A5084140984- Metal complexes synthesis and properties
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Magnetism in coordination complexes
- Crystallography and molecular interactions
- Metal-Catalyzed Oxygenation Mechanisms
- Metalloenzymes and iron-sulfur proteins
- Lanthanide and Transition Metal Complexes
- Chemical Synthesis and Analysis
- Crystal structures of chemical compounds
- Molecular Sensors and Ion Detection
- Organometallic Compounds Synthesis and Characterization
- Electron Spin Resonance Studies
- Enzyme Catalysis and Immobilization
- Porphyrin and Phthalocyanine Chemistry
- Synthesis and Catalytic Reactions
- Radioactive element chemistry and processing
- Metal-Organic Frameworks: Synthesis and Applications
- Pesticide and Herbicide Environmental Studies
- Electrochemical sensors and biosensors
- Organometallic Complex Synthesis and Catalysis
- Antibiotic Resistance in Bacteria
- Drug Transport and Resistance Mechanisms
- Inorganic and Organometallic Chemistry
- Photosynthetic Processes and Mechanisms
Heinrich Heine University Düsseldorf
2025
The University of Queensland
2015-2024
Brisbane School of Theology
2016-2020
Université Claude Bernard Lyon 1
2015
Centre National de la Recherche Scientifique
2015
Utah State University
2007-2010
Middlebury College
2008-2009
Australian National University
1997-2009
Universidade Federal de Santa Catarina
2006
Heidelberg University
2002
The τ5 parameter, first proposed by Addison and coworkers, is the principal measure of geometry five-coordinate transition metal complexes, with = 0 said to describe a perfect square pyramidal 1 trigonal geometry. Therefore, geometries all complexes are assumed lie on continuum between these two extremes. Herein we show that there significant number examples having > 1, leading an equatorially distorted bipyramidal ion lying out plane equatorial donor atoms. We also displaying very much...
We report first example of template assisted rhodium catalyzed <italic>para</italic>-C–H alkenylation.
Purple acid phosphatases (PAPs) are a family of binuclear metalloenzymes that catalyze the hydrolysis phosphoric esters and anhydrides. A PAP in sweet potato has unique, strongly antiferromagnetically coupled Fe(III)–Mn(II) center is distinguished from other PAPs by its increased catalytic efficiency for range activated unactivated phosphate esters, strict requirement Mn(II), presence μ-oxo bridge at pH 4.90. This enzyme displays maximum ( k cat / K m ) 4.5, whereas rate constant maximal...
Abstract This microreview describes the structures and properties of a number bimetallic complexes designed as both structural functional mimics active sites some specific metallohydrolase enzymes. The metalloenzymes in question include predominantly monoesterase‐activity‐displaying purple acid phosphatase (PAP) di‐ triesterase enzymes, which have significant roles bioremedial hydrolysis organophosphate pesticides nerve gases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Purple acid phosphatases (PAPs) are a group of metallohydrolases that contain dinuclear FeIIIMII center (MII = Fe, Mn, Zn) in the active site and able to catalyze hydrolysis variety phosphoric esters. The complex [(H2O)FeIII(μ-OH)ZnII(L-H)](ClO4)2 (2) with ligand 2-[N-bis(2-pyridylmethyl)aminomethyl]-4-methyl-6-[N′-(2-pyridylmethyl)(2-hydroxybenzyl) aminomethyl]phenol (H2L-H) has recently been prepared is found closely mimic coordination environment FeIIIZnII red kidney bean PAP (Neves et...
It is becoming increasingly apparent that the secondary coordination sphere can have a crucial role in determining functional properties of biomimetic metal complexes. We therefore designed and prepared variety ligands as metallo-hydrolase mimics, where hydrogen bonding second able to influence structure primary substrate binding. The assessment structure-function relationship based on derivates 2,6-bis{[bis(pyridin-2-ylmethyl)amino]methyl}-4-methylphenol (HBPMP = HL(1))...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTcrystal Structure and Electrospray Ionization Mass Spectrometry, Electron Paramagnetic Resonance, Magnetic Susceptibility Study of [Cu2(ascidH2)(1,2-.mu.-CO3)(H2O)2].cntdot.2H2O, the Bis(copper(II)) Complex Ascidiacyclamide (ascidH4), a Cyclic Peptide Isolated from Ascidian Lissoclinum patellaAnna L. van den Brenk, Karl A. Byriel, David P. Fairlie, Lawrence R. Gahan, Graeme Hanson, Clifford J. Hawkins, Alun Jones, Colin H. Kennard, Boujemaa...
Purple acid phosphatases belong to the family of binuclear metallohydrolases and are involved in a multitude biological functions, ranging from bacterial killing bone metabolism animals phosphate uptake plants. Due its role resorption purple phosphatase has evolved into promising target for development anti-osteoporotic chemotherapeutics. The design specific potent inhibitors this enzyme is aided by detailed knowledge reaction mechanism. However, despite considerable effort last 10 years...
