Peptide Stapling: How Chemical 'Staples' Lock Drug Molecules Into Their Active Shape | Research

The takeaway

Hydrocarbon stapling has become the leading method for stabilizing peptide drugs by locking them into spiral shapes that resist degradation, penetrate cells, and hit hard-to-drug targets.

Most widely adopted stapling method
Hydrocarbon stapling via ring-closing metathesis remains the dominant approach for stabilizing peptide drugs, enhancing their resistance to degradation and ability to enter cells

What the researchers found

Hydrocarbon stapling — using a chemical 'staple' to lock peptides into their spiral (alpha-helical) shape — has become the most widely adopted peptide stabilization strategy. The technique uses ruthenium-catalyzed ring-closing metathesis, a chemical reaction that forms a hydrocarbon bridge across one face of the peptide helix.

Recent advances include multiple-stapling (more than one staple per peptide), stitched peptides, aza-stapled peptides, and the integration of rigid anchoring amino acids that expand structural diversity. New modifications also enable imaging capabilities, such as Raman-active diyne bridges for diagnostic applications.

Why it matters

Regular peptides are floppy and get chewed up by enzymes in the body, limiting their use as drugs. Stapling locks them into their active shape, making them more stable, better at crossing cell membranes, and more biologically potent. This matters because stapled peptides can target protein-protein interactions — a class of drug targets that traditional small molecules largely can't reach, opening up treatment possibilities for cancers and other diseases.

The numbers in context

Most widely adopted stapling method · Ruthenium-catalyzed RCM · Strategies: mono-stapling, multi-stapling, stitched, aza-stapled · Compatible with solid-phase peptide synthesis

How the study worked

Review article summarizing advancements in hydrocarbon stapled peptide technology, covering synthetic strategies, structural innovations, and therapeutic/diagnostic applications.

Who was studied

Not applicable (chemistry/technology review)

What this study cannot tell us

As a review, no new experimental data is presented. The review focuses on chemical methodology and may not fully address in vivo efficacy or clinical translation challenges. Many stapled peptide candidates are still in early development.

How to read the evidence

This is a comprehensive chemistry review covering synthetic strategies and structural innovations in peptide stapling. It synthesizes advances across the field without presenting new experimental data.

When this study was published

Published in 2025, this is a very current review capturing the latest innovations in peptide stapling technology, including novel modifications like Raman-active bridges for imaging applications.

The bigger picture

Stapled peptides represent one of the most active areas in peptide drug development. By solving the stability and cell-penetration problems that plague regular peptides, stapling technology is enabling an entire new class of drugs that can reach previously 'undruggable' targets inside cells. Several stapled peptide candidates are in clinical trials, particularly for cancers driven by protein-protein interactions.

Questions still open

Which stapled peptide drug candidates are closest to FDA approval?
Can multi-stapling strategies improve oral bioavailability enough for pill-form stapled peptide drugs?
How do stapled peptides compare to cyclic peptides for targeting intracellular protein-protein interactions?

Common questions

What is peptide stapling and why is it important?

Peptide stapling is a technique that inserts a chemical bridge (a 'staple') across a peptide to lock it into its active spiral shape. Without stapling, peptides are floppy and get destroyed by enzymes in the body. Stapled peptides are more stable, can cross cell membranes, and are more biologically active — making them viable drug candidates for previously untreatable diseases.

What kind of diseases could stapled peptides treat?

Stapled peptides are particularly promising for cancers and diseases driven by protein-protein interactions — molecular handshakes between proteins that conventional small-molecule drugs can't disrupt. By stabilizing the peptide's shape and enabling cell penetration, stapling allows these drugs to get inside cells and break apart disease-driving protein complexes.

Read the original research

Advances in Hydrocarbon Stapled Peptides via Ring-Closing Metathesis: Synthetic Strategies, Structural Diversity, and Therapeutic Applications.

Chembiochem : a European journal of chemical biology, 26(23), e202500527

View on PubMed ↗Publisher’s paper ↗

Citation

Li, Linji; Li, Rong; Jiang, Yanan; Chao, Jingru; Chen, Si; Liao, Hongli; Li, Xiang. (2025). Advances in Hydrocarbon Stapled Peptides via Ring-Closing Metathesis: Synthetic Strategies, Structural Diversity, and Therapeutic Applications.. Chembiochem : a European journal of chemical biology, 26(23), e202500527. https://doi.org/10.1002/cbic.202500527