Prolyl-tRNA synthetases from Gram-negative bacteria: functional studies and search for new inhibitors of multidrug-resistant microorganisms

• Grant number: 23/02777-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2023
• End date: August 16, 2024
• Field of knowledge: Biological Sciences - Biochemistry - Biochemistry of Microorganisms
• Principal Investigator: Gustavo Fernando Mercaldi
• Grantee: Bárbara Carvalho dos Reis
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

Infections caused by pathogens with antimicrobial resistance (AMR) are a global public health problem, being identified by the World Health Organization (WHO) as a serious threat to human health. Klebsiella pneumoniae is a Gram-negative bacterium that usually causes infections in hospitalized and/or immunocompromised patients, but can also be observed in community-acquired cases with healthy patients. K. pneumonia is commonly associated with an AMR phenotype, which increases the mortality rates of infections involving this bacterium. This project aims to study the K. pneumoniae prolyl-tRNA synthetase enzyme (KpProRS) and explore this enzyme as a molecular target for the development of new antimicrobial agents to fight Gram-negative bacteria. ProRS2 is responsible for the addition of L-proline to cognate RNA transporters (tRNAPro), being essential for protein synthesis. Due to evolutionary divergences between the ProRSs of hosts and pathogens, selective inhibitors of ProRS have been described for several pathogens, especially for the parasite Plasmodium falciparum. Thus, we aim to carry out the biochemical and structural characterization of the KpProRS2 enzyme; run high-throughput screening (HTS) campaign to identify inhibitors of this enzyme; and to evaluate the inhibitors identified in in vitro phenotypic assays with Gram-negative bacteria and mammalian cells. In addition, biochemical and structural studies will be used to elucidate the mechanism of inhibition and determinants of interaction of the newly identified inhibitors. The results will expand knowledge about these enzymes and may deliver new inhibitors of ProRS2 from Gram-negative bacteria.