scholarly journals TMPRSS2 and RNA-dependent RNA polymerase are effective targets of therapeutic intervention for treatment of COVID-19 caused by SARS-CoV-2 variants (B.1.1.7 and B.1.351)

2021 ◽  
Author(s):  
Jihye Lee ◽  
JinAh Lee ◽  
Hyeon Ju Kim ◽  
Meehyun Ko ◽  
Youngmee Jee ◽  
...  
Keyword(s):  
Drug Development ◽  
Rna Polymerase ◽  
Viral Entry ◽  
Drug Repositioning ◽  
Therapeutic Interventions ◽  
Main Concern ◽  
Rna Dependent Rna Polymerase ◽  
Vitro Analysis ◽  
The Uk

SARS-CoV-2 is a causative agent of COVID-19 pandemic and the development of therapeutic interventions is urgently needed. So far, monoclonal antibodies and drug repositioning are the main methods for drug development and this effort was partially successful. Since the beginning of COVID-19 pandemic, the emergence of SARS-CoV-2 variants has been reported in many parts of the world and the main concern is whether the current vaccines and therapeutics are still effective against these variant viruses. The viral entry and viral RNA-dependent RNA polymerase (RdRp) are the main targets of current drug development, thus the inhibitory effects of TMPRSS2 and RdRp inhibitors were compared among the early SARS-CoV-2 isolate (lineage A) and the two recent variants (lineage B.1.1.7 and lineage B.1.351) identified in the UK and South Africa, respectively. Our in vitro analysis of viral replication showed that the drugs targeting TMPRSS2 and RdRp are equally effective against the two variants of concern.

scholarly journals Allosteric Activation of SARS-CoV-2 RNA-Dependent RNA Polymerase by Remdesivir Triphosphate and Other Phosphorylated Nucleotides

mBio ◽  
2021 ◽  
Author(s):  
Bing Wang ◽  
Vladimir Svetlov ◽  
Yuri I. Wolf ◽  
Eugene V. Koonin ◽  
Evgeny Nudler ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Drug Development ◽  
Rna Polymerase ◽  
Experimental Work ◽  
Allosteric Activation ◽  
Rna Dependent Rna Polymerase ◽  
Research Outcomes ◽  
Pandemic Response

In vitro interrogations of the central replicative complex of SARS-CoV-2, RNA-dependent RNA polymerase (RdRp), by structural, biochemical, and biophysical methods yielded an unprecedented windfall of information that, in turn, instructs drug development and administration, genomic surveillance, and other aspects of the evolving pandemic response. They also illuminated the vast disparity in the methods used to produce RdRp for experimental work and the hidden impact that this has on enzyme activity and research outcomes.

In Silico Identification of a Potent Arsenic Based Approved Drug Darinaparsin against SARS-CoV-2: Inhibitor of RNA Dependent RNA polymerase (RdRp) and Essential Proteases

2020 ◽  
Vol 20 ◽  
Author(s):  
Trinath Chowdhury ◽  
Gourisankar Roymahapatra ◽  
Santi M. Mandal
Keyword(s):  
Rna Polymerase ◽  
Viral Entry ◽  
In Silico ◽  
Rna Dependent Rna Polymerase ◽  
Replication Complex ◽  
In Silico Study ◽  
Life Threatening ◽  
In Vivo Analysis ◽  
3Cl Protease

