Thiazole-based helicase inhibitors targeting SARS-CoV-2

Introduction: The outbreak of COVID-19 demonstrated the scarcity of drugs in the development pipeline to decrease the mortality and morbidity caused by the new pathogenic SARS-CoV-2 virus. Despite the improved diagnosis and screening processes, broad directly-acting anticoronavirus drugs were not immediately available to treat viral infections. In response to this health threat, the Rapidly Emerging Read More …

Druggability and Amino Acid Variability of the Catalytic Site of SARS-CoV-2 Nsp15 Across Coronaviruses and SARS-CoV-2 Samples – Post 26

Today’s post focuses on another protein encoded by many coronaviruses, the non-structural protein 15 (nsp15), an endoribonuclease. Nsp15 is a nidoviral RNA uridylate-specific endoribonuclease (NendoU) with C-terminal catalytic activity. This protein belongs to the EndoU family, and they all carry an RNA endonuclease activity to produce 2’-3’ cyclic phosphodiester and 5’-hydroxyl termini. (Kim et al. Read More …

Druggability and Genetic Variability at nsp9 Peptide-bound Pockets and Beta-barrel Pockets Across Coronaviruses and SARS-CoV-2 Samples – Post 25

Today’s post focuses on another protein encoded in open reading frame 1a (ORF1a) of many coronaviruses, the non-structural protein 9 (nsp9). Nsp9 is thought to mediate viral replication. In SARS-CoV-1, nsp9’s role has been highlighted as a single-stranded RNA-binding subunit. (Egloff et al., 2004) The structure of SARS-CoV-2 nsp9 was solved in both apo and Read More …

Druggability and Genetic Variability of the Catalytic and Allosteric Sites of SARS-CoV-2 nsp14 Across Coronaviruses and SARS-CoV-2 Samples – Post 24

Hello and happy new year! I am back from my winter break and starting to get back to research. If you have followed my previous posts, you know that I have posted the druggability and genetic variability analysis of several protein targets of SARS-CoV-2. There are a few targets that I will be posting in Read More …

Druggability and Genetic Variability of the ATPase Site and Central Channel of SARS-CoV-2 nsp13 Helicase Across Coronaviruses and SARS-CoV-2 Samples – Post 23

One of the important enzymes in the replication cycle of the SARS-CoV-2 virus is the helicase, which is also known as non-structural protein 13 (nsp13). During the viral life cycle, the holo-RNA-dependent RNA polymerase, also known as nsp12, is thought to coordinate with several additional factors, including the nsp13 helicase (Snijder et al., 2016; Sola Read More …

Druggability and Genetic Variability of the ADP-bound Pocket of SARS-CoV-2 RNA-dependent RNA polymerase NiRAN domain Across Coronaviruses and SARS-CoV-2 Samples – Post 22

The RNA-dependent RNA-polymerase (RdRp) also known as non-structural protein 12 (nsp12) is the target of antiviral agent remdesivir. Nsp12 has an important role in viral genome replication and transcription. (Chen et al., 2020)  Chen et al. identified a new pocket on the N-terminal extension of nsp12 occupied by ADP-Mg2+ after solving the structure of the helicase-polymerase complex. This ADP-bound pocket is on the N-terminal nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain which Read More …

Production and purification of Ectodomain of SARS-CoV-2 Spike (S) protein

Production and purification of Ectodomain of SARS-CoV-2 Spike (S) protein Two different expression plasmids for prefusion S ectodomain residues 1−1208 of 2019-nCoV S (GenBank: MN908947) with proline substitutions (2P) at residues 986 and 987(1) and with six proline substitutions (HexaPro (at residues 817, 892, 899, 942, 986 and 987 (2), a “GSAS” substitution at the Read More …

Genetic Variability at An Allosteric site of SARS-CoV-2 RNA-dependent RNA polymerase Across Coronaviruses and SARS-CoV-2 Samples – Post 21

SARS-CoV-2 is a positive-strand RNA virus, depending on its multi-subunit machinery to replicate its RNA. This machinery is known as RNA-dependent RNA polymerase (RdRp). The catalytic subunit of RdRp, which is the core component of this machinery, is called nsp12. Nsp12 has little catalytic activity on its own and relies on accessory subunits to have Read More …

Production and purification of recombinant SARS COV-2 RBDSD1-Fc protein

Production and purification of recombinant SARS COV-2 RBDSD1-Fc protein from a transiently transfected EXPI293 mammalian cells. Expression plasmid for CoV-9-RBDSD1, residues of RBD R319−S591 with a C-terminal HRV3C protease cleavage site, a monomeric Fc tag and an 8XHisTag was generously gifted by Dr. McLellan’s lab (1). Secreted proteins were purified from a suspension culture cell Read More …

Production and purifications of the SARS-CoV-2 related proteins from the transiently transfected mammalian cells

Over the last few months, we have all become familiar with the COVID-19 global pandemic. The coronavirus is “decorated” with the Spike (S) protein, one of the 25 proteins of SARS-CoV-2 that are encoded in the viral genome. The infection starts with the attachment of the virus to the cell membrane to enter host cells. Read More …