Molecular motors are nanoscale engines which move along very thin rod-like filaments and, in this way, drive the heavy traffic of molecular cargo within biological cells. Both motors and filaments can be isolated from the cells and used to construct biomimetic transport systems. In order to increase the flux of the cargo transport, it would be necessary to increase the number of motors that contribute to this transport but, at the same time, avoid the build-up of traffic jams. Scientists from the Max Planck Institute of Colloids and Interfaces in Potsdam and from the University of Amsterdam have now modelled and simulated the motor traffic for different compartment geometries and filament arrangements, and have determined the optimal conditions for the transport of nanocargo in these systems (Biophysical Journal, 88, 3118-3132, May 2005).

Each cell of our body contains a huge number of small vesicles which exhibit complex patterns of intracellular traffic: some vesicles travel from the cell center to the periphery and vice versa, some shuttle between different organelles or cellular compartments. An extreme case is provided by the long-ranged transport of vesicles and organelles along the axons between our nerve cells, which can be as long as half a meter. All of these movements are based on two molecular components: very thin rod-like filaments, which form a complex network of rails, and molecular motors, which move along those filaments and carry vesicles and other nanocargo along. When bound to the filaments, the motors are able to transform the chemical energy of a single ATP molecule into mechanical work. In this way, they can utilize the smallest possible amount of fuel.

Both filaments and motors can be isolated from biological cells and used to construct biomimetic transport systems. A relatively simple example for
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Contact: Prof. Dr. Reinhard Lipowsky
Reinhard.Lipowsky@mpikg.mpg.de
49-331-567-9600
Max-Planck-Gesellschaft
5-May-2005