CDS&E: Cyclic Tetrapeptide Probes for Protein Binding Grant uri icon


  • With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Kevin Burgess of Texas A & M University to discover small molecules that affect how some proteins bind to each other. Protein-protein interactions are important to many biological processes in cells. Thus having small molecules that can either aid or or hinder protein-protein interactions could lead to potential new drugs to help treat various diseases. The project is creating new small molecules and studying their effect on protein-protein interactions. It also combines chemical synthesis, computer-aided molecular design and data-mining training for graduate and undergraduate students to help them tackle problems in contemporary life science.Cyclic peptides are known to mimic key regions involved in protein-protein interactions, i.e. to be Protein-Protein Interface (PPI) mimics. While cyclic pentapeptides are easy to make they tend to equilibrate between conformers. Conversely cyclic tetrapeptides from natural amino acids are difficult to make but are more conformationally stable. Thus, easily synthesized cyclic peptides from genetically encoded amino acids linked by main-chain amides can have ring sizes of 9, 12, 15, etc. i.e. 3n atoms, (n = # amino acids) which misses ring sizes between 12 and 15 that combine conformational rigidity with ease of synthesis. This work is showing that contrary to some earlier reports, cyclic Tetrapeptides from natural amino acids are conformationally rigid and are more synthetically accessible than previously thought. It is also showing that replacement of a genetically encoded residue with some rigid unnatural amino acids can be used to give cyclic tetrapeptides that rest at a useful crossroads between ease of synthesis and conformational rigidity.

date/time interval

  • 2016 - 2020