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Engineering Approaches to Biomolecular Motors: From in vitro to in vivo Poster Abstracts
53
29-POS
Board 29
Synthesis and Characterization of the Lawnmower: An Artificial Protein-based, Burnt-
bridges Molecular Motor
Damiano Verardo
1
, Chapin Korosec
2
, Martin J. Zuckermann
2
, Heiner Linke
1
, Nancy R. Forde
2
.
1
Lund University, Lund, Sweden,
2
Simon Fraser University, Vancouver, BC, Canada.
In this work we report progress towards constructing an artificial protein motor dubbed
Lawnmower, based on the burnt-bridges concept and inspired by matrix metalloproteinases
(MMPs), involved in the degradation of collagen fibrils.
The Lawnmower consists of a quantum dot hub (16nm diameter), conjugated to multiple trypsin
protease blades via flexible PEG linker molecules [1]. It is expected to undergo biased motion on
a peptide track through enzymatically cleaving peptides into product and seeking substrate-rich
areas, and will remain processive as long as the individual binding events occur before complete
detachment. To guide experiments, Langevin simulations are carried out to provide insight into
Lawnmower design criteria.
To demonstrate the motor's properties, 2D ensemble experiments on peptide covered,
lightguiding III-V nanowires will be performed. Nanowires are grown via metalorganic vapour
deposition, coated with silicon oxide, and alkyne-silanized in order to allow subsequent click
chemistry functionalization by modified peptides. It was recently observed that light emitted by
molecules close to the surface of these nanowires is waveguided to the tip due to coupling of
optical modes. Nanowires coated with peptides that emit fluorescent photons upon cleavage can
then be used as sensors to assess the speed and processivity of the Lawnmower in two
dimensions.
Following optimization of Lawnmower construction, 1D experiments are planned on peptide-
functionalized DNA, where biased motion of the Lawnmower should be clearly evident. This
DNA-supported peptide lawn has controllable average spacing between peptides, allowing
evaluation of processivity as a function of substrate density. Successful implementation of the
Lawnmower in the above assays would result in the first protein-based artificial molecular
motor.
[1] Kovacic, S.,
et al.
, Design and Construction of the Lawnmower, An Artificial Burnt-Bridges
Motor. IEEE Transactions on NanoBioscience, 14(3), 305–312.