Structure-function analysis of the antiangiogenic ATWLPPR peptide inhibiting VEGF(165) binding to neuropilin-1 and molecular dynamics simulations of the ATWLPPR/neuropilin-1 complex.
Heptapeptide ATWLPPR (A7R), identified in our laboratory by screening a mutated phage library, was shown to bind specifically to neuropilin-1 (NRP-1) and then to selectively inhibit VEGF(165) binding to this receptor. In vivo, treatment with A7R resulted in decreasing breast cancer angiogenesis and growth. The present work is focused on structural characterization of A7R. Analogs of the peptide, obtained by substitution of each amino acid with alanine (alanine-scanning) or by amino acid deletion, have been systematically assayed to determine the relative importance of the side chains of each residue with respect to the inhibitory effect of A7R on VEGF(165) binding to NRP-1. We show here the importance of the C-terminal sequence LPPR and particularly the key role of C-terminal arginine. In solution, A7R displays significant secondary structure of the backbone adopting an extended conformation. However, the functional groups of arginine are very flexible in the absence of NRP-1 pointing to an induced fit upon binding to the receptor. A MD trajectory of the A7R/NRP-1 complex in explicit water, based on the recent tuftsin/NRP-1 crystal structure, has revealed the hydrogen-bonding network that contributes to A7R's binding activity.
Starzec
Anna
A
Université Paris 13, UMR 7033, 74 rue Marcel Cachin, 93017 Bobigny, France.
Ladam
Patrick
P
Vassy
Roger
R
Badache
Sabah
S
Bouchemal
Nadia
N
Navaza
Alda
A
du Penhoat
Catherine Hervé
CH
Perret
Gérard Y
GY
D000595:Amino Acid Sequence; D020533:Angiogenesis Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D000818:Animals; D066298:In Vitro Techniques; D008958:Models, Molecular; D046912:Multiprotein Complexes; D039942:Neuropilin-1 / Q000378:metabolism*; D009842:Oligopeptides / Q000737:chemistry* / Q000494:pharmacology*; D011485:Protein Binding; D011487:Protein Conformation; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D046912:Multiprotein Complexes; D009842:Oligopeptides; D011994:Recombinant Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D039942:Neuropilin-1