Site-Specific Abiraterone Protein-Drug Conjugates via Hedgehog Autoprocessing

Protein lipoengineering is a promising approach for programming biomolecular assembly and function, yet its use has remained confined to biologically inert lipids. Here, we repurpose the hedgehog autoprocessing domain as a biocatalyst to install the anticancer sterol abiraterone as a noncanonical post-translational modification (ncPTM) on an intrinsically disordered protein scaffold. Artificial abirateronylation produced protein-drug conjugates (PDCs) with significantly enhanced solubility, tunable phase behavior, and dynamic self-association. The conjugates underwent slow hydrolytic release of abiraterone and reproduced the cytotoxic response of the free drug in prostate-cancer cells, achieving more uniform activity and distributions in 3D tumor spheroids. By extending this approach to a second steroidal prostate-cancer agent, galeterone, we demonstrate a generalizable ncPTM strategy for exploiting native lipidation machinery to construct molecularly defined, programmable protein-drug therapeutics.