We are heavily indebted to Jonathon Howard, whose group developed the basic protocol for a gliding motility assay which was subsequently adapted by us. Financial support from NSF grant DMR0645023 is gratefully acknowledged.

1.) Buffers and Reagents
These solutions should be prepared in advance and stored in conveniently sized aliquots. An aliquot should contain sufficient solution for a typical experiment and a fresh aliquot should be used for each motility assay. The storage conditions and typical aliquot sizes are also mentioned in the following protocols.
1. BRB80 buffer, (80 mM PIPES, 1 mM MgCl2, 1 mM EGTA in deionized distilled (dd) water, pH adjusted to 6.9 by KOH)
<...

<ol>
	<li>Agarwal, A., Hess, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomolecular+motors+at+the+intersection+of+nanotechnology+and+polymer+science.">Biomolecular motors at the intersection of nanotechnology and polymer science.</a> Progress in Polymer Science. 35 (1-2), 252-252 (2010).</li><li>Howard, J., Hunt, A. J., Baek, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assay+of+microtubule+movement+driven+by+single+kinesin+molecules.">Assay of microtubule movement driven by single kinesin molecules.</a> Methods Cell Biol. 39, 137-137 (1993).</li><li>Agarwal, A., Katira, P., Hess, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Millisecond+curing+time+of+a+molecular+adhesive+causes+velocity-dependent+cargo-loading+of+molecular+shuttles.">Millisecond curing time of a molecular adhesive causes velocity-dependent cargo-loading of molecular shuttles.</a> Nano Lett. 9 (3), 1170-1170 (2009).</li><li>Diez, S., Reuther, C., Dinu, C., Seidel, R., Mertig, M., Pompe, W., Howard, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stretching+and+Transporting+DNA+Molecules+Using+Motor+Proteins.">Stretching and Transporting DNA Molecules Using Motor Proteins.</a> Nano Lett. 3 (9), 1251-1251 (2003).</li><li>Bachand, G. D., Rivera, S. B., Boal, A. K., Gaudioso, J., Liu, J., Bunker, B. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assembly+and+transport+of+nanocrystal+CdSe+quantum+dot+nanocomposites+using+microtubules+and+kinesin+motor+proteins.">Assembly and transport of nanocrystal CdSe quantum dot nanocomposites using microtubules and kinesin motor proteins.</a> Nano Lett. 4 (5), 817-817 (2004).</li><li>Coy, D. L., Wagenbach, M., Howard, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinesin+takes+one+8-nm+step+for+each+ATP+that+it+hydrolyzes.">Kinesin takes one 8-nm step for each ATP that it hydrolyzes.</a> J. Biol. Chem. 274 (6), 3667-3667 (1999).</li><li>Katira, P., Agarwal, A., Fischer, T., Chen, H. -. Y., Jiang, X., Lahann, J., Hess, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+the+performance+of+protein-resisting+surfaces+at+ultra-low+protein+coverages+using+kinesin+motor+proteins+as+probes.">Quantifying the performance of protein-resisting surfaces at ultra-low protein coverages using kinesin motor proteins as probes.</a> Advanced Materials. 19, 3171-3171 (2007).</li><li>Vigers, G. P. A., Coue, M., McIntosh, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+Microtubules+Break+Up+Under+Illumination.">Fluorescent Microtubules Break Up Under Illumination.</a> J. Cell Biol. 107, 1011-1011 (1988).</li><li>Brunner, C., Hess, H., Ernst, K. -. H., Vogel, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lifetime+of+biomolecules+in+hybrid+nanodevices.">Lifetime of biomolecules in hybrid nanodevices.</a> Nanotechnology. 15 (10), S540-S540 (2004).</li></ol>

