Muscle Mechanics - the emerging techniques of note - I

The Monday morning muscle sessions started with two awesome talks on the relay loop of the myosin and its function in stabilizing the myofibril structure assembly and force generation. While the morning session talks were super interesting, of note were the new emerging techniques that were talked about.

Gravitational Force Spectroscopy (GFS) - a new technique developed in the Root lab, essentially exploits a two microsphere (small glass beads) system wherein the larger of the two micro-spheres is anchored and the smaller one is free floating. The distance between the centers of these two microspheres is at its minimum. As a myosin molecule tethers itself between the microspheres, gravitational force is exploited such that it is either parallel or perpendicular to the orientation of the molecule. As the free floating microsphere rotates based off the gravity, one can calculate the min. and max. distance between the centers of the two microspheres and thereby calculate the flexibility of the myosin tethered. It is a novel and neat technique, with lots of potential for experiments contrasting diseased and control states of various molecules and post translational modifications altering flexibility.

3- Optical bead Assay - Highlighted in the last two talks of the session was the 3-optical bead assay. The gist of the technique - mount two anchored polystyrene glass beads on two opposite ends on a coverslip. Motion sensors are attached to each of these beads. Actin filaments attach these two beads together. A third bead is positioned in between these two beads and a myosin head is tethered to it. As the myosin head forms a bond with the actin filament, the anchored beads move, the distance is sensed by the motion sensors and the step size of force generation by one head is revealed. Now if you attach small loads to each of the two beads attached to the actin filament, you get the working stroke  of the muscle under loaded conditions!

The other notable techniques that are emerging are the single myofibril technique, FRET, mass spectroscopy and cryo- EM. which i would cover in part II of this article later in the day. Have to rush to career workshops now!