Automated fast-flow synthesis of the immune checkpoint receptors PD-1 and PD-L1

Area of Science:

• Biochemistry
• Protein Chemistry
• Cancer Biology

Background:

• Programmed cell death protein 1 (PD-1) and its ligand PD-L1 are crucial targets in cancer immunotherapy.
• Producing these proteins in active, soluble forms for research and therapeutic development presents significant challenges due to their complex structures.

Purpose of the Study:

• To develop a rapid and efficient method for synthesizing active forms of PD-1 and PD-L1.
• To create stable, synthetic mutants of PD-1 and PD-L1 for further investigation in cancer therapy and drug discovery.

Main Methods:

• Utilized automated fast-flow peptide synthesis (AFPS) for rapid protein production.
• Employed oxidative refolding protocols to achieve active protein conformations.
• Introduced L-norleucine substitutions for L-methionine to create air-stable mutants.

Main Results:

• Successfully produced active, β-sheet-rich PD-1 and PD-L1 proteins using AFPS.
• Generated synthetic, air-stable mutants of PD-1 and PD-L1 by substituting methionine with norleucine.
• Demonstrated a rapid method for accessing these key cancer targets.

Conclusions:

• AFPS provides a fast route to active PD-1 and PD-L1 proteins.
• Synthetic mutants offer stable alternatives for studying protein function and developing new cancer therapies.
• This approach facilitates research into post-translational modifications and mirror-image drug analogs.