A5088264789- Light effects on plants
- Photoreceptor and optogenetics research
- Photosynthetic Processes and Mechanisms
- Algal biology and biofuel production
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Circadian rhythm and melatonin
- Plant Molecular Biology Research
- Hydrogels: synthesis, properties, applications
- bioluminescence and chemiluminescence research
- Lipid Membrane Structure and Behavior
- Amino Acid Enzymes and Metabolism
- Spectroscopy and Quantum Chemical Studies
- Microbial bioremediation and biosurfactants
- Photochromic and Fluorescence Chemistry
- Nanopore and Nanochannel Transport Studies
- Microbial Community Ecology and Physiology
- Nicotinic Acetylcholine Receptors Study
- Molecular Junctions and Nanostructures
- Atomic and Subatomic Physics Research
- Advanced Materials and Mechanics
- Analytical Chemistry and Sensors
- Biocrusts and Microbial Ecology
- Spectroscopy and Laser Applications
- Marine and coastal ecosystems
Bielefeld University
2016-2025
ETH Zurich
2018
Friedrich Schiller University Jena
2017
Freie Universität Berlin
2010
University of Oxford
2010
Forschungszentrum Jülich
2005-2010
University of Regensburg
2003-2009
Sorbonne Université
2006
Cryptochromes are flavoproteins that evolutionary related to the DNA photolyases but lack repair activity. Drosophila cryptochrome (dCRY) is a blue light photoreceptor involved in synchronization of circadian clock with environmental light-dark cycle. Until now, spectroscopic and structural studies on this other animal cryptochromes have largely been hampered by difficulties their recombinant expression. We therefore established an expression purification scheme enables us purify mg amounts...
Abstract Ice nucleation and growth is an important widespread environmental process. Accordingly, nature has developed means to either promote or inhibit ice crystal formation, for example ice-nucleating proteins in bacteria ice-binding antifreeze polar fish. Recently, it was found that birch pollen release macromolecules when suspended water. Here we show washing water exhibits also properties such as shaping recrystallization inhibition, similar proteins. We present spectroscopic evidence...
Cryptochromes are flavoproteins that act as sensory blue light receptors in insects, plants, fungi, and bacteria. We have investigated a cryptochrome from the green alga Chlamydomonas reinhardtii with sequence homology to animal cryptochromes (6-4) photolyases. In response red exposure, this animal-like (aCRY) alters light-dependent expression of various genes encoding proteins involved chlorophyll carotenoid biosynthesis, light-harvesting complexes, nitrogen metabolism, cell cycle control,...
Pulsed spray evaporation chemical vapor deposition (PSE-CVD) was employed for the synthesis of cobalt-based spinel oxide thin films, Co3−xFexO4 with x = 0–1.56. XRD, Raman scattering and FTIR emission spectroscopy show that normal structure retained 0 ≤x≤ 0.65 by selective insertion Fe3+ in octahedral sites. The inversion noticed above this range, whereas Fe2+ first indicated x≥ 1. room-temperature electrical resistivity films controlled between 9 0.007 Ω cm adjustment iron doping...
The kinetic analysis of irreversible protein reactions requires an analytical technique that provides access to time-dependent infrared spectra in a single shot. Here, we present spectrometer based on dual-frequency-comb spectroscopy using mid-infrared frequency combs generated by quantum cascade lasers. Attenuation the intensity molecular vibrational resonances results absorption covering 55 cm-1 fingerprint region. setup has native resolution 0.3 cm-1, noise levels μOD range, and achieves...
The understanding of signal transduction mechanisms in photoreceptor proteins is essential for elucidating how living organisms respond to light as environmental stimuli. In this study, we investigated the ATP binding, photoactivation and process photoactivatable adenylate cyclase from Oscillatoria acuminata (OaPAC) upon blue excitation. Structural models with bound active site native OaPAC at cryogenic well room temperature are presented. found one conformation cryogenic- two conformations...
Cryptochromes are blue-light photoreceptors that regulate a variety of responses in animals and plants, including circadian entrainment Drosophila photomorphogenesis Arabidopsis. They comprise photolyase homology region (PHR) about 500 amino acids C-terminal extension varying length. In the PHR domain, flavin adenine dinucleotide (FAD) is noncovalently bound. The presence second chromophore, such as methenyltetrahydrofolate, animal plant cryptochromes still under debate. Arabidopsis...
