Ruthenium(II) coordination to a model for the topasemiquinone cofactor of amine oxidases. Resolution of 1H and 99,101Ru EPR hyperfine structure

The paramagnetic complex (L2–˙) RuII(bpy)2, where L2–˙= 5-methyl-2-oxido-1,4-benzosemiquinone and bpy = 2,2′-bipyridine, was studied because the quinonoid form LH is a model of the topa-quinone (TPQ) cofactor of certain copper-dependent amine oxidases. For the metal complex the potential ortho- and para-quinonoid character of the LHn system was probed by high resolution EPR spectroscopy of the semiquinone state which could be obtained through oxidation of the basic catecholate form.

[1]  A. Lever,et al.  Substituent Effects and Bonding Characteristics in o- Benzoquinonediiminebis(bipyrdine) Ruthenium(II) Complexes , 1993 .

[2]  A. Dei,et al.  Magnetic and spectral properties of paramagnetic metal-ion polyoxolene radical complexes , 1992 .

[3]  S. Itoh,et al.  Synthesis and characterization of the model compound of active site cofactor TTQ of bacterial methylamine dehydrogenases , 1992 .

[4]  C. E. Cote,et al.  Pulsed EPR studies of the semiquinone state of copper-containing amine oxidases , 1992 .

[5]  J. Duine.  Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan-tryptophan quinone. , 1991, European journal of biochemistry.

[6]  Doreen E. Brown,et al.  Copper-quinone interactions in amine oxidases , 1991 .

[7]  M. Lidstrom,et al.  A new cofactor in a prokaryotic enzyme: tryptophan tryptophylquinone as the redox prosthetic group in methylamine dehydrogenase , 1991, Science.

[8]  A. Lever,et al.  The Control of Orbital Mixing in Ruthenium Complexes Containing Quinone Related Ligands , 1991 .

[9]  J. Klinman,et al.  The organic functional group in copper-containing amine oxidases. Resonance Raman spectra are consistent with the presence of topa quinone (6-hydroxydopa quinone) in the active site. , 1991, The Journal of biological chemistry.

[10]  N. Gordon,et al.  Properties of ruthenium bipyridyl dimers bridged by disubstituted anthraquinones , 1991 .

[11]  P. Knowles,et al.  A Cu(I)-semiquinone state in substrate-reduced amine oxidases , 1991, Nature.

[12]  D. Williams,et al.  The Biological Chemistry of the Elements , 1991 .

[13]  C. E. Cote,et al.  Coordination chemistry of copper-containing amine oxidases: nuclear magnetic relaxation dispersion studies of copper binding, solvent-water exchange, substrate and inhibitor binding, and protein aggregation , 1991 .

[14]  W. Pierpoint.  PQQ in plants. , 1990, Trends in biochemical sciences.

[15]  J. Klinman,et al.  A new redox cofactor in eukaryotic enzymes: 6-hydroxydopa at the active site of bovine serum amine oxidase. , 1990, Science.

[16]  A. Dei,et al.  Dinuclear ruthenium complexes with bridging 1,4,5,8-tetraoxonaphthalene : redox properties and mixed-valence interactions , 1990 .

[17]  C. E. Cote,et al.  Characterization of the active site of Arthrobacter P1 methylamine oxidase: evidence for copper-quinone interactions , 1990 .

[18]  W. Kaim,et al.  Ambidentes Verhalten des „neuen Vitamins”︁ Methoxatin (Cofaktor PQQ) gegenüber Metallen: Koordinative Stabilisierung der Pyrrolid‐ und der Semichinon‐Form , 1990 .

[19]  S. Ernst,et al.  ESR of homo- and heteroleptic mono- and dinuclear tris(.alpha.-diimine)ruthenium radical complexes , 1990 .

[20]  W. Kaim,et al.  Ambident Behavior of the “New Vitamin” Methoxatin (Cofactor PQQ) towards Metals: Coordinative Stabilization of the Pyrrolide Form and the Semiquinone Form , 1990 .

[21]  T. Ishida,et al.  Molecular and crystal structure of PQQ(methoxatin), a novel coenzyme of quinoproteins: extensive stacking character and metal ion interaction , 1989 .

[22]  S. Ernst,et al.  Stable binuclear o- and p-semiquinone complexes of [Ru(bpy)2]2+. Radical ion versus mixed-valence dimer formulation , 1989 .

[23]  W. Kaim.  The transition metal coordination chemistry of anion radicals , 1987 .

[24]  S. Padhye,et al.  Chelated paraquinone co-ordination in bis(phthiocolato)bis(pyridine)manganese(II) , 1987 .

[25]  M. Falk,et al.  Spatial relationship between the copper and carbonyl cofactors in the active site of pig plasma amine oxidase. , 1986, The Journal of biological chemistry.

[26]  A. Lever,et al.  Catechol-quinone redox series involving bis(bipyridine)ruthenium(II) and tetrakis(pyridine)ruthenium(II) , 1986 .

[27]  J. Hajdu,et al.  Interaction of metal ions with streptonigrin. 1. Formation of copper(II) and zinc(II) complexes of the antitumor antibiotic , 1981 .

[28]  J. Thiele,et al.  Ueber die Einwirkung von Essigsäureanhydrid und Schwefelsäure auf Chinone , 1900 .