Thermodynamically Stable Knots in Semiflexible Polymers

التفاصيل البيبلوغرافية
العنوان: Thermodynamically Stable Knots in Semiflexible Polymers
المؤلفون: Janke, Wolfhard, Majumder, Suman, Marenz, Martin, Paul, Subhajit
سنة النشر: 2024
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Soft Condensed Matter
الوصف: Semiflexible polymers are widely used as a paradigm for understanding structural phases in biomolecules including folding of proteins. Here, we compare bead-spring and bead-stick variants of coarse-grained semiflexible polymer models that cover the whole range from flexible to stiff by conducting extensive replica-exchange Monte Carlo computer simulations. In the data analysis we focus on knotted conformations whose stability is shown to depend on the ratio $r_b/r_{\rm min}$ with $r_b$ denoting the equilibrium bond length and $r_{\rm min}$ the distance of the strongest nonbonded interactions. For both models, our results provide evidence that at low temperatures for $r_b/r_{\rm min}$ outside a small range around unity one always encounters knots as generic stable phases along with the usual frozen and bent-like structures. By varying the bending stiffness, we observe rather strong first-order-like structural transitions between the coexisting phases characterized by these geometrically different motifs. Through analyses of the energy distributions close to the transition point, we present exploratory estimates of the free-energy barriers between the coexisting phases.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2402.10147
رقم الأكسشن: edsarx.2402.10147
قاعدة البيانات: arXiv