Adsorption of multivalent counterions on the charged surface of a macroion is known to lead to inversion of the macroion charge due to the strong lateral correlations of counterions. We consider a nontrivial role of the excluded volume of counterions on this effect. It is shown analytically that when the bare charge of the macroion increases, its net charge including the adsorbed counterions os...

We study the attractive interactions between rodlike charged polymers in solution that appear in the presence of multivalence counterions. The counterions condensed to the rods exhibit both a strong transversal polarization and a longitudinal crystalline arrangement. At short distances between the rods, the fraction of condensed counterions increases, and the majority of these occupy the region...

The problem of DNA-DNA interaction mediated by divalent counterions is studied using computer simulation. Although divalent counterions cannot condense free DNA molecules in solution, we show that if DNA configurational entropy is restricted, divalent counterions can cause DNA reentrant condensation similar to that caused by tri- or tetravalent counterions. DNA-DNA interaction is strongly repul...

We investigate the structural properties of rigid linear polyelectrolytes in dilute and semidilute solutions using an integral equation theory. The Polymer Reference Interaction Site Model together with the Reference Laria Wu Chandler Closure is solved numerically taking the counterions into account explicitly. The counterions and the polymer chains, modeled as linearly connected, charged hard ...

The problem of viral packaging (condensation) and ejection from viral capsid in the presence of multivalent counterions is considered. Experiments show divalent counterions strongly influence the amount of DNA ejected from bacteriophage. In this paper, the strong electrostatic interactions between DNA molecules in the presence of multivalent counterions is investigated. It is shown that experim...

– We study a two-dimensional model for a long cylindrical stiff charged macroion immersed in a charge-asymmetric electrolyte with charge ratio +2/−1. The model is integrable and it allows an exact analytical determination of the effective charge of the macroion, which characterizes the electrostatic potential at large distances (compared to the screening length) from the macroion. At at high co...

Screening of a strongly charged macroion by multivalent counterions is considered. It is shown that counterions form a strongly correlated liquid at the surface of the macroion. Cohesive energy of this liquid leads to additional attraction of counterions to the surface, which is absent in conventional solutions of the Poisson-Boltzmann equation. Away from the surface this attraction can be take...

The Aβ(16-22) sequence KLVFFAE spans the hydrophobic core of the Aβ peptide and plays an important role in its self-assembly. Apart from forming amyloid fibrils, Aβ(16-22) can self-associate into highly ordered nanotubes and ribbon-like structures depending on the composition of solvent used for dissolution. The Aβ(16-22) sequence which has FF at the 19th and 20th positions would be a good mode...

The problem of DNA- DNA interaction mediated by divalent counterions is studied using a generalized grand-canonical Monte-Carlo simulation for a system of two salts. The effect of the divalent counterion size on the condensation behavior of the DNA bundle is investigated. Experimentally, it is known that multivalent counterions have strong effect on the DNA condensation phenomenon. While tri- a...