Mechanism of action of pseudopteroxazole and pseudopterosin G: Diterpenes from marine origin

In this study, we investigated the modes of action of Ptx and pseudopterosin  G (PsG) inBacillus subtilis employing an unbiased approach that combines gel-based proteomics with a mathematical similarity analysis of response profiles. Proteomic responses to sublethal concentrations of Ptx and PsG were compared to a library of antibiotic stress response profiles revealing that both induce a stress response characteristic for agents targeting the bacterial cell envelope by interfering with membrane-bound steps of cell wall biosynthesis. Microscopy-based assays confirmed that both compounds compromise the integrity of the bacterial cell wall without disrupting the membrane potential. Furthermore, LC-MSE analysis showed that the greater potency of PsG againstB.  subtilis, reflected in a lower MIC and a more pronounced proteomic response, may be rooted in a more effective association with and penetration ofB. subtilis cells. We conclude that Ptx and PsG target the integrity of the gram-positive cell wall.
Source: Proteomics - Category: Biochemistry Authors: Tags: RESEARCH ARTICLE Source Type: research