Biochemical and Biophysical characterization of the main protease, 3-chymotrypsin-like protease (3CLpro), from the novel coronavirus disease 19 (COVID-19)

2020 ◽  
Author(s):  
Juliana C. Ferreira ◽  
Wael M. Rabeh

Abstract Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is responsible for the novel coronavirus disease 2019 (COVID-19). An appealing antiviral drug target is the coronavirus 3C-like protease (3CLpro) that is responsible for the processing of the viral polyproteins and liberation of functional proteins essential for the maturation and infectivity of the virus. In this study, multiple thermal analytical techniques have been implemented to acquire the thermodynamic parameters of 3CLpro at different buffer conditions. 3CLpro exhibited relatively high thermodynamic stabilities over a wide pH range; however, the protease was found to be less stable in the presence of salts. Divalent metal cations reduced the thermodynamic stability of 3CLpro more than monovalent cations; however, altering the ionic strength of the buffer solution did not alter the stability of 3CLpro. Furthermore, the most stable thermal kinetic stability of 3CLpro was recorded at pH 7.5, with the highest enthalpy of activation calculated from the slope of Eyring plot. The biochemical and biophysical properties of 3CLpro explored here will improve the solubility and stability of 3CLpro for optimum conditions for the setup of an enzymatic assay for the screening of inhibitors to be used as lead candidates in the drug discovery and antiviral design for therapeutics against COVID-19.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juliana C. Ferreira ◽  
Wael M. Rabeh

AbstractSevere acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is responsible for the novel coronavirus disease 2019 (COVID-19). An appealing antiviral drug target is the coronavirus 3C-like protease (3CLpro) that is responsible for the processing of the viral polyproteins and liberation of functional proteins essential for the maturation and infectivity of the virus. In this study, multiple thermal analytical techniques have been implemented to acquire the thermodynamic parameters of 3CLpro at different buffer conditions. 3CLpro exhibited relatively high thermodynamic stabilities over a wide pH range; however, the protease was found to be less stable in the presence of salts. Divalent metal cations reduced the thermodynamic stability of 3CLpro more than monovalent cations; however, altering the ionic strength of the buffer solution did not alter the stability of 3CLpro. Furthermore, the most stable thermal kinetic stability of 3CLpro was recorded at pH 7.5, with the highest enthalpy of activation calculated from the slope of Eyring plot. The biochemical and biophysical properties of 3CLpro explored here may improve the solubility and stability of 3CLpro for optimum conditions for the setup of an enzymatic assay for the screening of inhibitors to be used as lead candidates in the discovery of drugs and design of antiviral therapeutics against COVID-19.


2020 ◽  
Author(s):  
Micael Davi Lima de Oliveira ◽  
Kelson Mota Teixeira de Oliveira

According to the World Health Organisation, until 16 June, 2020, the number of confirmed and notified cases of COVID-19 has already exceeded 7.9 million with approximately 434 thousand deaths worldwide. This research aimed to find repurposing antagonists, that may inhibit the activity of the main protease (Mpro) of the SARS-CoV-2 virus, as well as partially modulate the ACE2 receptors largely found in lung cells, and reduce viral replication by inhibiting Nsp12 RNA polymerase. Docking molecular simulations were performed among a total of 60 structures, most of all, published in the literature against the novel coronavirus. The theoretical results indicated that, in comparative terms, paritaprevir, ivermectin, ledipasvir, and simeprevir, are among the most theoretical promising drugs in remission of symptoms from the disease. Furthermore, also corroborate indinavir to the high modulation in viral receptors. The second group of promising drugs includes remdesivir and azithromycin. The repurposing drugs HCQ and chloroquine were not effective in comparative terms to other drugs, as monotherapies, against SARS-CoV-2 infection.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Esraa M. O. A. Ismail ◽  
Shaza W. Shantier ◽  
Mona S. Mohammed ◽  
Hassan H. Musa ◽  
Wadah Osman ◽  
...  

