciences.

8.
Journal of Yunnan Agricultural University ; 37(5):790-798, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2275509

ABSTRACT

Purpose: To investigate the epidemic variation of porcine epidemic diarrhea virus (PEDV) strains in Sichuan Province, and to analyze the causes of poor vaccination effect. Methods: Piglet intestinal samples were collected from a pig farm in Sichuan Province for PCR detection, virus purification, determination of virus titer and virus infection experiments. Whole genome sequencing of isolated strains was determined. The S gene sequence of the isolated strain was compared with the strains from other regions and vaccine strains, and the phylogenetic tree was established. The amino acid site variation of S protein between the isolated strain and the classical vaccine strain CV777 was compared. Results: A PEDV strain was successfully isolated and named as PEDV SNJ-P. The determination of virus titer was 1..107.5/100 L. Animal infection experiments showed that the isolated strain could cause diarrhea, dehydration and other symptoms and lead to death in piglets. Genome sequencing and phylogenetic tree analysis showed that the whole gene of PEDV SNJ-P strain was 28003 bp, and the genotype of the strain was S non-INDEL type. The strains were closely related to the strains of PEDV-WS, CH/JLDH/2016 and CH/HNLH/2015 isolated from China, and were relatively distant with the same type vaccine strain, and were far from the classical vaccine strain. Compared with the classical vaccine strain CV777, the S protein of SNJ-P strain had multiple amino acid mutations, deletions and insertions. Conclusion: Due to the continuous variation of strains, SNJ-P strain is far from the vaccine strain, and the current vaccines cannot provide effective protection. The results of this study are expected to provide reference for the study of PEDV strains and vaccine development in China.

9.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 52(9):1137-1143, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2288750

ABSTRACT

In order to develop monoclonal antibody against Feline infectious peritonitis virus (FIPV) S1 protein, the truncated S1 protein (rS1) was expressed through Escherichia coli and subsequently purified. Then BALB/c mice were immunized with purified rSl. Three hybridoma cell strains, named 2D7,3D8 and 5G1, stably secreting antibodies against rSl were obtained by cell fusion and indirect ELISA screening. The identification of antibody subtype showed that antibody subtypes of 2D7,5G1 and 3d8 strains were IgG2a,IgG2a and IgGl,respectively. And the light chain of those three hybridoma cell strains was Kappa. Result of karyotype identification of hybridoma cells showed that the chromosome numbers of those three hybridoma cells were about 102,101 and 103, which was belonged to the karyotype of hybridoma. The titer of ascites antibody for indirect ELISA was 1 : 204 800, and monoclonal antibodies were purified. Moreover, all of 2D7,3D8 and 5G1 could react with rS1 by Western-blot and FIPV in cells by IFA. These data suggest that three monoclonal antibodies against rSl with good activities were ideal materials in the study of early diagnosis of FIPV and the biological function of FIPV in the future.

10.
Vietnam Journal of Science, Technology and Engineering ; 63(3):69-75, 2021.
Article in English | CAB Abstracts | ID: covidwho-2283237

ABSTRACT

The COVID-19 pandemic causing acute respiratory syndrome is a significant public health problem. Drugs that can treat this disease are currently a high priority. The SARS-CoV-2 spike protein and human ACE2 enzyme receptor, which both play important roles in virus entry into the host cell, are promising therapeutic targets for inhibiting viral infection. This research evaluates the potential of chalcone compounds to inhibit the spike proteins and ACE2 enzymes through molecular docking in silico approaches. Based on the ChemFaces database, we collected 92 chalcone compounds. These compounds were further docked to target the active sites of spike protein and human ACE2. After comparing the binding energies of the 92 compounds to artemisinin, ribavirin, and lopinavir, which have inhibitory activity to these protein targets of SARS-CoV-2, we chose 20 out of the 92 compounds that had a higher ability to inhibit the protein targets than the reference inhibitors. Next, five phytochemical compounds with the best binding energy were selected, which included flavanomarein, sarcandrone B, sarcandrone A, calyxin H, and sieboldin. Then, Lipinski's 5 rule was used to evaluate the druglike properties of these compounds. Predictive ADME/tox filtering tests were also applied to the top docked compounds. The results suggest that sarcandrone B has good pharmacokinetic properties, which should be further explored as an anti-SARS-CoV-2. To confirm these findings, experimental studies are recommended.