The OP (organophosphate)-degrading enzyme from Agrobacterium radiobacter (OpdA) is a binuclear metallohydrolase able to degrade highly toxic pesticides and nerve agents into less or non-toxic compounds. In the present study, effect of metal ion substitutions site-directed mutations on catalytic properties OpdA are investigated. study shows importance both composition hydrogen-bond network that connects centre with substrate-binding pocket using residues Arg254 Tyr257 in mechanism substrate...
A series of dinuclear cobalt(II) complexes has been prepared and characterized to generate functional spectroscopic models for substituted phosphoesterase enzymes such as the potential bioremediator GpdQ. Reaction ligands based on 2,2′-(((2-hydroxy-5-methyl-1,3-phenylene)bis(methylene))bis((pyridin-2-ylmethyl)azanediyl)))diethanol (L1) 2,6-bis(((2-methoxyethyl)(pyridin-2-ylmethyl)amino)methyl)-4-methylphenol (L2) with salts afforded [Co2(CO2EtH2L1)(CH3COO)2](PF6),...
We introduce PyPE_RESP, a tool to facilitate and standardize partial atomic charge derivation using the RESP approach. PyPE_RESP builds upon open-source Python package RDKit for chemoinformatics AMBER suite molecular simulations. provides an easy setup of multi-conformer multi-molecule Re-strained Electrostatic Potential (RESP) fitting while allowing comprehensive definition constraint groups through multiple methods. As command line tool, can be integrated into batch processes. The software...
The glycerophosphodiesterase (GpdQ) from Enterobacter aerogenes is a promiscuous binuclear metallohydrolase that catalyzes the hydrolysis of mono-, di-, and triester substrates, including some organophosphate pesticides products degradation nerve agents. GpdQ has attracted recent attention as promising enzymatic bioremediator. Here, we have investigated catalytic mechanism this versatile enzyme using range techniques. An improved crystal structure (1.9 Å resolution) illustrates presence (i)...
The currently accepted paradigm is that the purple acid phosphatases (PAPs) require a heterovalent, dinuclear metal-ion center for catalysis. It believed this an essential feature these enzymes in order them to operate under acidic conditions. A PAP from sweet potato unusual it appears have specific requirement manganese, forming unique FeIII-μ-(O)-MnII catalytically optimal conditions (Schenk et al. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 273). Herein, we demonstrate, with detailed...
The purple acid phosphatases (PAPs) are bimetallophosphatases that reported to lack phosphodiesterase activity based on the absence of reactivity with bis(p-nitrophenyl) phosphate. Yet, model systems designed mimic PAP active site preferentially hydrolyze phosphodiesters. We report PAPs from pig and red kidney bean efficiently diesters methyl nitrophenyl phosphate ethyl details diester reaction give insights into sequential steps involved in binding hydrolysis by metal center. Methyl...
The purple acid phosphatases (PAP) are binuclear metallohydrolases that catalyze the hydrolysis of a broad range phosphomonoester substrates. mode substrate binding during catalysis and identity nucleophile is subject to debate. Here, we used native Fe3+−Fe2+ pig PAP (uteroferrin; Uf) its Fe3+−Mn2+ derivative investigate effect metal ion substitution on mechanism catalysis. Replacement Fe2+ by Mn2+ lowers reactivity Uf. However, using stopped-flow measurements it could be shown this...
The glycerophosphodiesterase from Enterobacter aerogenes (GpdQ) belongs to the family of binuclear metallohydrolases and has attracted recent attention due its potential in bioremediation. Formation a catalytically competent center is promoted by substrate (Hadler et al. J. Am. Chem. Soc. 2008, 130, 14129). Using paramagnetic properties Mn(II), we estimated Kd values for metal ions α β sites be 29 344 μM, respectively, absence analogue. In presence, affinity site increases substantially (Kd...
The design and development of suitable biomimetic catalytic systems capable mimicking the functional properties enzymes continues to be a challenge for bioinorganic chemists. In this study, we report on synthesis, X-ray structures, physicochemical characterization novel isostructural [FeIIICoII(BPBPMP)(μ-OAc)2]ClO4 (1) [GaIIICoII(BPBPMP)(μ-OAc)2]ClO4 (2) complexes with unsymmetrical dinucleating ligand H2BPBPMP...
Abstract The synthesis and characterization of a novel dinucleating ligand L (L=4,11‐dimethyl‐1,8‐bis{2‐[ N ‐(di‐2‐pyridylmethyl)amino]ethyl}cyclam) its μ‐oxo‐bridged diferric complex [(H 2 L){Fe III (O)}(Cl) 4 ] 2+ are reported. This diiron(III) is the first example truly functional purple acid phosphatase (PAP) mimic as it accelerates hydrolysis activated phosphomonoester 2,4‐dinitrophenyl phosphate (DNPP). spectroscopic kinetic data indicate that only substrates monodentately bound to one...