The recent outbreak of the highly contagious coronavirus disease 2019 (COVID-19) caused by the novel coronavirus SARS-CoV-2 has created a global health crisis with socioeconomic impacts. Although, recently, vaccines have been approved for the prevention of COVID-19, there is still an urgent need for the discovery of more efficacious and safer drugs especially from natural sources. In this study, a number of quinoline and quinazoline alkaloids with antiviral and/or antimalarial activity were virtually screened against three potential targets for the development of drugs against COVID-19. Among seventy-one tested compounds, twenty-three were selected for molecular docking based on their pharmacokinetic and toxicity profiles. The results identified a number of potential inhibitors. Three of them, namely, norquinadoline A, deoxytryptoquivaline, and deoxynortryptoquivaline, showed strong binding to the three targets, SARS-CoV-2 main protease, spike glycoprotein, and human angiotensin-converting enzyme 2. These alkaloids therefore have promise for being further investigated as possible multitarget drugs against COVID-19.


BioTechniques ◽  
2020 ◽  
Vol 69 (2) ◽  
pp. 108-112 ◽  
Author(s):  
Bijun Cheng ◽  
Tianjiao Li

The outbreak of viral pneumonia caused by the novel coronavirus SARS-CoV-2 that began in December 2019 caused high mortality. It has been suggested that the main protease (Mpro) of SARS-CoV-2 may be an important target to discover pharmaceutical compounds for the therapy of this life-threatening disease. Remdesivir, ritonavir and chloroquine have all been reported to play a role in suppressing SARS-CoV-2. Here, we applied a molecular docking method to study the binding stability of these drugs with SARS-CoV-2 Mpro. It appeared that the ligand–protein binding stability of the alliin and SARS-CoV-2 Mpro complex was better than others. The results suggested that alliin may serve as a good candidate as an inhibitor of SARS-CoV-2 Mpro. Therefore, the present research may provide some meaningful guidance for the prevention and treatment of SARS-CoV-2.


2020 ◽  
Author(s):  
Sandra Westhaus ◽  
Marek Widera ◽  
Holger F. Rabenau ◽  
Sebastian Hoehl ◽  
Denisa Bojkova ◽  
...  

SummaryThe novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. Laboratory work with SARS-CoV-2 in a laboratory setting was rated to biosafety level 3 (BSL-3) biocontainment level. However, certain research applications in particular in molecular biology require incomplete denaturation of the proteins, which might cause safety issues handling contaminated samples. In particular, it is critical to provide proof of inactivation before samples can be removed from the BSL-3.In this study, the stability of the virus in cell culture media at 4°C and on touch panel surfaces used in laboratory environment was analyzed. In addition, we evaluated common lysis buffers that are used in molecular biological laboratories for their ability to inactivate SARS-CoV-2. We have found that guanidine thiocyanate and most of the tested detergent containing lysis buffers were effective in inactivation of SARS-CoV-2, however, the M-PER lysis buffer containing a proprietary detergent failed to inactivate SARS-CoV-2. Furthermore, we compared chemical and non-chemical inactivation methods including ethanol, acetone-methanol mixture, PFA, UV-C light, and heat inactivation.In conclusion, careful evaluation of the used inactivation methods are required and additional inactivation steps are necessary before removal of lysed viral samples from BSL-3.


2020 ◽  
Vol 5 (4) ◽  
pp. 319-331
Author(s):  
K. Gopalasatheeskumar ◽  
Karthikeyen Lakshmanan ◽  
Anguraj Moulishankar ◽  
Jerad Suresh ◽  
D. Kumuthaveni Babu ◽  
...  

COVID-19 is the infectious pandemic disease caused by the novel coronavirus. The COVID-19 is spread globally in a short span of time. The Ministry of AYUSH, India which promotes Siddha and other Indian system of medicine recommends the use of formulation like Nilavembu Kudineer and Kaba Sura Kudineer Chooranam (KSKC). The present work seeks to provide the evidence for the action of 74 different constituents of the KSKC formulation acting on two critical targets. That is main protease and SARS-CoV-2 RNAdependent RNA polymerase target through molecular docking studies. The molecular docking was done by using AutoDock Tools 1.5.6 of the 74 compounds, about 50 compounds yielded docking results against COVID-19 main protease while 42 compounds yielded against SARSCoV- 2 RNA-dependent RNA polymerase. This research has concluded that the KSKC has the lead molecules that inhibits COVID-19’s target of main protease of COVID-19 and SARS-CoV-2 RNA-dependent RNA polymerase.


