Search PubMedSearch

PubMed · 40257976

Design of nanobody targeting SARS-CoV-2 spike glycoprotein using CDR-grafting assisted by molecular simulation and machine learning.

Abstract

The design of proteins capable effectively binding to specific protein targets is crucial for developing therapies, diagnostics, and vaccine candidates for viral infections. Here, we introduce a complementarity-determining region (CDR) grafting approach for designing nanobodies (Nbs) that target specific epitopes, with the aid of computer simulation and machine learning. As a proof-of-concept, we designed, evaluated, and characterized a high-affinity Nb against the spike protein of SARS-CoV-2, the causative agent of the COVID-19 pandemic. The designed Nb, referred to as Nb Ab.2, was synthesized and displayed high-affinity for both the purified receptor-binding domain protein and to the virus-like particle, demonstrating affinities of 9 nM and 60 nM, respectively, as measured with microscale thermophoresis. Circular dichroism showed the designed protein's structural integrity and its proper folding, whereas molecular dynamics simulations provided insights into the internal dynamics of Nb Ab.2. This study shows that our computational pipeline can be used to efficiently design high-affinity Nbs with diagnostic and prophylactic potential, which can be tailored to tackle different viral targets.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Matheus V F Ferraz, W Camilla S Adan, Tayná E Lima, Adriele J C Santos, Sérgio O de Paula, Rafael Dhalia, Gabriel L Wallau, Rebecca C Wade, Isabelle F T Viana, Roberto D Lins. 2025-04-21. Design of nanobody targeting SARS-CoV-2 spike glycoprotein using CDR-grafting assisted by molecular simulation and machine learning.. https://doi.org/10.1371/journal.pcbi.1012921

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Structural and functional characterization of a conserved cryptic epitope on SARS-CoV-2 spike S2 subunit.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has undergone extensive evolution since its emergence in 2019, underscoring the continuous need for vaccines and therapeutics effective against multiple variants of concern (VOCs). The S2 subunit of the viral spike (S) glycoprotein is highly conserved among sarbecoviruses, making it an attractive target for broadly protective countermeasures. To elucidate the S2 antigenic landscape, we employed yeast surface display to isolate S2-targeted antibodies from COVID-19 convalescent donors. Biophysical characterization revealed that these S2 apex-directed antibodies preferentially bind to open spike conformations and a stabilized S2 construct but not to the closed, trimeric prefusion spike. Cryo-electron microscopy structures defined a cryptic epitope encompassing the upper helix and fusion peptide proximal region on S2. This epitope is conserved among sarbecoviruses but remains largely occluded in the closed prefusion conformation of the spikes. As a result, the antibodies exhibited weak neutralization activity against SARS-CoV-2 pseudoviruses, failed to neutralize authentic viruses, and did not provide protection in a lethal mouse challenge model using a mouse-adapted SARS-CoV-2 strain. These findings highlight a non-neutralizing epitope on S2 capable of eliciting antibodies during SARS-CoV-2 infection in humans and provide valuable reagents for probing S2 conformational dynamics and optimizing S2-based vaccine antigens.

Spike Glycoprotein, Coronavirus