The binding of zinc (II) to a double-stranded oligodeoxyribonucleotide. A voltammetric study.
Binding of zinc to a 19 mer double-stranded oligodeoxyribonucleotide was investigated by anodic stripping voltammetry and cyclic voltammetry in order to understand the roles of zinc in DNA cleavage catalyzed by mung bean nuclease. These methods rely on the direct monitoring of zinc oxidation current in the absence and in the presence of the oligo. Zinc titration curves with the ds-oligodeoxyribonucleotide were obtained in concentrations ranging from 3.62 x 10(-9) to 3.62 x 10(-8) M and 4.06 x 10(-10) to 5.25 x 10(-9) M. The acquired data were used to determine the dissociation constant, stoichiometry and zinc binding sites of the complex and to understand the specific changes of ds-oligodeoxyribonucleotide secondary structure by zinc binding. The oxidation-reduction process of zinc was also investigated by cyclic voltammetry through I (oxidation current) versus v(1/2) (square root of scan rate) curves in the absence and in the presence of the double-stranded oligodeoxyribonucleotide.
de Castro
C S Pires
CS
Laboratório de Espectrometria de Massa, Embrapa Recursos Genéticos e Biotecnologia, P.O. Box 02372, 70.770-900 Brasília-DF, Brazil. clarissa@cenargen.embrapa.br
Souzade
Jurandir Rodrigues
JR
Júnior
Carlos Bloch
CB
D010582:Bacteriophage lambda / Q000235:genetics; D001665:Binding Sites; D002413:Cations, Divalent; D004247:DNA / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004563:Electrochemistry; D007700:Kinetics; D008958:Models, Molecular; D009838:Oligodeoxyribonucleotides / Q000378:metabolism*; D010084:Oxidation-Reduction; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000494:pharmacology; D017186:Titrimetry; D015032:Zinc / Q000737:chemistry / Q000378:metabolism*
D002413:Cations, Divalent; D004277:DNA, Single-Stranded; D009838:Oligodeoxyribonucleotides; D004247:DNA; D015719:Single-Strand Specific DNA and RNA Endonucleases; D015032:Zinc