Salinibacter ruber ATCC ® BAA-605D-5™ Designation: Genomic DNA from Salinibacter ruber strain DSM 13855 TypeStrain=True Application:

Cellular lipid membranes can - and often do - support a transmembrane electric field, serving as biological capacitors that maintain a voltage difference between their two sides. It isnt hard to see why these voltage gradients matter; the electrical spiking of neurons gives rise to our thoughts and actions, and the voltage dynamics of cardiomyocytes keep our hearts beating. Studies of bioelectricity have historically relied on electrode-based techniques to perturb and measure membrane potential, but these techniques have inherent limitations. I present new optogenetic methods of studying membrane potential that will broaden the scope of electrophysiological investigations by complementing traditional approaches. I introduce the microbial rhodopsin Archaerhodopsin-3 (Arch), a transmembrane protein from Halorubrum sodomense. The fluorescence of Arch is a function of membrane potential, allowing it to serve as an optical voltage reporter. We use time-dependent pump-probe spectroscopy to ...

Cellular lipid membranes can - and often do - support a transmembrane electric field, serving as biological capacitors that maintain a voltage difference between their two sides. It isnt hard to see why these voltage gradients matter; the electrical spiking of neurons gives rise to our thoughts and actions, and the voltage dynamics of cardiomyocytes keep our hearts beating. Studies of bioelectricity have historically relied on electrode-based techniques to perturb and measure membrane potential, but these techniques have inherent limitations. I present new optogenetic methods of studying membrane potential that will broaden the scope of electrophysiological investigations by complementing traditional approaches. I introduce the microbial rhodopsin Archaerhodopsin-3 (Arch), a transmembrane protein from Halorubrum sodomense. The fluorescence of Arch is a function of membrane potential, allowing it to serve as an optical voltage reporter. We use time-dependent pump-probe spectroscopy to ...

SzR was first identified in Asgardarchaeota and is phylogenetically positioned between typical microbial rhodopsins and HeRs (Fig. 1). In this study, we showed that SzR is a new type of light-driven inward H+ pump (Fig. 2). XeR was previously reported as an inward H+ pump in the typical microbial rhodopsin family (9-11). Although the sequential homology between the two subfamilies is low (SzR1 and PoXeR show 15.7% identity and 42.6% similarity), the trimeric structure and the photocycle with a large M accumulation not accompanied by N and O intermediates of SzR are similar to those reported for XeR (9-11), despite a large phylogenetic distance between them. This suggests that XeR and SzR underwent convergent evolution at the molecular level to achieve the same biological function. The differences and similarities between SzR and XeR are listed in Fig. 6C. Asgardarchaeota contain not only SzRs but also typical microbial rhodopsins with a DTK motif in helix C and HeRs (8). Although the function of ...

Voltage imaging allows mapping of the membrane potential in living cells. Yet, current intensity-based imaging approaches are limited to relative membrane potential changes, missing important information conveyed by the absolute value of the membrane voltage. This challenge arises from various factors affecting the signal intensity, such as concentration, illumination intensity, and photobleaching. Here, we demonstrate electronic preresonance hyperspectral stimulated Raman scattering (EPR-hSRS) for spectroscopic detection of the membrane voltage using a near-infrared-absorbing microbial rhodopsin expressed in E. coli. This newly developed near-infrared active microbial rhodopsin enables electronic preresonance SRS imaging at high sensitivity. By spectral profiling, we identified voltage-sensitive SRS peaks in the fingerprint region in single E. coli cells. These spectral signatures offer a new approach for quantitation of the absolute membrane voltage in living cells ...

Thirty years after the first description and modeling of G protein coupled receptors (GPCRs), information about their mode of action is still limited. One of the questions that is hard to answer is: how do the allosteric changes in the GPCR induced by, e.g., ligand binding in the end activate a G protein-dependent intracellular pathway (e.g., via the cAMP or the phosphatidylinositol signal pathways). Another question relates to the role of prenylation of G proteins. Todays

Terpenoids, also known as isoprenoids, are a large class of natural products consisting of isoprene (C5) units. There are two biosynthetic pathways, the mevalonate pathway [MD:M00095] and the non-mevalonate pathway or the MEP/DOXP pathway [MD:M00096], for the terpenoid building blocks: isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). The action of prenyltransferases then generates higher-order building blocks: geranyl diphosphate (GPP), farsenyl diphosphate (FPP), and geranylgeranyl diphosphate (GGPP), which are the precursors of monoterpenoids (C10), sesquiterpenoids (C15), and diterpenoids (C20), respectively. Condensation of these building blocks gives rise to the precursors of sterols (C30) and carotenoids (C40). The MEP/DOXP pathway is absent in higher animals and fungi, but in green plants the MEP/DOXP and mevalonate pathways co-exist in separate cellular compartments. The MEP/DOXP pathway, operating in the plastids, is responsible for the formation of essential oil ...

