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BP: Fachverband Biologische Physik

BP 61: Topological Problems in the Physics of Polymers, Biopolymers and Fibers II (Joint Focus Session CPP/BP)

BP 61.5: Vortrag

Freitag, 24. März 2017, 11:45–12:00, ZEU 222

Entropic vs Energetic stiffness in biopolymers — Tatjana Škrbić¹, •Achille Giacometti¹, Trinh Hoang², Artem Badasyan³, and Rudolf Podgornik⁴ — ¹University of Venice, Italy — ²Institute of Physics, Hanoi, Vietnam — ³University of Nova Gorica, Slovenia — ⁴University of Ljubljana, Slovenia

Homopolymers form a high temperature swollen (coil) phase and a low temperature phase globular phase. The glassy nature of this ground state stems from the inability of homopolymers to reduce their entropy as temperature is decreased.

Recent attempts to introduce additional ingredients allowing the removal of this glassy ground state and hence the onset of alpha-helical and beta-sheet like structures, characteristic of proteins, will be presented. In particular, it will be shown how the introduction of an entropic stiffness breaks the spherical symmetry of the interactions and leads to the formation of protein secondary structures.

Further, the difference between this entropic stiffness and the conventional energetic stiffness characteristic of semi-flexible polymers will be pointed out, as well as the relevance of the latter for the ground state phase diagram of DNA in a bad solvent.

Finally, the relevance of the presented results for the protein design, as well as for the interpretation of experimental results on the DNA condensation, will be discussed.

References [1] T. Škrbić et al, J. Chem. Phys. (2016) [2] T. Škrbić et al, Soft Matter (2016) [3] T.X. Hoang et al, Phys. Rev. E (2015) [4] T.X. Hoang et al, J. Chem. Phys. (2014)