Background: COVID-19 is a life threatening novel corona viral infection to our civilization and spreading rapidly. Terrific efforts are generous by the researchers to search for a drug to control SARS-CoV-2. Methods: Here, a series of arsenical derivatives were optimized and analyzed with in silico study to search the inhibitor of RNA dependent RNA polymerase (RdRp), the major replication factor of SARS-CoV-2. All the optimized derivatives were blindly docked with RdRp of SARS-CoV-2 using iGEMDOCK v2.1. Results: Based on the lower idock score in the catalytic pocket of RdRp, darinaparsin (-82.52 kcal/mol) revealed most effective among them. Darinaparsin strongly binds with both Nsp9 replicase protein (-8.77 kcal/mol) and Nsp15 endoribonuclease (-8.3 kcal/mol) of SARS-CoV-2 as confirmed from the AutoDock analysis. During infection, the ssRNA of SARS-CoV2 is translated into large polyproteins forming viral replication complex by specific proteases like 3CL protease and papain protease. This is also another target to control the virus infection where darinaparsin also perform the inhibitory role to proteases of 3CL protease (-7.69 kcal/mol) and papain protease (-8.43 kcal/mol). Conclusion: In host cell, the furin protease serves as a gateway to the viral entry and darinaparsin docked with furin protease which revealed a strong binding affinity. Thus, screening of potential arsenic drugs would help in providing the fast invitro to in-vivo analysis towards development of therapeutics against SARS-CoV-2.

scholarly journals Targeting SARS-CoV-2 Polymerase with New Nucleoside Analogues

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3461
Author(s):  
Vasiliki Daikopoulou ◽  
Panagiotis Apostolou ◽  
Sofia Mourati ◽  
Ioanna Vlachou ◽  
Maria Gougousi ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Drug Repositioning ◽  
Nucleoside Analogues ◽  
In Vitro Assays ◽  
Rna Dependent Rna Polymerase ◽  
Sugar Moiety ◽  
The Family ◽  
Approved Drugs ◽  
Fda Approved Drugs

Despite the fact that COVID-19 vaccines are already available on the market, there have not been any effective FDA-approved drugs to treat this disease. There are several already known drugs that through drug repositioning have shown an inhibitory activity against SARS-CoV-2 RNA-dependent RNA polymerase. These drugs are included in the family of nucleoside analogues. In our efforts, we synthesized a group of new nucleoside analogues, which are modified at the sugar moiety that is replaced by a quinazoline entity. Different nucleobase derivatives are used in order to increase the inhibition. Five new nucleoside analogues were evaluated with in vitro assays for targeting polymerase of SARS-CoV-2.

scholarly journals Analysis of Ribonucleotide 5′-Triphosphate Analogs as Potential Inhibitors of Zika Virus RNA-Dependent RNA Polymerase by Using Nonradioactive Polymerase Assays

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Gaofei Lu ◽  
Gregory R. Bluemling ◽  
Paul Collop ◽  
Michael Hager ◽  
Damien Kuiper ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Zika Virus ◽  
Nonstructural Protein ◽  
Rna Dependent Rna Polymerase ◽  
Antiviral Compounds ◽  
Double Stranded Dna ◽  
Virus Rna ◽  
Potential Inhibitors

ABSTRACT Zika virus (ZIKV) is an emerging human pathogen that is spreading rapidly through the Americas and has been linked to the development of microcephaly and to a dramatically increased number of Guillain-Barré syndrome cases. Currently, no vaccine or therapeutic options for the prevention or treatment of ZIKV infections exist. In the study described in this report, we expressed, purified, and characterized full-length nonstructural protein 5 (NS5) and the NS5 polymerase domain (NS5pol) of ZIKV RNA-dependent RNA polymerase. Using purified NS5, we developed an in vitro nonradioactive primer extension assay employing a fluorescently labeled primer-template pair. Both purified NS5 and NS5pol can carry out in vitro RNA-dependent RNA synthesis in this assay. Our results show that Mn2+ is required for enzymatic activity, while Mg2+ is not. We found that ZIKV NS5 can utilize single-stranded DNA but not double-stranded DNA as a template or a primer to synthesize RNA. The assay was used to compare the efficiency of incorporation of analog 5′-triphosphates by the ZIKV polymerase and to calculate their discrimination versus that of natural ribonucleotide triphosphates (rNTPs). The 50% inhibitory concentrations for analog rNTPs were determined in an alternative nonradioactive coupled-enzyme assay. We determined that, in general, 2′-C-methyl- and 2′-C-ethynyl-substituted analog 5′-triphosphates were efficiently incorporated by the ZIKV polymerase and were also efficient chain terminators. Derivatives of these molecules may serve as potential antiviral compounds to be developed to combat ZIKV infection. This report provides the first characterization of ZIKV polymerase and demonstrates the utility of in vitro polymerase assays in the identification of potential ZIKV inhibitors.

