Publication date: Oct 01, 2025
The persistent circulation of SARS-CoV-2 and limited efficacy of current vaccines in preventing viral transmission underscore the critical need for broad-spectrum antivirals. Here, we report a novel engineering strategy to develop A3M6L35HR2 (FL), a cholesterol-free recombinant peptide derived from our previously reported A1L35HR2, by incorporating an optimized angiotensin-converting enzyme 2 (ACE2)-mimetic peptide A3M6 with six residue mutations. A3M6L35HR2 (FL) exhibited superior inhibitory potency against diverse SARS-CoV-2 variants with IC from 1. 7 to 16. 2 nM, including antigenically distinct Omicron sublineages, achieving 2- to 29-fold enhanced activity compared to A1L35HR2. A3M6L35HR2 (FL) exhibits a higher α-helicity (70 %) and stronger binding affinity (K = 0. 03 nM) with the viral HR1 domain, thereby effectively suppressing spike-mediated membrane fusion at nanomolar concentrations. Combining A3M6L35HR2 (FL) with RBD-targeting protein T-ACE2 exhibited antagonistic effect, attributed to competitive RBD binding by both agents. These findings establish A3M6L35HR2 (FL) as a promising antiviral candidate against current and emerging SARS-CoV-2 variants.

Semantics
| Type | Source | Name |
|---|---|---|
| drug | DRUGBANK | Cholesterol |
| disease | MESH | COVID-19 |
| disease | IDO | protein |