A5021167351- Light effects on plants
- Photosynthetic Processes and Mechanisms
- Photoreceptor and optogenetics research
- Coffee research and impacts
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Metalloenzymes and iron-sulfur proteins
- Essential Oils and Antimicrobial Activity
- Hydrogen Storage and Materials
- Plant and Biological Electrophysiology Studies
- Ethnobotanical and Medicinal Plants Studies
- Plant Pathogens and Fungal Diseases
- Food Waste Reduction and Sustainability
- Electrocatalysts for Energy Conversion
- Advanced Fluorescence Microscopy Techniques
- Inorganic Chemistry and Materials
- Probiotics and Fermented Foods
- Lanthanide and Transition Metal Complexes
- Circadian rhythm and melatonin
- Metal complexes synthesis and properties
- Molecular Spectroscopy and Structure
- Food, Nutrition, and Cultural Practices
- Seed and Plant Biochemistry
- Algal biology and biofuel production
- Biochemical Analysis and Sensing Techniques
Technische Universität Berlin
2012-2022
Reference Institute for Bioanalytics
2019
Abstract Phytochromes are modular photoreceptors of plants, bacteria and fungi that use light as a source information to regulate fundamental physiological processes. Interconversion between the active inactive states is accomplished by photoinduced reaction sequence which couples sensor with output module. However, underlying molecular mechanism yet not fully understood due lack structural data functionally relevant intermediate states. Here we report crystal structure Meta-F state an Agp2...
Cyanobacteriochromes are members of the phytochrome superfamily. In contrast to classical phytochromes, these small photosensors display a considerable variability electronic absorption maxima. We have studied light-induced conversions second GAF domain AnPixJ, AnPixJg2, phycocyanobilin-binding protein from cyanobacterium Anabaena PCC 7120, using low-temperature resonance Raman spectroscopy combined with molecular dynamics simulations. AnPixJg2 is formed biosynthetically as red-absorbing...
Phytochromes are a collection of bilin-containing photoreceptors that regulate diverse array processes in microorganisms and plants through photoconversion between two stable states, red light-absorbing Pr form, far Pfr form. Recently, novel set phytochrome-like chromoproteins was discovered cyanobacteria, designated here as cyanochromes, instead photoconvert blue green forms Pb Pg, respectively. Here, we show the distinctive absorption properties cyanochromes facilitated binding...
Insights in active sites: Hydrogen-conversion by hydrogenase is mediated a sophisticated, metal-containing catalytic center. Resonance Raman spectroscopy used for the first time characterization of site these biocatalysts. An integrated spectroscopic and computational approach gives insights into structural photochemical properties an oxygen-tolerant [NiFe] hydrogenase. As service to our authors readers, this journal provides supporting information supplied authors. Such materials are peer...
Phytochromes are biological red/far-red light sensors found in many organisms. Photoisomerization of the linear methine-bridged tetrapyrrole triggers transient proton translocation events chromophore binding pocket (CBP) leading to major conformational changes protein matrix that turn associated with signaling. By combining pH-dependent resonance Raman and UV–visible absorption spectroscopy, we analyzed protonation-dependent equilibria CBP Cph1 involving proposed Pr-I Pr-II substates prevail...
Abstract The biological function of phytochromes is triggered by an ultrafast photoisomerization the tetrapyrrole chromophore biliverdin between two rings denoted C and D . mechanism which this process induces extended structural changes protein unclear. Here we report proton-coupled upon excitation parent state (Pfr) bacteriophytochrome Agp2. Transient deprotonation chromophore’s pyrrole ring or into a hydrogen-bonded water cluster, revealed broad continuum infrared band, electronic...
The second GAF domain of AnPixJ, AnPixJg2, a bilin-binding protein from the cyanobacterium Anabaena PCC 7120, undergoes photoinduced interconversion between red-absorbing state, Pr, and green-absorbing Pg. Combining ultraviolet-vis (UV-vis), infrared, resonance Raman (RR), magic-angle spinning (MAS) nuclear magnetic (NMR) spectroscopy, we have studied this cyanobacteriochrome (CBCR) assembled with phycocyanobilin (PCB) either in vivo or vitro. In both assembly routes, spectroscopic data Pr...
Melanoidins present in coffee silverskin, the only by-product of roasting process, are formed via Maillard reaction. The exact structure, biological properties, and mechanism action silverskin melanoidins, remain unknown. This research work aimed to contribute this novel knowledge. To achieve goal, melanoidins were obtained from an aqueous extract Arabica (WO2013004873A1) was isolated through ultrafiltration (>10 kDa). isolation protocol optimized chemical composition high molecular...
