title: Discovering small molecule ligands of vascular endothelial growth factor that block VEGF-KDR binding using label-free microarray-based assays.
abstract: We present here a label-free microarray-based assay platform that we used to identify inhibitors of vascular endothelial growth factor (VEGF)-kinase-insertion domain receptor (KDR) binding. Supported by a combination of special ellipsometry-based optical detection and small molecule microarrays (SMM), this platform consists of three assays: (1) the first assay detects binding of a target protein with SMM and identifies ligands to the protein as inhibitor candidates; (2) the second assay detects binding of a receptor protein with identical SMM and subsequent binding of the target protein (a sandwich assay) to identify the ligands to the receptor protein that do not interfere with the target-receptor binding; (3) the third assay detects binding of the target protein to the receptor protein in the presence of the ligands of the target protein identified from the first assay, with the receptor protein immobilized to a solid surface through the ligands identified in the second assay, to yield dose-response curves. Using this platform, we screened 7,961 compounds from the National Cancer Institute and found 12 inhibitors to VEGF-KDR (VEGFR2) interactions with IC₅₀ ranging from 0.3 to 60 μM. The inhibitory potency of these inhibitors found in the microarray-based assay was confirmed by their inhibition of VEGF-induced VEGFR2 phosphorylation in a cell-based assay.
authors.affiliation: Department of Physics, University of California at Davis, Davis, CA 95616, USA.
authors.forename: James P
authors.initials: JP
authors.lastname: Landry
authors.forename: Yiyan
authors.initials: Y
authors.lastname: Fei
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Zhu
authors.forename: Yaohuang
authors.initials: Y
authors.lastname: Ke
authors.forename: Guoliang
authors.initials: G
authors.lastname: Yu
authors.forename: Pierre
authors.initials: P
authors.lastname: Lee
mesh_terms: D015195:Drug Design; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D008024:Ligands; D010455:Peptides / Q000737:chemistry*; D040081:Protein Array Analysis / Q000379:methods*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods; D013194:Staining and Labeling; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors* / Q000737:chemistry*
chemical_list: D008024:Ligands; D010455:Peptides; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2