Structure-Based Optimization of Pyridone α-Ketoamides as Inhibitors of the SARS-CoV-2 Main Protease.

The main protease M is a clinically validated target to treat infections by the coronavirus SARS-CoV-2. Among the first reported M inhibitors was the peptidomimetic α-ketoamide , whose cocrystal structure with M paved the way for multiple lead-finding studies. We established structure-activity relationships for the series by modifying residues at the P1', P3, and P4 sites.

Why is the Omicron main protease of SARS-CoV-2 less stable than its wild-type counterpart? A crystallographic, biophysical, and theoretical study of the free enzyme and its complex with inhibitor 13b-K.

During the continuing evolution of SARS-CoV-2, the Omicron variant of concern emerged in the second half of 2021 and has been dominant since November that year. Along with its sublineages, it has maintained a prominent role ever since. The Nsp5 main protease (M) of the Omicron virus is characterized by a single dominant mutation, P132H.

From Repurposing to Redesign: Optimization of Boceprevir to Highly Potent Inhibitors of the SARS-CoV-2 Main Protease.

The main protease (M) of the betacoronavirus SARS-CoV-2 is an attractive target for the development of treatments for COVID-19. Structure-based design is a successful approach to discovering new inhibitors of the M. Starting from crystal structures of the M in complexes with the Hepatitis C virus NS3/4A protease inhibitors boceprevir and telaprevir, we optimized the potency of the alpha-ketoamide boceprevir against the M by replacing its P1 cyclobutyl moiety by a γ-lactam as a glutamine surrogate.

Structural Features of a Full-Length Ubiquitin Ligase Responsible for the Formation of Patches at the Plasma Membrane.

Plant U-box armadillo repeat (PUB-ARM) ubiquitin (Ub) ligases have important functions in plant defense through the ubiquitination of target proteins. Defense against pathogens involves vesicle trafficking and the formation of extracellular vesicles. The PUB-ARM protein SENESCENCE ASSOCIATED UBIQUITIN E3 LIGASE1 (SAUL1) can form patches at the plasma membrane related to tethering multi-vesicular bodies (MVBs) to the plasma membrane.