Congresso Nazionale della Divisione di Chimica dei Sistemi Biologici

In recent years, PROteolysis TArgeting Chimera (PROTAC) technology has become a promising strategy in drug design, and with the spread of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) in 2020, it has been explored to address coronavirus (CoV) disease (1). An attractive approach for contrasting future outbreaks due to CoV infections relies on the development of PROTAC degraders against the Sars-CoV-2 main viral protease (3-chymotrypsin-like protease, 3CLPro). The latter is a promising target to investigate as it is highly conserved among all Coronavirus genera and members of the Enterovirus genus, it is essential for viral replication and transcription and has no related homologues in humans (2,3,4). Unlabelled and isotope-labelled 3CLPro was produced and purified by our research group, achieving high final yields and purity levels. 1H-15N Heteronuclear single quantum coherence (HSQC) NMR experiments were performed to structurally characterize the interaction between novel warhead ligands, as well as the corresponding PROTACs, and the viral target, identifying the key residues involved in binding through chemical shift perturbation mapping analysis. To gain further insight into the binding mode of both the warhead and PROTAC ligands with 3CLPro, crystallization studies were carried out. In the near future, NMR experiments suitable for large MW complexes will be exploited to structurally characterize the 3CLPro:PROTAC:E3 ternary complex and results from NMR chemical shift perturbation will allow us to build a 3D-structural model by taking advantages of data-driven docking approaches.