Rutaretin1′-(6″-sinapoylglucoside): promising inhibitor of COVID 19 mpro catalytic dyad from the leaves of Pittosporum dasycaulon miq (Pittosporaceae)

2021 ◽  
pp. 1-17
Author(s):  
Riyas Chakkinga Thodi ◽  
Junaida M. Ibrahim ◽  
Vivek Arinchedathu Surendran ◽  
Achuthsankar S. Nair ◽  
Swapna Thacheril Sukumaran
Keyword(s):  
Catalytic Dyad ◽  
Pittosporum Dasycaulon

Identification of Main Protease of Coronavirus SARS-CoV-2 (Mpro)Inhibitors from Melissa officinalis

2020 ◽  
Vol 17 ◽  
Author(s):  
Olusola O. Elekofehinti ◽  
Opeyemi Iwaloye ◽  
Courage D. Famusiwa ◽  
Olanrewaju Akinseye ◽  
Joao B. T. Rocha
Keyword(s):  
Qsar Model ◽  
Computational Approach ◽  
Melissa Officinalis ◽  
Lead Compounds ◽  
Main Protease ◽  
The World ◽  
Recent Outbreak ◽  
Global Concern ◽  
Catalytic Dyad ◽  
Potential Therapeutic Intervention

Background: he recent outbreak of Coronavirus SARS-CoV-2 (Covid-19) which has rapidly spread around the world in about three months with tens of thousands of deaths recorded so far is a global concern. An urgent need for potential therapeutic intervention is of necessity. Mpro is an attractive druggable target for the development of anti-COVID-19 drug development. Compounds previously characterized from Melissa officinalis were queried against main protease of coronavirus SARS-CoV-2 using computational approach. Results: Melitric acid A and salvanolic acid A had higher affinity than lopinavir and ivermectin using both AutodockVina and XP docking algorithms. The computational approach was employed in the generation of QSAR model using automated QSAR, and in the docking of ligands from Melissa officinalis with SARS-CoV-2 Mpro inhibitors. The best model obtained was KPLS_Radial_28 (R2 = 0.8548 and Q2=0.6474, and was used in predicting the bioactivity of the lead compounds. Molecular mechanics based MM-GBSA confirmed salvanolic acid A as the compound with the highest free energy and predicted bioactivity of 4.777; it interacted with His-41 of the catalytic dyad (Cys145-His41) of SARS-CoV-2 main protease (Mpro), as this may hinder the cutting of inactive viral protein into active ones capable of replication. Conclusion: Salvanolic acid A can be further evaluated as potential Mpro inhibitor.

Identification and functional characterization of legumain in amphioxus Branchiostoma belcheri

2009 ◽  
Vol 30 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Lei Teng ◽  
Hiroshi Wada ◽  
Shicui Zhang
Keyword(s):  
Functional Characterization ◽  
Specific Substrate ◽  
Glycosylation Sites ◽  
Branchiostoma Belcheri ◽  
Hen’S Egg ◽  
Hind Gut ◽  
Catalytic Dyad ◽  
Pepstatin A

Legumain has been reported from diverse sources such as plants, parasites (animals) and mammals, but little is known in the lower chordates. The present study reports the first characterization of legumain cDNA from the protochordate Branchiostoma belcheri. The deduced 435-amino-acid-long protein is structurally characterized by the presence of a putative N-terminal signal peptide, a peptidase_C13 superfamily domain with the conserved Lys123-Gly124-Asp125 motif and catalytic dyad His153 and Cys195 and two potential Asn-glycosylation sites at Asn85 and Asn270. Phylogenetic analysis demonstrates that B. belcheri legumain forms an independent cluster together with ascidian legumain, and is positioned at the base of vertebrate legumains, suggesting that B. belcheri legumain gene may represent the archetype of vertebrate legumain genes. Both recombinant legumain expressed in yeast and endogenous legumain are able to be converted into active protein of ~37 kDa via a C-terminal autocleavage at acid pH values. The recombinant legumain efficiently degrades the legumain-specific substrate Z-Ala-Ala-Asn-MCA (benzyloxycarbonyl-L-alanyl-L-alanyl-L-asparagine-4-methylcoumaryl-7-amide) at optimum pH 5.5; and the enzymatic activity is inhibited potently by iodoacetamide and N-ethylmaleimide, partially by hen's-egg white cystatin, but not by E-64 [trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane], PMSF and pepstatin A. In addition, legumain is expressed in vivo in a tissue-specific manner, with main expression in the hepatic caecum and hind-gut of B. belcheri. Altogether, these results suggest that B. belcheri legumain plays a role in the degradation of macromolecules in food.

scholarly journals GRL-0920, an Indole Chloropyridinyl Ester, Completely Blocks SARS-CoV-2 Infection

