Accueil > Séminaires > Précédents séminaires > Cooperative folding of muscle myosins

Cooperative folding of muscle myosins

Matthieu Caruel M3DISIM, Inria, Saclay

Mechanically induced folding of passive cross-linkers is a fundamental biological phenomenon. A typical example is a conformational change in myosin II responsible for the power-stroke in skeletal muscles. In this presentation I will present a description of such folding by analyzing the simplest purely mechanical prototype : a parallel bundle of bi-stable units attached to a common backbone.
I will show that in this analytically transparent model, characterized by a rugged energy landscape, the ground states are always highly coherent, single-phase configurations. Such cooperative behavior, ensuring collective conformational change, is due to the dominance of long-range interactions making the system non-additive. The detailed predictions of our model are in agreement with experimentally observed non-equivalence of fast force recovery in skeletal muscles loaded in soft and hard devices. Some features displayed by the model are also recognizable in the behavior of other biological systems with passive multi-stability and long-range interactions including detaching adhesive binders and pulled RNA/DNA hairpins.

Bifurcation diagram showing existence of non-cooperative and