Molecular features of CoIII tetra- and pentammines affect their influence on DNA structure

Alison Rodger; Andrew Parkinson; Stephen Best

Molecular features of CoIII tetra- and pentammines affect their influence on DNA structure

Alison Rodger^*, Andrew Parkinson, Stephen Best

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

12 Citations (Scopus)

Abstract

The polyamines spermine and spermidine cause a range of structural effects on DNA. [Co(NH₃)₆]³⁺ is known to mimic many of these effects and we have shown previously that (+)[Co(en)₃]³⁺ and (-)-[Co(en)₃]³⁺ (en = ethylenediamine) do so as well. In this paper the effects of mono- and disubstitution of the Co^III ammines by aqua, halo and nitro groups is explored. The overall effectiveness of the amines in conferring thermal stability on the ct-DNA proceeds in the order: spermine > (+)-[Co(en)₃]³⁺ ≈ (-)-[Co(en)₃]³⁺ ≈ [Co(NH₃)₆]³⁺ ≈ spermidine > [Pt(NH₃)₄]²⁺ > [Co(NH₃)₅H₂O]³⁺ ≈ [Co(NH₃)₅Cl]²⁺ ≈ [Co(NH₃)₅Br]²⁺ > cis-[Co(en)₂NH₃Cl]²⁺ > [Co(NH₃)₅(NO₂)]²⁺ ≈ trans-[Co(NH₃)₄(H₂O)₂] ³⁺; whereas the B→Z transition-induction ordering is: spermine ≈ [Co(NH₃)₆]³⁺ > (+)-[Co(en)₃]³⁺ ≈ [Co(NH₃)₅(H₂O)]³⁺ > (-)-[Co(en)₃]³⁺ > [Co(NH₃)₅Br]²⁺ > [Co(NH₃)₅Cl]²⁺, with the other amines failing to cause the transition under the 11 mM salt concentration and temperature ramp conditions used; the DNA bending ranking is: spermine > [Co(NH₃)₆]³⁺ > (+)-[Co(en)₃]³⁺ > (-)-[Co(en)₃]³⁺ > [Co(NH₃)₅(H₂O)]³⁺ > trans-[Co(NH₃)₄(H₂O)₂] ³⁺ > spermidine, with the other 2+ amines (the aquo complexes will be 2+ at neutral pH), especially the bromo and nitro compounds, having comparatively little effect. While the presentation of NNN triangular faces is found to be important in the B→Z transition, the fact that the halo ligands are probably substituted by the DNA phosphates plays a role, especially in the DNA bending, where deep penetration of the major groove is concluded to be required. A favourable interaction between the backbone and the aquo ligands may enhance the B→Z transition.

Original language	English
Pages (from-to)	2311-2316
Number of pages	6
Journal	European Journal of Inorganic Chemistry
Issue number	9
Publication status	Published - 2001
Externally published	Yes

Keywords

Bioinorganic chemistry
Circular dichroism
Coordination chemistry
Non-covalent interactions
UV/Vis spectroscopy

Cite this

@article{ab1c1046a98b4979b36984fd4aff34b0,

title = "Molecular features of CoIII tetra- and pentammines affect their influence on DNA structure",

abstract = "The polyamines spermine and spermidine cause a range of structural effects on DNA. [Co(NH3)6]3+ is known to mimic many of these effects and we have shown previously that (+)[Co(en)3]3+ and (-)-[Co(en)3]3+ (en = ethylenediamine) do so as well. In this paper the effects of mono- and disubstitution of the CoIII ammines by aqua, halo and nitro groups is explored. The overall effectiveness of the amines in conferring thermal stability on the ct-DNA proceeds in the order: spermine > (+)-[Co(en)3]3+ ≈ (-)-[Co(en)3]3+ ≈ [Co(NH3)6]3+ ≈ spermidine > [Pt(NH3)4]2+ > [Co(NH3)5H2O]3+ ≈ [Co(NH3)5Cl]2+ ≈ [Co(NH3)5Br]2+ > cis-[Co(en)2NH3Cl]2+ > [Co(NH3)5(NO2)]2+ ≈ trans-[Co(NH3)4(H2O)2] 3+; whereas the B→Z transition-induction ordering is: spermine ≈ [Co(NH3)6]3+ > (+)-[Co(en)3]3+ ≈ [Co(NH3)5(H2O)]3+ > (-)-[Co(en)3]3+ > [Co(NH3)5Br]2+ > [Co(NH3)5Cl]2+, with the other amines failing to cause the transition under the 11 mM salt concentration and temperature ramp conditions used; the DNA bending ranking is: spermine > [Co(NH3)6]3+ > (+)-[Co(en)3]3+ > (-)-[Co(en)3]3+ > [Co(NH3)5(H2O)]3+ > trans-[Co(NH3)4(H2O)2] 3+ > spermidine, with the other 2+ amines (the aquo complexes will be 2+ at neutral pH), especially the bromo and nitro compounds, having comparatively little effect. While the presentation of NNN triangular faces is found to be important in the B→Z transition, the fact that the halo ligands are probably substituted by the DNA phosphates plays a role, especially in the DNA bending, where deep penetration of the major groove is concluded to be required. A favourable interaction between the backbone and the aquo ligands may enhance the B→Z transition.",

keywords = "Bioinorganic chemistry, Circular dichroism, Coordination chemistry, Non-covalent interactions, UV/Vis spectroscopy",

author = "Alison Rodger and Andrew Parkinson and Stephen Best",

year = "2001",

language = "English",

pages = "2311--2316",

journal = "European Journal of Inorganic Chemistry",

issn = "1434-1948",

publisher = "Wiley-VCH, Wiley",

number = "9",

}

TY - JOUR

T1 - Molecular features of CoIII tetra- and pentammines affect their influence on DNA structure