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Shin-ichiro Hattori ◽  
Nobuyo Higshi-Kuwata ◽  
Jakka Raghavaiah ◽  
Debananda Das ◽  
Haydar Bulut ◽  
...  
Keyword(s):  
High Performance ◽  
Cytopathic Effect ◽  
Structural Modeling ◽  
Covalent Bonding ◽  
Liquid Chromatography Mass Spectrometry ◽  
Viral Breakthrough ◽  
Main Protease ◽  
Significant Toxicity ◽  
Catalytic Dyad ◽  
Shed Light

ABSTRACT We assessed various newly generated compounds that target the main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and various previously known compounds reportedly active against SARS-CoV-2, employing RNA quantitative PCR (RNA-qPCR), cytopathicity assays, and immunocytochemistry. Here, we show that two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, exerted potent activity against SARS-CoV-2 in cell-based assays performed using VeroE6 cells and TMPRSS2-overexpressing VeroE6 cells. While GRL-0820 and the nucleotide analog remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred. No significant anti-SARS-CoV-2 activity was found for several compounds reportedly active against SARS-CoV-2 such as lopinavir, nelfinavir, nitazoxanide, favipiravir, and hydroxychroloquine. In contrast, GRL-0920 exerted potent activity against SARS-CoV-2 (50% effective concentration [EC50] = 2.8 μM) and dramatically reduced the infectivity, replication, and cytopathic effect of SARS-CoV-2 without significant toxicity as examined with immunocytochemistry. Structural modeling shows that indole and chloropyridinyl of the derivatives interact with two catalytic dyad residues of Mpro, Cys145 and His41, resulting in covalent bonding, which was verified using high-performance liquid chromatography–mass spectrometry (HPLC/MS), suggesting that the indole moiety is critical for the anti-SARS-CoV-2 activity of the derivatives. GRL-0920 might serve as a potential therapeutic for coronavirus disease 2019 (COVID-19) and might be optimized to generate more-potent anti-SARS-CoV-2 compounds. IMPORTANCE Targeting the main protease (Mpro) of SARS-CoV-2, we identified two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, active against SARS-CoV-2, employing RNA-qPCR and immunocytochemistry and show that the two compounds exerted potent activity against SARS-CoV-2. While GRL-0820 and remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred as examined with immunocytochemistry. In contrast, GRL-0920 completely blocked the infectivity and cytopathic effect of SARS-CoV-2 without significant toxicity. Structural modeling showed that indole and chloropyridinyl of the derivatives interacted with two catalytic dyad residues of Mpro, Cys145 and His41, resulting in covalent bonding, which was verified using HPLC/MS. The present data should shed light on the development of therapeutics for COVID-19, and optimization of GRL-0920 based on the present data is essential to develop more-potent anti-SARS-CoV-2 compounds for treating COVID-19.

scholarly journals Potential Binding Efficiency of Antiviral Drug Lopinavir Targeted to the Catalytic Dyad, His41 - Cys145 of SARS CoV -2 Main Protease

2020 ◽  
Author(s):  
Muthu Raj S ◽  
Manohar M ◽  
Mohan M ◽  
Ganesh P ◽  
Marimuthu K
Keyword(s):  
Antiviral Drug ◽  
Emergency Situation ◽  
Viral Disease ◽  
New Drugs ◽  
Viral Population ◽  
Protease Inhibition ◽  
Main Protease ◽  
Model Drug ◽  
Approved Drugs ◽  
Catalytic Dyad

<p>The spread of SARS CoV 2 across the globe rushed the scientific community to find out the potential inhibitor for controlling the viral disease. The main protease (Mpro) or Chymotrypsin protease (3CLpro) is involved in the cleavage of polyproteins, duplication of intracellular materials and release of nonstructural proteins. Cys-His catalytic dyad is located in the SARS-CoV Mpro which is the substrate-binding site located in domains I and II. There are many approved drugs that have their active protease inhibition capability. The targeting of the active site of the main protease is the better option to fight against the viral population. Lopinavir, ritonavir, Remdesivir and Chloroquine are some of the drug candidates considered to be involved in the treatment of SARS CoV 2 under emergency situation as a trial basis. In the present investigation we used lopinavir as a drug to bind the catalytic dyad His41, Cys145 of main protease. The minimum binding of energy of -11.45 kcal/mol observed with the binding of Cys145 and -10.93 kcal/mol was noted with the residue His41. The inhibition constant was also found to be relevant to the binding efficiency of the drug. This is considered to be a model drug target which is initiating the finding of many new drugs to target the current outbreak created by the virus SARS.CoV - 2.</p>

scholarly journals Crystal structure of SARS-CoV-2 main protease in complex with a Chinese herb inhibitor shikonin

