Engineering a Plant Viral Coat Protein for In Vitro Hybrid Self-Assembly of CO2‑Capturing Catalytic Nanofilaments

Plant virus-based nanoparticles are used as self-assembled protein scaffolds for the construction of enzyme nanocarriers. To date, one-pot production and coupling of both enzymes and scaffolds by genetic conjugation have been demonstrated only in plants. Herein, we report bacterial production and in vitro self-assembly of nanofilaments for CO2 capture. Filamentous virus-like particles (VLPs) were successfully formed by genetically fusing carbonic anhydrase from Hydrogenovibrio marinus (hmCA) to the N terminus of the coat protein (CPPVY) of potato virus Y with a flexible linker. The instability of VLPs against proteolytic degradation was circumvented by the periplasmic export of the fusion protein. The truncated form of CPPVY coexpressed by internal translation was crucial for the successful formation of long filamentous VLPs by alleviating steric hindrance via hybrid assembly. The fast and economic bottom-up fabrication of highly active nanobiocatalyst allows the nanofilaments to be efficiently used and recovered in potential biocatalytic and biosensor systems.