Proceedings of Annual Meeting of the Brazilian Biophysical Society
Proceedings of the 47th Annual Meeting of the Brazilian Biophysical Society - Vol. 1 2023

Chagas Disease, caused by the parasite Trypanosoma cruzi, continues to afflict millions of individuals worldwide, lacking effective vaccines and proper treatment options for its chronic phase. The infection and survival of the parasite within the host involves the regulation of gene expression at the post-transcriptional level. Emerging evidence suggests that epigenetic mechanisms play a pivotal role in the biology of these parasites, presenting a promising approach for targeted drug discovery. To unravel the complex workings of these mechanisms, it becomes imperative to explore the chromatin organization, the atomic structure of histones and, therefore, the nucleosome core particles (NCPs). This study aims to undertake a comprehensive investigation into the structure of histones, produced through recombinant expression techniques, as well as the NCPs themselves, using Cryogenic Electron Microscopy (Cryo-EM) techniques. Moreover, it seeks to investigate the kinetic and thermodynamic properties governing NCP assembly and its interaction with DNA. To achieve these objectives, both canonical histones (H2A, H2B, H3, and H4) and variant histones (H2A.Z, H2B.V, H3.V, and H4.V) are being expressed separately and also as polycistronic constructs, to overcome instabilities in the natural folding of these proteins. The biophysical aspects of NCP formation and its interaction with specific regions of T. cruzi's genome are being evaluated using fluorescence anisotropy techniques. Structural investigations will be conducted using Cryo-EM in order to obtain a comprehensive understanding of the organization of NCPs in T. cruzi. The preliminary results obtained thus far underscore the critical importance of further studies to acquire the necessary knowledge regarding the genetic regulation of T. cruzi, thereby laying the foundation for the development of innovative and effective drugs.