Site-Specific Abiraterone Protein-Drug Conjugates via Hedgehog Autoprocessing

Area of Science:

• Biochemistry
• Protein Engineering
• Drug Delivery

Background:

• Protein lipoengineering has been limited to inert lipids.
• Developing methods to functionalize proteins with bioactive molecules is crucial for advanced therapeutics.

Purpose of the Study:

• To develop a novel biocatalytic method for installing anticancer sterols onto proteins.
• To create programmable protein-drug conjugates (PDCs) with improved therapeutic properties.

Main Methods:

• Repurposed the hedgehog autoprocessing domain as a biocatalyst.
• Installed abiraterone, an anticancer sterol, as a noncanonical post-translational modification (ncPTM) on an intrinsically disordered protein.
• Synthesized protein-drug conjugates (PDCs) and evaluated their properties in prostate-cancer cells and 3D tumor spheroids.

Main Results:

• Achieved enhanced protein solubility, tunable phase behavior, and dynamic self-association of PDCs.
• Demonstrated slow hydrolytic release of abiraterone from PDCs.
• Showcased cytotoxic response in prostate-cancer cells with uniform activity in 3D tumor spheroids.
• Successfully extended the method to galeterone, another steroidal agent.

Conclusions:

• Established a generalizable ncPTM strategy for constructing molecularly defined, programmable protein-drug therapeutics.
• This approach leverages native lipidation machinery for advanced drug development.