In vitro Characterization of Peptidomimetic Proteolysis Targeting Chimera (PROTAC) as a Degrader of 3-Chymotrypsin-Like Protease (Mpro/3CLpro) against SARS-CoV-2

Mirko Giuseppe Liturri; Annalisa Bergna; Alessia Lai; Carla Della Ventura; Arianna Gabrieli; Ioana Seravalli; Simone Ciofi‐Baffoni; Elena Lenci; Andrea Trabocchi; Stefano Rusconi

doi:10.1101/2025.10.30.685646

MicrobiologybioRxivOct 30, 2025

Preprint

In vitro Characterization of Peptidomimetic Proteolysis Targeting Chimera (PROTAC) as a Degrader of 3-Chymotrypsin-Like Protease (Mpro/3CLpro) against SARS-CoV-2

Mirko Giuseppe Liturri iD, Annalisa Bergna iD, Alessia Lai iD, Carla Della Ventura iD, Arianna Gabrieli iD, Ioana Seravalli, Simone Ciofi‐Baffoni iD, Elena Lenci iD, Andrea Trabocchi iD, Stefano Rusconi iD

Abstract

The SARS-CoV-2 main protease (3CLpro) is a key target for antiviral development. We investigated FT235, a peptidomimetic PROTAC linking a GC-376 warhead to pomalidomide for targeted degradation. FT235 bound 3CLpro, inhibiting activity (IC50 = 21.2 {micro}M), and reducing protease levels in cells. In vitro data showed no cytotoxicity up to 100 {micro}M and variant-dependent antiviral activity, with increased potency in the presence of a P-gp inhibitor. These results support PROTAC-based antivirals as promising therapeutic candidates.

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