Biological light-driven proton pumps use light to move protons across a cell membrane, creating a proton gradient. Although photochromic compounds such as spiropyrans can reversibly convert between two structures with differing pKa values, spiropyrans have not been used to generate either a light-driven proton pump or an electrical current. Here, we report an artificial light-harvesting system based on a supported liquid membrane doped with a spiropyran. Irradiating the membrane with ultraviolet light induces a ring-opening reaction, converting spiropyran to merocyanine, whereas irradiation with visible light induces the reverse reaction. When the membrane is irradiated with ultraviolet and visible light on opposite sides, H+ is taken up by merocyanine, carried through the polymeric membrane and released on the other side. We show that this system produces a light-induced proton flux, an electrical current with an efficiency of ~0.12%, an open-circuit voltage of ~210 mV and a membrane gradient of ~3.6

The introduction of two microbial opsin-based tools, channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR), to neuroscience has generated interest in fast, multimodal, cell type-specific neural circuit control. Here we describe a cation-conducting channelrhodopsin (VChR1) from Volvox carteri that can drive spiking at 589 nm, with excitation maximum red-shifted approximately 70 nm compared with ChR2. These results demonstrate fast photostimulation with yellow light, thereby defining a functionally distinct third category of microbial rhodopsin proteins ...

First optogenetic experiments were performed in the lab of Gero Miesenböck (University of Oxford), who transferred the photosensory protein cascade from the eye of the fruitfly Drosophila to mammalian neurons and could evoke activity upon light application (Zemelman et al. 2002). These experiments, while somewhat complicated and too slow to trigger neurons at meaningful timescales, sparked an interest in similar approaches. Around the same time, a photopharmacological approach was promoted by Isacoff, Trauner and Kramer: They first used untethered inhibitors of ion channels, which were photoswitchable from inactive to active conformations, in order to trigger neuronal activity; later these chemical photoswitches were tethered to modified channels, thereby achieving genetic addressability (Banghart et al. 2004; Szobota et al. 2007). The most successful and widely used optogenetic tools, i.e. the microbial rhodopsins, have their origins in Germany. In 2002 and 2003, Nagel, Hegemann and ...

CEF Focus Project Symposium Part I ‐ Current CEF Focus Projects 9:00 Welcome and introduction - Volker Dötsch 9:05 Structural and functional remodeling of mitochorndria during permeability transition Ulrich Brandt, Werner Kühlbrandt, Ina Koch, Heinz Osiewacz & Stefan Dörse 9:35 Ubiquitin modifications as key signaling hubs for the regulation of survival and of cell death pathways Ivan Dikic, Volker Dötsch, Simone Fulda, Mike Heilemann & Ina Koch 10:05 Dynamics of RNA and RNP distribution in cells Erin Schuman, Alexander Heckel & Thomas Deller 10:35 Coupling microbial rhodopsins with intrinsic ion channels Alexander Gottschalk, Ernst Bamberg, Clemens Glaubitz, Thomas Prisner & Josef Wachtveitl 11:05 coffee break Part II ‐ Proposals for new CEF Focus Projects ...

Graphical view by InterProScan indicates a graphical display of the arrangment of the predicted domains by InterProScan.. show/hide icon is a toggle switch to show or hide the graphical display.. PNG icon indicates the link of the PNG file of the graphical display. Table view by InterProScan indicates the summary table of the InterProScan prediction. Each InterPro ID indicates the link to the InterPro entry. [S] links to the list of genes which predicted the InterPro ID (Gloeobacter species-wise prediction). [D] links to the list of genes which predicted the InterPro ID (cyanobase dataset-wise prediction). GO terms indicate the link to the GO entry. show/hide icon is a toggle switchto show or hide the table.. TableView icon indicates the link of the table page.. GFF3 icon indicates the link of the GFF file of the InterProScan prediction. Transmembrane regions predicted by SOSUI indicates the SOSUI predicted regions. Go SOSUI bottun link to the SOSUI prediction. ...

