A5087699949- Photosynthetic Processes and Mechanisms
- Photoreceptor and optogenetics research
- Hemoglobin structure and function
- Spectroscopy and Quantum Chemical Studies
- Electrochemical Analysis and Applications
- Electrochemical sensors and biosensors
- Enzyme Structure and Function
- Metal-Catalyzed Oxygenation Mechanisms
- Mitochondrial Function and Pathology
- Microbial Metabolic Engineering and Bioproduction
- Lipid Membrane Structure and Behavior
- ATP Synthase and ATPases Research
- Spectroscopy Techniques in Biomedical and Chemical Research
- Acoustic Wave Resonator Technologies
- Metalloenzymes and iron-sulfur proteins
- Mechanical and Optical Resonators
- Protein Structure and Dynamics
- Polymer Surface Interaction Studies
- Enzyme Catalysis and Immobilization
- Nitric Oxide and Endothelin Effects
- Microbial Fuel Cells and Bioremediation
- Molecular Junctions and Nanostructures
- Neuroscience and Neural Engineering
- Microbial Community Ecology and Physiology
- Force Microscopy Techniques and Applications
University of Limerick
2015-2024
Science Foundation Ireland
2021-2024
Science and Technology on Surface Physics and Chemistry Laboratory
2019
Paul Scherrer Institute
2002-2010
University of Crete
2003-2005
National Institutes of Natural Sciences
2005
Okazaki Institute for Integrative Bioscience
2005
RWTH Aachen University
1993-2004
Centre National de la Recherche Scientifique
1998-2004
Institut de Biologie Structurale
2004
Single crystal L-amino acids can exhibit technologically useful piezoelectric and nonlinear optical properties. Here we predict, using density functional theory, the charge strain voltage tensors of racemic amino acid DL alanine, use modeling data to guide first macroscopic nanoscopic measurements on DL-alanine single crystals polycrystalline aggregates. We demonstrate generation up 0.8 V from films under simple manual compression, twice as high other crystals. Our results suggest that net...
We show that the heme-copper terminal oxidases of Thermus thermophilus (called ba 3 and caa ) are able to catalyze reduction nitric oxide (NO) nitrous (N 2 O) under reducing anaerobic conditions. The rate NO consumption N O production were found be linearly dependent on enzyme concentration, activity was abolished by denaturation. Thus, contrary eukaryotic enzyme, both T. display a reductase (3.0 ± 0.7 mol NO/mol × min 32 8 at [NO] ≈ 50 μM 20°C) that, though considerably lower than bona fide...
The mechanism of inhibition cytochrome (cyt) c oxidase by nitric oxide (NO) has been investigated stopped flow transient spectroscopy and singular value decomposition analysis. Following the time course cyt oxidation at different O2/NO ratios, we observed that onset inhibition: (i) is fast a high NO concentration complete during first turnover; (ii) sensitive to ratio; (iii) independent incubation oxidized enzyme with NO. Analysis reaction kinetics computer simulations support conclusion...
A combination of chemotherapy with nonconventional nanoparticle based physical destruction therapy has been proposed clinically to reduce the prospect evolution drug resistance in cancer. Superparamagnetic nanoparticles have actively used for synergetic cancer including magnetic fluid hyperthermia (MFH) guided by resonance imaging (MRI). To explore this direction potential applications therapy, we functionalized superparamagnetic La0.7Sr0.3MnO3 (SPMNPs) an oleic acid-polyethylene glycol...
A novel device for capillary-free mounting of protein crystals is described. controlled stream air allows an accurate adjustment the humidity at crystal. The crystal held on tip a micropipette. With video system (CCD camera), two-dimensional shadow projections can be recorded optical analysis. Instead micropipette, standard loop also used. Experiments and results different systems demonstrate use this method, in combination with shock-freezing, to improve order. Working oxygen-free gases...
Abstract Following hints from X‐ray data (Ostermeier C et al., 1997, Proc Natl Acad Sci USA 94 :10547–10553; Yoshikawa S 1998, Science 280 :1723–1729), chemical evidence is presented four distantly related cytochrome‐ c oxidases for the existence of a copper B ‐coordinated His240–Tyr244) cross‐link at O 2 ‐activating Heme Fea 3 –Cu center in catalytic subunit I enzyme. The early evolutionary invention this unusual structure may have prevented demaging OH‐radical release e – ‐transfer to...
