Long range Trp-Trp interaction initiates the folding pathway of a pro-angiogenic β-hairpin peptide.

HPLW, a designed VEGF (Vascular Endothelium Growth Factor) receptor-binding peptide, assumes a well folded β-hairpin conformation in water and is able to induce angiogenesis in vivo. In this study, we investigated at atomic resolution the thermal folding/unfolding pathway of HPLW by means of an original multi-technique approach combining DSC, NMR, MD and mutagenesis analyses. In particular, careful NMR investigation of the single proton melting temperatures together with DSC analysis accurately delineate the peptide folding mechanism, which is corroborated by computational folding/unfolding simulations.

Functional binding surface of a β-hairpin VEGF receptor targeting peptide determined by NMR spectroscopy in living cells.

In this study, the functional interaction of HPLW peptide with VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) was determined by using fast (15)N-edited NMR spectroscopic experiments. To this aim, (15)N uniformly labelled HPLW has been added to Porcine Aortic Endothelial Cells. The acquisition of isotope-edited NMR spectroscopic experiments, including (15)N relaxation measurements, allowed a precise characterization of the in-cell HPLW epitope recognized by VEGFR2.

Design, structural and biological characterization of a VEGF inhibitor β-hairpin-constrained peptide.

The design, structural and biological characterization of a novel VEGF inhibitor peptide is described. The peptide was designed on the β5-β6 hairpin region of Placenta Growth Factor. NMR studies showed that the peptide assumes in solution a β-hairpin conformation similarly to the corresponding region of the natural ligand.

Semi-synthesis of labeled proteins for spectroscopic applications.

Since the introduction of SPPS by Merrifield in the 60s, peptide chemists have considered the possibility of preparing large proteins. The introduction of native chemical ligation in the 90s and then of expressed protein ligation have opened the way to the preparation of synthetic proteins without size limitations. This review focuses on semi-synthetic strategies useful to prepare proteins decorated with spectroscopic probes, like fluorescent labels and stable isotopes, and their biophysical applications.