One-step detection of T4 polynucleotide kinase activity based on single particle-confined enzyme reaction and digital particle counting  

作　　者：Dailu Jia Wenjiao Fan Wei Ren Chenghui Liu 

机构地区：[1]Key Laboratory of Applied Surface and Colloid Chemistry,Ministry of Education,Xi’an 710119,China [2]Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province,School of Chemistry&Chemical Engineering,Shaanxi Normal University,Xi’an 710119,China

出　　处：《Chinese Chemical Letters》2023年第4期459-463,共5页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 22074088, 21622507, 21904083);the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT_15R43);the Innovation Capability Support Program of Shaanxi (No. 2021TD-42);the Fundamental Research Funds for the Central Universities (Nos. GK202101001 and GK202201009)。

摘　　要：T4 polynucleotide kinase(T4 PNK) is a pivotal enzyme for DNA replication, recombination, and DNA damage repair. Herein, a robust single particle counting-based assay has been developed for the high-sensitive determination of T4 PNK activity through only a simple one-step reaction. Taking benefit of the exceptional space-confined enzymatic property of T4 PNK towards DNA substrates on a single nanoparticle,the T4 PNK activity can be precisely determined by counting the fluorescence-positive nanoparticles in a digital manner with a total internal reflection fluorescent microscope(TIRFM). Due to the featured spatial-confined enzymatic property of T4 PNK and the single particle counting-based signal readout, T4PNK can be effectively differentiated from other interfering enzymes. This facile strategy has been also successfully applied to screen T4 PNK inhibitor and accurately determine T4 PNK activity in complex biological samples, paving a potential avenue for the digital analysis of biomarkers.

关 键 词：Single particle counting Total internal reflection fluorescent MICROSCOPE Space-confined enzyme reaction Nanoparticles 

分 类 号：Q503[生物学—生物化学]