AU - Rodger, Alison

AU - Parkinson, Andrew

AU - Best, Stephen

PY - 2001

Y1 - 2001

N2 - The polyamines spermine and spermidine cause a range of structural effects on DNA. [Co(NH3)6]3+ is known to mimic many of these effects and we have shown previously that (+)[Co(en)3]3+ and (-)-[Co(en)3]3+ (en = ethylenediamine) do so as well. In this paper the effects of mono- and disubstitution of the CoIII ammines by aqua, halo and nitro groups is explored. The overall effectiveness of the amines in conferring thermal stability on the ct-DNA proceeds in the order: spermine > (+)-[Co(en)3]3+ ≈ (-)-[Co(en)3]3+ ≈ [Co(NH3)6]3+ ≈ spermidine > [Pt(NH3)4]2+ > [Co(NH3)5H2O]3+ ≈ [Co(NH3)5Cl]2+ ≈ [Co(NH3)5Br]2+ > cis-[Co(en)2NH3Cl]2+ > [Co(NH3)5(NO2)]2+ ≈ trans-[Co(NH3)4(H2O)2] 3+; whereas the B→Z transition-induction ordering is: spermine ≈ [Co(NH3)6]3+ > (+)-[Co(en)3]3+ ≈ [Co(NH3)5(H2O)]3+ > (-)-[Co(en)3]3+ > [Co(NH3)5Br]2+ > [Co(NH3)5Cl]2+, with the other amines failing to cause the transition under the 11 mM salt concentration and temperature ramp conditions used; the DNA bending ranking is: spermine > [Co(NH3)6]3+ > (+)-[Co(en)3]3+ > (-)-[Co(en)3]3+ > [Co(NH3)5(H2O)]3+ > trans-[Co(NH3)4(H2O)2] 3+ > spermidine, with the other 2+ amines (the aquo complexes will be 2+ at neutral pH), especially the bromo and nitro compounds, having comparatively little effect. While the presentation of NNN triangular faces is found to be important in the B→Z transition, the fact that the halo ligands are probably substituted by the DNA phosphates plays a role, especially in the DNA bending, where deep penetration of the major groove is concluded to be required. A favourable interaction between the backbone and the aquo ligands may enhance the B→Z transition.

AB - The polyamines spermine and spermidine cause a range of structural effects on DNA. [Co(NH3)6]3+ is known to mimic many of these effects and we have shown previously that (+)[Co(en)3]3+ and (-)-[Co(en)3]3+ (en = ethylenediamine) do so as well. In this paper the effects of mono- and disubstitution of the CoIII ammines by aqua, halo and nitro groups is explored. The overall effectiveness of the amines in conferring thermal stability on the ct-DNA proceeds in the order: spermine > (+)-[Co(en)3]3+ ≈ (-)-[Co(en)3]3+ ≈ [Co(NH3)6]3+ ≈ spermidine > [Pt(NH3)4]2+ > [Co(NH3)5H2O]3+ ≈ [Co(NH3)5Cl]2+ ≈ [Co(NH3)5Br]2+ > cis-[Co(en)2NH3Cl]2+ > [Co(NH3)5(NO2)]2+ ≈ trans-[Co(NH3)4(H2O)2] 3+; whereas the B→Z transition-induction ordering is: spermine ≈ [Co(NH3)6]3+ > (+)-[Co(en)3]3+ ≈ [Co(NH3)5(H2O)]3+ > (-)-[Co(en)3]3+ > [Co(NH3)5Br]2+ > [Co(NH3)5Cl]2+, with the other amines failing to cause the transition under the 11 mM salt concentration and temperature ramp conditions used; the DNA bending ranking is: spermine > [Co(NH3)6]3+ > (+)-[Co(en)3]3+ > (-)-[Co(en)3]3+ > [Co(NH3)5(H2O)]3+ > trans-[Co(NH3)4(H2O)2] 3+ > spermidine, with the other 2+ amines (the aquo complexes will be 2+ at neutral pH), especially the bromo and nitro compounds, having comparatively little effect. While the presentation of NNN triangular faces is found to be important in the B→Z transition, the fact that the halo ligands are probably substituted by the DNA phosphates plays a role, especially in the DNA bending, where deep penetration of the major groove is concluded to be required. A favourable interaction between the backbone and the aquo ligands may enhance the B→Z transition.

KW - Bioinorganic chemistry

KW - Circular dichroism

KW - Coordination chemistry

KW - Non-covalent interactions

KW - UV/Vis spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=0034869049&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0034869049

SN - 1434-1948

SP - 2311

EP - 2316

JO - European Journal of Inorganic Chemistry

JF - European Journal of Inorganic Chemistry

IS - 9

ER -

Molecular features of CoIII tetra- and pentammines affect their influence on DNA structure

Abstract

Keywords

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