Effects of potential environmental interferents on kinesin-powered molecular shuttles

Biomolecular motor-powered active transport represents an alternate means for analyte processing in nanoscale biosensors and bioanalytical devices. For example, a prototype "smart dust" biosensor has recently been reported in which the motor protein kinesin processes antibody-functionalized microtubules (MTs) to capture and separate optically tagged protein analytes. A potential limitation of this technology, however, involves the inhibition of transport function by interfering compounds that may be present in raw samples. Here we characterized the response of kinesin-MT transport to a range of potential interferents including solvents, acids, oxidizers, and environmental contaminants. The results of kinesin motility assays suggest that, among the tested interferents, only acetic acid and sodium hypochlorite adversely affected MT transport, primarily due to depolymerization of MT filaments. While negative effects were not observed for the remaining compounds tested, enhancement in motility was observed in the presence of acetone, antifreeze, and organic matter. Overall, the data suggest that kinesin-MT transport is resilient against a variety of common interferents, but primarily susceptible to failure due to significant changes in pH or the presence of an oxidizer.