Fig. 1
From: Targeting oncofetal fibronectin and neuropilin-1 in solid tumors with PL2 peptide
Identification and characterization of the PL2 peptide binding to Fn-EDB and NRP-1. (A) Biopanning of T7 phage-displayed X7 peptide libraries on immobilized Fn-EDB resulted in ~ 3000-fold enrichment in phage binding after the sixth round of selection. (B) The selected PL2 peptide phage bound to immobilized Fn-EDB and NRP-1 b1b2 but not to control protein TNC-C, or Nucleolin. Phage binding is expressed as fold over control phage displaying heptaglycine (G7) peptide. (C) Alanine substitutions were introduced at each position of the PL2 peptide, and changes in binding were verified by measuring the percentage of changes in binding to immobilized Fn-EDB and NRP-1. The first peptide from the bottom without red in the box represents the parental PL2 peptide. (D) The interaction of synthetic FAM-PL2 peptide immobilized on an ELISA plate with recombinant His-tagged Fn-EDB was probed and detected using a rabbit anti-His-tag primary antibody and secondary goat anti-rabbit HRP antibody, followed by chromogenic peroxidase reaction. Values are expressed as mean ± standard deviation (SD) from 3 independent experiments; statistical analysis was performed using Student unpaired t-test; all statistical tests were two-sided; *p < 0.05; **p < 0.01.
