Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1175175 (SARS)
 19,188 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The spike (S) glycoprotein is one of the major structure proteins of SARS-associated coronavirus (CoV). Fragment 450-650 (S450-650) of the S protein contains receptor-binding domain and neutralizing epitopes. In this study, S450-650 was expressed with a histidine tag in Escherichia coli BL21. Bacterial inclusion bodies containing the recombinant S450-650 were solubilized with 8 M urea and then applied onto a Ni-nitrilotriacetic acid column. On-column refolding and purification was performed. Reduced glutathione and oxidized glutathione were included in the refolding buffer. In the wash and elution buffers, glycerol and glucose were necessary additives to prevent protein aggregation during purification. This refolding and purification procedure allowed production of S450-650 at up to 500 microg/ml in soluble form, which maintained appropriate antigenicity and immunogenicity. It was able to induce strong IgG responses in BALB/c mice. In Western blot assays, the recombinant S450-650 was recognized by monoclonal Ab against the His-tag and also sera from a convalescent SARS patient. S450-650-based ELISA system was able to detect anti-SARS-CoV IgG Abs in patient sera.
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PMID:Prokaryotic expression, refolding, and purification of fragment 450-650 of the spike protein of SARS-coronavirus. 1564 67

Fragment 450-650 of the spike (S) protein (S450-650) of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) contains epitopes capable of being recognized by convalescent sera of SARS patients. Vaccination of mice with recombinant S450-650 (rS450-650) can induce Abs against SARS-CoV, although the titer is relatively low. In the present study, a fusion protein linking a fragment (residues 39-272) of murine calreticulin (CRT) to S450-650 in a prokaryotic expression system was created. Compared with target antigen alone, the recombinant fusion product (rS450-650-CRT) has much improved hydrophilicity and immunogenicity. The S450-650-specific IgG Abs of BALB/c mice subcutaneously immunized with rS450-650-CRT were in substantially higher titer (approximately fivefold more). Furthermore, the fusion protein, but not rS450-650 alone, was able to elicit S450-650-specific IgG responses in T cell deficient nude mice. Given that rCRT/39-272 can drive the maturation of bone-marrow-derived dendritic cells, directly activate macrophages and B cells, and also elicit helper T cell responses in vivo, we propose that fragment 39-272 of CRT is an effective molecular adjuvant capable of enhancing target Ag-specific humoral responses in both a T cell-dependent and independent manner. Fusion protein rS450-650-CRT is a potential candidate vaccine against SARS-CoV infection.
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PMID:Calreticulin as a hydrophilic chimeric molecular adjuvant enhances IgG responses to the spike protein of severe acute respiratory syndrome coronavirus. 2253 Sep 18

The world has recently been struck by the SARS-Cov-2 pandemic, a situation that people have never before experienced. Infections are increasing without reaching a peak. The WHO has reported more than 25 million infections and nearly 857,766 confirmed deaths. Safety measures are insufficient and there are still no approved drugs for the COVID-19 disease. Thus, it is an urgent necessity to develop a specific inhibitor for COVID-19. One of the most attractive targets in the virus life cycle is the polymerase enzyme responsible for the replication of the virus genome. Here, we describe our Structure-Based Drug Design (SBDD) protocol for designing of a new potential inhibitor for SARS-COV-2 RNA-dependent RNA Polymerase. Firstly, the crystal structure of the enzyme was retrieved from the protein data bank PDB ID (7bv2). Then, Fragment-Based Drug Design (FBDD) strategy was implemented using Discovery Studio 2016. The five best generated fragments were linked together using suitable carbon linkers to yield compound MAW-22. Thereafter, the strength of the binds between compound MAW-22 and the SARS-COV-2 RNA-dependent RNA Polymerase was predicted by docking strategy using docking software. MAW-22 achieved a high docking score, even more so than the score achieved by Remdesivir, indicating very strong binding between MAW-22 and its target. Finally, three molecular dynamic simulation experiments were performed for 150 ns to validate our concept of design. The three experiments revealed that MAW-22 has a great potentiality to inhibit the SARS-COV-2 RNA-dependent RNA Polymerase compared to Remdesivir. Also, it is thought that this study has proven SBDD to be the most suitable avenue for future drug development for the COVID-19 infection.
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PMID:Identification of a New Potential SARS-COV-2 RNA-Dependent RNA Polymerase Inhibitor via Combining Fragment-Based Drug Design, Docking, Molecular Dynamics, and MM-PBSA Calculations. 3319 80