Transient helix formation in charged semiflexible polymers without confinement effects.

Switching on generic interactions e.g. the Coulomb potential or other long ranged spherically symmetric repulsive interactions between monomers of bead-spring model of a semi-flexible polymer induce instabilities in a semiflexible polymer chain to form transient helical structures. The helical structures can be long lived for chains with relatively low persistence lengths. This mechanism could explain the spontaneous emergence of helices in stiff (bio-)polymers a chain gets charged from a neutral state, though to stabilize the helical structures hydrogen bonding or other additional mechanisms would be required. The emergence of the helix is independent of the molecular details of the monomer constituent. The key factors which control the emergence of the helical structure is the persistence length and the charge density. We have avoided using torsional potentials to obtain transient helices. Moreover, we can drive the semiflexible polymer to form helices in a recurring manner by periodically increasing and decreasing the effective charge of the monomers. This method could possibly be used to apply force at localized spots at length scales of nm-10μ.