A5019031580- Enzyme-mediated dye degradation
- Photosynthetic Processes and Mechanisms
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Arsenic contamination and mitigation
- Nitric Oxide and Endothelin Effects
- Electrochemical sensors and biosensors
- Metal-Catalyzed Oxygenation Mechanisms
- Prion Diseases and Protein Misfolding
- Peroxisome Proliferator-Activated Receptors
- Alzheimer's disease research and treatments
- Amyotrophic Lateral Sclerosis Research
- Protein Interaction Studies and Fluorescence Analysis
- Electrochemical Analysis and Applications
- Neurological diseases and metabolism
- Hemoglobin structure and function
- Dementia and Cognitive Impairment Research
- Mitochondrial Function and Pathology
- Eosinophilic Disorders and Syndromes
- Adipose Tissue and Metabolism
- Redox biology and oxidative stress
- Photoreceptor and optogenetics research
- Parkinson's Disease Mechanisms and Treatments
- RNA regulation and disease
- Analytical chemistry methods development
- Immune cells in cancer
Medical University of Vienna
2010-2024
BOKU University
1997-2005
University of Agricultural Sciences, Dharwad
2000-2003
Max Planck Institute of Biochemistry
2002
University of Florence
2002
Max Planck Society
2002
Leipzig University
2002
University of Vienna
1995-1999
Case Western Reserve University
1994
X-linked adrenoleukodystrophy (X-ALD), an inherited peroxisomal disorder, is caused by mutations in the ABCD1 gene encoding ATP-binding cassette (ABC) transporter (adrenoleukodystrophy protein, ALDP). Biochemically, X-ALD characterized accumulation of very long-chain fatty acids and partially impaired β-oxidation. In this study, we used primary human fibroblasts from Zellweger syndrome patients to investigate β-oxidation defect. Our results show that degradation C26:0-CoA esters as severely...
Deposition of amyloid-β (Aβ) in the brain parenchyma and vessels is one hallmarks Alzheimer disease (AD). Recent observations Aβ deposition iatrogenic Creutzfeldt-Jakob (iCJD) after dural grafting or treatment with pituitary extracts raised concerns whether capable transmitting as seen prion diseases by disease-associated protein. To address this issue, we re-sampled re-evaluated archival material, including grafted dura mater two cases iCJD (28 33-years-old) without mutations AβPP, PSEN1...
Lactoperoxidase (LPO) is found in mucosal surfaces and exocrine secretions, including milk, tears, saliva, has physiological significance antimicrobial defense which involves (pseudo-) halide oxidation. This study for the first time presents transient kinetic measurements of reactivity its competent redox intermediate compound I with halides thiocyanate, using sequential stopped-flow technique. Compound was produced either H2O2 [(1.1 ± 0.1) × 107 M-1 s-1] or hypochlorous acid [(3.2 s-1]. At...
Background and purpose Cerebrospinal fluid ( CSF ) tau neurofilament light chain NF ‐L) proteins have proved to be reliable biomarkers for neuronal damage; however, there is a strong need blood‐based tests. Methods The present study included 132 autopsy cases with rapidly progressive neurological syndromes, including Alzheimer disease AD (21), sporadic (65) genetic (21) Creutzfeldt–Jakob CJD ), 25 vascular, neoplastic inflammatory alterations, additionally 18 healthy control individuals. ‐L...
Abstract Creutzfeldt‐Jakob disease (CJD) is a human prion with different etiologies. To determine the spectrum of tau pathologies in CJD, we assessed phospho‐Tau (pTau) immunoreactivities 75 sporadic CJD cases including an evaluation entorhinal cortex and six hippocampal subregions. Twelve (16%) showed only small tau‐immunoreactive neuritic profiles. Fifty‐two (69.3%) additional pathology medial temporal lobe compatible primary age related tauopathy (PART). In 22/52 lower pTau...
Compound I of peroxidases takes part in both the peroxidation and halogenation reaction. This study for first time presents transient kinetic measurements formation compound human eosinophil peroxidase (EPO) its reaction with halides thiocyanate, using sequential-mixing stopped-flow technique. Addition 1 equiv hydrogen peroxide to native EPO leads complete I. At pH 7 15 °C, apparent second-order rate constant is (4.3 ± 0.4) × 107 M-1 s-1. The by hypochlorous acid (5.6 0.7) unstable decays a...
X-linked adrenoleukodystrophy is caused by ATP-binding cassette transporter D1 (ABCD1) mutations and manifests default as slowly progressive spinal cord axonopathy with associated demyelination (adrenomyloneuropathy). In 60% of male cases, however, converts to devastating cerebral inflammation (cerebral adrenoleukodystrophy) infiltrating blood-derived monocytes macrophages cytotoxic T cells that can only be stopped allogeneic haematopoietic stem cell transplantation or gene therapy at an...
