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Tuning the Anti-Angiogenic Effect of the P15 Peptide Using Cyclic Trypsin Inhibitor Scaffolds
Lai Yue Chan1, Junqiao Du1, David J Craik1
1Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072, Australia.
Abstract:
Angiogenesis is important for tumor growth, and accordingly, targeting angiogenesis has become an important pathway for antitumor therapy. A novel proapoptotic peptide, CIGB-300 (P15-Tat), has been shown to be involved in the casein kinase II phosphorylation pathway, conferring it with antiangiogenic activity. Cyclic peptides have been widely used as scaffolds in drug design studies due to their high stability and favorable biopharmaceutical properties. Here, we chose two very stable cyclic trypsin inhibitors, MCoTI-II and SFTI-1, as frameworks to incorporate the bioactive epitope P15 into various backbone loops. NMR studies revealed that all re-engineered analogs had similar secondary structures to their native cyclic frameworks. One key analog, MCoP15, displayed significant improvement for inhibiting human umbilical vein endothelial cell migration, was nontoxic, and had higher stability than the P15 epitope alone. Overall, the results show the value of P15 being engineered into cyclic trypsin inhibitor scaffolds for improving antiangiogenic activity and stability. More broadly, the study highlights the versatility of cyclic peptide frameworks in drug design for antiangiogenic therapies.
Insights
Researchers engineered a novel anti-cancer peptide (P15) into stable cyclic peptide scaffolds. The resulting compound, MCoP15, demonstrated enhanced anti-angiogenic activity and stability, offering a promising new avenue for cancer therapy development.
Area of Science:
- Biochemistry
- Molecular Biology
- Drug Discovery
Background:
- Tumor growth relies on angiogenesis, making anti-angiogenic strategies crucial for cancer therapy.
- The proapoptotic peptide CIGB-300 (P15-Tat) exhibits anti-angiogenic properties via the casein kinase II pathway.
- Cyclic peptides offer enhanced stability and favorable biopharmaceutical characteristics for drug design.
Purpose of the Study:
- To incorporate the P15 epitope into stable cyclic peptide scaffolds (MCoTI-II and SFTI-1) to enhance anti-angiogenic activity and stability.
- To evaluate the structural integrity and anti-angiogenic efficacy of the engineered cyclic peptides.
Main Methods:
- Design and synthesis of cyclic peptide analogs incorporating the P15 epitope into MCoTI-II and SFTI-1 frameworks.
- Nuclear Magnetic Resonance (NMR) spectroscopy to confirm secondary structures of engineered analogs.
- In vitro assays to assess inhibition of human umbilical vein endothelial cell migration and cytotoxicity.
Main Results:
- Engineered cyclic peptides maintained similar secondary structures to their native scaffolds.
- The analog MCoP15 showed significantly improved inhibition of endothelial cell migration compared to P15 alone.
- MCoP15 exhibited no cytotoxicity and demonstrated enhanced stability.
Conclusions:
- Engineering the P15 epitope into cyclic trypsin inhibitor scaffolds effectively enhances anti-angiogenic activity and stability.
- Cyclic peptide frameworks are versatile platforms for developing novel anti-angiogenic therapeutics.
- This approach holds promise for advancing antitumor therapies by targeting angiogenesis.
