Design and Non-Covalent DNA Binding of Platinum(II) Metallacalix[4]arenes

Research output: Contribution to journalArticle

Authors

  • MA Galindo
  • D Olea
  • MA Romero
  • J Gómez
  • Pd Castillo
  • A Rodger
  • F Zamora
  • JAR Navarro

Colleges, School and Institutes

Abstract

A set of cyclic tetranuclear complexes of the metallacalix[4]arene type with formula [{Pt(en)(L)}(4)](4+) (en=ethylenediamine; 2: LH=5-chloro-2-hydroxypyrimidine (5-Cl-Hpymo); 3: LH=5-bromo-2-hydroxypyrimidine (5-Br-Hpymo); 4: LH=5-iodo-2-hydroxypyrimidine (5-I-Hpymo)) have been obtained from the reaction between cis-protected square-planar [Pt(en)(H(2)O)(2)](2+) metal entities and LH in aqueous media. Additionally, the binding properties of 2, 3, 4 and their congener [{Pt(en)(L)}(4)](4+) (1: LH=2-hydroxypyrimidine (Hpymo)) with calf thymus-DNA (ct-DNA) have been studied by using different techniques including circular and linear dichroism (CD and LD, respectively) and UV-visible absorbance spectroscopies, gel electrophoresis, fluorescence competitive-binding studies and atomic force microscopy (AFM). The results are consistent with significant non-covalent interactions taking place between the polynuclear cyclic species and ct-DNA. Moreover, gel electrophoresis, linear dichroism titrations and AFM images of ct-DNA with metallacalixarenes show ct-DNA coiling at low metallacalixarene concentrations and upon subsequent increments in metallacalixarene concentration ct-DNA can be seen to uncoil with concomitant formation of long and inflexible ct-DNA structures.

Details

Original languageEnglish
Pages (from-to)5075
Number of pages1
JournalChemistry: A European Journal
Volume13
Issue number18
Publication statusPublished - 15 Jun 2007

Keywords

  • platinum, binding studies, metallacalixarenes, atomic force microscopy, DNA