Enhancing Monodispersity and Thermal Stability of Human H-Ferritin as a Nanocarrier by Protein Design

Cage-like ferritin has been explored as a new class of nanovehicle in the field of food and nutrition, but its aggregation characteristics and low thermal stability limit its further application. This study focused on improving the monodispersity and thermal stability of recombinant human H-ferritin (rHuHF) for enhanced cargo molecule delivery. With the aid of AlphaFold 3.0, we designed a ferritin mutant by removing cysteine residues of rHuHF to improve monodispersity during storage while introducing histidine mutations at the C3 and C4 interfaces to enhance thermal stability. Notably, the designed protein structure was validated by a resolved crystal structure at the atomic level. As expected, the designed ferritin nanocage exhibited significantly improved monodispersity and thermal stability, enhancing its cargo loading capacity and cellular uptake efficiency. Such designed ferritin offers a more stable, efficient nanocarrier for cargo delivery and cargo protection under heat stress as compared to wild-type rHuHF.