Download Proteins as Supramolecular Building Blocks

Proteins as supramolecular building blocks: towards active nanoscaffolds
Juliet A. Gerrard 1, Tong Zhu 1, Grant Pearce 1 2
1
Mac Diarmid Institute and Biomolecular Interaction Centre, University of Canterbury
The last decade has witnessed a huge gain in understanding of the way in which small
molecules can be assembled into discrete and polymeric 1, 2 and 3D architectures. Key
challenges remain before this knowledge can be harnessed in nanoscale devices. Integral to
these challenges is the question of scale: well characterised self-assembling systems typically
use components of 1 -2 nm dimensions, whilst nanoscale devices demand 10-100 nm. In this
research, we aim to bridge the scale gap by using proteins as our building blocks.
We are u sing the methods of protein engineering to assemble non-native quaternary
st ructures and active nanoscaffolds. Two model systems are being explored: a TIM barrel
enzyme, representing the most common protein fold and therefore scaffold for activity; and
the peroxiredoxins, a family of proteins that have already revealed themselves to have unique
self-assembly properties controlled by a redox switch.
Non-native architectures have been obtained and progress is being made in the controlled
assembly of these structures using ligand triggered assembly or changes in redox properties
of the solvent. Specifically: the assembly of the TIM-barrel protein may be controlled by the
binding of pyruvate; and the assembly of an expressed peroxiredoxin can be controlled by a
single mutation at the interface. This is a promising approach for the assembly of active
materials on the nanoscale, as we refine the triggered assembly and disassembly of these
st ructures by an environmental trigger and expand the repertoire of chemical and biological
activities incorporated into the scaffold.