|
?:abstract
|
-
Three coronaviruses (CoVs): severe acute respiratory syndrome coronavirus (SARS-CoV-1), Middle East respiratory syndrome coronavirus (MERS-CoV), and the recently identified SARS-CoV-2 in December 2019, have caused deadly pneumonia in humans since the beginning of the 21st century The SARS-CoV-2 causes coronavirus disease-19 (COVID-19) with influenza-like symptoms ranging from mild discomfort to severe lung injury and multi-organ failure, eventually leading to death As of April 30, 2020, more than three million (3,175,207) COVID-19 cases were reported worldwide, and more than 220,000 (224,172) patients have died (https://www who int/emergencies/diseases/novel-coronavirus-2019) Effective treatments and vaccines for SARS-CoV-2 infection do not currently exist Thus, it will be of great benefit to identify and repurpose already well-characterized compounds and approved drugs for use in combating COVID-19 /CoVs are positive-sense RNA viruses that replicate in the cytoplasm of infected cells Replication and transcription of the CoV RNA genome are achieved by a complex RNA replication/transcription machinery, consisting of at least 16 viral nonstructural proteins (nsp) Previous studies demonstrated that nsp16 proteins of SARS-CoV-1 and MERS-CoV have methyltransferase (MTase) activities that catalyze methylation of the first transcribed nucleotide at the ribose 2’-O position (2’-O-Me) The 2’-O-Me of virus caRNAs protects itself from degradation by 5′-3′ exoribonucleases, ensures efficient translation, and helps to prevent recognition by the host innate immune system The importance of nsp16 2\'-O-MTase activity for CoV infection and pathogenesis was previously documented by in vitro and in vivo studies For SARS-CoV-1, the absence of nsp16 2′-O-MTase activity results in significant attenuation characterized by decreased viral replication, reduced weight loss, and limited breathing dysfunction in mice In addition, nsp16 down-regulates the activities of innate immune sensing factors: retinoic acid-inducible gene (RIG-I) and melanoma differentiation-associated gene 5 protein (MDA5) Thus, inhibition of nsp16 2’-O-MTase activities should restrain viral replication and enable recognition by the host innate immune system, making the nsp16-MTase a promising target for the identification of new anti-SARS-CoV-2 drugs /In the present study, we employed structural analysis, virtual screening, and systematic drug repurposing approaches to identify “approved†drugs which can act as promising inhibitors against nsp16 2′-O-MTase of SARS-CoV-2 We first performed comparative analysis of primary amino acid sequences and crystal structures of seven human CoVs and defined the key residues for nsp16 2-O’-MTase functions From the virtual screening against nsp16 2′-O-MTase of SARS-CoV-2, we provide a ranking of the predicted binding affinities of 1,380 tohit compounds corresponding to 967 “approved†drugs Furthermore, we have calculated various structural parameters of our top-ranking drugs Our studies provided the foundation to further test and repurpose these candidate drugs experimentally and clinically for COVID-19 treatment /br
|
![[This page as RDF]](https://research.tib.eu/covid-19/static/rdf-icon.gif){kind=icon}