2020 ◽  
Author(s):  
Jian Li ◽  
Xuelan Zhou ◽  
Yan Zhang ◽  
Fanglin Zhong ◽  
Cheng Lin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Conformational Changes ◽  
Drug Targets ◽  
Chinese Herb ◽  
Binding Modes ◽  
High Potency ◽  
Main Protease ◽  
Covalent Inhibitors ◽  
Catalytic Dyad ◽  
Important Drug

AbstractMain protease (Mpro, also known as 3CLpro) has a major role in the replication of coronavirus life cycle and is one of the most important drug targets for anticoronavirus agents. Here we report the crystal structure of main protease of SARS-CoV-2 bound to a previously identified Chinese herb inhibitor shikonin at 2.45 angstrom resolution. Although the structure revealed here shares similar overall structure with other published structures, there are several key differences which highlight potential features that could be exploited. The catalytic dyad His41-Cys145 undergoes dramatic conformational changes, and the structure reveals an unusual arrangement of oxyanion loop stabilized by the substrate. Binding to shikonin and binding of covalent inhibitors show different binding modes, suggesting a diversity in inhibitor binding. As we learn more about different binding modes and their structure-function relationships, it is probable that we can design more effective and specific drugs with high potency that can serve as effect SARS-CoV-2 anti-viral agents.

Probing catalytic rate enhancement during intramembrane proteolysis

2016 ◽  
Vol 397 (9) ◽  
pp. 907-919 ◽  
Author(s):  
Elena Arutyunova ◽  
Cameron C. Smithers ◽  
Valentina Corradi ◽  
Adam C. Espiritu ◽  
Howard S. Young ◽  
...  
Keyword(s):  
Active Site ◽  
Serine Proteases ◽  
Homology Model ◽  
Intramembrane Proteolysis ◽  
Oxyanion Hole ◽  
Rate Enhancement ◽  
Transition State Stabilization ◽  
The Family ◽  
Catalytic Dyad

Abstract Rhomboids are ubiquitous intramembrane serine proteases involved in various signaling pathways. While the high-resolution structures of the Escherichia coli rhomboid GlpG with various inhibitors revealed an active site comprised of a serine-histidine dyad and an extensive oxyanion hole, the molecular details of rhomboid catalysis were unclear because substrates are unknown for most of the family members. Here we used the only known physiological pair of AarA rhomboid with its psTatA substrate to decipher the contribution of catalytically important residues to the reaction rate enhancement. An MD-refined homology model of AarA was used to identify residues important for catalysis. We demonstrated that the AarA active site geometry is strict and intolerant to alterations. We probed the roles of H83 and N87 oxyanion hole residues and determined that substitution of H83 either abolished AarA activity or reduced the transition state stabilization energy (ΔΔG‡) by 3.1 kcal/mol; substitution of N87 decreased ΔΔG‡ by 1.6–3.9 kcal/mol. Substitution M154, a residue conserved in most rhomboids that stabilizes the catalytic general base, to tyrosine, provided insight into the mechanism of nucleophile generation for the catalytic dyad. This study provides a quantitative evaluation of the role of several residues important for hydrolytic efficiency and oxyanion stabilization during intramembrane proteolysis.

X-ray structure of an inactive zymogen clostripain-like protease from Parabacteroides distasonis

2019 ◽  
Vol 75 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Gonzalo E. González-Páez ◽  
Emily J. Roncase ◽  
Dennis W. Wolan
Keyword(s):  
Immune Responses ◽  
Cysteine Proteases ◽  
Gastrointestinal Diseases ◽  
Active Site Residues ◽  
Bacterial Strains ◽  
Commensal Bacterium ◽  
X Ray ◽  
Host Immune Responses ◽  
Π Stacking Interaction ◽  
Catalytic Dyad

The clostripain-like (C11) family of cysteine proteases are ubiquitously produced by the vast majority of the bacterial strains that make up the human distal gut microbiome. Recent reports show that some C11 proteases promote host immune responses and bacterial pathogenesis, including the induction of neutrophil phagocytosis and the activation of bacterial pathogenic toxins, respectively. The crystal structure of distapain, the only C11 protease predicted within the genome of the commensal bacterium Parabacteroides distasonis, was determined in the inactive zymogen state to 1.65 Å resolution. This is the first C11 protease structure of a zymogen, and the structure helped to uncover key unique conformations among critical active-site residues that are likely to assist in preserving the inactive protease. His135, a member of the catalytic dyad, is repositioned approximately 5.5 Å from the orientation found in active C11 structures and forms a hydrogen bond to Asp180 and a π-stacking interaction with Trp133. The structure sheds light on the potential importance of Asp180 and Trp133, as these residues are highly conserved across C11 proteases. Structure elucidation of C11 proteases will ultimately help to identify new ways to chemically and/or biologically regulate this family of enzymes, which represent potential drug-discovery targets in microbiome-related gastrointestinal diseases.

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