Peptidomimetics of Beta-Turn Motifs Library
Peptidomimetics present organic molecules that mimic the action of peptides. These molecules may structurally resemble peptides but are distinctly different in terms of their side chains or their molecular backbones.
An attractive approach for the discovery of modulators of protein-protein interactions is to mimic the key interaction residues using small-molecule mimetics of β-turn recognition motifs. The β-turn is one of the three main secondary structural motifs found in proteins and peptides and occurs where the polypeptide strand reverses direction. A type I β-turn has the carbonyl oxygen from the amide bond between the i+1 and i+2 oriented away from the observer while in a type II turn it is oriented toward the observer. [1]
Mimetics of β-turns have been extensively investigated and utilized to discover compounds that can mimic or disrupt β-turn-mediated recognition events. Designing peptidomimetics to mimic the behavior of β-turns is easier as most of the designs are less prone to conformational changes than those for α-helix. To be considered effective, peptidomimetic must, at the least, interact with the protein in a way that is similar to the native ligand. An ideal β-turn mimetic scaffold around which to build a screening library is constrained to approximate the correct geometric display of the amino acid side-chain functionality found within a β-turn. It is sufficiently flexible to allow the side chains to approximate the side-chain vectors of the many turn types and is amenable to robust library synthesis. [2]
[1] Lam, Sang Q. (2005). Contributions to peptidomimetic design: predictive computational studies and syntheses of linker molecules. Master's thesis, Texas A&M University. Texas A&M University.
[2] L. R. Whitby, Y. Ando, V. Setola, P. K. Vogt, B. L. Roth, and D. L. Boger, “Design, synthesis, and validation of a β-turn mimetic library targeting protein - Protein and peptide - Receptor interactions,” J. Am. Chem. Soc., vol. 133, no. 26, pp. 10184–10194, 2011, doi: 10.1021/ja201878v.