Fig. 1: Design principle, spike binding kinetics, and viral inhibition using trimeric ACE2 constructs.
From: Development of an ultrahigh affinity, trimeric ACE2 biologic as a universal SARS-CoV-2 antagonist
a Diagram depicting density modeling for three ACE2 monomers (pink) binding the RBDs of SARS-CoV-2 spike (blue) with average distances between N-termini (residue S22) of five EM structures was 49 ± 5 Å (blue dashes), and between C-termini (residue Y613) was 113 ± 7 Å (red dashes); and construction of monomeric and trimeric ACE2 antagonists where trimeric antagonists fuse collagen XVIII trimerization domain (TD) to the N-terminus of ACE2 extracellular domain (ACE2). White-cyan dashes represent variable linker lengths. b, c SPR sensograms of ACE2 constructs binding to b SARS-CoV-2 recombinant spike HexaPro protein, and c SARS-CoV recombinant spike protein, n = 2. d, e ACE2 constructs inhibition in a single-round infection of HEK293-hACE2 cells against an HIV-based pseudotyped virus using full-length SARS-CoV-2 spike protein from: Wuhan-Hu-1, Delta B.1.617.2, or Omicron BA.1 strains, and select T3A constructs tested against Arcturus XBB.1.1 strain, n = 3; and e select T3A constructs and ACE2 monomer against stabilized, wildtype SARS-CoV-1 spike protein, n = 2. Errors described by standard deviation from n biological replicates. For clarity, all sensograms and infectivity curves generated from a single, representative experiment.
