Reactions of copper(II)-oligopeptide complexes with hydrogen peroxide: Effects of biological reductants

Ueda, Jun-ichi; Shimazu, Yoshie; Ozawa, Toshihiko

doi:10.1016/0891-5849(94)00213-4

Cited by 24 publications

(15 citation statements)

References 8 publications

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“…On the other hand, copper as cofactor has redox capabilities and its excess promotes uncontrolled production of potentially damaging ROS (reactive oxygen species) through Fenton and Haber-Weiss reactions. ROS induce oxidative stress and deleterious modifications in macromolecules [3].…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic study of Cu2+ binding to the DAHK and GHK peptides by isothermal titration calorimetry (ITC) with the weaker competitor glycine

et al. 2011

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The peptides Asp-Ala-His-Lys (DAHK) and Gly-His-Lys (GHK) are naturally occurring copper(II)-chelating motives in human serum and cerebrospinal fluid. Here the sensitive thermodynamic technique isothermal titration calorimetry (ITC) has been used to study the energetics of copper(II) binding to DAHK and GHK peptides in the presence of the weaker ligand glycine as a competitor. DAHK and GHK bind Cu(II) predominantly in a 1:1 stoichiometry with conditional dissociation constants (i.e. at pH 7.4, in the absence of the competing chelators glycine and HEPES buffer) of 2.6 +/-0.4 x 10 -14 M and of 7.0 +/-1.0 x 10 -14 M, respectively. Furthermore, the apparent ΔH values were measured and the number of protons released upon Cu(II) binding was determined by performing experiments in different buffers. This allowed us to determine the conditional ΔG, ΔH, and ΔS, i.e. corrected for the contributions of the weaker ligand glycine and the buffer at pH 7.4. We found that the entropic and enthalpic contributions to the Cu(II)-binding to GHK and DAHK are distinct, with a higher enthalpic contribution for GHK. The obtained thermodynamic parameters correspond well to those in the literature obtained by other techniques, suggesting that the use of the weaker ligand glycine as a competitor in ITC provides accurate data for Cu(II)-binding to high affinity peptides, which cannot be accurately determined without the use of a competitor ligand.3

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Section: Introductionmentioning

confidence: 99%

Thermodynamic study of Cu2+ binding to the DAHK and GHK peptides by isothermal titration calorimetry (ITC) with the weaker competitor glycine

et al. 2011

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“…The DMPO/SO 3 •− spin adduct signal was more intense than with copper peptide complexes ( Figure 5F), showing that free copper(II) ions enhanced the sulfite radical production in the medium.…”

Section: S(iv) or Cumentioning

confidence: 95%

“…It could be produced by reactions 3-6 or by low Fe(III) concentration (10 -8 -10 -7 mol L −1 ), present as impurity. 42 Thus, the Cu III L formed reacts with sulfite to generate SO 3 •− radical (equation 7). In the autocatalytic process, Cu •− and SO 5 •− are already described in the literature.…”

Section: Mechanism Of Copper Peptides Oxidation In the Presence Of S(mentioning

confidence: 99%

“…A adição de S(IV) a uma solução saturada com ar contendo Cu II GGA (GGA = glicilglicil-L-alanina), Cu II G 3 (G 3 = triglicina) ou Cu II G 4 (G 4 = tetraglicina) e traços de Ni(II) origina a formação rápida do respectivo complexo de Cu(III), com o simultâneo consumo de oxigênio e a oxidação de S(IV). SO 3 •− e HO • foram detectados por experimentos de EPR-spin trapping. As quebras das fitas de DNA foram atribuídas aos radicais de óxido de enxofre formados.…”

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“…[2][3][4][5][6] In these studies the generation of reactive oxygen species in a Fenton type mechanism was proposed, where Cu(II) is reduced to Cu(I) which reacts with H 2 O 2 to generate HO…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Oxidative DNA damage induced by S(IV) in the presence of Cu(II) and Cu(I) complexes

Alipázaga¹,

Cerchiaro²,

Moya³

et al. 2009

J. Braz. Chem. Soc.

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Reactive Oxygen Species Generated from the Reaction of Copper(II) Complexes with Biological Reductants Cause DNA Strand Scission

Ueda¹,

Takai²,

Shimazu³

et al. 1998

Archives of Biochemistry and Biophysics

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Reactions of copper(II)-oligopeptide complexes with hydrogen peroxide: Effects of biological reductants

Cited by 24 publications

References 8 publications

Thermodynamic study of Cu2+ binding to the DAHK and GHK peptides by isothermal titration calorimetry (ITC) with the weaker competitor glycine

Thermodynamic study of Cu2+ binding to the DAHK and GHK peptides by isothermal titration calorimetry (ITC) with the weaker competitor glycine

Oxidative DNA damage induced by S(IV) in the presence of Cu(II) and Cu(I) complexes

Reactive Oxygen Species Generated from the Reaction of Copper(II) Complexes with Biological Reductants Cause DNA Strand Scission

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