Abstract Rhodopsins had long been considered non-fluorescent until a peculiar voltage-sensitive fluorescence was reported for archaerhodopsin-3 (Arch3) derivatives. These proteins named QuasArs have used imaging membrane voltage changes in cell cultures and small animals. However due to the low intensity, these constructs require use of much higher light intensity than other optogenetic tools. To develop next generation sensors, it is indispensable first understand molecular basis its...
Phytochromes constitute a class of photoreceptors that can be photoconverted between two stable states. The tetrapyrrole chromophore absorbs in the red spectral region and displays fluorescence maxima above 700 nm, albeit with low quantum yields. Because this wavelength is particularly advantageous for fluorescence-based deep tissue imaging, there strong interest to engineer phytochrome variants increased Such targeted design efforts would substantially benefit from deeper understanding...
Phytochromes are biological photoreceptors that can be reversibly photoconverted between a dark and photoactivated state. The underlying reaction sequences initiated by the photoisomerization of tetrapyrrole cofactor, which in plant cyanobacterial phytochromes phytochromobilin (PΦB) phycocyanobilin (PCB), respectively. transition two states represents an on/off-switch output module activating or deactivating downstream physiological processes. In addition, state, i.e., Pfr canonical...
Phytochromes are bimodal photoreceptors which, upon light absorption by the tetrapyrrole chromophore, can be converted between a red-absorbing state (Pr) and far-red-absorbing (Pfr). In bacterial phytochromes, either Pr or Pfr thermally stable states, thereby constituting classes of prototypical bathy respectively. this work, we have employed vibrational spectroscopies to elucidate origin thermal stability states in phytochromes. Here, present first detailed spectroscopic analysis RpBphP6...
Abstract Bacteriophytochromes are promising tools for tissue microscopy and imaging due to their fluorescence in the near-infrared region. These applications require optimization of originally low quantum yields via genetic engineering. Factors that favour over other non-radiative excited state decay channels yet poorly understood. In this work we employed resonance Raman spectroscopy analyse consequences multiple amino acid substitutions on iRFP713 benchmark protein. Two groups mutations...
Phytochromes are biological photoswitches that interconvert between two parent states (Pr and Pfr). The transformation is initiated by photoisomerization of the tetrapyrrole chromophore, followed a sequence chromophore protein structural changes. In last step, phytochrome-specific peptide segment (tongue) undergoes secondary structure change, which in prokaryotic phytochromes associated with (de)activation output module. focus this work Pfr-to-Pr photoconversion bathy bacteriophytochrome...
Phytochromes, found in plants, fungi, and bacteria, exploit light as a source of information to control physiological processes via photoswitching between two states different activity, i.e. red-absorbing Pr far-red-absorbing Pfr state. Depending on the relative stability dark, bacterial phytochromes are divided into prototypical bathy phytochromes, where stable state is Pfr, respectively. In this work we studied representatives these groups (prototypical Agp1 Agp2 from Agrobacterium fabrum)...
Abstract Phytochromes are red/far-red light sensing photoreceptors employing linear tetrapyrroles as chromophores, which covalently bound to a cysteine (Cys) residue in the chromophore-binding domain (CBD, composed of PAS and GAF domain). Recently, near-infrared (NIR) fluorescent proteins (FPs) engineered from bacterial phytochromes binding biliverdin IXα (BV), such iRFP series, have become invaluable probes for multicolor fluorescence microscopy vivo imaging. However, all current NIR FPs...
Bacteriophytochromes harboring a biliverdin IXα (BV) chromophore undergo photoinduced reaction cascades to switch between physiologically inactive and active states. Employing vibrational spectroscopic computational methods, we analyzed the role of propionic substituents BV in transformations parent states Pr Pfr prototypical (Agp1) bathy (Agp2) phytochromes from Agrobacterium fabrum. Both proteins form adducts with monoesters (BVM), esterified at side chain B (PsB) or C (PsC), but each...
Abstract Agp1 is a prototypical bacterial phytochrome from Agrobacterium fabrum harboring biliverdin cofactor which reversibly photoconverts between red‐light‐absorbing (Pr) and far‐red‐light‐absorbing (Pfr) states. The reaction mechanism involves the isomerization of bilin‐chromophore followed by large structural changes protein matrix that are coupled to protonation dynamics at chromophore binding site. Histidines His250 His280 participate in this process. Although three‐dimensional...