SU3327: A multi-target compound targeting bacterial menaquinone and DNA

Area of Science:

• Microbiology
• Biochemistry
• Drug Discovery

Background:

• Antibiotic resistance (AMR) is a growing global health threat, necessitating novel antimicrobial agents.
• SU3327 (Halicin), identified via deep learning, shows broad-spectrum antibacterial activity but its mechanism is unknown.
• Understanding SU3327's mechanism is crucial for developing new treatments against resistant bacteria.

Purpose of the Study:

• To elucidate the antibacterial mechanism of SU3327.
• To investigate SU3327's potential as a multi-target therapeutic agent.
• To explore the dual-action antibacterial properties of SU3327.

Main Methods:

• Microbiological, biochemical, biophysical, mass spectrometry, electrochemical, and transcriptomic analyses were employed.
• Impact on proton motive force (PMF), ATP synthesis, and electron transport chain (ETC) function were assessed.
• Nitroreductase bioactivation, metabolite identification, and DNA damage quantification were performed.

Main Results:

• SU3327 targets menaquinone (MK) in the ETC, inhibiting Complex I, disrupting PMF, and impairing ATP synthesis.
• SU3327 undergoes bioactivation in E. coli to form hydroxylamine, causing oxidative DNA damage.
• SU3327 exhibits a dual-target mechanism: disrupting respiration and inducing DNA damage.

Conclusions:

• SU3327 is a novel multi-target antibacterial agent with two synergistic mechanisms.
• Its dual action may enhance efficacy and reduce the likelihood of resistance development.
• SU3327 shows potential as a new antibiotic, particularly for veterinary applications.