Physical Review E 104, L012101 (2021)

ISSN: 2470-0045, SCIE

Spontaneous dimensional reduction and ground state degeneracy in a simple chain model

Tatjana Škrbić, Trinh Xuan Hoang, Achille Giacometti, Amos Maritan, and Jayanth R. Banavar

Chain molecules play a key role in the polymer field and in living cells. Our focus is on a new homopolymer model of a linear chain molecule subject to an attractive self-interaction promoting compactness. We analyze the model using simple analytic arguments complemented by extensive computer simulations. We find several striking results: there is a first-order transition from a high-temperature random coil phase to a highly unusual low-temperature phase; the modular ground states exhibit significant degeneracy; the ground state structures exhibit spontaneous dimensional reduction and have a two-layer structure; and the ground states are assembled from secondary motifs of helices and strands connected by tight loops. We discuss the similarities and notable differences between the ground state structures [we call these PoSSuM (Planar Structures with Secondary Motifs)] in the phase and protein native state structures.

URL: https://journals.aps.org/pre/abstract/10.1103/PhysRevE.104.L012101

DOI: 10.1103/PhysRevE.104.L012101

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