Covalently Engineered Protein Minibinders with Enhanced Neutralization Efficacy against Escaping SARS-CoV-2 Variants br

The rapid emergence and spread of escaping mutations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has significantly challenged our efforts infighting against the COVID-19 pandemic. A broadly neutralizing reagent againstthese concerning variants is thus highly desirable for the prophylactic and therapeutic treatments of SARS-CoV-2 infection. Weherein report a covalent engineering strategy on protein minibinders for potent neutralization of the escaping variants such asB.1.617.2 (Delta), B.1.617.1 (Kappa), and B.1.1.529 (Omicron) through in situ cross-linking with the spike receptor binding domain(RBD). The resulting covalent minibinder (GlueBinder) exhibited enhanced blockage of RBD-human angiotensin-convertingenzyme 2 (huACE2) interaction and more potent neutralization effect against the Delta variant than its noncovalent counterpart asdemonstrated on authentic virus. By leveraging the covalent chemistry against escaping mutations, our strategy may be generally applicable for restoring and enhancing the potency of neutralizing antibodies to SARS-CoV-2 and other rapidly evolving viral targets.