A5101911083- Photosynthetic Processes and Mechanisms
- Light effects on plants
- Photoreceptor and optogenetics research
- Photochemistry and Electron Transfer Studies
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Electron Spin Resonance Studies
- Legionella and Acanthamoeba research
- Spectroscopy and Quantum Chemical Studies
- Advanced NMR Techniques and Applications
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Magnetism in coordination complexes
- Organometallic Complex Synthesis and Catalysis
- Crystallography and molecular interactions
- Electromagnetic Fields and Biological Effects
- Vibrio bacteria research studies
- Bacterial biofilms and quorum sensing
- Metalloenzymes and iron-sulfur proteins
- Porphyrin and Phthalocyanine Chemistry
- Radical Photochemical Reactions
- Synthesis and characterization of novel inorganic/organometallic compounds
- bioluminescence and chemiluminescence research
- Circadian rhythm and melatonin
- Heme Oxygenase-1 and Carbon Monoxide
- Microbial Natural Products and Biosynthesis
University of Freiburg
2016-2025
University Medical Center Freiburg
2020-2025
ETH Zurich
2007-2021
Institute of Physical Chemistry
2020
University of Fribourg
2018-2020
Instituto de Estudos Avançados da Universidade de São Paulo
2017
École Polytechnique Fédérale de Lausanne
2006-2014
University of Groningen
2011-2012
Freie Universität Berlin
2000-2010
Board of the Swiss Federal Institutes of Technology
2010
The identity of the interstitial light atom in center FeMo cofactor nitrogenase has been enigmatic since its discovery. Atomic-resolution x-ray diffraction data and an electron spin echo envelope modulation (ESEEM) analysis now provide direct evidence that ligand is a carbon species.
Among the biological phenomena that fall within emerging field of “quantum biology” is suggestion magnetically sensitive chemical reactions are responsible for magnetic compass migratory birds. It has been proposed transient radical pairs formed by photo-induced electron transfer in cryptochrome proteins and their coherent spin dynamics influenced geomagnetic leading to changes quantum yield signaling state protein. Despite a variety supporting evidence, it still not clear whether...
High capacitance (13.2 μA h cm<sup>−2</sup>) double layer hybrid supercapacitor consisting of reduced graphene oxide/Fe doped Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> (rGO/LTO) and graphite.
The causative agent of Legionnaires' disease, Legionella pneumophila, employs the intracellular multiplication (Icm)/defective organelle trafficking (Dot) type IV secretion system (T4SS) to upregulate phagocytosis and establish a replicative vacuole in amoebae macrophages. Legionella-containing vacuoles (LCVs) do not fuse with endosomes but recruit early secretory vesicles. Here we analyze role host cell phosphoinositide (PI) metabolism during uptake replication L. pneumophila. Genetic...
The causative agent of Legionnaires disease, Legionella pneumophila, forms a replicative vacuole in phagocytes by means the intracellular multiplication/defective organelle trafficking (Icm/Dot) type IV secretion system and translocated effector proteins, some which subvert host GTP phosphoinositide (PI) metabolism. Icm/Dot substrate SidC anchors to membrane Legionella-containing vacuoles (LCVs) specifically binding phosphatidylinositol 4-phosphate (PtdIns(4)P). Using nonbiased screen for...
Legionella pneumophila, the causative agent of Legionnaires' disease, uses intracellular multiplication/defective organelle trafficking (Icm/Dot) type IV secretion system to establish within amoebae and macrophages an endoplasmic reticulum (ER)-derived replication-permissive compartment, Legionella-containing vacuole (LCV). The Icm/Dot substrate SidC its paralogue SdcA anchor LCVs via phosphatidylinositol-4 phosphate [PtdIns(4)P]. Here we identify unique 20 kDa PtdIns(4)P-binding domain...
Legionella pneumophila is an opportunistic human pathogen that replicates within environmental amoebae including Acanthamoeba castellanii and Dictyostelium discoideum. The Icm/Dot type IV secretion system promotes phagocytosis intracellular replication of L. in endoplasmic reticulum-derived 'Legionella-containing vacuole' (LCV). adopts a biphasic life cycle consisting replicative growth phase transmissive (stationary) phase, the latter which characterized by preferential expression genes...
Compass component: Blue-light excitation of the photoreceptor cryptochrome generates a transient radical pair by electron transfer from tryptophan (Trp) at surface to flavin cofactor in center protein (see picture; FAD=flavin adenine dinucleotide). Simulated EPR spectra show that electronic coupling parameters these pairs are suitable for animal magnetoreception.
