Type III Secretion Filaments as Templates for Metallic Nanostructure Synthesis

Area of Science:

• Biomaterials Science
• Nanotechnology
• Synthetic Biology

Background:

• Interfacing nanostructured materials with living cells offers unique chemical and biological possibilities.
• Precisely controlling the shape and composition of cell-associated nanomaterials remains a significant challenge.

Purpose of the Study:

• To genetically modify and isolate a self-assembling filament protein (PrgI) from Salmonella enterica for binding gold nanoparticles.
• To develop a strategy for assembling PrgI-based filaments on live cells for gold conjugation.

Main Methods:

• Genetic modification of Salmonella enterica PrgI protein to enable gold nanoparticle binding.
• In vitro chemical reduction of Au-conjugated filaments to form wires and networks.
• Assembly of PrgI-based filaments on live cells, with options for shearing or tethering.

Main Results:

• Successfully created gold-conjugated PrgI filaments that self-assemble into wires and networks up to several micrometers long.
• Demonstrated a method to assemble these filaments directly onto live cells.
• Established a foundation for controlled interactions between inorganic and organic systems.

Conclusions:

• The developed protocol provides a novel method for creating cell-associated gold nanostructures.
• This approach facilitates precise control over the interface between biological and inorganic materials.
• The strategy can be extended to other metal nanoparticles by identifying suitable peptide binding partners.