A group of microbial retinal proteins most closely related to the proton pump xanthorhodopsin has a novel sequence motif and a novel function. Instead of, or in addition to, proton transport, they perform light-driven sodium ion transport, as reported for one representative of this group (KR2) from Krokinobacter. In this paper, we examine a similar protein, GLR from Gillisia limnaea, expressed in Escherichia coli, which shares some properties with KR2 but transports only Na(+). The absorption spectrum of GLR is insensitive to Na(+) at concentrations of ≤3 M. However, very low concentrations of Na(+) cause profound differences in the decay and rise time of photocycle intermediates, consistent with a switch from a Na(+)-independent to a Na(+)-dependent photocycle (or photocycle branch) at ∼60 μM Na(+). The rates of photocycle steps in the latter, but not the former, are linearly dependent on Na(+) concentration. This suggests that a high-affinity Na(+) binding site is created transiently ...

Gloeobacter violaceus ATCC ® 29082D-5™ Designation: Genomic DNA from Gloeobacter violaceus strain PCC 7421 TypeStrain=False Application:

Light-gated rhodopsin cation channels from chlorophyte algae have transformed neuroscience research through their use as membrane-depolarizing optogenetic tools for targeted photoactivation of neuron firing. Photosuppression of neuronal action potentials has been limited by the lack of equally efficient tools for membrane hyperpolarization. We describe Anion Channel Rhodopsins (ACRs), a family of light-gated anion channels from cryptophyte algae that provide highly sensitive and efficient membrane hyperpolarization and neuronal silencing through light-gated chloride conduction. ACRs strictly conducted anions, completely excluding protons and larger cations, and hyperpolarized the membrane of cultured animal cells with much faster kinetics at less than one-thousandth of the light intensity than required by the most efficient currently available optogenetic proteins. Natural ACRs provide optogenetic inhibition tools with unprecedented light sensitivity and temporal precision. ...

Cyanobacteria are an ancient group of photosynthetic prokaryotes, which are significant in biogeochemical cycles. The most primitive among living cyanobacteria, Gloeobacter violaceus, shows a unique ancestral cell organization with a complete absence of inner membranes (thylakoids) and an uncommon structure of the photosynthetic apparatus. Numerous phylogenetic papers proved its basal position among all of the organisms and organelles capable of plant-like photosynthesis (i.e., cyanobacteria, chloroplasts of algae and plants). Hence, G. violaceus has become one of the key species in evolutionary study of photosynthetic life. It also numbers among the most widely used organisms in experimental photosynthesis research. Except for a few related culture isolates, there has been little data on the actual biology of Gloeobacter, being relegated to an evolutionary curiosity with an enigmatic identity. Here we show that members of the genus Gloeobacter probably are common rock-dwelling cyanobacteria. On the

Microbial rhodopsins and G-protein coupled receptors (GPCRs, which include animal rhodopsins) are two distinct (super) families of heptahelical (7TM) membrane proteins that share obvious structural similarities but no significant sequence similarity. Comparison of the recently solved high-resolution structures of the sodium-translocating bacterial rhodopsin and various Na+-binding GPCRs revealed striking similarity of their sodium-binding sites. This similarity allowed us to construct a structure-guided sequence alignment for the two (super)families, which highlighted their evolutionary relatedness. Our analysis supports a common underlying molecular mechanism for both families that involves a highly conserved aromatic residue playing a pivotal role in rotation of the 6th transmembrane helix. This article was reviewed by Oded Beja, G. P. S. Raghava and L. Aravind.

Altschul S. F., W. Gish, W. Miller, E. W. Myers and D. J. Lipman. 1990. Basic local alignment search tool. J. Mol. Biol. 215:3389-3402. [PubMED]. Anton J., E. Llobet-Brossa, F. Rodríguez-Valera and R. I. Amann. 1999. Fluorescence in situ hybridization analysis of the prokaryotic community inhabiting crystallizer ponds. Environ. Microbiol. 1:517-523. [PubMED]. Anton J., R. Rosselló-Mora, F. Rodríguez-Valera and R. Amann. 2000. Extremely halophilic Bacteria in crystallizer ponds from solar salterns. Appl. Environ. Microbiol. 66:3052-3057. [PubMED]. Anton J., A. Pena, F. Santos, M. Martinez-Garcia, P. Schmitt-Kopplin and R. Rossello-Mora. 2008. Distribution, abundance and diversity of the extremely halophilic bacterium. Salinibacter ruber. Saline Systems. 4:15. [PubMED]. Baati H., S. Guermazi, R. Amdouni, N. Gharsallah, A. Sghir and E. Ammar. 2008. Prokaryotic diversity of a Tunisian multipond solar saltern. Extremophiles. 12:505-518. [PubMED]. Benlloch S., A. López-López, E. O. Casamayor, L. ...