The standard reduction potential of the redox couple compound I/native enzyme has been determined for human myeloperoxidase (MPO) and eosinophil peroxidase (EPO) at pH 7.0 25 °C. This was achieved by rapid mixing peroxidases with either hydrogen peroxide or hypochlorous acid measuring spectrophotometrically concentrations reacting species products equilibrium. By using peroxide, °C 1.16 ± 0.01 V MPO 1.10 EPO, independently concentration peroxidases. In case acid, potentials were dependent on...
In developing ideas of how protein structure modifies haem reactivity, the activity Class I plant peroxidase superfamily (including cytochrome c peroxidase, ascorbate and catalase-peroxidases (KatGs)) is an exciting field research. Despite striking sequence homologies, there are dramatic differences in catalytic substrate specificity with KatGs being only member substantial catalase activity. Based on multiple alignment performed for peroxidases, we present a hypothesis pronounced KatGs....
Catalase-peroxidases have a predominant catalase activity but differ from monofunctional catalases in exhibiting substantial peroxidase and having different residues the heme cavity. We present kinetic study of formation key intermediate compound I by probing role conserved distal amino acid triad Arg-Trp-His recombinant catalase-peroxidase its reaction with hydrogen peroxide, peroxoacetic acid, <i>m</i>-chloroperbenzoic acid. Both wild-type enzyme six mutants (R119A, R119N, W122F, W122A,...
X-linked adrenoleukodystrophy (X-ALD) is a fatal neurodegenerative disease caused by mutations in the ABCD1 gene, encoding member of peroxisomal ABC transporter family. The protein transports CoA-activated very long-chain fatty acids (VLCFAs) into peroxisomes for degradation via β-oxidation. In severest form, X-ALD patients suffer from inflammatory demyelination brain. As extent metabolic defect main immune cells unknown, we explored their phenotypes concerning mRNA expression pattern three...
Blood-based biomarkers may add a great benefit in detecting the earliest neuropathological changes patients with Alzheimer's disease (AD). We examined utility of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) regarding clinical diagnosis differentiation between amyloid positive negative patients. To evaluate practical application these routine setting, we conducted this study heterogeneous memory-clinic population.
The reaction of native myeloperoxidase (MPO) and its redox intermediate compound I with hydrogen peroxide, ethyl hydroperoxide, peroxyacetic acid, t-butyl 3-chloroperoxybenzoic acid cumene hydroperoxide was studied by multi-mixing stopped-flow techniques. Hydroperoxides are decomposed MPO two mechanisms. Firstly, the undergoes a two-electron reduction to corresponding alcohol heme iron is oxidized I. At pH 7 15 degrees C, rate constant between ferric similar that peroxide (1.8x10(7) M(-1)...
Structural and biochemical characterization of aspartate 152 at the distal heme side catalase-peroxidase (KatG) from Synechocystis PCC 6803 reveals an important functional role for this residue. In wild-type protein, chain carboxyl group Asp152 is 7.8 Å apart iron hydrogen-bonded to two water molecules a KatG-specific large loop. We have prepared site-specific variants Asp152Asn, Asp152Ser, Asp152Trp, Pro151Ala. Exchange exhibited dramatic consequences on bifunctional activity unique...
Alzheimer's disease (AD) accounts for more than 60% of the dementia cases and currently there is no curative treatment it. With emergence potentially modifying treatments, early diagnosis key to identify patient groups that would benefit from such aiming prevent severe cognitive decline. We previously identified a set DNA methylation signatures allow accurate AD in cortical neurons brain tissue, even before clinical manifestation [1]. Here we investigate 11 these signature regions via...
The nitrogen-fixing filamentous cyanobacterium Nostoc PCC 7120 (formerly named Anabaena 7120) possesses two genes for superoxide dismutase, a unique membrane-associated manganese dismutase (MnSOD) and soluble iron (FeSOD). A phylogenetic analysis of FeSODs shows that cyanobacterial enzymes form well separated cluster with species found in one subcluster unicellular the other. Activity staining, inhibition patterns, immunogold labeling show FeSOD is localized cytosol vegetative cells...
Catalase-peroxidases are bifunctional peroxidases exhibiting an overwhelming catalase activity and a substantial peroxidase activity. Here we present kinetic study of the formation reduction key intermediate compound I by probing role conserved tryptophan at distal haem cavity site. Two wild-type proteins three mutants Synechocystis catalase-peroxidase (W122A W122F) Escherichia coli (W105F) have been investigated steady-state stopped-flow spectroscopy. W122F W122A completely lost their...
The Synechocystis PCC 6803 katG gene encodes a dual-functional catalase-peroxidase (EC 1.11.1.7). We have established system for the high level expression of fully active recombinant form this enzyme. Its entire coding DNA was extended using synthetic oligonucleotide encoding hexa-histidine tag at C-terminus and expressed in Escherichia coli [BL21-(DE3)pLysS] pET-3a vector. Hemin added to culture medium ensure its proper association with KatG upon induction. protein purified homogeneity by...