Zur katalatischen und peroxidatischen Aktivität von Cu2+-Komplexen

Sigel, Helmut

doi:10.1002/ange.19690810502

Cited by 60 publications

(7 citation statements)

References 62 publications

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“…[73,74] To conclude, based on the summarized observations it is evident that N7 will also be released from the M 2 + coordination sphere upon formation of the MA C H T U N G T R E N N U N G (ATP)(Ha) 2À species. In fact, this is confirmed by the results described below (see Sections 2.4 and 2.5).…”

Section: H T U N G T R E N N U N G (Atp)(oh)mentioning

confidence: 94%

Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni²⁺, Cu²⁺, or Zn²⁺, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP⁴⁻) or Uridine 5′‐Triphosphate (UTP⁴⁻): An Intricate Network of Equilibria

Knobloch

Mucha

Operschall

et al. 2011

Chemistry A European J

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With a view on protein-nucleic acid interactions in the presence of metal ions we studied the "simple" mixed-ligand model systems containing histamine (Ha), the metal ions Ni(2+), Cu(2+), or Zn(2+) (M(2+)), and the nucleotides adenosine 5'-triphosphate (ATP(4-)) or uridine 5'-triphosphate (UTP(4-)), which will both be referred to as nucleoside 5'-triphosphate (NTP(4-)). The stability constants of the ternary M(NTP)(Ha)(2-) complexes were determined in aqueous solution by potentiometric pH titrations. We show for both ternary-complex types, M(ATP)(Ha)(2-) and M(UTP)(Ha)(2-), that intramolecular stacking between the nucleobase and the imidazole residue occurs and that the stacking intensity is approximately the same for a given M(2+) in both types of complexes: The formation degree of the intramolecular stacks is estimated to be 20 to 50%. Consequently, in protein-nucleic acid interactions imidazole-nucleobase stacks may well be of relevance. Furthermore, the well-known formation of macrochelates in binary M(2+) complexes of purine nucleotides, that is, the phosphate-coordinated M(2+) interacts with N7, is confirmed for the M(ATP)(2-) complexes. It is concluded that upon formation of the mixed-ligand complexes the M(2+)-N7 bond is broken and the energy needed for this process corresponds to the stability differences determined for the M(UTP)(Ha)(2-) and M(ATP)(Ha)(2-) complexes. It is, therefore, possible to calculate from these stability differences of the ternary complexes the formation degrees of the binary macrochelates: The closed forms amount to (65±10)%, (75±8)%, and (31±14) % for Ni(ATP)(2-), Cu(ATP)(2-), and Zn(ATP)(2-), respectively, and these percentages agree excellently with previous results obtained by different methods, confirming thus the internal validity of the data and the arguments used in the evaluation processes. Based on the overall results it is suggested that M(ATP)(2-) species, when bound to an enzyme, may exist in a closed macrochelated form only, if no enzyme groups coordinate directly to the metal ion.

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Section: H T U N G T R E N N U N G (Atp)(oh)mentioning

confidence: 94%

Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni²⁺, Cu²⁺, or Zn²⁺, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP⁴⁻) or Uridine 5′‐Triphosphate (UTP⁴⁻): An Intricate Network of Equilibria

Knobloch

Mucha

Operschall

et al. 2011

Chemistry A European J

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“…The dimethylglyoximato monoanion (in its Co 111 complex) is degradated as well by H202 14 . Quite generally, it appears that the catalase-like activity is closely connected with a peroxidase-like one 5 . …”

