Developing Covalent Protein Drugs via Proximity-Enabled Reactive Therapeutics

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Covalent drugs offer therapeutic advantages over noncovalent ones for complex diseases.
• Developing covalent protein drugs has been challenging due to proteins' inherent inability to form covalent bonds with targets.

Purpose of the Study:

• To introduce a novel proximity-enabled reactive therapeutics (PERx) approach for generating covalent protein drugs.
• To engineer human programmed cell death protein-1 (PD-1) to selectively bind PD-L1 covalently.

Main Methods:

• Utilized genetic code expansion to incorporate the bioreactive amino acid fluorosulfate-L-tyrosine (FSY) into PD-1.
• Demonstrated selective covalent reaction between FSY on PD-1 and a proximal histidine on PD-L1 upon target interaction.
• Evaluated the in vitro and in vivo efficacy of the engineered covalent PD-1(FSY) in immune-humanized mice.

Main Results:

• Engineered PD-1(FSY) achieved selective and irreversible binding to PD-L1.
• Covalent PD-1(FSY) demonstrated significantly enhanced antitumor efficacy compared to noncovalent wild-type PD-1.
• Therapeutic efficacy of covalent PD-1(FSY) was comparable or superior to anti-PD-L1 antibody treatment.

Conclusions:

• The PERx approach provides a versatile platform for creating covalent protein binders from interacting protein pairs.
• This technology enables specific covalent protein targeting, opening new therapeutic avenues for diseases.
• PERx technology overcomes limitations of conventional noncovalent protein drugs, offering enhanced therapeutic potential.