Han K.-Y.,Illinois Eye and Ear Infirmary |
Azar D.T.,Illinois Eye and Ear Infirmary |
Sabri A.,Illinois Eye and Ear Infirmary |
Jain S.,Illinois Eye and Ear Infirmary |
And 2 more authors.
Protein and Peptide Letters | Year: 2012
Corneal angiogenesis and lymphangiogenesis are induced by vascular endothelial growth factors (VEGFs) signaling through its receptors VEGFR-1,-2, and-3. Endostatin is a peptide antagonist of these receptors that causes inhibition of bFGF-induced corneal angiogenesis and lymphangiogenesis. Here we show that binding of VEGF-C and endostatin to recombinant VEGFR-3 is competitive. Alignments of the primary amino acid sequences of VEGF-C and the C-terminal endostatin peptide (mEP: LEQKAASCHNSYIVLCIENSFMTSFSK) identified two conserved cysteine residues separated by seven amino acids. Peptides of VEGF-C and mEP containing these conserved residues bound toVEGFR-3. However, substitution of alanine for either of the cysteines in the mEP peptide perturbed the secondary structure, and this mutated peptide was unable to bind to VEGFR-3. Analysis by surface plasmon resonance demonstrated that the binding of the mEP peptide for recombinant VEGFR-3 had a Ka of 1.41×10 7M-1s-1, Kd of 0.6718 s-1, and a KD of 4.78×10-8M. Characterization of the mechanism of endostatin binding to VEGFR-3 may lead to the development of novel therapies for lymphangiogenesis-related disorders, such as transplant rejection, lymphedema, and cancer metastasis. © 2012 Bentham Science Publishers.