In-cell design of solid biocatalyst via crystalline inclusion protein A and ferritin fusion

Abstract Crystalline inclusion protein A is a protein crystal that spontaneously forms in living cells. To construct a hybrid solid material, we engineered crystalline inclusion protein A by fusion with functionalized ferritin at the C-terminal. When ferritin was mutated with His residues, the resulting solid material exhibited peroxidase mimetic oxidation of 3,3ʹ,5,5ʹ-tetramethylbenzidine in the presence of hydrogen peroxide. This study provides a simple method to develop functional solid materials.