Cu(II) complex with poly(dG-dC): structure determination with the help of pulse EPR spectroscopy

Antoni, Pm; Spingler, B; Jeschke, G

Risultato della ricerca: Paper

Abstract

Pulse EPR spectroscopy is used to investigate possible structural features of the copper(II) ion coordinated to poly(dG-dC).poly(dG-dC) in a frozen aqueous solution, and the structural changes of the polynucleotide induced by the presence of the metal ion. Two different copper species were identified and their geometry explained by a molecular model. According to this model, one species is exclusively coordinated to a single guanine with the N7 nitrogen atom forming a coordinative bond with the copper. In the other species, a guanine and a cytosine form a ternary complex together with the copper ion. A copper crosslink between the N7 of guanine and N3 of cytosine is proposed as the most probable coordination site. Moreover, no evidence was found for an interaction of either copper species with a phosphate group or equatorial water molecules. In addition, circular dichroism (CD) spectroscopy showed that the DNA of the CuII-poly(dG-dC)•poly(dG-dC) adducts resembles the left-handed Z-form. These results suggest that metal-mediated Hoogsteen base pairing, as previously proposed for a right-handed DNA duplex, can also occur in a double-stranded left-handed DNA (Santangelo et al. [1]).
Lingua originaleEnglish
Stato di pubblicazionePublished - 2012

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Paramagnetic resonance
Copper
Spectroscopy
Guanine
Cytosine
Z-Form DNA
Ions
Circular dichroism spectroscopy
Polynucleotides
DNA
Metal ions
poly(dC-dG)
Nitrogen
Metals
Phosphates
Atoms
Molecules
Geometry
Water

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Cu(II) complex with poly(dG-dC): structure determination with the help of pulse EPR spectroscopy. / Antoni, Pm; Spingler, B; Jeschke, G.

2012.

Risultato della ricerca: Paper

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title = "Cu(II) complex with poly(dG-dC): structure determination with the help of pulse EPR spectroscopy",
abstract = "Pulse EPR spectroscopy is used to investigate possible structural features of the copper(II) ion coordinated to poly(dG-dC).poly(dG-dC) in a frozen aqueous solution, and the structural changes of the polynucleotide induced by the presence of the metal ion. Two different copper species were identified and their geometry explained by a molecular model. According to this model, one species is exclusively coordinated to a single guanine with the N7 nitrogen atom forming a coordinative bond with the copper. In the other species, a guanine and a cytosine form a ternary complex together with the copper ion. A copper crosslink between the N7 of guanine and N3 of cytosine is proposed as the most probable coordination site. Moreover, no evidence was found for an interaction of either copper species with a phosphate group or equatorial water molecules. In addition, circular dichroism (CD) spectroscopy showed that the DNA of the CuII-poly(dG-dC)•poly(dG-dC) adducts resembles the left-handed Z-form. These results suggest that metal-mediated Hoogsteen base pairing, as previously proposed for a right-handed DNA duplex, can also occur in a double-stranded left-handed DNA (Santangelo et al. [1]).",
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author = "{Antoni, Pm; Spingler, B; Jeschke, G} and Santangelo, {Maria Grazia}",
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T1 - Cu(II) complex with poly(dG-dC): structure determination with the help of pulse EPR spectroscopy

AU - Antoni, Pm; Spingler, B; Jeschke, G

AU - Santangelo, Maria Grazia

PY - 2012

Y1 - 2012

N2 - Pulse EPR spectroscopy is used to investigate possible structural features of the copper(II) ion coordinated to poly(dG-dC).poly(dG-dC) in a frozen aqueous solution, and the structural changes of the polynucleotide induced by the presence of the metal ion. Two different copper species were identified and their geometry explained by a molecular model. According to this model, one species is exclusively coordinated to a single guanine with the N7 nitrogen atom forming a coordinative bond with the copper. In the other species, a guanine and a cytosine form a ternary complex together with the copper ion. A copper crosslink between the N7 of guanine and N3 of cytosine is proposed as the most probable coordination site. Moreover, no evidence was found for an interaction of either copper species with a phosphate group or equatorial water molecules. In addition, circular dichroism (CD) spectroscopy showed that the DNA of the CuII-poly(dG-dC)•poly(dG-dC) adducts resembles the left-handed Z-form. These results suggest that metal-mediated Hoogsteen base pairing, as previously proposed for a right-handed DNA duplex, can also occur in a double-stranded left-handed DNA (Santangelo et al. [1]).

AB - Pulse EPR spectroscopy is used to investigate possible structural features of the copper(II) ion coordinated to poly(dG-dC).poly(dG-dC) in a frozen aqueous solution, and the structural changes of the polynucleotide induced by the presence of the metal ion. Two different copper species were identified and their geometry explained by a molecular model. According to this model, one species is exclusively coordinated to a single guanine with the N7 nitrogen atom forming a coordinative bond with the copper. In the other species, a guanine and a cytosine form a ternary complex together with the copper ion. A copper crosslink between the N7 of guanine and N3 of cytosine is proposed as the most probable coordination site. Moreover, no evidence was found for an interaction of either copper species with a phosphate group or equatorial water molecules. In addition, circular dichroism (CD) spectroscopy showed that the DNA of the CuII-poly(dG-dC)•poly(dG-dC) adducts resembles the left-handed Z-form. These results suggest that metal-mediated Hoogsteen base pairing, as previously proposed for a right-handed DNA duplex, can also occur in a double-stranded left-handed DNA (Santangelo et al. [1]).

KW - DNA, copper, EPR

UR - http://hdl.handle.net/10447/66303

M3 - Paper

ER -