Polyampholyte sequence controls the type of electrostatic coil-globule transition in good solvent

The Journal of Chemical Physics, Год журнала: 2025, Номер 162(5)

Опубликована: Фев. 3, 2025

Coarse-grained molecular dynamics simulations are employed to explore the conformational behavior of globally neutral polyampholytes under good solvent conditions. The interplay between non-Coulomb repulsions and sequence-dependent Coulomb attractions monomers results in qualitatively different types electrostatically driven chain contraction for diblock, random, alternating statistics. At increasing solution Bjerrum length lb, diblock random exhibit a smooth coil-globule crossover, with globule size continuously decreasing lb according theoretical power laws. This confirms scaling picture interior consisting oppositely charged blobs attracting each other via long-range electrostatic forces repelling short-range two-body interactions. In contrast, collapse completely analogously chains because interactions them effectively dipole–dipole short-range. transition region shrinks length, implying phase limit infinitely long chains. These curves fall on universal master curve, which is well-fitted by theory transitions demonstrates that renormalize (reduce) dimensionless second virial coefficient δB∝−lb2. study highlights profound impact primary sequence charge-balanced solvents, particularly nature they undergo.

Язык: Английский

Sequence-dependent biomolecular phase separation driven by short-range interaction: From material properties to coarsening dynamics

Physical review. E, Год журнала: 2025, Номер 111(5)

Опубликована: Май 8, 2025

Язык: Английский