scholarly journals Peptidomimetic α-Acyloxymethylketone Warheads with Six-Membered Lactam P1 Glutamine Mimic: SARS-CoV-2 3CL Protease Inhibition, Coronavirus Antiviral Activity, and in Vitro Biological Stability

Author(s):  
Bing Bai ◽  
Alexandr Belovodskiy ◽  
Mostofa Hena ◽  
Appan Srinivas Kandadai ◽  
Michael A. Joyce ◽  
...  
Author(s):  
Britton Boras ◽  
Rhys M. Jones ◽  
Brandon J. Anson ◽  
Dan Arenson ◽  
Lisa Aschenbrenner ◽  
...  

AbstractCOVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential to the viral life cycle across a broad spectrum of coronaviruses with no close human analogs. The designed phosphate prodrug PF-07304814 is metabolized to PF-00835321 which is a potent inhibitor in vitro of the coronavirus family 3CL pro, with selectivity over human host protease targets. Furthermore, PF-00835231 exhibits potent in vitro antiviral activity against SARS-CoV-2 as a single agent and it is additive/synergistic in combination with remdesivir. We present the ADME, safety, and in vitro antiviral activity data to warrant clinical evaluation.One Sentence SummaryThe phosphate prodrug PF-07304814 is disclosed as an investigational novel intravenous small molecule 3CL protease inhibitor for COVID-19.


2020 ◽  
Author(s):  
Carlos A. Ramos-Guzmán ◽  
J. Javier Ruiz-Pernía ◽  
Iñaki Tuñón

<p>We here investigate the mechanism of SARS-CoV-2 3CL protease inhibition by one of the most promising families of inhibitors, those containing an aldehyde group as warhead. These compounds are covalent inhibitors that inactivate the protease forming a stable hemithioacetal complex. Inhibitor 11a is a potent inhibitor that has been already tested in vitro and in animals. Using a combination of classical and QM/MM simulations we determined the binding mode of the inhibitor into the active site and the preferred rotameric state of the catalytic histidine. In the noncovalent complex the aldehyde group is accommodated into the oxyanion hole formed by the NH main chain groups of residues 143 to 145. In this pose, P1-P3 groups of the inhibitor mimic the interactions established by the natural peptide substrate. The reaction is initiated with the formation of the catalytic dyad ion pair after a proton transfer from Cys145 to His41. From this activated state, covalent inhibition proceeds with the nucleophilic attack of the deprotonated Sg atom of Cys145 to the aldehyde carbon atom and a water mediated proton transfer from the Ne atom of His41 to the aldehyde oxygen atom. Our proposed reaction transition state structure is validated by comparison with x-ray data of recently reported inhibitors, while the activation free energy obtained from our simulations agrees with the experimentally derived value, supporting the validity of our findings. Our study stresses the interplay between the conformational dynamics of the inhibitor and the protein with the inhibition mechanism and the importance of including conformational diversity for accurate predictions about the inhibition of the main protease of SARS-CoV-2. The conclusions derived from our work can also be used to rationalize the behavior of other recently proposed inhibitor compounds, including aldehydes and ketones with high inhibitory potency.</p>


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S354-S354
Author(s):  
Khalid Eljaaly ◽  
Hani Asfour ◽  
Tarek Ibrahim ◽  
Osama Ahmed ◽  
Nabil Alhakamy ◽  
...  

Abstract Background The outbreak of COVID-19 pandemic in China regarded as a major health/economic hazard. The importance of coming up with mechanisms for preventing or treating COVID-19 has been felt across the world. This work aimed at examining the efficiency of Sitagliptin (SIT) and human immunodeficiency virus type 1 (HIV-1) trans-activator transcription peptide (TAT) against SARS-CoV-2. Methods SIT-TAT nano-conjugates were prepared according to a full three-factor bi-level (23) factorial design. SIT concentration (mM, X1), TAT concentration (mM, X2), and pH (X3) were selected as the factors. Particle size (nm, Y1) and zeta potential (mV, Y2) were assessed as responses. Characterization of the optimized formula for Fourier-transformed infrared (FTIR) and Transmission electron microscope was carried out. In addition, IC50 in Vero E6 cells, In vitro 3CL-protease inhibition and docking tests were investigated. Results The prepared complex’s formula was as follows 1: 1 SIT: TAT molar ratio, whereas zeta potential and particle size values were at 34.17 mV and 97.19 nm, respectively. This combination did exhibit its antiviral potentiality against SARS-CoV-2 via IC50 values of 9.083 5.415, and 16.14 µM for TAT, SIT-TAT, and SIT, respectively. In addition, the complex SIT-TAT showed a significant (P &lt; 0.001) viral-3CL-protease inhibitory effect (IC50 = 3.959 µM ± 0.011) in comparison to isolated components (IC50 = 10.93 µM ± 0.25) and TAT (IC50 = 8.128 µM ± 0.42). This was further confirmed via in silico study. Molecular docking investigation has shown promising binding affinity of the formula components towards SARS-CoV-2 main protease (3-CL). Conclusion While offering significant binding interactions with protein’s key pocket residues, an optimized formulation of SIT-TAT could guarantee both the enhanced delivery to the target cells and the improved cellular uptake. The presented findings would guarantee further investigations regarding formula optimization against SARS-CoV-2. Disclosures All Authors: No reported disclosures


