All-in-One Luminescent Lanthanide Coordination Polymer Nanoprobe for Facile Detection of Protein Kinase Activity
Baoxia Liu, Yaoyao Zhang, Yuanqiang Hao, Xu Zhu, Yintang Zhang, Yanli Zhou, Hongliang Tan, Maotian Xu
Abstract
This study developed a novel luminescent assay for kinase activity using metal–organic coordination polymer nanoparticles (Tb/ATP-Zn) as the probe. Tb/ATP-Zn, self-assembled by adenosine triphosphate (ATP), Zn2+, and Tb3+, is non-luminescent. Protein kinase A (PKA) can catalyze the transformation of ATP within Tb/ATP-Zn nanoparticles to adenosine diphosphate (ADP), which in turn effectively sensitizes the luminescence of Tb3+. Based on this mechanism, Tb/ATP-Zn can realize the facile luminescent “turn-on” sensing of protein kinase activity without the use of external ATP and substrate peptide. Under optimized conditions, the fluorescence intensities of Tb/ATP-Zn at 550 nm are linear with the PKA activity within a range of 0.3–1.5 U·μL–1. The LOD (S/N = 3) of this method is down to 0.001 U·μL–1. The presented assay also features high selectivity, long-term stability, fast response, and convenient operation. Furthermore, Tb/ATP-Zn was successfully employed for monitoring PKA activity in cell lysis solutions. Probe Tb/ATP-Zn is thus expectable to be a powerful tool for the practical study of PKA in relevant biological events.