Biological & Soft Matter Seminar: Unfolding of macromolecules with compactly folded domains

Abstract:

Certain types of macromolecules include an arrangement of bi-stable domains that can switch between compactly folded or unfolded configurations, depending on conditions. This molecular structure gives rise to a saw-tooth pattern in single molecule force-extension measurements. A classic example is the muscle protein titin, which uses these abrupt unfolding events in order to dissipate energy. Clearly, the behavior of such macromolecules is dominated by a wiggly energy landscape and thermal fluctuations. This gives rise to a stochastic rate-dependent and temperature-dependent response. The overdamped dynamics of a bistable chain subjected to thermal fluctuations is prototypical of such behavior. By studying this model-system, we obtain universal relations for predicting statistical properties of the response for a wide range of rates, temperatures, and structural properties.

Seminar Organizer: Guy Yaacoby