Nanoscale patterning of kinesin motor proteins and its role in guiding microtubule motility.

Biomolecular motor proteins have the potential to be used as 'nano-engines' for controlled bioseparations and powering nano- and microelectromechanical systems. In order to engineer such systems, biocompatible nanofabrication processes are needed. In this work, we demonstrate an electron beam nanolithography process for patterning kinesin motor proteins. This process was then used to fabricate discontinuous kinesin tracks to study the directionality of microtubule movement under the exclusive influence of surface bound patterned kinesin. Microtubules moved much farther than predicted from a model assuming infinite microtubule stiffness on tracks with discontinuities of 3 mum or less, consistent with a free-end searching mechanism. As the track discontinuities exceeded 3 mum, the measured and predicted propagation distances converged. Observations of partially fixed microtubules suggest that this behavior results from the interaction of the microtubules with the surface and is not governed predominately by the microtubule flexural rigidity.