FtsZ, the main coordinating protein of bacterial cell division: search for new inhibitors by automated microscopy

Abstract

Bacteria that cause various infectious diseases are increasingly multi-resistant to current antibiotics, resulting in a high mortality rate. Existing drugs are limited to few targets such as protein synthesis, nucleic acid synthesis, and cell wall synthesis. To circumvent the bacterial resistance to the antibiotics that already exist, we need molecules with new mechanisms of action. Therefore, we propose the inhibition of the FtsZ protein, the main coordinator of bacterial cell division, as a target for identification of a new class of antibiotics. We will use Bacillus subtilis as a model, which is well known and studied as representative of Gram-positive bacteria. From the ChemBridge DIVERset compound library, we will look for cell division inhibitory molecules that block the action of FtsZ. Screening of these compounds will be performed by automated microscopy of Bacillus subtilis cells, because this is the best method to detect the phenotype of interest (inhibition of cell division). The hits, compounds that cause inhibition of cell division, will be evaluated by fluorescence microscopy to identify the effect of inhibitors on Z-ring and septum formation. Subsequently, it will be verified whether the inhibition of bacterial cell division occurs by blocking the FtsZ protein, through in vitro assays of GTPase activity and FtsZ polymerization.