DNA-condensation, redissolution and mesocrystals induced by tetravalent counterions

TL;DR

This study uses computer simulations to explore how tetravalent counterions influence DNA interactions, revealing conditions for DNA condensation, redissolution, and mesocrystal formation, advancing understanding of DNA phase behavior.

Contribution

It provides detailed phase diagrams and insights into DNA behavior with tetravalent counterions, highlighting the mechanisms behind condensation and mesocrystal formation.

Findings

Counterions induce an attractive potential minimum at short distances

DNA condenses and redissolves depending on counterion concentration

Stable mesocrystals form at high counterion concentrations

Abstract

The distance-resolved effective interaction potential between two parallel DNA molecules is calculated by computer simulations with explicit tetravalent counterions and monovalent salt. Adding counterions first yields an attractive minimum in the potential at short distances which then disappears in favor of a shallower minimum at larger separations. The resulting phase diagram includes a DNA-condensation and redissolution transition and a stable mesocrystal with an intermediate lattice constant for high counterion concentration.