Biomolecular traffic control

Dutch researchers have developed a biomotor that steers microtubules to a specific location on a chip. The breakthrough takes nanotechnologists a step closer to developing finely controlled nanometre-scale transport systems.

Microtubules, which are composed of tubulin proteins, form a star-shaped transport network inside living cells. Molecular biomotors, such as kinesin motor proteins, are the workhorses of the cell. Kinesin proteins attach their two heads to a microtubule and then ’walk’ along the tubule by stepping forward with alternating heads. This allows the biomotors to carry cargo, such as vesicles or viruses, through the cell.

Cees Dekker and colleagues at Delft University’s Kavli Institute of Nanoscience based their nanoscale transport system on this biological model. They constructed a Y-shaped enclosed channel on a chip, and lined this fluid-filled channel with a carpet of kinesin biomotors. To demonstrate that the biomotors could direct individual microtubules to specific locations on a chip, the researchers inserted rhodamine (red) and fluorescein (green)
-labeled microtubules into the channel. They collected separate pools of red and green microtubules by applying electric forces that shunted the negatively-charged tubules down a specific arm of the Y-shaped channel. 

This is ’the first traffic control system in biomolecular motor nanotechnology,’ said materials scientist Henry Hess of the University of Florida in Gainesville, US. ’For engineers, active transport in biology inspires visions of molecular conveyor belts and forklifts for nanometre-scale manufacturing,’ he said. The Delftteam predicts future developments, ranging from pharmaceutical labs-on-chips to purification applications. 

Yfke Hager