LABORATOIRE DE PHYSIQUE THEORIQUE DE LA MATIERE CONDENSEE

Vittore Scolari (Institut Pasteur, Paris)

Kinetic signature of cooperativity in the irreversible collapse of a polymer

We investigated the kinetics of a polymer collapse due to the formation of irreversible crosslinks between its monomers. We use the contact probability as a function of the monomeric distance as a scale dependent order parameter and show in simulations the emergence of acooperative pearling instability. This produces a sharp conformational transition in time, inducing a crossover between short and long distance behaviour due to the formation of pearls. The size of pearls and the transition time depends on the equilibrium dynamics of the polymer and the rate at which cross links are formed. We finally confirm experimentally the existence of this transition using a chromosome conformation capture experiment.