Encapsidic production and isolation of degradation-prone polypeptides

Abstract

Degradation during production and delivery is a significant bottleneck in developing biomolecular therapies. Protein cages, formed by engineered variants of lumazine synthase, present an effective strategy for the microbial production and isolation of labile biomolecular therapies. Genetic fusion of the target polypeptide to a cage component protomer ensures its efficient encapsulation within the cage during production in host bacterial cells, thereby protecting it from degradation. Furthermore, controlled cage opening outside the cellular environment facilitates the isolation of the encapsulated cargo through sequence-specific protease cleavage. Notably, the system features a modular patchwork assembly to prevent guest overloading, avoiding unwanted incomplete cage formation and insoluble aggregates. The broad applicability of the “encapsidic” approach is demonstrated by the efficient production of six distinct, intrinsically disordered polypeptides with proven therapeutic potential.