The Trypanosoma cruzi (T. cruzi) parasite is the cause of Chagas disease, a neglected disease endemic in South America. The life cycle of the T. cruzi parasite is complex and includes transitions between distinct life stages. This change in phenotype (without a change in genotype) could be controlled by epigenetic regulation, and might involve the bromodomain-containing factors 1-5 (TcBDF1-5). However, little is known about the function of the TcBDF1-5. Here we describe a fragment-based approach to identify ligands for T. cruzi bromodomain-containing factor 3 (TcBDF3). We expressed a soluble construct of TcBDF3 in E. coli, and used this to develop a range of biophysical assays for this protein. Fragment screening identified twelve compounds that bind to the TcBDF3 bromodomain. Based on this screen, we developed functional ligands containing a fluorescence or 19F reporter group, and a photo-crosslinking probe for TcBDF3. These tools compounds will be invaluable in future studies on the function of TcBDF3 and will provide insight into the biology of T. cruzi.
Laurin et al SI final