Search for inhibitors of the enzyme deoxyhypusine synthase of eukaryotic organisms that cause neglected tropical diseases by high-throughput in vitro drug screening

Abstract

The eukaryotic initiation translation factor 5A (eIF5A) is highly conserved in eukaryotes and undergoes a specific post-translational modification, called hypusination. Hypusination is required for eIF5A function in the cell and is only present in eIF5A. Deoxyhypusine synthase (DHPS) catalyzes the first step of this modification in eIF5A. Both DHPS and eIF5A are essential for cell viability of all organisms tested so far. Furthermore, the therapeutic potential of DHPS for the treatment of eukaryotic pathogenic organisms that cause neglected tropical diseases has also been demonstrated. Thus, the main goal of this project is to search for structural differences between DHPS of human and some pathogenic organisms (Leishmania major, Paracoccidioides brasiliensis, Histoplasma capsulatum and Brugia malayi) to find inhibitors which minimally affect the human enzyme. To improve the results obtained so far in the project in Brazil, we propose the design of new constructs and new expression tests for the isoforms A and B from L. major DHPS; scale up of DHPS enzymatic in vitro assay to allow high-throughput drug screening using the drug collections available in the laboratory of Dr. Van Voorhis; and, finally, assuming new compounds that causes inhibition in the DHPS activity are discovered, we will perform cocrystallization assays that could help to guide future medicinal chemistry approaches to optimize the hits to a lead compound. This project is extremely relevant because there is an urgent need for the discovery of new, safe, effective and affordable active molecules for the treatment of neglected tropical diseases.