Repurposing Peptide Nanomaterials as Synthetic Biomolecular Condensates in Bacteria

Area of Science:

• Biochemistry
• Synthetic Biology
• Materials Science

Background:

• Peptide nanomaterials have shown promise for in vitro applications like drug delivery.
• Organizing bacterial cytoplasm biochemistry is crucial for metabolic engineering and synthetic biology.

Purpose of the Study:

• To explore the utility of de novo peptide nanomaterials for organizing biochemistry within the bacterial cytoplasm.
• To investigate the formation and function of biomolecular condensates derived from coiled-coil triblock peptides in bacteria.

Main Methods:

• Discovery and characterization of ABC coiled-coil triblock peptides forming gel-like biomolecular condensates.
• Expression of triblock peptides in bacteria and observation of cell pole accumulation via nucleoid occlusion.
• Demonstration of client sequestration by synthetic biomolecular condensates at the cell pole.
• In vitro and in vivo phase separation studies of triblock peptides and RNase E.

Main Results:

• ABC coiled-coil triblock peptides form biomolecular condensates with a critical saturation concentration (c_sat) of 10 μM.
• Peptide expression in bacteria results in cell pole localization driven by nucleoid occlusion.
• Synthetic biomolecular condensates effectively sequester target molecules at the bacterial cell pole.
• Triblock peptides and RNase E exhibit distinct phase separation behavior in vitro and in vivo.

Conclusions:

• De novo peptide nanomaterials can form functional biomolecular condensates within the bacterial cytoplasm.
• These synthetic condensates can be localized to specific cellular regions, such as the cell pole.
• Peptide-based biomolecular condensates offer potential for dividing the bacterial cytoplasm into distinct subcellular zones.
• This work lays the foundation for future applications in metabolic engineering and synthetic biology, enabling precise control over cellular organization and function.