Molecular Motors - information flow from the nanoscale to the microscale

Our lab’s interest in non-equiblibrium thermodynamics and particularly in the field of information thermodynamics (for a review, see the excellent Thermodynamics of Information by Parrondo et al.) naturally led us to think about how we could observe the exchange of information and energy.

Unfortunately, the order of magnitude at which information plays a part is \(kT \ln{2}\), so of the order of \(2 pN.nm\). Hard to observe. Although some labs have done this (see the experiments described in the Parrondo review), we thought about doing something different: use microtubules (microscale) on a bed of molecular motors(nanoscale). We could then observe the motion of the microtubule and hopefully gain some insight on the fluctuations of the nanoscale molecular motor. Incidentally, this well known setup is called a motility assay, and has been used for just about everything cool you could think about, see for example my PI’s review.

In the end the setup worked well, and we were able to derive some cool results about the behavior of the nanoscale motors by looking at the velocity fluctuations of the microtubules, using a Brownian dynamics simulation. Read the whole thing here.