Structure-Based Adaptation of a SARS-CoV-2 Neutralizing Peptide to New Virus Variants.

The starting point of this work was a SARS-CoV-2 neutralizing peptide (LW25.13), which binds to the receptor-binding domain of the viral spike protein and inhibits the attachment of the virus to its cellular receptor ACE2. As LW25.13 is unable to neutralize later SARS-CoV-2 variants, such as omicron, we have extended the neutralization breadth of LW25.13 through structural and bioinformatic analysis. This involved the systematic variation of a range of positions and yielded peptides neutralizing SARS-CoV-2 beta and omicron at low nanomolar concentrations, while preserving the strong neutralizing capacity against earlier virus variants (wild-type, alpha, delta), as well as the proteolytic stability and α-helical conformation of the peptide. This gain in neutralizing breadth illustrates the utility of the peptide as a scaffold that can be adapted to different virus variants, which may prove useful for the development of peptides against new coronavirus variants of concern in the future.