Recent scientific advancements have unveiled an enzyme that holds the potential to significantly enhance the effectiveness of GLP-1 medications, particularly semaglutide, the active component in popular treatments like Ozempic and Wegovy. By transforming these medications into ring-shaped structures, researchers aim to improve their durability and efficacy.
The Importance of Cyclic Peptides in Medicine
Ring-shaped peptides present numerous benefits compared to their linear counterparts. Co-author Karsten Eastman, a research associate at the University of Utah's Department of Chemistry and co-founder of Sethera Therapeutics, notes that these structures exhibit increased stability, prolonged activity, and superior interaction with biological targets.
"Peptides can be challenging to manipulate due to their reactive nature, but this also makes them valuable in biological processes. Our study introduces an enzymatic technique that allows for precise modifications of peptides, paving the way for next-generation therapeutics," Eastman explained, having completed his Ph.D. in 2023 under the guidance of Professor Vahe Bandarian.
Sethera Therapeutics, founded by Eastman and Bandarian, is focused on translating these discoveries into practical applications, with backing from the National Institutes of Health. Their innovation was recently acknowledged with the title of 2025 Founders of the Year by the university's Technology Licensing Office for their PolyMacrocyclic Peptide (pMCP) Discovery Platform.
Simplifying Peptide Modification
The conventional methods for closing peptide chains into rings have often been complex and expensive, particularly in later stages of drug development. The enzyme PapB offers a more efficient alternative, forming precise bonds between peptide ends without the need for additional "leader" sequences typically required for enzyme recognition.
In their study, published in ACS Bio & Med Chem Au, the research team utilized PapB, a "radical SAM" enzyme, to successfully connect the ends of GLP-1-like peptides, forming thioether bonds. Laboratory tests confirmed PapB's ability to create these ring structures, even with nonstandard building blocks found in modern incretin drugs.
Adaptable Enzyme for Complex Drug Structures
Lead author Jake Pedigo, a graduate student in Bandarian's lab, remarked on the enzyme's surprising flexibility. "PapB functioned effectively without the usual leader sequence and adapted well to different amino acids, making it a valuable tool for peptide engineering," he noted.
Previous studies had hinted at the viability of this ring-forming strategy, but the current research substantiates its practical application. The team demonstrated that PapB could transform three distinct GLP-1-like peptides from linear to ring structures, showcasing its potential as a versatile tool in drug development.
Enhancing Drug Longevity
This innovative approach addresses a critical challenge in peptide-based therapies: the rapid breakdown of these drugs by proteases in the body. Eastman emphasized, "By sealing the peptide ends, we can effectively shield them from common proteases, potentially extending their therapeutic lifespan."
Future Prospects for GLP-1 Therapeutics
The findings indicate that PapB's capabilities could revolutionize peptide drug development, allowing for more stable, targeted, and easier-to-manufacture therapies. Eastman concluded, "While current GLP-1 medications are already effective, our enzymatic modifications could enhance their performance, stability, and signaling capabilities, thereby improving patient outcomes."