An orally available P1'-5-fluorinated M inhibitor blocks SARS-CoV-2 replication without booster and exhibits high genetic barrier.

We identified a 5-fluoro-benzothiazole-containing small molecule, TKB272, through fluorine-scanning of the benzothiazole moiety, which more potently inhibits the enzymatic activity of SARS-CoV-2's main protease (M) and more effectively blocks the infectivity and replication of all SARS-CoV-2 strains examined including Omicron variants such as SARS-CoV-2 and SARS-CoV-2 than two M inhibitors: nirmatrelvir and ensitrelvir. Notably, the administration of ritonavir-boosted nirmatrelvir and ensitrelvir causes drug-drug interactions warranting cautions due to their CYP3A4 inhibition, thereby limiting their clinical utility. When orally administered, TKB272 blocked SARS-CoV-2 replication without ritonavir in B6.

Fine-tuning probes for fluorescence polarization binding assays of bivalent ligands against polo-like kinase 1 using full-length protein.

Polo-like kinase 1 (Plk1) is an important cell cycle regulator that is a recognized target for development of anti-cancer therapeutics. Plk1 is composed of a catalytic kinase domain (KD), a flexible interdomain linker and a polo-box domain (PBD). Intramolecular protein-protein interactions (PPIs) between the PBD and KD result in "auto-inhibition" that is an essential component of proper Plk1 function.

Respiratory-gated proton beam therapy for intrahepatic cholangiocarcinoma without fiducial markers.

Background: Intrahepatic cholangiocarcinoma (ICC) is a challenging primary liver cancer with a poor prognosis, especially in unresectable cases. Traditional palliative irradiation is limited in reducing liver doses. This study aimed to evaluate the efficacy and toxicity of respiratory-gated proton beam therapy without fiducial markers for intrahepatic cholangiocarcinoma.

Naphthalen-1-ylethanamine-containing small molecule inhibitors of the papain-like protease of SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has not yet been eradicated. SARS-CoV-2 has two types of proteases, a main protease (M) and a papain-like protease (PL), which together process two translated non-structural polyproteins, pp1a and pp1ab, to produce functional viral proteins. In this study, effective inhibitors against PL of SARS-CoV-2 were designed and synthesized using GRL-0048 as a lead.

Structural and virologic mechanism of the emergence of resistance to M inhibitors in SARS-CoV-2.

We generated SARS-CoV-2 variants resistant to three SARS-CoV-2 main protease (M) inhibitors (nirmatrelvir, TKB245, and 5h), by propagating the ancestral SARS-CoV-2 in VeroE6 cells with increasing concentrations of each inhibitor and examined their structural and virologic profiles. A predominant E166V-carrying variant (SARS-CoV-2), which emerged when passaged with nirmatrelvir and TKB245, proved to be resistant to the two inhibitors. A recombinant SARS-CoV-2 was resistant to nirmatrelvir and TKB245, but sensitive to 5h.