An ultrasensitive bioluminogenic probe of γ-Glutamyltranspeptidase in vivo and in human serum for tumor diagnosis.

Abnormal expression of γ-Glutamyltranspeptidase (GGT) in living organisms is closely implicated in the development of several human tumors. The GGT levels in tissue and serum have emerged as a potential criterion for tumor diagnosis. However, precise "light up" GGT activity in vivo is still challenging due to the signal interferes of background. Bioluminescence based on the firefly luciferase-catalyzed reaction for light production provides a feasible strategy for GGT detection in vivo. In this report, a bioluminogenic probe, Glu-Luc, was designed and synthesized by connecting D-luciferin with γ-glutamyl group. The cleavage of γ-glutamyl group is triggered by GGT, resulting in the release of D-luciferin, which generates a bright bioluminescence emission in the present of luciferase and ATP. The probe exhibits very high selectivity and sensitivity toward GGT activity from in vitro to in vivo and in clinical samples, which offers a promising tool for investigations of the GGT-overexpressing related biological process including tumor diagnosis and prognosis in living organisms.