Nickel (II) Ions Interaction with Polynucleotides and DNA of Different GC Composition

TL;DR

This study investigates how Ni(II) ions interact with DNA of various GC compositions using ultraviolet difference spectroscopy, revealing specific binding modes and effects on DNA stability and structure.

Contribution

It provides new insights into Ni(II) binding preferences and mechanisms with DNA and polynucleotides, especially regarding GC-rich regions and crosslink formation.

Findings

Ni(II) binds to DNA via outer-spherical interactions at the major groove.

Ni(II) preferentially forms G-G interstrand crosslinks at specific sites.

Binding induces point defects and depurinization in DNA.

Abstract

The goal of the work was to study the role of GC alternative dimmers in the binding of DNA with Ni (II) ions. The method of ultraviolet difference spectroscopy has been applied to investigate Ni (II) ions interactions with DNA extracted from Clostridium perfringens, Mice liver (C3HA line), Calf thymus, Salmon sperm, Herring sperm, E.coli, Micrococcus luteus and polynucleotides Poly (dA-dT)xPoly (dA-dT), Poly (dG)x Poly (dC), Poly (dG-dC)xPoly (dG-dC). It is shown that Ni (II) ions at outer-spherical binding with DNA double helix from the side of the major groove choose more stable dimmers 3^'-C-G-5^' . . 5^'-G-C-3^' and get bound with N7 atoms of both guanines in dimmer forming G-G interstrand crosslink. It directly correlates to the process of forming point defects of Watson-Crick wrong pair type (creation of rare keto-enolic and amino-imino tautomeric forms) and depurinization.