title: Fluorophore labeling enables imaging and evaluation of specific CXCR4-ligand interaction at the cell membrane for fluorescence-based screening.
abstract: Development of CXCR4-specific ligands is an important issue in chemotherapy of HIV infection, cancer metastasis, and rheumatoid arthritis, and numerous potential ligands have been developed to date. However, it is difficult to assess their binding mode and specificity because of uncertainties in the structure of the CXCR4-ligand complexes. To address this problem, we have synthesized fluorophore labeled Ac-TZ14011, which is derived from T140, a powerful CXCR4 antagonist. Binding of Ac-TZ14011 to CXCR4 on the cell membrane was observed by fluorescence microscope, and analysis of the binding data produced IC 50 values of several ligands comparable to those obtained in RI-based assays. This fluorescence-based assay is applicable to explore new pharmacophores of CXCR4-specific ligands with high-throughput screening and also to screening of the other GPCR binding ligands.
authors.affiliation: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo 101-0062, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Nomura
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsutsumi
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tanaka
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohba
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tamamura
mesh_terms: D001665:Binding Sites; D015374:Biosensing Techniques / Q000379:methods*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000138:chemical synthesis*; D008024:Ligands; D008856:Microscopy, Fluorescence / Q000379:methods*; D009842:Oligopeptides / Q000737:chemistry*; D019718:Receptors, CXCR4 / Q000737:chemistry / Q000378:metabolism*; D013194:Staining and Labeling
chemical_list: D005456:Fluorescent Dyes; D008024:Ligands; D009842:Oligopeptides; D019718:Receptors, CXCR4; C116977:T140 peptide