Section: (11)mentioning

confidence: 99%

“…In the first transition series, iron 1-4 and copper 5 ions, and complexes thereof, are especially effective catalysts. From the catalase-like activity of Cu 20 complexes it is known 5 that the reaction occurs within the coordination sphere.…”

mentioning

confidence: 99%

Metal Ions and Hydrogen Peroxide. XXV

Waldmeier

Prijs

Sigel

1972

Zeitschrift Für Naturforschung B

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The decomposition of H202 , catalyzed by the Co 2 ® complex of 4,4',4",4'"-tetrasulfophthalocyanine (ConPTS), was investigated in the pH range 3.8 through 10 by measuring the initial rate, i;0=d(O2)/d£, of the increasing formation of 02 (25°; 1 = 0.1). In this pH range v0 is proportional to the initial concentration of H202 (determined at pH 5.0 and 9.2). Due to the dimerization (log KD=5.47±0.09 at natural ionic strength and about 7.63 ±0.16 in 0.1m NaC104; 25°) and polymerization of ConPTS the catalyst and its reaction order are difficult to establish: Based on the experimental evidence it is suggested that v0 is proportional to the concentration of monomer CoHPTS. Additionally, there is evidence that the experimentally determined v0 contains the contributions of a pH-independent and a pH-dependent reaction course. These results are analog to those obtained earlier with FelHPTS as catalyst. A mechanism for the catalyzed disproportionation of H202 by Co n PTS is proposed. The catalase-like activity of Co In PTS(OH) is smaller than that of Co n PTS and the pH-dependence is different.The decomposition of hydrogen peroxide according to equation (1) 2 H202 02 + 2 H20 (1) is catalyzed by metal ions and metal ion complexes. In the first transition series, iron 1-4 and copper 5 ions, and complexes thereof, are especially effective catalysts. From the catalase-like activity of Cu 20 complexes it is known 5 that the reaction occurs within the coordination sphere. Therefore, the kind of ligand bound to the metal ion has a strong influence on the activity. This means, the activity is dependent (beside other parameters) on the saturation degree of the coordination sphere of the metal ion. This explains why Cu 2 ® complexes formed with tetradentate ligands, like 4,4 / ,4",4'"-tetrasulfophthalocyanine (PTS), are catalytically inactive. Of course, this does not mean that all metal ion-PTS complexes are inactive; those formed with a metal ion having a coordination number >4 may well be active 2 .Among the PTS complexes formed with the metal ions of the second half of the first transition series those with Co and Fe show a catalase-like activity 2 . The interesting feature of these complexes is their structural uniformity which is determined by the planar PTS ligand. This fact offersRequests for reprints should be sent to PD Dr. HELMUT SIGEL, Institute of Inorganic Chemistry, University of Basel, Spitalstrasse 51, Switzerland. the possibility to compare the kinetics and mechanism of the disproportionation of H202, catalyzed by metal ions held under identical structural conditions. This should help to evaluate the question: Do different metal ions require different reaction mechanisms 2 ? Recently, the kinetics of the decomposition of H202 by Fe m PTS were studied Now we are investigating the qualities of Co n PTS and partly those of Co m PTS(OH) as catalysts for reaction (1). ConPTSThe catalase-like activity of these Co complexes was measured under several different conditions in the pH range 3.8 to 10 using an oxygen sens...

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“…Unfortunately, the coordination behavior of ITP is less clear cut. However, as the N(7); usually the latter two are favored.In solution, Cu2+ prefers a square-planar (or grossly distorted) coordination sphere [13,14] ; hence, in Cu(Bipy)2+ only two positions remain available for the binding of a second ligand [la], the coordination of which results in a ternary complex. In fact, for Cu(Bipy)(ATP)2-it was shown by means of proton magnetic resonance (PMR) that in this mixedligand complex the adenine moiety does not interact any more with Cu2+ [16].…”

