Proteins have been optimized by evolution for billions of years to work on a nanometer scale. Therefore, they are extremely promising for nanotechnological applications. Cytoskeletal filaments propelled by surface-attached motor proteins have been recently established as versatile transport platforms for nano-sized cargo in molecular sorting and nano-assembly devices. However, in this gliding motility setup, cargo and motors share the filament lattice as a common substrate for their activity. Therefore, it is important to understand the influence of cargo-loading on transport properties.
By performing single molecule stepping assays on biotinylated microtubules, it was shown that kinesin-1 motors first stop and then detach when they encounter a streptavidin obstacle on their path along the microtubule. Consequently, the deceleration of streptavidin coated microtubules in gliding assays could be attributed to an obstruction of kinesin-1's path on the microtubule rather than to "frictional" streptavidin-surface interactions.
The insights gained by studying kinesin-1's behavior at obstacles were then used to demonstrate a novel sensing application: Using a mixture of two distinct microtubule populations that each bind a different kind of protein, the presence of these proteins was detected via speed changes in the respective microtubule populations. In future applications, this detection scheme could be combined with other recent advancements in the field, creating highly integrated lab-on-a-chip devices that use microtubule based transport to detect, sort and concentrate analytes.
It has been envisioned that the kinesin-1-microtubule system could be used for even more complex appliances like nano-assembly lines. However, currently available control mechanisms for kinesin-1 based transport are not precise enough. Therefore, improved temporal control mechanisms for kinesin-1 were investigated: Using a polymer that changes its size in solution with temperature, starting and stopping of gliding microtubules was demonstrated. In combination with local heating by light, this effect could be used to control the gliding of single microtubules. Finally, a strategy to create photo-switchable kinesin-1 was developed and tested for feasibility using molecular modeling.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa.de:bsz:14-qucosa-26443 |
| Date | 28 January 2010 |
| Creators | Korten, Till |
| Contributors | Technische Universität Dresden, Fakultät Mathematik und Naturwissenschaften, Max-Planck-Institut für Molekulare Zellbiologie und Genetik, Diez Group, Dr. Stefan Diez, Prof. Dr. Anthony Hyman, Prof. Dr. Henry Hess |
| Publisher | Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:doctoralThesis |
| Format | application/pdf |
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