title: A therapeutic aptamer inhibits angiogenesis by specifically targeting the heparin binding domain of VEGF165.
abstract: Aptamers recognize their targets with extraordinary affinity and specificity. The aptamer-based therapeutic, Macugen, is derived from a modified 2'fluoro pyrimidine RNA inhibitor to vascular endothelial growth factor (VEGF) and is now being used to treat the wet form of age-related macular degeneration. This VEGF(165) aptamer binds specifically to the VEGF(165) isoform, a dimeric protein with a receptor-binding domain and a heparin-binding domain (HBD). To understand the molecular recognition between VEGF and this aptamer, binding experiments were used to show that the HBD contributes the majority of binding energy in the VEGF(165)-aptamer complex. A tissue culture-based competition assay demonstrated that the HBD effectively competes with VEGF(165) for aptamer binding in vivo. Comparison of NMR spectra revealed that structural features of the smaller HBD-aptamer complex are present in the full-length VEGF(164)-aptamer complex. These data show that the HBD provides the binding site for the aptamer and is the primary determinant for the affinity and specificity in the VEGF(165)-aptamer complex.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA.
authors.forename: Joon-Hwa
authors.initials: JH
authors.lastname: Lee
authors.forename: Marella D
authors.initials: MD
authors.lastname: Canny
authors.forename: Andrea
authors.initials: A
authors.lastname: De Erkenez
authors.forename: Dominik
authors.initials: D
authors.lastname: Krilleke
authors.forename: Yin-Shan
authors.initials: YS
authors.lastname: Ng
authors.forename: David T
authors.initials: DT
authors.lastname: Shima
authors.forename: Arthur
authors.initials: A
authors.lastname: Pardi
authors.forename: Fiona
authors.initials: F
authors.lastname: Jucker
mesh_terms: D052157:Aptamers, Nucleotide / Q000494:pharmacology; D001665:Binding Sites; D001667:Binding, Competitive; D002478:Cells, Cultured; D019281:Dimerization; D004730:Endothelium, Vascular / Q000166:cytology; D006493:Heparin / Q000737:chemistry*; D006801:Humans; D008268:Macular Degeneration; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009389:Neovascularization, Pathologic; D010843:Pichia / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D020033:Protein Isoforms; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011743:Pyrimidines / Q000494:pharmacology; D012313:RNA / Q000737:chemistry; D015398:Signal Transduction; D013816:Thermodynamics; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism / Q000502:physiology*
chemical_list: D052157:Aptamers, Nucleotide; D020033:Protein Isoforms; D011743:Pyrimidines; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C495058:pegaptanib; D011092:Polyethylene Glycols; D012313:RNA; D006493:Heparin