mentioning

confidence: 99%

Adenosine and Inosine 5′‐triphosphates

Naumann¹,

Prijs²,

Sigel³

1974

European Journal of Biochemistry

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The chemical shift of the protons, H(2) and H(8), in the proton magnetic resonance spectra of ATP, ITP, and inosine was measured in aqueous solution in dependence on pH (2 to 12). Based on these data the sites of protonation or deprotonation are identified and the acidity constants determined. A comparison of the constants due to the nucleotides with the corresponding ones of the nucleosides evidences that the basicity of the nucleic base increases somewhat under the influence of the triphosphate chain. The possibility of an intramolecular hydrogen bound between N(7) and the proton of the y-phosphate group is discussed.From the line broadening effects in the presence of Cu2+ it is concluded that this metal ion interacts mainly with N(7) of ATP, but with the N(l), 0 (6) is nearly completely formed) reveal the surprising fact that in the pH range 2 to 6 the line broadening of the signal due to H(8), and H(2) as well, increases signiticantly compared with a system containing only ITP and Cua+. This observation is easily explained by the assumption of a chargetransfer interaction within the ternary complex, Cu(Bipy) (ITP)2-, i.e. between the purine part of the nucleotide and 2,2'-bipyridyl. This interaction could indeed be contirmed by spectrophotometric measurements in the ultraviolet (Amax = 313 nm). Similar results were obtained for the mixed-ligand complex, Cu(Bipy) (ATP)2-. The distance between the planes of the aromatic rings in these systems is estimated and a structure for these metal-ion-bridged charge-transfer complexes is suggested. The biological implications of such ternary, metal-ion-bridged, charge-transfer complexes are briefly indicated.Recent studies on the dephosphorylation of the binary and ternary complexes, CU(ATP)~-and Cu(Bipy)(ATP)2- [3,4], and the extension of this work to other nucleotide complexes (H. Sigel, D. H. Buisson and B. Prijs, unpublished results) prompted us to investigate the coordination behavior of ITP in mixed-ligand complexes. For reasons of comparison inosine and ATP were included' in this work. From earlier studies on binary complexes [6,6] it is known that Cu2+ coordinates to the j3-and y-phosphate groups of ATP4-as well as to N(7) of the adenine moiety, and thus a macrochelate is formed [6, 71, which is crucial indeed for the Cu2+-accelerated dephosphorylation of ATP [2,4,7]. Unfortunately, the coordination behavior of ITP is less clear cut. However, as the N(7); usually the latter two are favored.In solution, Cu2+ prefers a square-planar (or grossly distorted) coordination sphere [13,14] ; hence, in Cu(Bipy)2+ only two positions remain available for the binding of a second ligand [la], the coordination of which results in a ternary complex. In fact, for Cu(Bipy)(ATP)2-it was shown by means of proton magnetic resonance (PMR) that in this mixedligand complex the adenine moiety does not interact any more with Cu2+ [16]. It is believed that this is Eur. J. Biochem. 41 (1974)

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Zur katalatischen und peroxidatischen Aktivität von Cu2+-Komplexen

Cited by 60 publications

References 62 publications

Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni²⁺, Cu²⁺, or Zn²⁺, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP⁴⁻) or Uridine 5′‐Triphosphate (UTP⁴⁻): An Intricate Network of Equilibria

Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni²⁺, Cu²⁺, or Zn²⁺, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP⁴⁻) or Uridine 5′‐Triphosphate (UTP⁴⁻): An Intricate Network of Equilibria

Metal Ions and Hydrogen Peroxide. XXV

Adenosine and Inosine 5′‐triphosphates

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Zur katalatischen und peroxidatischen Aktivität von Cu2+-Komplexen

Cited by 60 publications

References 62 publications

Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni2+, Cu2+, or Zn2+, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP4−) or Uridine 5′‐Triphosphate (UTP4−): An Intricate Network of Equilibria

Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni2+, Cu2+, or Zn2+, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP4−) or Uridine 5′‐Triphosphate (UTP4−): An Intricate Network of Equilibria

Metal Ions and Hydrogen Peroxide. XXV

Adenosine and Inosine 5′‐triphosphates

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Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni²⁺, Cu²⁺, or Zn²⁺, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP⁴⁻) or Uridine 5′‐Triphosphate (UTP⁴⁻): An Intricate Network of Equilibria

Stability and Structure of Mixed‐Ligand Metal Ion Complexes That Contain Ni²⁺, Cu²⁺, or Zn²⁺, and Histamine, as well as Adenosine 5′‐Triphosphate (ATP⁴⁻) or Uridine 5′‐Triphosphate (UTP⁴⁻): An Intricate Network of Equilibria