RESUMEN
Chemical investigation on a Streptomyces sp. strain MS180069 isolated from a sediment sample collected from the South China Sea, yielded the new benzo[f]isoindole-dione alkaloid, bhimamycin J (1). The structure was determined by extensive spectroscopic analysis, including HRMS, 1D, 2D NMR, and X-ray diffraction techniques. A molecular docking study revealed 1 as a new molecular motif that binds with human angiotensin converting enzyme2 (ACE2), recently described as the cell surface receptor responsible for uptake of 2019-CoV-2. Using enzyme assays we confirm that 1 inhibits human ACE2 79.7 % at 25â µg/mL.
Asunto(s)
Alcaloides/química , Sedimentos Geológicos/microbiología , Isoindoles/química , Streptomyces/química , Alcaloides/metabolismo , Alcaloides/farmacología , Alcaloides/uso terapéutico , Enzima Convertidora de Angiotensina 2/antagonistas & inhibidores , Enzima Convertidora de Angiotensina 2/metabolismo , Sitios de Unión , COVID-19/virología , Hongos/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Isoindoles/aislamiento & purificación , Isoindoles/metabolismo , Isoindoles/farmacología , Espectroscopía de Resonancia Magnética , Conformación Molecular , Simulación del Acoplamiento Molecular , SARS-CoV-2/aislamiento & purificación , Streptomyces/aislamiento & purificación , Streptomyces/metabolismo , Tratamiento Farmacológico de COVID-19RESUMEN
The main protease (Mpro or 3CLpro) of SARS-CoV-2 virus is a cysteine enzyme critical for viral replication and transcription, thus indicating a potential target for antiviral therapy. A recent repurposing effort has identified ebselen, a multifunctional drug candidate as an inhibitor of Mpro. Our docking of ebselen to the binding pocket of Mpro crystal structure suggests a noncovalent interaction for improvement of potency, antiviral activity and selectivity. To test this hypothesis, we designed and synthesized ebselen derivatives aimed at enhancing their non-covalent bonds within Mpro. The inhibition of Mpro by ebselen derivatives (0.3 µM) was screened in both HPLC and FRET assays. Nine ebselen derivatives (EBs) exhibited stronger inhibitory effect on Mpro with IC50 of 0.07-0.38 µM. Further evaluation of three derivatives showed that EB2-7 exhibited the most potent inhibition of SARS-CoV-2 viral replication with an IC50 value of 4.08 µM in HPAepiC cells, as compared to the prototype ebselen at 24.61 µM. Mechanistically, EB2-7 functions as a noncovalent Mpro inhibitor in LC-MS/MS assay. Taken together, our identification of ebselen derivatives with improved antiviral activity may lead to developmental potential for treatment of COVID-19 and SARS-CoV-2 infection.
Asunto(s)
Antivirales/química , Proteasas 3C de Coronavirus/química , Isoindoles/química , Compuestos de Organoselenio/química , SARS-CoV-2/enzimología , Antivirales/metabolismo , Antivirales/farmacología , Antivirales/uso terapéutico , Sitios de Unión , COVID-19/virología , Dominio Catalítico , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Proteasas 3C de Coronavirus/metabolismo , Diseño de Fármacos , Transferencia Resonante de Energía de Fluorescencia , Humanos , Isoindoles/metabolismo , Isoindoles/farmacología , Isoindoles/uso terapéutico , Simulación del Acoplamiento Molecular , Compuestos de Organoselenio/metabolismo , Compuestos de Organoselenio/farmacología , Compuestos de Organoselenio/uso terapéutico , SARS-CoV-2/aislamiento & purificación , Relación Estructura-Actividad , Espectrometría de Masas en Tándem , Tratamiento Farmacológico de COVID-19RESUMEN
We compared the electrostatic properties of the spike proteins (S-proteins) of three coronaviruses, SARS-CoV, MERS-CoV, and SARS-CoV-2, and their interactions with photosensitizers (PSs), octacationic octakis(cholinyl)zinc phthalocyanine (Zn-PcChol8+) and monocationic methylene blue (MB). We found a major common PS binding site at the connection of the S-protein stalk and head. The molecules of Zn-PcChol8+ and MB also form electrostatic encounter complexes with large area of negative electrostatic potential at the head of the S-protein of SARS-CoV-2, between fusion protein and heptad repeat 1 domain. The top of the SARS-CoV spike head demonstrates a notable area of electrostatic contacts with Zn-PcChol8+ and MB that corresponds to the N-terminal domain. The S-protein protomers of SARS-CoV-2 in "open" and "closed" conformations demonstrate different ability to attract PS molecules. In contrast with Zn-PcChol8+, MB possesses the ability to penetrate inside the pocket formed as a result of SARS-CoV-2 receptor binding domain transition into the "open" state. The existence of binding site for cationic PSs common to the S-proteins of SARS-CoV, SARS-CoV-2, and MERS-CoV creates prospects for the wide use of this type of PSs to combat the spread of coronaviruses.
Asunto(s)
Colina/metabolismo , Indoles/metabolismo , Isoindoles/metabolismo , Coronavirus del Síndrome Respiratorio de Oriente Medio/química , Compuestos Organometálicos/metabolismo , Fármacos Fotosensibilizantes/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo , Compuestos de Zinc/metabolismo , Sitios de Unión , Indoles/química , Azul de Metileno/metabolismo , Modelos Moleculares , Simulación de Dinámica Molecular , Compuestos Organometálicos/química , Conformación Proteica , Dominios Proteicos , Subunidades de Proteína/química , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/química , SARS-CoV-2/química , Glicoproteína de la Espiga del Coronavirus/química , Electricidad EstáticaRESUMEN
Inhibition of coronavirus (CoV)-encoded papain-like cysteine proteases (PLpro ) represents an attractive strategy to treat infections by these important human pathogens. Herein we report on structure-activity relationships (SAR) of the noncovalent active-site directed inhibitor (R)-5-amino-2-methyl-N-(1-(naphthalen-1-yl)ethyl) benzamide (2 b), which is known to bind into the S3 and S4 pockets of the SARS-CoV PLpro . Moreover, we report the discovery of isoindolines as a new class of potent PLpro inhibitors. The studies also provide a deeper understanding of the binding modes of this inhibitor class. Importantly, the inhibitors were also confirmed to inhibit SARS-CoV-2 replication in cell culture suggesting that, due to the high structural similarities of the target proteases, inhibitors identified against SARS-CoV PLpro are valuable starting points for the development of new pan-coronaviral inhibitors.