11.
American Journal of Respiratory and Critical Care Medicine ; 206(8):961-972, 2022.
Article in English | CAB Abstracts | ID: covidwho-2264829

ABSTRACT

Rationale: Autopsy and biomarker studies suggest that endotheliopathy contributes to coronavirus disease (COVID-19)-associated acute respiratory distress syndrome. However, the effects of COVID-19 on the lung endothelium are not well defined. We hypothesized that the lung endotheliopathy of COVID-19 is caused by circulating host factors and direct endothelial infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Objectives: We aimed to determine the effects of SARS-CoV-2 or sera from patients with COVID-19 on the permeability and inflammatory activation of lung microvascular endothelial cells. Methods: Human lung microvascular endothelial cells were treated with live SARS-CoV-2;inactivated viral particles;or sera from patients with COVID-19, patients without COVID-19, and healthy volunteers. Permeability was determined by measuring transendothelial resistance to electrical current flow, where decreased resistance signifies increased permeability. Inflammatory mediators were quantified in culture supernatants. Endothelial biomarkers were quantified in patient sera. Measurements and Main Results: Viral PCR confirmed that SARS-CoV-2 enters and replicates in endothelial cells. Live SARS-CoV-2, but not dead virus or spike protein, induces endothelial permeability and secretion of plasminogen activator inhibitor 1 and vascular endothelial growth factor. There was substantial variability in the effects of SARS-CoV-2 on endothelial cells from different donors. Sera from patients with COVID-19 induced endothelial permeability, which correlated with disease severity. Serum levels of endothelial activation and injury biomarkers were increased in patients with COVID-19 and correlated with severity of illness. Conclusions: SARS-CoV-2 infects and dysregulates endothelial cell functions. Circulating factors in patients with COVID-19 also induce endothelial cell dysfunction. Our data point to roles for both systemic factors acting on lung endothelial cells and viral infection of endothelial cells in COVID-19-associated endotheliopathy.

12.
Mol Gen Microbiol Virol ; 37(4): 209-225, 2022.
Article in English | MEDLINE | ID: covidwho-2288894

ABSTRACT

Objective: To compare the repertoire of proteins of the human hemostatic system and fragments mimicking these proteins in the proteins of influenza A/H1N1 viruses and coronaviruses. Material and methods. Influenza viruses A/H1N1 (A/Brevig Mission/1/18), A/St. Petersburg /RII04/2016 (H1N1)pdm09, coronaviruses SARS-CoV and SARS-CoV-2 (strain Wuhan-Hu-1) were used for comparative computer analysis. The sources of the primary structures of proteins of the analyzed viruses and 41 proteins of the human hemostatic system were publicly available Internet databases, respectively, www.ncbi.nlm.nih.gov and www.nextprot.org. The search for homologous sequences in the structure of viral proteins and hemostatic proteins was carried out by comparing fragments of 12 amino acids in length, taking as related those that showed identity at ≥8 positions. Results. Comparative analysis of the repertoire of cellular proteins of the hemostatic system and fragments mimicking these proteins in the structure of proteins of viruses A/H1N1 1918, A(H1N1)pdm09 isolated in 2016, SARS-CoV and SARS-CoV-2, showed a significant difference between SARS-CoV-2 and analyzed viruses. In the protein structure of the SARS-CoV-2 virus, mimicry was revealed for almost all analyzed hemostasis proteins. As for the comparison of viruses A/H1N1 1918, A(H1N1)pdm09 2016 and SARS-CoV, the influenza virus A/H1N1 1918 and SARS-CoV are the closest in the repertoire of hemostatic proteins. Conclusion. Obtained bioinformatic analysis data can serve as a basis for further study of the role of homologous fragments in the regulation of hemostasis of the host organism.

