Recognition and Selective Binding of DNA by Ionenes of Different Charge Density

Abstract

The ability of aliphatic ionenes to recognize and bind DNA or poly(methacrylic acid) (PMA) in the equimolar mixture of these polyanions was studied by fluorescence quenching technique. Within a particular system, the selectivity of competitive interactions was shown to be determined by a component with the lowest degree of polymerization (DP). Ionene polycations with lowest DP values did not exhibit pronounced selectivity in binding DNA or PMA with higher values of DP. Increase in ionene DP resulted in a steady increase in selectivity of interaction and ultimately in almost exclusive binding of one of the two polyanions. The ability of the ionene to recognize and bind DNA in the mixture of polyanions was shown not to correlate with the affinity of the ionene to DNA in their binary mixture. Although ionenes with a higher charge density exhibited preferential binding to PMA, the ionenes with the lowest charge density selectively bound DNA.

Isothermal Microcalorimetry to Investigate Non Specific Interactions in Biophysical Chemistry

“…There has been considerable effort to investigate the mechanisms of polyelectrolyte-polyelectrolyte interactions [79] in terms of the influence of polymerisation degree, pH in the case of weak polyelectrolytes (among which belong proteins) [80], charge density [81–84], and the presence of low molecular weight electrolytes aimed to screen the electrostatic forces [85]. The structure of such complexes [86–90] as well as their dynamics [82,91–95] has also been intensively investigated. Proton pulsed field gradient NMR has been used to demonstrate that the complexes between poly(diallyldimethylamonium chloride) and bovine serum albumin (BSA) can disintegrate and that dense domains may reform depending on the interaction strength between both partners [91].…”

Turbidity diagrams of polyanion/polycation complexes in solution as a potential tool to predict the occurrence of polyelectrolyte multilayer deposition

“…This relationship between a turbidity diagram and multilayer buildup has been established on poly(methacrylic acid) and quaternized poly(vinyl pyridine) (QPVP) [56]. It has been demonstrated that the stability of polyelectrolyte-polyelectrolyte or polyelectrolyte-protein complexes (where the proteins have to be considered as colloids carrying a heterogeneous surface charge distribution) depends among other parameters on the chain length [57], the linear charge density of the polyelectrolyte [58][59][60][61], the ionic strength of the solution [62], the pH in the case of weak polyelectrolytes or proteins [62] and the temperature. Hence, the physicochemical parameters governing the interpolyelectrolyte complexation in solution appear to be basically the same as those governing the buildup of PEM films.…”

Thermodynamic analysis of the interaction of partially hydrophobic cationic polyelectrolytes with sodium halide salts in water

“…The antimicrobial activity of ionenes against Gram-positive and Gram-negative bacteria was more recently reported by Punyani and Singh [14] and against yeasts and moulds by Kourai et al [15]. Studies exist on the binding of ionene polymers to protoplasts [16] and other model membranes [17], on the recognition and binding of DNA by ionenes [18], on the stability of their complexes with DNA [19], and on the applicability of ionenes as non-vector gene delivery systems [20], to mention only a few. Since ionenes can selectively bind to protoplasts and other model membranes, they were also considered as potential cancer drugs [21].…”