Engineering filamentous bacteriophages for enhanced gold binding and metallization properties

Area of Science:

• Biotechnology
• Nanotechnology
• Materials Science

Background:

• Filamentous bacteriophages are nanowire-like viral particles with single-stranded DNA genomes enclosed in protein cages.
• Bacteriophages can be genetically modified to display peptides on their surface.
• Gold nanoparticles and nanostructures have diverse applications in electronics and sensing.

Purpose of the Study:

• To engineer filamentous bacteriophages with enhanced gold (Au) binding and reduction properties by displaying tyrosine-containing peptides.
• To investigate the impact of specific peptide sequences on phage-gold interactions.
• To explore the potential of these engineered phages as biotemplates for nanomaterial fabrication.

Main Methods:

• Genetic engineering of fd phage to display specific 5-mer peptide sequences (YYYYY, AYSSG, AYGDD) on p8 coat proteins.
• Characterization using Quartz Crystal Microbalance (QCM), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDX).
• One-step metallization reaction to form gold clusters on engineered phages.

Main Results:

• Engineered phages with tyrosine-containing peptides exhibited increased gold binding affinities compared to wild-type phage.
• The YYYYY phage displayed the strongest binding affinities to gold surfaces and gold nanoparticles (AuNPs).
• Recombinant phages were successfully coated with gold clusters after a single metallization step.

Conclusions:

• Displaying tyrosine-containing peptides on filamentous bacteriophages significantly enhances their gold binding and reduction capabilities.
• Engineered phages, particularly YYYYY variants, serve as effective biotemplates for gold nanostructure formation.
• Further genetic modifications can optimize phages for self-assembly in bottom-up manufacturing for nanoelectronics and biosensors.