2020 ◽  
Vol 4 (1) ◽  
pp. 12-17
Author(s):  
Fábio Barbosa ◽  
Leonardo Pezzi ◽  
Julia Sorrentino ◽  
Martin Steppe ◽  
Nadia Volpato ◽  
...  

Stability studies correspond to a set of tests designed to assess changes in the quality of a given drug over time and under the influence of a number of factors. Among these factors, pH plays an important role, due to the catalytic effect that hydronium and hydroxide ions can play in several reactions. In the present study, the degradation kinetics of nitazoxanide was evaluated over a wide pH range, and the main degradation product generated was identified by LC-MS/MS. Nitazoxanide showed first-order degradation kinetics in the pH range of 0.01 to 10.0 showing greater stability between pH 1.0 and 4.0. The degradation rate constant calculated for these pH was 0.0885 x 10-2 min-1 and 0.0689 x 10-2 min-1, respectively. The highest degradation rate constant value was observed at pH 10.0 (0.7418 x 10-2 min-1) followed by pH 0.01 (0.5882 x 10-2 min-1). A major degradation product (DP-1) was observed in all conditions tested. Through LC-MS/MS analysis, DP-1 was identified as a product of nitazoxanide deacetylation. The effect of pH on the stability of nitazoxanide and the kinetic data obtained contribute to a better understanding of the intrinsic stability characteristics of nitazoxanide.


Author(s):  
Linlin Zhang ◽  
Daizong Lin ◽  
Xinyuanyuan Sun ◽  
Katharina Rox ◽  
Rolf Hilgenfeld

AbstractA novel coronavirus has been identified as the causative agent of a massive outbreak of atypical pneumonia originating at Wuhan, Hubei province, China. Involved in the formation of the coronavirus replication complex, the viral main protease (Mpro, also called 3CLpro) represents an attractive target for therapy. We determined the crystal structure of the unliganded Mpro at 1.75 Å resolution and used this structure to guide optimization of a series of alpha-ketoamide inhibitors. The main goal of the optimization efforts was improvement of the pharmacokinetic properties of the compounds. We further describe 1.95- and 2.20-Å crystal structures of the complex between the enzyme and the most potent alpha-ketoamide optimized this way. These structures will form the basis for further development of these compounds to antiviral drugs.


2021 ◽  
Vol 22 (17) ◽  
pp. 9427
Author(s):  
Simone Di Micco ◽  
Simona Musella ◽  
Marina Sala ◽  
Maria C. Scala ◽  
Graciela Andrei ◽  
...  

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified as the pathogen responsible for the outbreak of a severe, rapidly developing pneumonia (Coronavirus disease 2019, COVID-19). The virus enzyme, called 3CLpro or main protease (Mpro), is essential for viral replication, making it a most promising target for antiviral drug development. Recently, we adopted the drug repurposing as appropriate strategy to give fast response to global COVID-19 epidemic, by demonstrating that the zonulin octapeptide inhibitor AT1001 (Larazotide acetate) binds Mpro catalytic domain. Thus, in the present study we tried to investigate the antiviral activity of AT1001, along with five derivatives, by cell-based assays. Our results provide with the identification of AT1001 peptide molecular framework for lead optimization step to develop new generations of antiviral agents of SARS-CoV-2 with an improved biological activity, expanding the chance for success in clinical trials.


2020 ◽  
Vol 7 ◽  
Author(s):  
Arkadeep Sarkar ◽  
Deepak Shilkar ◽  
Arindam Maity ◽  
Sarmi Sardar ◽  
Sudhan Debnath ◽  
...  

The 2019 novel coronavirus infection or COVID-19 can be designated as a global threat. Till date, there is a lack of dedicated therapeutics available against this fatal infection. In the present work, we performed structure-based drug design studies in order to identify clinically used molecules exhibiting crucial binding with 2019-coronavirus main protease enzyme. Based on ligand binding energy and interaction with essential amino acids, two molecules were selected. The stability of the complexed molecules with main protease enzyme was further studied by performing molecular dynamics simulation.


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