Detail záznamu - Carotenoid response to retinal excitation and photoisomerization dynamics in xanthorhodopsin - Detail záznamu - Knihovna Akademie věd České republiky

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Channelrhodopsins, the directly light‐gated ion channels from green algae, provide a powerful tool for basic research in neuroscience as well as potential applications for treating neurological diseases and disorders

Bacterial rhodopsins [1,2,3] are a family of retinal-containing proteins found in extremely halophilic bacteria which provide light-dependent ion transport and sensory functions for these organisms. Bacterial rhodopsins are integral membrane proteins with seven transmembrane regions. The retinal choromophore is covalently linked, via a Schiffs base, to the epsilon-amino group of a conserved lysine residue in the middle of the last transmembrane helix (called helix G). There are at least three types of bacterial rhodopsins: ...

A study conducted by Steiger et al., 2005, revealed that Gloeobacter violaceus is a cyanobacterium isolated from other groups by lack of thylakoids and unique structural features of its photosynthetic protein complexes. They investigated carotenoid biosynthesis with respect to the carotenoids formed and the genes and enzymes involved. Their carotenoid analysis identified ss-carotene as major carotenoid and echinenone as a minor component. This composition is quite unique and the cellular amounts are up to 10-fold lower than in other unicellular cyanobacteria. Also, carotenoid biosynthesis was also found to be up-regulated in a light-dependent manner. This enhanced biosynthesis partially compensates for photooxidation especially of ss-carotene. They also sequenced the genome of Gloeobacter violaceus and analyzed several gene candidates homologous to carotenogenic genes from other organisms obtained. Functional expression of all candidates and complementation in Escherichia coli led to the ...

Visual rhodopsins in vertebrates undergo irreversible structural changes leading to a loss of the chromophore (bleaching) when triggered by light, whereas microbial rhodopsins undergo a series of cyclic changes comprising a photocycle, eventually returning back to their initial state. The photocycle can take anywhere from milliseconds to several seconds, depending on the type of rhodopsin.. The physiological functions of rhodopsins vary widely. Visual rhodopsins found in the rod and cone cells of your eyes function as the primary light receptors in vision due to their role in activating G-proteins, which through a biochemical cascade control cyclic-nucleotide regulated ion channels. Light signaling rhodopsins called sensory rhodopsins are also present in microbes. For example, sensory rhodopsins I and II initiate either negative or positive phototaxis, signaling the cell to move away from or towards a light source depending on its wavelength. In this case sensory rhodopsins activate transducer ...

Rhodopsins are broadly distributed. In this work, we analyzed 23 metagenomes corresponding to marine sediment samples from four regions that share cold climate conditions (Norway; Sweden; Argentina and Antarctica). In order to investigate the genes evolution of viral rhodopsins, an initial set of 6224 bacterial rhodopsin sequences according to COG5524 were retrieved from the 23 metagenomes. After selection by the presence of transmembrane domains and alignment, 123 viral (51) and non-viral (72) sequences (>50 amino acids) were finally included in further analysis. Viral rhodopsin genes were homologs of Phaeocystis globosa virus and Organic lake Phycodnavirus. Non-viral microbial rhodopsin genes were ascribed to Bacteroidetes, Planctomycetes, Firmicutes, Actinobacteria, Cyanobacteria, Proteobacteria, Deinococcus-Thermus and Cryptophyta and Fungi. A rescreening using Blastp, using as queries the viral sequences previously described, retrieved 30 sequences (>100 amino acids). Phylogeographic ...

The aerial surface of plants, the phyllosphere, is colonized by numerous bacteria displaying diverse metabolic properties that enable their survival in this specific habitat. Recently, we reported on the presence of microbial rhodopsin harbouring bacteria on the top of leaf surfaces. Here, we report on the presence of additional bacterial populations capable of harvesting light as a means of supplementing their metabolic requirements. An analysis of six phyllosphere metagenomes revealed the presence of a diverse community of anoxygenic phototrophic bacteria, including the previously reported methylobacteria, as well as other known and unknown phototrophs. The presence of anoxygenic phototrophic bacteria was also confirmed in situ by infrared epifluorescence microscopy. The microscopic enumeration correlated with estimates based on metagenomic analyses, confirming both the presence and high abundance of these microorganisms in the phyllosphere. Our data suggest that the phyllosphere contains a ...

