New Results on the Chemistry of Metal-Tetrahydro-Pterin Complexes

Fischer, Berthold; Schäfer, Andrea; Bosshard, R.; Hesse, Manfred; Viscontini, M.

doi:10.1515/pteridines.1993.4.4.206

Cited by 7 publications

(7 citation statements)

References 4 publications

(4 reference statements)

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“…Similarly, tetrahydropterins have been shown to coordinate to Cu(I1) and Fe(I1) bound to small organic ligands by the O(4) and N(5) functions and the structures of some of these complexes have been suggested [34]. The biological relevance of such complexes is, however, still not established.…”

Section: Discussionmentioning

confidence: 99%

Mössbauer, Electron‐Paramagnetic‐Resonance and X‐ray‐Absorption Fine‐Structure Studies of the Iron Environment in Recombinant Human Tyrosine Hydroxylase

Meyer‐Klaucke

Winkler

Schünemann

et al. 1996

European Journal of Biochemistry

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European Molecular Biology Laboratory, Outstation at Deutsches Elektronen Synchrotron, Hamburg, Germany Isoforms (1 -4) of human tyrosine hydroxylase (TH) have been expressed in Escherichia coli and purified as apoenzymes (metal-free). Apo-human TH binds 1 .0 atom Fe(II)/enzyme subunit, and iron binding is associated with an immediate and dramatic (40-fold) increase in specific activity. For X-ray absorption fine structure (XAFS) and electron paramagnetic resonance (EPR) measurements the apoenzyme was reconstituted with 5bFe and for Mossbauer measurements with -"Fe. XAFS measurements at the Fe-K edge of human TH were performed on the native form [Fe(II)-human TH], as well as after addition of stoichiometric amounts of the substrate tetrahydropterin, the inhibitor dopamine and of H202. The addition of dopamine or H202 oxidizes the ferrous iron of the native human TH to the ferric state. In both redox states the iron is octahedrally coordinated by low-Z backscatterers, thus sulfur coordination can be excluded. From the multiple scattering analysis of the EXAFS region is was surmised that part of the iron coordination is due to (3 2 1) imidazols. Addition of tetrahydropterin does not significantly change the iron coordination of the Fe (1I)

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Section: Discussionmentioning

confidence: 99%

Mössbauer, Electron‐Paramagnetic‐Resonance and X‐ray‐Absorption Fine‐Structure Studies of the Iron Environment in Recombinant Human Tyrosine Hydroxylase

Meyer‐Klaucke

Winkler

Schünemann

et al. 1996

European Journal of Biochemistry

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“…Copper(II) complexes of dipeptides also chelate H 4 pterin weakly without radical formation [93]. Reactions of ferric ions with tetrahydropterins were also interpreted as yielding trihydropterin-Fe(II) complexes antiferromagnetically coupled making them EPR silent, analogous to Mo(6+) complexes (see below) albeit much less stable and unisolable [96,97]. Fischer et al reported that pyranopteridine is oxidized by two electrons when reacted with Mo(VI) and Fe(III) complexes with opening of the pyrano ring.…”

Section: Pterin Redox Chemistrymentioning

confidence: 99%

Pterin chemistry and its relationship to the molybdenum cofactor

Basu

Burgmayer

2011

Coordination Chemistry Reviews

115

112

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The molybdenum cofactor is composed of a molybdenum coordinated by one or two rather complicated ligands known as either molybdopterin or pyranopterin. Pterin is one of a large family of bicyclic N-heterocycles called pteridines. Such molecules are widely found in Nature, having various forms to perform a variety of biological functions. This article describes the basic nomenclature of pterin, their biological roles, structure, chemical synthesis and redox reactivity. In addition, the biosynthesis of pterins and current models of the molybdenum cofactor are discussed.