With minor modifications, this protocol has been successfully used by a variety of groups to assemble kinesin-microtubule based motility assays. 10 mM DTT in the final motility solution can be replaced with 0.5% &beta;-mercaptoethanol. Standard solutions (BRB80AF, KIN20 and MT1000) more than 2 hours old should not used. Any solution containing taxol and especially microtubules should never be placed on ice. Excessive exposure of the flow cell to UV excitation light results in photodamage to the functional components: mic...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Adenosine-5&#x2019;-triphosphate (ATP)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>A1049</td>
<td>&nbsp;</td>
<tr>
<td>Biotin tubulin</td>
<td>&nbsp;</td>
<td>Cytoskeleton Inc.</td>
<td>T333</td>
<td>&nbsp;</td>
<tr>
<td>Casein</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>C-0376</td>
<td>&nbsp;</td>
<tr>
<td>Catalase</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>C-9322</td>
<td>&nbsp;</td>
<tr>
<td>D-(+)-Glucose</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>G-7528</td>
<td>&nbsp;</td>
<tr>
<td>Dimethylsulfoxide (DMSO)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>D-8779</td>
<td>&nbsp;</td>
<tr>
<td>Dithiotreitol (DTT)</td>
<td>&nbsp;</td>
<td>Bio-Rad</td>
<td>161-0610</td>
<td>&nbsp;</td>
<tr>
<td>Ethylene glycol-bis(2-aminoethylether)-N,N,N&#x2032;,N&#x2032;-tetraacetic acid (EGTA)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>E-4378</td>
<td>&nbsp;</td>
<tr>
<td>FluoSpheres Biotinylated microspheres, 40 nm, yellow-green fluorescent (505/515)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>F-8766</td>
<td>&nbsp;</td>
<tr>
<td>Glucose oxidase</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>G-7016</td>
<td>&nbsp;</td>
<tr>
<td>Guanosine-5&#x2019;-triphosphate (GTP)</td>
<td>&nbsp;</td>
<td>Roche Diagnostic</td>
<td>106399</td>
<td>&nbsp;</td>
<tr>
<td>Magnesium Chloride (MgCl2)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>63069</td>
<td>&nbsp;</td>
<tr>
<td>Paclitaxel (Taxol)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>T1912</td>
<td>&nbsp;</td>
<tr>
<td>1,4-Piperazinediethanesulfonic acid, Piperazine-1,4-bis(2-ethanesulfonic acid), Piperazine-N,N&#x2032;-bis(2-ethanesulfonic acid) (PIPES)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>P-6757</td>
<td>&nbsp;</td>
<tr>
<td>Potassium hydroxide (KOH)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>P-6310</td>
<td>&nbsp;</td>
<tr>
<td>Sodium hydroxide (NaOH)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>480878</td>
<td>&nbsp;</td>
<tr>
<td>Streptavidin Alexa Fluor 568 conjugate</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>S11226</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

cargo loading onto kinesin powered molecular shuttles

Cells have evolved sophisticated molecular machinery, such as kinesin motor proteins and microtubule filaments, to support active intracellular transport of cargo. While kinesins tail domain binds to a variety of cargoes, kinesins head domains utilize the chemical energy stored in ATP molecules to step along the microtubule lattice. The long, stiff microtubules serve as tracks for long-distance intracellular transport.
These motors and filaments can also be employed in microfabricated synthetic environments as components of molecular shuttles 1. In a frequently used design, kinesin motors are anchored to the track surface through their tails, and functionalized microtubules serve as cargo carrying elements, which are propelled by these motors. These shuttles can be loaded with cargo by utilizing the strong and selective binding between biotin and streptavidin. The key components (biotinylated tubulin, streptavidin, and biotinylated cargo) are commercially available.
Building on the classic inverted motility assay 2, the construction of molecular shuttles is detailed here. Kinesin motor proteins are adsorbed to a surface precoated with casein; microtubules are polymerized from biotinylated tubulin, adhered to the kinesin and subsequently coated with rhodamine-labeled streptavidin. The ATP concentration is maintained at subsaturating concentration to achieve a microtubule gliding velocity optimal for loading cargo 3. Finally, biotinylated fluorescein-labeled nanospheres are added as cargo. Nanospheres attach to microtubules as a result of collisions between gliding microtubules and nanospheres adhering to the surface.
The protocol can be readily modified to load a variety of cargoes such as biotinylated DNA4, quantum dots 5 or a wide variety of antigens via biotinylated antibodies 4-6.

Watch this Scientific Journal Video about Cargo Loading onto Kinesin Powered Molecular Shuttles at JoVE.com

Cargo Loading onto Kinesin Powered Molecular Shuttles

Molecular shuttles consisting of functionalized microtubules gliding on surface-adhered kinesin motor proteins can serve as a nanoscale transport system. Here, the assembly of a typical shuttle system is described.

Cells have evolved sophisticated molecular machinery, such as kinesin motor proteins and microtubule filaments, to support active intracellular transport ...

cargo-loading-onto-kinesin-powered-molecular-shuttles

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Biology

10.4K visualizações.  University of Florida. Shuttles molecular composta por microtúbulos funcionalizados deslizando na superfície, aderiram proteínas cinesina motor pode servir como um sistema de transporte em nanoescala. Aqui, a montagem de um sistema de transporte típico é descrito.