False Positives in a Reporter Gene Assay: Identification and Synthesis of Substituted N-Pyridin-2-ylbenzamides as Competitive Inhibitors of Firefly Luciferase
摘要:
Luciferase reporter-gene assays are a commonly used technique in high-throughput screening campaigns. In this study, we report on a luciferase inhibitor (1), which emerged from an antagonistic G protein-coupled receptor luciferase reporter-gene assay screen. Instead of displaying receptor activity, compound I was shown to potently inhibit luciferase in an in vitro enzymatic assay with an IC50 value of 1.7 +/- 0.1 mu M. In addition, 1 was a competitive inhibitor with respect to the substrate luciferin. A database search yielded another inhibitor (3) with a similar N-pyridin-2-ylbenzamide core. Subsequently, several analogues were prepared to investigate the structure-activity relationships of these luciferase inhibitors. This yielded the most potent inhibitor of this series (6) with an IC50 value of 0.069 +/- 0.01 mu M. Further molecular modeling studies suggested that 6 can be accommodated in the luciferin binding site. This paper is meant to alert users of luciferase reporter-gene assays for possible false positive hits including highly "druglike" molecules due to direct luciferase inhibition.
False Positives in a Reporter Gene Assay: Identification and Synthesis of Substituted <i>N</i>-Pyridin-2-ylbenzamides as Competitive Inhibitors of Firefly Luciferase
作者:Laura H. Heitman、Jacobus P. D. van Veldhoven、Annelien M. Zweemer、Kai Ye、Johannes Brussee、Adriaan P. IJzerman
DOI:10.1021/jm8004509
日期:2008.8.1
Luciferase reporter-gene assays are a commonly used technique in high-throughput screening campaigns. In this study, we report on a luciferase inhibitor (1), which emerged from an antagonistic G protein-coupled receptor luciferase reporter-gene assay screen. Instead of displaying receptor activity, compound I was shown to potently inhibit luciferase in an in vitro enzymatic assay with an IC50 value of 1.7 +/- 0.1 mu M. In addition, 1 was a competitive inhibitor with respect to the substrate luciferin. A database search yielded another inhibitor (3) with a similar N-pyridin-2-ylbenzamide core. Subsequently, several analogues were prepared to investigate the structure-activity relationships of these luciferase inhibitors. This yielded the most potent inhibitor of this series (6) with an IC50 value of 0.069 +/- 0.01 mu M. Further molecular modeling studies suggested that 6 can be accommodated in the luciferin binding site. This paper is meant to alert users of luciferase reporter-gene assays for possible false positive hits including highly "druglike" molecules due to direct luciferase inhibition.