Avimer Bio and CNIO Crack Atomic Precision in Protein Cage Design

Traditional protein engineering often faltered when building blocks exhibited natural flexibility, as designers struggled to predict how these segments would behave during assembly. The team addressed this by developing computational algorithms that map the bending of alpha helices. This approach allows the inherent flexibility of protein molecules to serve the assembly process rather than hindering it. The resulting cubic cages, composed of twelve subunits, maintain stability in solution at molecular masses exceeding 600 kilodaltons.

Validation came through high-resolution cryo-electron microscopy conducted at CNIO in Madrid. Led by Pablo San Segundo-Acosta and Roger Castells-Graells, the imaging confirmed that physical assemblies matched computational models with structural deviations as low as 2 angstroms. Such precision allows these cages to display multiple therapeutic proteins in specific, controlled arrangements, offering a significant advantage over conventional antibodies that rely on only two binding arms.

This programmable architecture holds promise for treating autoimmune conditions like rheumatoid arthritis and ulcerative colitis by precisely engaging immune cell receptors. In oncology, the cages can be engineered to cluster receptors that trigger immune responses against tumors. Because the platform utilizes single-subunit compositions and requires minimal mutations to natural sequences, it offers a streamlined production path while minimizing potential immunogenicity in patients.