title: A novel conjugable translocator protein ligand labeled with a fluorescence dye for in vitro imaging.
abstract: A conjugable analogue of the benzodiazepine 4' '-chlorodiazepam (Ro5-4864), C6Ro5-4864 was synthesized to probe the binding sites of translocator protein (18 kDa; TSPO), previously known as the peripheral benzodiazepine receptor for molecular imaging. The amino group in this analogue allows universal conjugation to signaling molecules. Lissamine-C6Ro5-4864, synthesized from C6Ro5-4864 and a lissamine fluorescence dye, was investigated in this study. This imaging agent exhibited micromolar binding affinity (Ki = 2.6 microM) to TSPO and was successfully imaged in TSPO rich glioma and breast cancer cell lines. These findings suggest that C6Ro5-4864 may provide opportunities in imaging disease states where TSPO levels are affected, such as cancer and neurologic diseases.
authors.affiliation: Department of Chemistry, Vanderbilt University, VU Station B 351822 Nashville, Tennessee 37235-1822, USA.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Bai
authors.forename: Shelby K
authors.initials: SK
authors.lastname: Wyatt
authors.forename: Zeqiu
authors.initials: Z
authors.lastname: Han
authors.forename: Vassilios
authors.initials: V
authors.lastname: Papadopoulos
authors.forename: Darryl J
authors.initials: DJ
authors.lastname: Bornhop
mesh_terms: D000818:Animals; D001570:Benzodiazepinones / Q000737:chemistry / Q000378:metabolism*; D045744:Cell Line, Tumor; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D051381:Rats; D018079:Receptors, GABA / Q000737:chemistry / Q000378:metabolism*; D012235:Rhodamines / Q000737:chemistry / Q000378:metabolism
chemical_list: D001570:Benzodiazepinones; D005456:Fluorescent Dyes; D008024:Ligands; D018079:Receptors, GABA; D012235:Rhodamines; C499229:TSPO protein, human; C028513:4'-chlorodiazepam; C027305:Lissamine Rhodamine B sulfonyl chloride