Comparison of proteomic responses as global approach to antibiotic mechanism of action elucidation

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. New antibiotics are urgently needed to address the mounting resistance challenge. In early drug discovery, one of the bottlenecks is the elucidation of targets and mechanisms. To accelerate antibiotic research, we provide a proteomic approach for the rapid classification of compounds into those with precedented and unprecedented modes of action. We established a proteomic response library of Bacillus subtilis covering 91 antibiotics and comparator compounds, and a mathematical approach was developed to aid data analysis. Comparison of proteomic responses (CoPR) allows the rapid identification of antibiotics with dual mechanisms of action as shown for atypical tetracyclines. It also aids in generating hypotheses on mechanisms of action as presented for salvarsan (arsphenamine) and the antirheumatic agent auranofin, which is under consideration for repurposing. Proteomic profiling also provides insights into the impact of antibiotics on bacterial physiology through analysis of marker proteins indicative of the impairment of cellular processes and structures. As demonstrated for trans-translation, a promising target not yet exploited clinically, proteomic profiling supports chemical biology approaches to investigating bacterial physiology

Effects of ionophores and aminosterol antibiotics on the proteome of Bacillus subtilis\textit {Bacillus subtilis}

Auf der Suche nach antimikrobiellen Substanzen wurde Squalamin aus Geweben des Dornhais $\textit {Squalus acanthias}$ isoliert. Um den Wirkmechanismus von Squalamin in $\textit {Bacillus subtilis}$-Zellen zu untersuchen, wurden zwei komplementäre, auf Massenspektrometrie basierende Methoden und ein GFP-MinD-Assay angewendet. So konnte der Einfluss von Squalamin auf die bakterielle Membran nachgewiesen werden. Vergleichende zweidimensionale Gelelektrophorese-Untersuchungen mit den Squalamin-Derivaten ASD und NV503 zeigten, dass die strukturellen Modifikationen eine Veränderung des Wirkmechanismus zur Folge hat. In einem weiteren Teilprojekt wurden physiologische Effekte der Ionophoren A23187 und Ionomycin auf $\textit {B. subtilis}$-Zellen untersucht. Der durch die Ionophore induzierte $Mn^{2+}$-und $Fe^{2+}$-Mangel bewirkt eine Derepression der Peroxidstress-Enzyme AhpC/F, KatA und MrgA. Die aufgestellten Proteomsignaturen bieten eine Referenz für zukünftige Studien strukturell neuer Substanzen mit unbekanntem Wirkmechanismus

Comparison of Proteomic Responses as Global Approach to Antibiotic Mechanism of Action Elucidation

New antibiotics are urgently needed to address the mounting resistance challenge. In early drug discovery, one of the bottlenecks is the elucidation of targets and mechanisms. To accelerate antibiotic research, we provide a proteomic approach for the rapid classification of compounds into those with precedented and unprecedented modes of action. We established a proteomic response library of Bacillus subtilis covering 91 antibiotics and comparator compounds, and a mathematical approach was developed to aid data analysis. Comparison of proteomic responses (CoPR) allows the rapid identification of antibiotics with dual mechanisms of action as shown for atypical tetracyclines. It also aids in generating hypotheses on mechanisms of action as presented for salvarsan (arsphenamine) and the antirheumatic agent auranofin, which is under consideration for repurposing. Proteomic profiling also provides insights into the impact of antibiotics on bacterial physiology through analysis of marker proteins indicative of the impairment of cellular processes and structures. As demonstrated for trans-translation, a promising target not yet exploited clinically, proteomic profiling supports chemical biology approaches to investigating bacterial physiology