We prepared conceptually novel, fully rigid, spiro compact electron donor (Rhodamine B, lactam form, RB)/acceptor (naphthalimide; NI) orthogonal dyad to attain the long-lived triplet charge-transfer (3 CT) state, based on spin control using spin-orbit charge transfer intersystem crossing (SOCT-ISC). Transient absorption (TA) spectra indicate first separation (CS) takes place within 2.5 ps, subsequent SOCT-ISC 8 ns produce 3 NI* state. Then slow secondary CS (125 ns) gives CT state (0.94 μs...
Abstract Drosophila have been used as model organisms to explore both the biophysical mechanisms of animal magnetoreception and possibility that weak, low-frequency anthropogenic electromagnetic fields may biological consequences. In cases, presumed receptor is cryptochrome, a protein thought be responsible for magnetic compass sensing in migratory birds variety behavioural responses insects. Here, we demonstrate photo-induced electron transfer reactions melanogaster cryptochrome are indeed...
clCRY4 has the biophysical and molecular attributes necessary to function as a light-dependent magnetosensor.
Two kinds of electrode materials were produced to fabricate asymmetric supercapacitor devices: (i) Highly defective, n-type wide bandgap semiconductor ZnO nanocrystalline electrodes below 50 nm synthesized with the aid high energy ball milling technique. (ii) Flexible 3D-graphene foams via chemical vapor deposition Extensive defect structure analysis was performed enhanced characterization techniques mainly spectroscopy ones: electron paramagnetic resonance (EPR), Raman, and...
ABSTRACT Legionella pneumophila persists for a long time in aquatic habitats, where the bacteria associate with biofilms and replicate within protozoan predators. While L. serves as paradigm intracellular growth protozoa, it is less clear whether form or absence of protozoa. In this study, we analyzed surface adherence biofilm formation by rich medium that supported axenic replication. Biofilm virulent strain JR32 clinical environmental isolates was confocal microscopy crystal violet...
The blue-light sensitive photoreceptor, phototropin, is a flavoprotein which regulates the phototropism response of higher plants. photoinduced triplet state and photoreactivity flavin-mononucleotide (FMN) cofactor in two LOV domains Avena sativa, Adiantum capillus-veneris, Chlamydomonas reinhardtii phototropin have been studied by time-resolved electron paramagnetic resonance (EPR) UV-vis spectroscopy at low temperatures (T < or = 80 K). Differences electronic structure FMN as reflected...
Legionella pneumophila, the causative agent of Legionnaires' disease, replicates within a specific vacuole in amoebae and macrophages. To form these 'Legionella-containing vacuoles' (LCVs), bacteria employ Icm/Dot type IV secretion system effector proteins, some which anchor to LCV membrane via host glycolipid phosphatidylinositol 4-phosphate [PtdIns(4)P]. Here we analysed role inositol polyphosphate 5-phosphatases (IP5Ps) during L. pneumophila infections. Bacterial replication formation...
One of the two principal hypotheses put forward to explain primary magnetoreception event underlying magnetic compass sense migratory birds is based on a magnetically sensitive chemical reaction. It has been proposed that spin-correlated radical pair produced photochemically in cryptochrome and rates yields subsequent reactions depend orientation protein Earth's field. The suitability for this purpose argued, part, by analogy with DNA photolyase, although no effects applied fields have yet...
The protective effect of antibodies (Abs) is generally attributed to neutralization or complement activation. Using Legionella pneumophila and Mycobacterium bovis bacillus Calmette–Guérin as a model, we discovered an additional mechanism Ab-mediated protection effective against intracellular pathogens that normally evade lysosomal fusion. We show Fc receptor (FcR) engagement by Abs, which can be temporally spatially separated from bacterial infection, renders the host cell nonpermissive for...
Phenothiazine (PTZ)–anthracene (An) compact electron donor/acceptor dyads were synthesized. The molecular conformation was constrained by rotation restriction to achieve an orthogonal geometry between the donor (PTZ) and acceptor (An), with aim enhance spin–orbit charge-transfer intersystem crossing (SOCT–ISC). substitution positions on PTZ An moieties varied attain different mutual orientations of as well rotation-steric hindrances. electronic coupling strengths quantified matrix elements...
The perhalogenated closo-dodecaborate dianions [B12 X12 ](2-) (X=H, F, Cl, Br, I) are three-dimensional counterparts to the two-dimensional aromatics C6 X6 I). Whereas oxidation of parent compounds H12 and benzene does not lead isolable radicals, analogues can be oxidized by chemical or electrochemical methods give stable radicals. with strong oxidizer AsF5 in liquid sulfur dioxide (lSO2 ) yielded corresponding radical anions ](⋅-) (X=F, Br). presence ions was proven EPR UV/Vis spectroscopy...