Engineering Hybrid Nanostructures With Phage Particles

Lee Makowski Sr Biophysicist Biosciences Division Argonne National Laboratory Bldg:202, Rm: B225   Biographical Sketch Publications Group Members

Assembling complex structures comprising multiple, inorganic functional elements represents a significant engineering challenge.  The exquisite affinity and specificity of biomolecules are protypical of the properties required of the structural elements in a complex nanostructure.  Re-engineering biomolecules to fulfill the design specifications of a nanoassembly takes advantage of the tools of structural and molecular biology to adapt appropriate molecular scaffolds to new purpose.  Phage represents a particulary attractive source of structural elements: (i) Their genomes are readily manipulated for the design of protein variants exhibiting required properties.  (ii) Their capsids have evolved a physical and chemical resilience required for survival outside the cytoplasm of host cells.  (iii) Combinatorial libraries can be constructed on their surface for ready selection of novel binding motifs.  We have constructed hybrid nanostructures based on T7 and M13 phage and incorporating a variety of metals and metal oxides.  Synthesis of these structures demonstrates the level of control that is possible with this approach, but, as of yet, only hints at the complexity that will soon be possible.

 

 

M13 as a scaffold for placement of iron particles

Davidovich, Kischenko, and Makowski

Why Phage Particles?

• Reproducible Geometry
  • Huge populations can be produced in whch every particle is virtually identical
    
    
• Incorporation of Inorganic Particles
  • Inorganic material can be encapsulated in phage shells
  • Phage can be generated that will bind to inorganic components
    
    
• Combinatorial libraries can be constructed and screened
  • Allows selection of desirable properties - e.g. binding affinity
    
    
• Massively parallel assembly
  • Directed assembly can make possible fabrication of large numbers of identical nanostructures
    
    
• Resilience
  • Can be obtained by post-assembly processing

Incorporating metals in a protein shell : T7 bacteriophage

 

Chinmei Liu, Seok-Hwan Chung, Qiaoling Jin, April, Sutton, Funing Yan, Axel Hoffman, Brian K Kay, Samuel D. Badera, Lee Makowski, Liaohai Chen

 

	functional exterior     functional interior
T7 virion scaffold

 

 

Step 1 : remove DNA (making ghost particles)

Step 2 : Replace with metallic core

Cobalt containing phage particles

Step 3 : Engineer surface through fusion of affinity reagent groups

Cobalt containing phage particles with affinity to M13

Design and Construction of Microphage Particles

Leon Specthrie, Esther Bullitt, Kensuke Horiuchi, Peter Model, Marjorie Russel, and Lee Makowski

The power of molecular biology makes possible the design of a wide variety of particles, based on naturally occurring systems, but altered to satisfy the needs of engineered systems.  One example is the construction of M13 microphage particles, about 50 nm in length.  This was carried out by constructing a plasmid that contained, sequentially, the origin of replication, the packaging signal, and a replication termination signal.  When bacteria harboring this plasmid were infected with a helper phage, the bacteria produced microphage particles containing all the structural elements of M13.