title: Near-infrared fluorescent oligodeoxyribonucleotide reporters for sensing NF-kappaB DNA interactions in vitro.
abstract: Two types of reporters for optical sensing of NF-kappaB p50 protein-oligodeoxyribonucleotide (ODN) duplex interactions were designed and compared in vitro. The reporters were based on the effect of fluorescence resonance energy transfer (FRET) between the pair donor Cy5.5 near-infrared (NIR) fluorochrome and either 800CW emitting fluorescence dye acceptor (800CW-Cy), or a nonemitting QSY 21 dye quencher (QSY-Cy). The donor and the acceptor dyes were covalently linked to the complementary oligonucleotides, respectively: Cy dye was conjugated to 3'-thiol, whereas 800CW or QSY21 were conjugated to a hydrophilic internucleoside phosphate amino linker. The reporters were tested initially using recombinant NF-kappaB p50 protein binding assays. Both reporters were binding p50 protein, which protected oligonucleotide duplex from degradation in the presence of exonuclease.The incubation of 800CW-Cy reporter in the presence of control or IL-1beta treated human endothelial cells showed the uptake of the reporter in the cytoplasm and the nucleus. The measurement of NIR fluorescence ratio (i.e. Cy5.5/800CW) showed a partial loss of FRET and the increased Cy5.5 fluorescence in nontreated, control cells. Thus, the specific p50 binding to ODN duplex reporters affected the donor-acceptor fluorochrome pair. NF-kappaB p50 exhibited the protective effect on FRET between NIR fluorochromes linked to the complementary strands of the reporter duplex.
authors.affiliation: Laboratory of Molecular Imaging Probes, Department of Radiology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, Massachusetts, USA.
authors.forename: Surong
authors.initials: S
authors.lastname: Zhang
authors.forename: Valeri
authors.initials: V
authors.lastname: Metelev
authors.forename: David
authors.initials: D
authors.lastname: Tabatadze
authors.forename: Paul
authors.initials: P
authors.lastname: Zamecnik
authors.forename: Alexei
authors.initials: A
authors.lastname: Bogdanov
mesh_terms: D002460:Cell Line; D004247:DNA / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes; D017930:Genes, Reporter; D006801:Humans; D052002:NF-kappa B p50 Subunit / Q000138:chemical synthesis / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D005456:Fluorescent Dyes; D052002:NF-kappa B p50 Subunit; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D004247:DNA