Bioconjugate Chemistry 2007-01-01

A novel conjugable translocator protein ligand labeled with a fluorescence dye for in vitro imaging.

Mingfeng Bai, Shelby K Wyatt, Zeqiu Han, Vassilios Papadopoulos, Darryl J Bornhop

Index: Bioconjug. Chem. 18(4) , 1118-22, (2007)

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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.