A Quenched Size‐Expanded Nucleotide Reports Activity of the Leukemia Biomarker Terminal Deoxynucleotidyl Transferase (TdT)**

Abstract

Terminal deoxynucleotidyl Transferase (TdT) is a template-independent DNA polymerase that plays an essential role in the human adaptive immune system and is upregulated in several types of leukemia. It has therefore gained interest as a leukemia biomarker and potential therapeutic target. Herein, we describe a FRET-quenched fluorogenic probe based on a sizeexpanded deoxyadenosine that reports directly on TdT enzymatic activity. The probe enables real-time detection of primer extension and de novo synthesis activity of TdT and displays selectivity over other polymerase and phosphatase enzymes. Importantly, TdT activity and its response to treatment with a promiscuous polymerase inhibitor could be monitored in human Tlymphocyte cell extract and Jurkat cells using a simple fluorescence assay. Finally, employing the probe in a high-throughput assay resulted in the identification of a non-nucleoside TdT inhibitor.

A comparative analysis of peptide-delivered antisense antibiotics employing diverse nucleotide mimics

“…Since bacteria lack eukaryotic uptake mechanisms that allow the uptake of nanoparticles, new approaches need to be developed. There have been reports of successful delivery of ASOs across the bacterial membrane with vitamin B12, DNA nanocages, bolaamphiphiles, siderophores and other macromolecules (Hegarty et al 2016;Zhang et al 2018;Rownicki et al 2019;Bost et al 2021;Long et al 2021;Pereira et al 2021b;Liu et al 2023;Pals et al 2023). These recent advances in the design of macromolecular carriers might open up more avenues for the use of negASOs as antibacterials.…”