2020 ◽  
Author(s):  
Carlos A. Ramos-Guzmán ◽  
J. Javier Ruiz-Pernía ◽  
Iñaki Tuñón

<p>We here investigate the mechanism of SARS-CoV-2 3CL protease inhibition by one of the most promising families of inhibitors, those containing an aldehyde group as warhead. These compounds are covalent inhibitors that inactivate the protease forming a stable hemithioacetal complex. Inhibitor 11a is a potent inhibitor that has been already tested in vitro and in animals. Using a combination of classical and QM/MM simulations we determined the binding mode of the inhibitor into the active site and the preferred rotameric state of the catalytic histidine. In the noncovalent complex the aldehyde group is accommodated into the oxyanion hole formed by the NH main chain groups of residues 143 to 145. In this pose, P1-P3 groups of the inhibitor mimic the interactions established by the natural peptide substrate. The reaction is initiated with the formation of the catalytic dyad ion pair after a proton transfer from Cys145 to His41. From this activated state, covalent inhibition proceeds with the nucleophilic attack of the deprotonated Sg atom of Cys145 to the aldehyde carbon atom and a water mediated proton transfer from the Ne atom of His41 to the aldehyde oxygen atom. Our proposed reaction transition state structure is validated by comparison with x-ray data of recently reported inhibitors, while the activation free energy obtained from our simulations agrees with the experimentally derived value, supporting the validity of our findings. Our study stresses the interplay between the conformational dynamics of the inhibitor and the protein with the inhibition mechanism and the importance of including conformational diversity for accurate predictions about the inhibition of the main protease of SARS-CoV-2. The conclusions derived from our work can also be used to rationalize the behavior of other recently proposed inhibitor compounds, including aldehydes and ketones with high inhibitory potency.</p>


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Britton Boras ◽  
Rhys M. Jones ◽  
Brandon J. Anson ◽  
Dan Arenson ◽  
Lisa Aschenbrenner ◽  
...  

AbstractCOVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential across a broad spectrum of coronaviruses with no close human analogs. PF-00835231, a 3CL protease inhibitor, has exhibited potent in vitro antiviral activity against SARS-CoV-2 as a single agent. Here we report, the design and characterization of a phosphate prodrug PF-07304814 to enable the delivery and projected sustained systemic exposure in human of PF-00835231 to inhibit coronavirus family 3CL protease activity with selectivity over human host protease targets. Furthermore, we show that PF-00835231 has additive/synergistic activity in combination with remdesivir. We present the ADME, safety, in vitro, and in vivo antiviral activity data that supports the clinical evaluation of PF-07304814 as a potential COVID-19 treatment.


2018 ◽  
Vol 20 (3) ◽  
pp. 201-212 ◽  
Author(s):  
Hasan Hüseyin Doğan ◽  
Sami Karagöz ◽  
Rüstem Duman

2020 ◽  
Vol 16 (5) ◽  
pp. 677-688 ◽  
Author(s):  
Sandra Piras ◽  
Paola Corona ◽  
Roberta Ibba ◽  
Federico Riu ◽  
Gabriele Murineddu ◽  
...  

Background: Coxsackievirus infections are associated with cases of aseptic meningitis, encephalitis, myocarditis, and some chronic disease. Methods: A series of benzo[d][1,2,3]triazol-1(2)-yl derivatives (here named benzotriazol-1(2)-yl) (4a-i, 5a-h, 6a-e, g, i, j and 7a-f, h-j) were designed, synthesized and in vitro evaluated for cytotoxicity and antiviral activity against two important human enteroviruses (HEVs) members of the Picornaviridae family [Coxsackievirus B 5 (CVB-5) and Poliovirus 1 (Sb-1)]. Results: Compounds 4c (CC50 >100 μM; EC50 = 9 μM), 5g (CC50 >100 μM; EC50 = 8 μM), and 6a (CC50 >100 μM; EC50 = 10 μM) were found active against CVB-5. With the aim of evaluating the selectivity of action of this class of compounds, a wide spectrum of RNA (positive- and negativesense), double-stranded (dsRNA) or DNA viruses were also assayed. For none of them, significant antiviral activity was determined. Conclusion: These results point towards a selective activity against CVB-5, an important human pathogen that causes both acute and chronic diseases in infants, young children, and immunocompromised patients.


