Abstract
Replication of SARS-CoV-2, the coronavirus causing COVID-19, requires a main protease (Mpro) to cleave viral proteins. Consequently, Mpro is a target for antiviral agents. We and others previously demonstrated that GC376, a bisulfite prodrug with efficacy as an anti-coronaviral agent in animals, is an effective inhibitor of Mpro in SARS-CoV-2. Here, we report structure-activity studies of improved GC376 derivatives with nanomolar affinities and therapeutic indices >200. Crystallographic structures of inhibitor-Mpro complexes reveal that an alternative binding pocket in Mpro, S4, accommodates the P3 position. Alternative binding is induced by polar P3 groups or a nearby methyl. NMR and solubility studies with GC376 show that it exists as a mixture of stereoisomers and forms colloids in aqueous media at higher concentrations, a property not previously reported. Replacement of its Na+ counter ion with choline greatly increases solubility. The physical, biochemical, crystallographic, and cellular data reveal new avenues for Mpro inhibitor design.
【저자키워드】 COVID-19, main protease, Crystallography, Protease inhibitor, Structure-guided design, GC376 analogs, 【초록키워드】 Structure, SARS-CoV-2, Efficacy, coronavirus, media, Viral proteins, protease, MPro, Antiviral agents, therapeutic, group, inhibitor, NMR, binding, cellular, biochemical, nanomolar affinity, binding pocket, effective inhibitor, derivative, replacement, physical, concentrations, reported, form, increase, demonstrated, complexes, polar, cleave, colloid, counter ion, 【제목키워드】 antiviral drug, SARS-CoV-2 Mpro, inhibitor, Improved, increased solubility,