Cordycepin as a Promising Inhibitor of SARS-CoV-2 RNA dependent RNA polymerase (RdRp)

2021 ◽  
Vol 28 ◽  
Author(s):  
Shabana Bibi ◽  
Mohammad Mehedi Hasan ◽  
Yuan-Bing Wang ◽  
Stavros P. Papadakos ◽  
Hong Yu
Keyword(s):  
Rna Polymerase ◽  
Drug Repositioning ◽  
Human Life ◽  
Drug Candidate ◽  
Active Site Residues ◽  
Rna Dependent Rna Polymerase ◽  
Economic Downturns ◽  
Inhibitory Potential ◽  
Dynamics Simulations ◽  
Global Threat

Background: SARS-CoV-2, which emerged in Wuhan, China, is a new global threat that has killed millions of people and continues to do so. This pandemic has not only threatened human life but has also triggered economic downturns across the world. Researchers have made significant strides in discovering molecular insights into SARS-CoV-2 pathogenesis and developing vaccines, but there is still no successful cure for SARS-CoV-2 infected patients. Objective: The present study has proposed a drug-repositioning pipeline for the design and discovery of an effective fungal-derived bioactive metabolite as a drug candidate against SARS-CoV-2. Methods: Fungal derivative “Cordycepin” was selected for this study to investigate the inhibitory properties against RNA-dependent RNA polymerase (RdRp) (PDB ID: 6M71) of SARS-CoV-2. The pharmacological profile, intermolecular interactions, binding energy, and stability of the compound were determined utilizing cheminformatic approaches. Subsequently, molecular dynamic simulation was performed to better understand the binding mechanism of cordycepin to RdRp. Results: The pharmacological data and retrieved molecular dynamics simulations trajectories suggest excellent drug-likeliness and greater structural stability of cordycepin, while the catalytic residues (Asp760, Asp761), as well as other active site residues (Trp617, Asp618, Tyr619, Trp800, Glu811) of RdRp, showed better stability during the overall simulation span. Conclusion: Promising results of pharmacological investigation along with molecular simulations revealed that cordycepin exhibited strong inhibitory potential against SARS-CoV-2 polymerase enzyme (RdRp). Hence, cordycepin should be highly recommended to test in a laboratory to confirm its inhibitory potential against the SARS-CoV-2 polymerase enzyme (RdRp).

scholarly journals In vitro analysis of a transcription termination site for RNA polymerase II.

1990 ◽  
Vol 10 (11) ◽  
pp. 5782-5795 ◽  
Author(s):  
D K Wiest ◽  
D K Hawley
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Dna Sequences ◽  
Nuclear Extract ◽  
Transcription Unit ◽  
Dependent Manner ◽  
Wide Range ◽  
Vitro Analysis

Transcription from the adenovirus major late (ML) promoter has previously been shown to pause or terminate prematurely in vivo and in vitro at a site within the first intron of the major late transcription unit. We are studying the mechanism of elongation arrest at this site in vitro to define the DNA sequences and proteins that determine the elongation behavior of RNA polymerase II. Our assay system consists of a nuclear extract prepared from cultured human cells. With standard reaction conditions, termination is not observed downstream of the ML promoter. However, in the presence of Sarkosyl, up to 80% of the transcripts terminate 186 nucleotides downstream of the start site. Using this assay, we showed that the DNA sequences required to promote maximal levels of termination downstream of the ML promoter reside within a 65-base-pair region and function in an orientation-dependent manner. To test whether elongation complexes from the ML promoter were functionally homogeneous, we determined the termination efficiency at each of two termination sites placed in tandem. We found that the behavior of the elongation complexes was different at these sites, with termination being greater at the downstream site over a wide range of Sarkosyl concentrations. This result ruled out a model in which the polymerases that read through the first site were stably modified to antiterminate. We also demonstrated that the ability of the elongation complexes to respond to the ML termination site was promoter specific, as the site did not function efficiently downstream of a heterologous promoter. Taken together, the results presented here are not consistent with the simplest class of models that have been proposed previously for the mechanism of Sarkosyl-induced termination.