13.
7th International Conference on Advanced Production and Industrial Engineering, ICAPIE 2022 ; 27:565-570, 2022.
Article in English | Scopus | ID: covidwho-2198468

ABSTRACT

The pandemic that started in 2019 in Wuhan caused a vast number of deaths worldwide due to the absence of effective therapy against SARS-CoV-2. The present study investigates the interaction of AMP with viral protein and host receptors. We screened plant-derived antimicrobial peptides (AMP) from the docking web server with the help of PDB ID. We selected five anti-microbial peptides based on their antiviral and physiological activities. The interaction of anti-microbial peptide and Mpro was analyzed using the HADDOCK web server. The results revealed that the minimum Z-score was obtained by the 6LU7-1N4N complex followed by 6LU7-1GPS docked complex. The docking results showed the interaction potency of AMP with 6LU7. The dynamic simulation study of 100ns was performed to check the stability of the docked complexes of AMP and 6LU7. From the stable and positive results of dynamics studies, we can conclude that these selected AMPs have immense potential to be used as therapeutic agents for the treatment of disease. © 2022 The authors and IOS Press.

14.
2022 International Conference on Biomedical and Intelligent Systems, IC-BIS 2022 ; 12458, 2022.
Article in English | Scopus | ID: covidwho-2193342

ABSTRACT

The new virus was initially defined in Wuhan, China, in 2019. Because of its quick transmission, a pandemic spread over the world. The SARS-CoV-2 virus is a subtype of the coronavirus family, the seventh virus type after SARS. The virus enters organisms' cells and produces mRNA in the host cell through a series of processes including replication and transcription. mRNA is translated into the corresponding viral protein in the cell and released from the host cell. To stop the spread of the disease, various vaccines have been developed and put into use in a short time. This paper details the design of a newer type of mRNA vaccine against COVID-19, its advantages and disadvantages, and compares it with other types of vaccines. The comparison reveals that mRNA vaccines have apparent advantages in terms of speed of production and safety, but at the same time their delivery conditions and instability are issues that need to be addressed. If the mRNA vaccines' storage conditions are improved, such as by raising the temperature at which they are stored, extending their half-life, and lowering the stringent storage standards, in the future, mRNA vaccines will play a larger clinical role. © 2022 SPIE. All rights reserved.

15.
Tianjin Medical Journal ; 50(10):1110-1114, 2022.
Article in Chinese | GIM | ID: covidwho-2168278

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a genome similar to that of the SARSCoV, which has been circulating since 2002 and encodes multiple viral proteins. The accessory protein ORF8 has low sequence homology with SARS-CoV ORF8, and has characteristics of rapid evolution and mutation. It has functions of inhibiting type I interferon and down-regulating the expression of major histocompatibility complex I (MHC I). This paper reviews the structure and function of accessory protein ORF8 and the diagnostic and therapeutic prospects for COVID-19.

16.
Life Sci ; 313: 121271, 2023 Jan 15.
Article in English | MEDLINE | ID: covidwho-2159516

ABSTRACT

Mitochondria are dynamic cellular organelles with diverse functions including energy production, calcium homeostasis, apoptosis, host innate immune signaling, and disease progression. Several viral proteins specifically target mitochondria to subvert host defense as mitochondria stand out as the most suitable target for the invading viruses. They have acquired the capability to control apoptosis, metabolic state, and evade immune responses in host cells, by targeting mitochondria. In this way, the viruses successfully allow the spread of viral progeny and thus the infection. Viruses employ their proteins to alter mitochondrial dynamics and their specific functions by a modulation of membrane potential, reactive oxygen species, calcium homeostasis, and mitochondrial bioenergetics to help them achieve a state of persistent infection. A better understanding of such viral proteins and their impact on mitochondrial forms and functions is the main focus of this review. We also attempt to emphasize the importance of exploring the role of mitochondria in the context of SARS-CoV2 pathogenesis and identify host-virus protein interactions.


