Models of Molecular Motors
Molecular motors in living cells
are complex protein assemblies that perform mechanical tasks, such
as intracellular transport, ion pumping, DNA replication and protein
synthesis. Distinct from macroscopic, man-made machines, molecular
motors work in a very noisy environment, where thermal fluctuations
are significant and probably important to the operation of the motor.
Molecular machines are also capable of transforming chemical energy
directly into mechanical work, unlike man-made heat engines that
need an extra step (heat).
To help understanding the basic physical principles that govern
molecular motors it is helpful to develop relatively simple model
systems. The goal of such models is not necessarily to replicate the usually
very complex biological reality, but to create controlled environments
that can teach us about the basic principles that may be in common
to all nanoscale, thermal machines.
Our group uses both numerical and experimental methods to create
such models, many of which are related to ratchets
and Brownian motors.
Most recently, we completed mechanochemical model of Myosin V (PNAS 2009). Here you can watch an animation of myosin-V with realistic thermal motion based on Brownian dynamics simulations of a coarse-grained version of the molecule.
Within an HFSP funded project, we are developing a synthetic protein motor.
Freely-jointed chain polymer in a flashing ratchet (PRE
73, 011909 (2006)).
Dimer in a flashing ratchet.
Erin Craig (theory)
Brian Long (experiment)
Ben Lopez (experiment)
Martin Zuckermann, Simon Fraser University , Canada
Matthew Downton, Simon Fraser University , Canada
Michael Plischke, Simon Fraser University , Canada
, Nanometer Structure Consortium,
E. M. Craig, M.J. Zuckermann, and H. Linke: Mechanical
coupling in flashing ratchets.
M. T. Downton, M.J. Zuckermann, E. M. Craig, M. Plischke and
H. Linke: Single-polymer motor: a simulation study.
Phys. Rev. E 73, 011909 (2006)
H. Linke, M. T. Downton and M.J. Zuckermannn: Performance
Characteristics of Brownian motors
Chaos 15 , 026111 (2005)
NSF Career Award PHY0239764 (2003 - 2008)