Enhancing effect of zinc acetate on the binding of 1-nitropyrene to polydeoxyguanylic-polydeoxycytidylic acid in the hypoxanthine-xanthine oxidase system

Biol Pharm Bull. 1994 Jul;17(7):970-2. doi: 10.1248/bpb.17.970.

Abstract

The main aim of this research was to investigate whether conformational alteration of polydeoxyguanylic-polydeoxycytidylic acid (poly[dG-dC].poly[dG-dC]) by zinc acetate would have an effect on the binding of 1-nitropyrene(1-NP) to poly[dG-dC].poly[dG-dC]. The binding of 1-NP to poly[dG-dC].poly[dG-dC] in the hypoxanthine-xanthine oxidase system in vitro was increased by zinc acetate. This increase was abolished when EDTA was added to the preincubated mixture of poly[dG-dC].poly[dG-dC] and zinc ions. Neither the production of 1-aminopyrene and its expected intermediates, N-hydroxy-1-aminopyrene and 1-nitrosopyrene, nor the 1-NP remaining in the reaction mixture was altered by the addition of zinc acetate without poly[dG-dC].poly[dG-dC]. From these findings, it seems that the hypoxanthine-xanthine oxidase system is not activated by zinc acetate. On the other hand, under the same reaction conditions but the hypoxanthine-xanthine oxidase system and 1-NP, it has been reported that zinc ions or complexes transform the B-form of poly[dG-dC].poly[dG-dC] to the Z-form. Therefore, these findings indicate that the formation of the Z-form or intermediates from the B-form by zinc ions may promote the binding of 1-NP to poly[dG-dC].poly[dG-dC].

MeSH terms

  • Acetates / pharmacology*
  • Acetic Acid
  • Hypoxanthine
  • Hypoxanthines / metabolism*
  • Molecular Conformation
  • Polydeoxyribonucleotides / chemistry
  • Polydeoxyribonucleotides / metabolism*
  • Pyrenes / metabolism*
  • Xanthine Oxidase / metabolism*

Substances

  • Acetates
  • Hypoxanthines
  • Polydeoxyribonucleotides
  • Pyrenes
  • poly(dC-dG)
  • Hypoxanthine
  • Xanthine Oxidase
  • Acetic Acid
  • 1-nitropyrene