Subject(s)
Mitochondria , Viral Proteins , Humans , Calcium/metabolism , Mitochondria/metabolism , Mitochondria/virology , RNA, Viral/metabolism , Viral Proteins/metabolism , Viruses/pathogenicity
17.
Chinese Journal of Virology ; 38(1):175-186, 2022.
Article in Chinese | GIM | ID: covidwho-2115892

ABSTRACT

COVID-19 pandemic, caused by infection Of severe acute respiratory syndrome Coronavirus 2 (SARS -CoV-2), is an ongoing and severe threat to public health and safety. The Coronavirus nucleoeapsid(N) protein mainly functions as a key structural protein, responsible for binding and packaging viral genome RNA into nucleocapsid and recruiting membrane(M) protein for virion assembly. In addition. the N protein functions as a regulatory protein and plays important roles in suppression of the host innate immune response, and localization with replication transcription complex (RTC) to facilitate Viral transcription and replication. Accumulating evidences have emerged recently that SARS-CoV-2 N protein undergoes liquid-liquid phase separation (LLPS) with RNA or other proteins. Importantly, phase separation of the N protein has been Shown to be essential for its structural and regulatory roles. Here, we summarize recent research progress on the phase separation of SARS-CoV-2 N protein. The potential of the phase separation of the N protein as a therapeutic drug targets is also discussed.

18.
Meditsinski Pregled / Medical Review ; 58(6):57-61, 2022.
Article in Bulgarian | GIM | ID: covidwho-2112067

ABSTRACT

Over two and a half years have passed since the WHO declared the SARS-CoV-2 pandemic. Thanks to the accumulated vast experience, especially in countries with a well-developed healthcare, systematized and reliable diagnostic approaches have been made available. Using such molecular biological methods, a current infection with SARS-CoV-2 can be diagnosed: either via sequencing viral nucleic acids or by using chromatographic tests demonstrating viral proteins (rapid antigen tests). Individuals presenting with symptoms consistent with COVID-19, should be tested for a SARS-CoV-2 infection and the sample should be taken from the upper respiratory tract (nasopharynx, nasal and/or oropharynx). It is generally accepted that RT-PCR is the most sensitive and specific diagnostic test. This method allows for qualitative detection of SARS-CoV-2 nucleic acid, by specifically targeting ORF1ab, N and Edomain in the viral genome. The "rapid antigen tests" detect the virus as early as 3-7 days after infection. The sensitivity of the rapid antigen tests does not change compared to the variants of the virus discovered thus far, including the new subtypes of the "Omicron" variant. The principal of this test is based on the detection of the N-protein (nuclear protein). Since the N-protein has remained relatively stable with respect to structural changes, the sensitivity of rapid antigen tests remains high.

19.
Biomolecules ; 12(9)2022 09 15.
Article in English | MEDLINE | ID: covidwho-2043569

ABSTRACT

Novel and efficient strategies need to be developed to interfere with the SARS-CoV-2 virus. One of the most promising pharmaceutical targets is the nucleocapsid protein (N), responsible for genomic RNA packaging. N is composed of two folded domains and three intrinsically disordered regions (IDRs). The globular RNA binding domain (NTD) and the tethered IDRs are rich in positively charged residues. The study of the interaction of N with polyanions can thus help to elucidate one of the key driving forces responsible for its function, i.e., electrostatics. Heparin, one of the most negatively charged natural polyanions, has been used to contrast serious cases of COVID-19 infection, and we decided to study its interaction with N at the molecular level. We focused on the NTR construct, which comprises the NTD and two flanking IDRs, and on the NTD construct in isolation. We characterized this interaction using different nuclear magnetic resonance approaches and isothermal titration calorimetry. With these tools, we were able to identify an extended surface of NTD involved in the interaction. Moreover, we assessed the importance of the IDRs in increasing the affinity for heparin, highlighting how different tracts of these flexible regions modulate the interaction.


Subject(s)
Enoxaparin , Nucleocapsid Proteins , SARS-CoV-2 , COVID-19 , Enoxaparin/pharmacology , Humans , Nucleocapsid Proteins/chemistry , Nucleocapsid Proteins/genetics , Polyelectrolytes , RNA , SARS-CoV-2/drug effects
20.
Zhongguo Bingyuan Shengwuxue Zazhi / Journal of Pathogen Biology ; 15(9):997-1004, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-2040442

ABSTRACT

Objective: To investigate the molecular mechanism of the action by which the MERS-CoV E proxein induces autophagy in 293T cells.

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