Enhancing effect of zinc acetate on the binding of 1-nitropyrene to polydeoxyguanylic-polydeoxycytidylic acid in the hypoxanthine-xanthine oxidase system.
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].
Sakai
K
K
Faculty of Pharmaceutical Sciences, Chiba University, Japan.
Nakajima
J
J
Niimura
M
M
Uchida
R
R
Yamane
Y
Y
D000085:Acetates / Q000494:pharmacology*; D019342:Acetic Acid; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000378:metabolism*; D008968:Molecular Conformation; D011089:Polydeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism*; D011721:Pyrenes / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000378:metabolism*
D000085:Acetates; D007042:Hypoxanthines; D011089:Polydeoxyribonucleotides; D011721:Pyrenes; C019530:poly(dC-dG); D019271:Hypoxanthine; D014969:Xanthine Oxidase; D019342:Acetic Acid; C032668:1-nitropyrene