Multidomain bromodomain-containing proteins regulate gene expression via chromatin binding, interactions with the transcriptional machinery, and by recruiting enzymatic activity. Selective inhibition of members of the bromodomain and extra-terminal (BET) family is important to understand their role in disease and gene regulation, although due to the similar binding sites of BET bromodomains, selective inhibitor discovery has been
challenging.

To support the bromodomain inhibitor discovery process, herein is reported the first application of protein-observed fluorine (PrOF) NMR to the tandem bromodomains of BRD4 and BRDT to quantify the selectivity of their interactions with acetylated histones as well as small molecules.

The researchers further determined the selectivity profile of a new class of ligands, 1,4-acylthiazepanes, and find them to have ≥3−10-fold selectivity for the C-terminal bromodomain of both BRD4 and BRDT. Given the speed and lower protein concentration required over traditional protein-observed NMR methods, they envision that these fluorinated tandem proteins may find use in fragment screening and evaluating nucleosome and transcription factor interactions.

Title:
Quantifying the Selectivity of Protein−Protein and Small Molecule Interactions with Fluorinated Tandem Bromodomain Reader Proteins
Authors:
Prakriti Kalra, Logan McGraw, Jennifer R. Kimbrough, Anil K. Pandey, Jonathan Solberg, Huarui Cui, Anand Divakaran, Kristen John, Jon E. Hawkinson, and William C. K. Pomerantz
Citation:
ACS Chem. Biol. 2020, 15, 3038−3049
URL:
https://pubs.acs.org/doi/10.1021/acschembio.0c00720