2021 ◽  
Vol 22 (2) ◽  
pp. 687
Author(s):  
Tong Zhou ◽  
Bolan Zhou ◽  
Yasong Zhao ◽  
Qing Li ◽  
Guili Song ◽  
...  

Most currently available bioreactors have some defects in the expression, activity, or purification of target protein and peptide molecules, whereas the mucus gland of fish can overcome these defects to become a novel bioreactor for the biopharmaceutical industry. In this study, we have evaluated the practicability of developing a mucus gland bioreactor in loach (Paramisgurnus dabryanus). A transgenic construct pT2-krt8-IFN1 was obtained by subcloning the promoter of zebrafish keratin 8 gene and the type I interferon (IFN1) cDNA of grass carp into the SB transposon. The IFN1 expressed in CIK cells exhibited an antiviral activity against the replication of GCRV873 and activated two genes downstream of JAK-STAT signaling pathway. A transgenic loach line was then generated by microinjection of the pT2-krt8-IFN1 plasmids and in vitro synthesized capped SB11 mRNA. Southern blots indicated that a single copy of IFN1 gene was stably integrated into the genome of transgenic loach. The expression of grass carp IFN1 in transgenic loaches was detected with RT-PCR and Western blots. About 0.0825 µg of grass carp IFN1 was detected in 20 µL mucus from transgenic loaches. At a viral titer of 1 × 103 PFU/mL, plaque numbers on plates containing mucus from transgenic loaches reduced by 18% in comparison with those of the control, indicating that mucus of IFN1-transgenic loaches exhibited an antiviral activity. Thus, we have successfully created a mucus gland bioreactor that has great potential for the production of various proteins and peptides.


Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 36
Author(s):  
Audrien Alves Andrade de Souza ◽  
Lauana Ribas Torres ◽  
Lyana Rodrigues Pinto Lima Capobianco ◽  
Vanessa Salete de Paula ◽  
Cynthia Machado Cascabulho ◽  
...  

Despite the severe morbidity caused by Zika fever, its specific treatment is still a challenge for public health. Several research groups have investigated the drug repurposing of chloroquine. However, the highly toxic side effect induced by chloroquine paves the way for the improvement of this drug for use in Zika fever clinics. Our aim is to evaluate the anti-Zika virus (ZIKV) effect of hybrid compounds derived from chloroquine and sulfadoxine antimalarial drugs. The antiviral activity of hybrid compounds (C-Sd1 to C-Sd7) was assessed in an in-vitro model of human cervical and Vero cell lines infected with a Brazilian (BR) ZIKV strain. First, we evaluated the cytotoxic effect on cultures treated with up to 200 µM of C-Sds and observed CC50 values that ranged from 112.0 ± 1.8 to >200 µM in cervical cells and 43.2 ± 0.4 to 143.0 ± 1.3 µM in Vero cells. Then, the cultures were ZIKV-infected and treated with up to 25 µM of C-Sds for 48 h. The treatment of cervical cells with C-Sds at 12 µM induced a reduction of 79.8% ± 4.2% to 90.7% ± 1.5% of ZIKV–envelope glycoprotein expression in infected cells as compared to 36.8% ± 2.9% of infection in vehicle control. The viral load was also investigated and revealed a reduction of 2- to 3-logs of ZIKV genome copies/mL in culture supernatants compared to 6.7 ± 0.7 × 108 copies/mL in vehicle control. The dose–response curve by plaque-forming reduction (PFR) in cervical cells revealed a potent dose-dependent activity of C-Sds in inhibiting ZIKV replication, with PFR above 50% and 90% at 6 and 12 µM, respectively, while 25 µM inhibited 100% of viral progeny. The treatment of Vero cells at 12 µM led to 100% PFR, confirming the C-Sds activity in another cell type. Regarding effective concentration in cervical cells, the EC50 values ranged from 3.2 ± 0.1 to 5.0 ± 0.2 µM, and the EC90 values ranged from 7.2 ± 0.1 to 11.6 ± 0.1 µM, with selectivity index above 40 for most C-Sds, showing a good therapeutic window. Here, our aim is to investigate the anti-ZIKV activity of new hybrid compounds that show highly potent efficacy as inhibitors of ZIKV in-vitro infection. However, further studies will be needed to investigate whether these new chemical structures can lead to the improvement of chloroquine antiviral activity.


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