Several amino acid residues that have been shown to be essential for proton transfer in most cytochrome c oxidases are not conserved the ba 3 ‐type oxidase from thermophilic eubacterium Thermus thermophilus . So far, it has unclear whether Th. can nevertheless function as an electrogenic pump. In this study, we combined charge translocation measurements on a lipid bilayer with two independent methods of pumping show enzymatic turnover is indeed coupled generation electrocurrent and across...
Here, we present experimental evidence of the direct piezoelectric effect in globular protein, lysozyme. Piezoelectric materials are employed many actuating and sensing applications because they can convert mechanical energy into electrical vice versa. Although originally studied inorganic materials, several biological including amino acids bone, also exhibit piezoelectricity. The exact mechanisms supporting piezoelectricity not known, nor is it known whether conforms strictly to criteria...
Metal organic frameworks (MOFs) have been used to encapsulate an array of enzymes in a rapid and facile manner; however, the stability MOFs as supports for has not examined detail. This study examines with different compositions (Fe-BTC, Co-TMA, Ni-TMA, Cu-TMA, ZIF-zni) buffered solutions commonly enzyme immobilization biocatalysis. Stability was assessed via quantification release metals by inductively coupled plasma optical emission spectroscopy. The buffers had varied effects on MOF...
The interactions of yeast iso‐1 cytochrome c with bovine oxidase were studied using variants in which lysines the binding domain substituted by alanines. Resonance Raman spectra fully oxidized complexes both proteins reveal structural changes heme and hemes a 3 . are same as those observed upon to phospholipid vesicles where bound protein exists two conformers, B1 B2. Whereas structure is that unbound , formation B2 associated substantial alterations pocket. In oxidase, refer more subtle...
A new rapid procedure for the preparation of monodispersed highly active cytochrome-c oxidase from bovine heart is described. The crucial step separation reductase by selective solubilization in non-ionic detergents Triton X-100 or lauryl beta-D-maltoside. enzyme purified subsequent anion-exchange chromatography. finished within two days yielding approximately 60% present mitochondria. has a heme alpha/protein ratio 9.7 +/- 0.5 nmol/mg, equal to theoretical value 9.77 nmol/mg based on...
Gold nanoparticles (GNPs) possess various interesting plasmonic properties that can provide a variety of diagnostic and therapeutic functionalities for biomedical applications. Compared to other inorganic metal (NPs), GNPs are less toxic more biocompatible. However, the in vivo toxicity gold on humans be significant due size effect. This work aims study effect multiple doses small-size (≈20 nm) vital organs Wistar rats. The includes oxidative stress (liver, brain, kidney) caused by...
An immobilized bi-enzymatic (ALDH Tt -LDH) flow reactor has been develeoped for the selective oxidation of aldehydes.
The kinetic properties of the ba3 oxidase from Thermus thermophilus were investigated by stopped-flow spectroscopy in temperature range 5−70 °C. Peculiar behavior reaction with physiological substrates and classical ligands (CO CN-) was observed. In O2 reaction, decay F intermediate is significantly slower (k' = 100 s-1 at 5 °C) than mitochondrial enzyme, an activation energy E* 10.1 ± 0.9 kcal mol-1. cyanide-inhibited oxidizes cyt c522 quickly (k ≈ × 106 M-1 25 selectively, 10.9 mol-1, but...
NO laughing matter: The enzymatic production of gas (N2O) from two molecules requires the formation NN bond and subsequent cleavage NOH bond. Resonance Raman spectroscopic studies have now provided evidence for key intermediate, hyponitrite species (see optimized molecular structure), in heme a3 FeCuB binuclear center ba3-oxidoreductase Thermus thermophilus.
Inverted colloidal-nanocrystal-based LEDs (NC-LEDs) are highly interesting and invaluable for large-scale display technology flexible electronics. Semiconductor nanorods (NRs), in addition to the tunable wavelengths of emitted light (achieved, example, by variation NR diameter or core a core-shell configuration), also exhibit linearly polarized emission, larger Stokes shift, faster radiative decay, slower bleaching kinetics than quantum dots (QDs). Despite these advantages, it is difficult...
A novel homobinuclear Cu2 complex describes best the CuA center of cytochrome-c oxidase from bovine heart mitochondria according to EXAFS investigations. In this complex, which contains two terminal histidine residues, cysteine sulfur bridges, and probably a bridging oxygen donor function, CuCu distance 2.46 Å is very short. The structure Fea3-CuB was likewise determined.