Modeling single microtubules as a colloidal system to measure the harmonic interactions between tubulin dimers in bovine brain derived versus cancer cell derived microtubules
The local properties of tubulin dimers dictate the properties of the larger microtubule assembly. In order to elucidate this connection, tubulin-tubulin interactions are be modeled as harmonic interactions to map the stiffness matrix along the length of the microtubule. The strength of the interactions are measured by imaging and tracking the movement of segments along the microtubule over time, and then performing a fourier transform to extract the natural vibrational frequencies. Using this method the first ever reported experimental phonon spectrum of the microtubule is reported. This method can also be applied to other biological materials, and opens new doors for structural analysis in the life sciences.
Methods used in colloidal soft matter physics were also adapted to the study of the microtubule to develop new methods to measure local stiffness in biological materials. Using this method it is shown that there is local variability in the mechanical properties of bovine brain derived versus cancer cell derived microtubules. This provide insight to how local changes affect the dynamic instability of microtubules of different types.
Finally, a nanofluidic device to isolate single microtubules is also reported, and is designed to be used for the study of any biological polymer. It can also be adapted to incorporate nano-scale electrodes for the sensing and actuation of single isolated proteins