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“…A ternary Cu(II) complex containing pterin-6-carboxylate (PC) and 2,2‘-bipyridine (bpy) revealed a unique terdentate coordination of PC with the 5-nitrogen atom (N(5)) in the coordination plane , and established by the structural determinations. ,− Cu(II) has been found to undergo a redox reaction with 6,7-dimethyl-5,6,7,8-tetrahydropterin to give Cu(I) and the protonated trihydropterin radical …”

Section: Introductionmentioning

confidence: 95%

“…24 However, exogenous ligands such as catechols are bound to the metal center to inhibit the catalytic reaction. 24 Studies on the metal-pteridine complexes with emphasis on their biological aspects have been reported for Mo, Mn, Fe, Co, Ni, and Cu, [25][26][27][28][29][30][31][32][33][34][35][36] and some complexes were isolated and structurally characterized by the X-ray diffraction method. Because of the potential importance of iron in the enzymatic activity, detailed information on the iron complexes has been awaited.…”

Section: Introductionmentioning

confidence: 99%

Structures and Spectral Properties of Iron(II), Cobalt(II), and Copper(II) Complexes Involving 2-(Dimethylamino)-4(3H)-pteridinone

et al. 1997

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With a view to understanding the pterin cofactor-metal ion interactions, some divalent transition metal complexes containing 2-(dimethylamino)-4(3H)-pteridinone (NDMP), M(NDMP) 2 (CH 3 OH) 2 (M ) Fe(II) (1), Co(II) (2), Cu(II) (3)) and Fe(NDMP) 2 Cl 2 (4), have been prepared and investigated by magnetic, spectroscopic, and X-ray diffraction methods. Complexes 1, 2, and 4 were found to be in a typical high-spin state, and complex 3 was found to be in a d x 2 -y 2 ground state. Complexes 1-3 were structurally determined. [Fe(NDMP) 2 (CH 3 OH) 2 ]‚2CH 3 -OH (1) crystallizes in the triclinic system, space group P1 h, with a ) 8.54 (1) (2) is isomorphous with 1 with a ) 8.4753 (6) Å, b ) 9.430(1) Å, c ) 8.3695(5) Å, R ) 95.885(7)°, ) 98.412(6)°, γ ) 79.421(8)°, V ) 648.48 Å 3 , and Z ) 2. [Cu(NDMP) 2 (CH 3 OH) 2 ] (3) crystallizes in the monoclinic system, space group P2 1 /a, with a ) 8.428(1) Å, b ) 14.3857(8) Å, c ) 8.9570(8) Å, ) 95.225(8)°, V ) 1081.5 Å 3 , and Z ) 4. The final R and R w values are 0.042 and 0.033 for 1, 0.056 and 0.040 for 2, and 0.040 and 0.018 for 3, respectively. The geometries around the metal ions are essentially the same, and each metal ion is octahedrally coordinated with 4-carbonyl oxygens and 5-nitrogens of NDMP molecules in the equatorial positions and two methanol molecules in the axial positions. The Fe(II) complexes 1 and 4 exhibited an absorption band centered at 568 nm ( ) 1900 M -1 cm -1 ) in DMF and a peak at 674 nm in the reflectance spectrum, respectively, both of which are assigned to a charge transfer. This and other spectroscopic and structural properties have been comparatively discussed.

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New Results on the Chemistry of Metal-Tetrahydro-Pterin Complexes

Cited by 7 publications

References 4 publications

Mössbauer, Electron‐Paramagnetic‐Resonance and X‐ray‐Absorption Fine‐Structure Studies of the Iron Environment in Recombinant Human Tyrosine Hydroxylase

Mössbauer, Electron‐Paramagnetic‐Resonance and X‐ray‐Absorption Fine‐Structure Studies of the Iron Environment in Recombinant Human Tyrosine Hydroxylase

Pterin chemistry and its relationship to the molybdenum cofactor

Structures and Spectral Properties of Iron(II), Cobalt(II), and Copper(II) Complexes Involving 2-(Dimethylamino)-4(3H)-pteridinone

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