Dual coiled-coil protein domain mimic and drug delivery vehicle for SARS-CoV-2

Abstract

SARS-CoV-2 has emerged as a strong target for the development of protein domain mimics (PDMs) as it relies on the helical protein-protein interaction (PPI) between the N-terminal α-helix of ACE2, ACEBINDER, with the SARS-CoV-2 receptor binding domain (RBD). We have recently developed an ACEBINDER-based multivalent assembled protein (ACE-MAP) that relies on fusion of a binding domain to the cartilage oligomeric matrix protein coiled-coil domain (COMPcc) by way of a kinked rigid linker. Using an optimized binding sequence, ACEBINDER2, and an optimized kinked linker for increased solvent exposure, we generate ACE-MAP-2 for resilient binding across SARS-CoV-2 variants including D614G, B.1.617.2, BA.2, and XBB1.5. We furthermore demonstrate that ACE-MAP-2 can be used for synergistic neutralization of SARS-CoV-2 by utilizing its coiled-coil pore for small molecule encapsulation of ritonavir, imbuing ACE-MAP-2 was the capability of both a drug delivery vehicle and PDM antagonist. Where there does not exist antibody-drug conjugates (ADCs) for SARS-CoV-2, these properties of ACE-MAP-2 allow it to possess unique, but similar characteristics to ADCs, where covalent linkage is not required for the ability for ACE-MAP-2 to encapsulate and deliver a targeted therapeutic payload.