P024
Proteins as supramolecular building blocks: engineering
nanoscale structures
Leonardo Negron, Helen Ashmead and Juliet Gerrard
Callaghan Innovation, Wellington, New Zealand
Complex nanoscale devices have great potential for use in
the development of new materials, biosensors, electronics
and pharmaceuticals. The potential to produce nanodevices is
well supported by the numerous examples of self-assembling
proteins found in nature. We are exploring self-assembling
proteins as molecular building blocks to engineer nanocomponents. A promising candidate for engineering self-assembling
nanocomponents is Lsr2. Lsr2 is a DNA binding protein present
in mycobacterium and related actinobacteria that regulates
gene expression. The key features of Lsr2 are that it contains a
site for DNA binding and another for triggered oligomerisation.
Collectively, these sites can serve as access points for regulating
protein self-assembly and altering the nanocomponent architecture. Summers et al (2012) have recently shown that limited
proteolytic cleavage of Lsr2 at the N-terminal end of the protein
results in self-assembly via antiparallel pairing of single β-strands
from neighbouring proteins to form a linear chain of repeating
protein units. The linear chains are nanotubular in appearance
(TEM) and approximately 20 nm wide. The simplicity of structure,
self-assembling potential and multiple sites of oligomerisation
make this protein an ideal candidate for the fabrication of nanocomponents. Herein, we report preliminary experiments designed
to utilise Lsr2 as a building block of nanocomponents and control
self-assembly via environmental triggers. Our results suggest
that such triggers can be used to control the activation of selfassembly as well as manipulate the nanoscale structures into
varied geometries.