scholarly journals RNA-Dependent RNA Polymerase from Heterobasidion RNA Virus 6 Is an Active Replicase In Vitro

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1738
Author(s):  
Alesia A. Levanova ◽  
Eeva J. Vainio ◽  
Jarkko Hantula ◽  
Minna M. Poranen
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Rna Virus ◽  
Polymerization Reaction ◽  
Rna Dependent Rna Polymerase ◽  
Independent Manner ◽  
Nucleotidyl Transferase ◽  
Rna Polymerization ◽  
The Family

Heterobasidion RNA virus 6 (HetRV6) is a double-stranded (ds)RNA mycovirus and a member of the recently established genus Orthocurvulavirus within the family Orthocurvulaviridae. The purpose of the study was to determine the biochemical requirements for RNA synthesis catalyzed by HetRV6 RNA-dependent RNA polymerase (RdRp). HetRV6 RdRp was expressed in Escherichia coli and isolated to near homogeneity using liquid chromatography. The enzyme activities were studied in vitro using radiolabeled UTP. The HetRV6 RdRp was able to initiate RNA synthesis in a primer-independent manner using both virus-related and heterologous single-stranded (ss)RNA templates, with a polymerization rate of about 46 nt/min under optimal NTP concentration and temperature. NTPs with 2′-fluoro modifications were also accepted as substrates in the HetRV6 RdRp-catalyzed RNA polymerization reaction. HetRV6 RdRp transcribed viral RNA genome via semi-conservative mechanism. Furthermore, the enzyme demonstrated terminal nucleotidyl transferase (TNTase) activity. Presence of Mn2+ was required for the HetRV6 RdRp catalyzed enzymatic activities. In summary, our study shows that HetRV6 RdRp is an active replicase in vitro that can be potentially used in biotechnological applications, molecular biology, and biomedicine.

scholarly journals Identifying SARS-CoV-2 Antiviral Compounds by Screening for Small Molecule Inhibitors of Nsp12/7/8 RNA-dependent RNA Polymerase

2021 ◽  
Author(s):  
Agustina P. Bertolin ◽  
Florian Weissmann ◽  
Jingkun Zeng ◽  
Viktor Posse ◽  
Jennifer C. Milligan ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Virus ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Etiologic Agent ◽  
Host Cells ◽  
Rdrp Activity ◽  
Chemical Library ◽  
Rna Dependent Rna Polymerase

SummaryThe coronavirus disease 2019 (COVID-19) global pandemic has turned into the largest public health and economic crisis in recent history impacting virtually all sectors of society. There is a need for effective therapeutics to battle the ongoing pandemic. Repurposing existing drugs with known pharmacological safety profiles is a fast and cost-effective approach to identify novel treatments. The COVID-19 etiologic agent is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a single-stranded positive-sense RNA virus. Coronaviruses rely on the enzymatic activity of the replication-transcription complex (RTC) to multiply inside host cells. The RTC core catalytic component is the RNA-dependent RNA polymerase (RdRp) holoenzyme. The RdRp is one of the key druggable targets for CoVs due to its essential role in viral replication, high degree of sequence and structural conservation and the lack of homologs in human cells. Here, we have expressed, purified and biochemically characterised active SARS-CoV-2 RdRp complexes. We developed a novel fluorescence resonance energy transfer (FRET)-based strand displacement assay for monitoring SARS-CoV-2 RdRp activity suitable for a high-throughput format. As part of a larger research project to identify inhibitors for all the enzymatic activities encoded by SARS-CoV-2, we used this assay to screen a custom chemical library of over 5000 approved and investigational compounds for novel SARS-CoV-2 RdRp inhibitors. We identified 3 novel compounds (GSK-650394, C646 and BH3I-1) and confirmed suramin and suramin-like compounds as in vitro SARS-CoV-2 RdRp activity inhibitors. We also characterised the antiviral efficacy of these drugs in cell-based assays that we developed to monitor SARS-CoV-2 growth.

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