Photoreceptors are chromoproteins that undergo fast conversion from dark to signaling states upon light absorption by the chromophore. The state starts signal transduction in vivo and elicits a biological response. Therefore, photoreceptors ideally suited for analysis of protein activation time-resolved spectroscopy. We focus on plant cryptochromes which blue sensors regulating development daily rhythm plants. these flavoproteins is neutral radical flavin It forms microsecond time scale...
Abstract BLUF (blue light sensor using flavin) domains regulate the activity of various enzymatic effector in bacteria and euglenids. features a unique photoactivation through restructuring hydrogen-bonding network as opposed to redox reaction or an isomerization chromophore. A conserved glutamine residue close flavin chromophore plays central role response, but underlying modification is still unclear. We labelled this with 15 N two representative performed time-resolved infrared double...
The first stage in biological signaling is based on changes the functional state of a receptor protein triggered by interaction with its ligand(s). light-triggered nature photoreceptors allows studies mechanism such proteins using wide range biophysical methods and superb time resolution. Here, we critically evaluate current understanding proton electron transfer photosensory their involvement both primary photochemistry subsequent processes that lead to formation state. An insight emerging...
Flavin-dependent halogenases catalyse halogenation of aromatic compounds. In most cases, this reaction proceeds with high regioselectivity and requires only the presence FADH2, oxygen, halide salts. Since marine habitats contain concentrations halides, organisms populating oceans might be valuable sources yet undiscovered halogenases. A new Hidden-Markov-Model (HMM) based on PFAM tryptophan halogenase model was used for analysis metagenomes. Eleven metagenomes were screened leading to...
Phytochrome proteins regulate many photoresponses of plants and microorganisms. Light absorption causes isomerization the biliverdin chromophore, which triggers a series structural changes to activate signaling domains protein. However, are elusive, therefore molecular mechanism signal transduction remains poorly understood. Here, we apply two-color step-scan infrared spectroscopy bacteriophytochrome from Deinococcus radiodurans. We show by recordings in H2O D2O that hydrogen bonds D-ring...
Plant cryptochromes are blue light photoreceptors that regulate key responses in growth and daily rhythm of plants might be involved magnetoreception. They show structural homology to the DNA repair enzyme photolyase bind flavin adenine dinucleotide as chromophore. Blue absorption initiates photoreduction from oxidized dark state neutral radical, which is signaling sensor. Previous time-resolved studies process have been limited observation decay radical millisecond time domain. We monitored...
Aureochromes have recently been shown to act as blue-light-regulated transcription factors in the stramenopile alga Vaucheria frigida. They comprise a light-, oxygen-, or voltage-sensitive (LOV) domain sensory module with flavin mononucleotide (FMN) chromophore and basic region leucine zipper (bZIP) an effector. are only members of large LOV protein family, where effector is located N-terminal sensor domain. This inversion positions linking Jα helix other proteins terminus, raising question...
Diatoms possess several genes for proteins of the cryptochrome/photolyase family. A typical sequence a plant cryptochrome was not found in our analysis Phaeodactylum tricornutum genome, but one protein grouped with higher and green algal cryptochromes. This protein, CryP, binds FAD 5,10-methenyltetrahydrofolate, according to spectroscopic studies on heterologously expressed protein. 5,10-Methenyltetrahydrofolate binding is feature common both cyclobutane pyrimidine dimer photolyases DASH In...
Cryptochromes constitute a group of flavin-binding blue light receptors in bacteria, fungi, plants, and insects. Recently, the response cryptochromes to was extended nearly entire visible spectral region on basis activity animal-like cryptochrome aCRY green alga Chlamydomonas reinhardtii. This finding explained by absorption red flavin neutral radical as dark state receptor, which then forms anionic fully reduced state. In this study, time-resolved UV-visible spectroscopy full-length...
Cryptochromes are flavin-binding proteins that act as blue light receptors in bacteria, fungi, plants, and insects components of the circadian oscillator mammals. Animal plant cryptochromes evolutionarily divergent, although unicellular alga Chlamydomonas reinhardtii (Chlamydomonas throughout) has both an animal-like cryptochrome a (pCRY; formerly designated CPH1). Here, we show pCRY protein accumulates at night part complex. Functional characterization was performed based on insertional...