SBP1 is a 23 amino acid fragment of the angiotensin-converting enzyme 2 (ACE2) peptidase domain (PD) alpha1 helix, a key domain for the interaction of ACE2 with the severe acute respiratory syndrome coronavirus receptor binding domain (SARS-CoV-2-RBD). SBP1 binds to the SARS-CoV-2-RBD with an affinity comparable with the corresponding spike protein of SARS-CoV, and can potentially block the mechanism by which SARS-CoV-2 enters into cells. SBP1 offers an opportunity for therapeutic intervention in COVID-19.