Enhancing bioactivity, physicochemical, and pharmacokinetic properties of a nano-sized, anti-VEGFR2 Adnectin, through PASylation technology

Sci Rep. 2019 Feb 27;9(1):2978. doi: 10.1038/s41598-019-39776-0.


The crucial role of VEGF receptor 2 (VEGFR2) signaling in the angiogenesis and metastasis of solid tumors has prompted the development of inhibitors with minimal bystander effects. Recently, Adnectin C has attracted attention for cancer treatment. To overcome the problematic properties of Adnectin, a novel form of Adnectin C has been designed by its fusion to a biodegradable polymeric peptide containing Pro/Ala/Ser (PAS) repetitive residues. E. coli-expressed recombinant fused and unfused proteins were compared in terms of bioactivity, physicochemical, and pharmacokinetic properties using standard methods. Dynamic light scattering (DLS) analysis of PASylated adnectin C revealed an approximate 2-fold increase in particle size with a slight change in the net charge. Additionally, fusion of the PAS sequence improved its stability against the growth of thermo-induced aggregated forms. The high receptor-binding and improved binding kinetic parameters of PASylated Adnectin C was confirmed by ELISA and surface plasmon resonance assays, respectively. Pharmacokinetic studies showed a noticeable increase in the terminal half-life of Adnectin C-PAS#1(200) by a factor of 4.57 after single dose by intravenous injection into female BALB/c mice. The results suggest that PASylation could offer a superior delivery strategy for developing Adnectin-derived drugs with improved patient compliance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine
  • Animals
  • Escherichia coli
  • Female
  • Fibronectins / isolation & purification
  • Fibronectins / metabolism
  • Fibronectins / pharmacokinetics*
  • Fibronectins / pharmacology*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Kinetics
  • Mice
  • Mice, Inbred BALB C
  • Peptide Fragments / pharmacokinetics
  • Peptide Fragments / pharmacology
  • Proline
  • Protein Domains / physiology
  • Protein Engineering / methods
  • Serine
  • Surface Plasmon Resonance / methods
  • Vascular Endothelial Growth Factor Receptor-2 / antagonists & inhibitors*
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism


  • CT-322
  • Fibronectins
  • Peptide Fragments
  • fibronectin type III like peptide, human
  • Serine
  • Proline
  • KDR protein, human
  • Vascular Endothelial Growth Factor Receptor-2
  • Alanine