SARS-CoV caused the SARS epidemic in 2002–2003, with over 8,000 infections and a fatality rate around 10%. In late 2019, another coronavirus emerged as a human pathogen in the city of Wuhan in China, producing symptoms such as fever, severe respiratory impairment, and pneumonia (Petersen et al., 2020). This new coronavirus has been denominated SARS-CoV-2 for its genetic resemblance with SARS-CoV (∼80%), and its related disease has been named COVID-19 (COronaVIrus Disease 2019). Owing to its high reproduction number R0 (2–3), SARS-CoV-2 has rapidly diffused in several countries and is currently posing a significant global health threat. On March 11, 2020, the WHO has declared the COVID-19 outbreak a pandemic. The early discovery that SARS-CoV-2 also engages ACE2 as entry door for cell infection has prompted an intense research effort to elucidate the biochemical determinants of CoV-ACE2 interactions.