Download MendeleyThe Cyclic Cystine Ladder of Theta-Defensins as a Stable, Bifunctional Scaffold: A Proof-of-Concept Study Using the Integrin-Binding RGD Motif
Conibear, A.C., Bochen, A., Rosengren, K.J., Stupar, P., Wang, C., Kessler, H., Craik, D.J.(2014) Chembiochem 15: 451-459
- PubMed: 24382674 Search on PubMed
- DOI: https://doi.org/10.1002/cbic.201300568
- Primary Citation Related Structures:
2M77, 2M78, 2M79 - PubMed Abstract:
Peptides have the specificity and size required to target the protein-protein interactions involved in many diseases. Some cyclic peptides have been utilised as scaffolds for peptide drugs because of their stability; however, other cyclic peptide scaffolds remain to be explored. θ-Defensins are cyclic peptides from mammals; they are characterised by a cyclic cystine ladder motif and have low haemolytic and cytotoxic activity. Here we demonstrate the potential of the cyclic cystine ladder as a scaffold for peptide drug design by introducing the integrin-binding Arg-Gly-Asp (RGD) motif into the θ-defensin RTD-1. The most active analogue had an IC50 of 18 nM for the αv β3 integrin as well as high serum stability, thus demonstrating that a desired bioactivity can be imparted to the cyclic cystine ladder. This study highlights how θ-defensins can provide a stable and conformationally restrained scaffold for bioactive epitopes in a β-strand or turn conformation. Furthermore, the symmetry of the cyclic cystine ladder presents the opportunity to design peptides with dual bioactive epitopes to increase activity and specificity.
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Brisbane, St. Lucia, Brisbane, QLD 4072 (Australia).
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