Our results show that, upon use of the psbA2 promoter, bacterial rhodopsins (PR or GR) are expressed in Synechocystis, at a level of up to 105 molecules per cell, presumably as pentamers and trimers, respectively, with approximately equal distribution (on a protein-content basis) over the thylakoid and the cytoplasmic membrane fraction. Functional assays have revealed that PR but not GR can enhance the growth rate of Synechocystis and its ΔPSI derivative strain. Notably, the stimulatory effect is most significant in the ΔPSI strain. Moreover, our results confirm that Synechocystis sp. PCC 6803 has the capacity to synthesize all-trans-retinal, thereby making use of the SynACO enzyme (encoded by sll1541). By supplying a red-shifted retinal analogue to a sll1541-knockout mutant we could show that an infrared-absorbing PR derivative is formed in Synechocystis ...

Sigma-Aldrich offers abstracts and full-text articles by [Aharon Oren, Said Abu-Ghosh, Tal Argov, Eliahu Kara-Ivanov, Dror Shitrit, Adi Volpert, Rael Horwitz].

Optical silencing of activity provides a way to test the necessity of neurons in behaviour. Two light-gated anion channels, GtACR1 and GtACR2, have recently been shown to potently inhibit activity in cultured mammalian neurons and in Drosophila. Here, we test the usefulness of these channels in larval zebrafish, using spontaneous coiling behaviour as the assay. When the GtACRs were expressed in spinal neurons of embryonic zebrafish and actuated with blue or green light, spontaneous movement was inhibited. In GtACR1-expressing fish, only 3 μW/mm2 of light was sufficient to have an effect; GtACR2, which is poorly trafficked, required slightly stronger illumination. No inhibition was seen in non-expressing siblings. After light offset, the movement of GtACR-expressing fish increased, which suggested that termination of light-induced neural inhibition may lead to activation. Consistent with this, two-photon imaging of spinal neurons showed that blue light inhibited spontaneous activity in spinal neurons of

The invention, in some aspects relates to compositions and methods for altering cell activity and function and the introduction and use of light-activated ion channels.

Proteorhodopsin (PR), a ubiquitous membrane photoprotein in marine environments, acts as a light-driven proton pump and can provide energy for bacterial cellular metabolism. However, knowledge of factors that regulate PR gene expression in different bacteria remains strongly limited. Here, experiments with Vibrio sp. AND4 showed that PR phototrophy promoted survival only in cells from stationary phase and not in actively growing cells. PR gene expression was tightly regulated, with very low values in exponential phase, a pronounced peak at the exponential/stationary phase intersection, and a marked decline in stationary phase. Thus, PR gene expression at the entry into stationary phase preceded, and could therefore largely explain, the stationary phase light-induced survival response in AND4. Further experiments revealed nutrient limitation, not light exposure, regulated this differential PR expression. Screening of available marine vibrios showed that the PR gene, and thus the potential for PR ...

is a microbial-type rhodopsin. Its specific characteristic is that it functions as a light-driven cation-selective channel. It has been reported that the channelrhodopsin-2 transforms inner light-insensitive retinal neurons to light-sensitive neurons. Herein, we introduce new strategies for restoring vision by using channelrhodopsins and discuss the properties of adeno-associated virus vectors widely used in gene therapy.. ...

There is growing evidence that loss of mitochondrial function is closely associated with the development of various human maladies such as cardiovascular diseas...

Description: Desoxymethyltestosterone (DMT) is a 17aa steroid with equal toxicity as other 17aa oral steroids. While nearly all anabolic steroid molecules have a 3-keto group, Desoxymethyltestosterone lacks it, and has a 2-ene structure. This...

Ketoses are the isomers of aldoses except that, with very few exceptions, the keto group appears at position 2. As a result, there is one less asymmetric center than in an aldose with the same number of carbons.. ...

Plasmid pAAV-EF1a-double floxed-hChR2(H134R)-EYFP-WPRE-HGHpA from Dr. Karl Deisseroths lab contains the insert channelrhodopsin-2. This plasmid is available through Addgene.

Gloeobacter violaceus sp. PCC 7421 is an unusual cyanobacterium with only one cellular membrane, which lacks the thylakoid membranes found in other oxygenic photosynthetic organisms. The cell membrane lipids in G. violaceus sp. PCC 7421 are monogalactosyl diacylglycerol, digalactosyl diacylglycerol, phosphatidyl glycerol and phosphatidic acid in the molar proportion of 51, 24, 18 and 4% respectively. This lipid composition resembles that of the cell membrane from other cyanobacteria, but completely lacks sulfoquinovosyl diacylglycerol. This lack of sulfoquinovosyl diacylglycerol is exceptional for a photosynthetic membrane. The membrane lipids are esterified to 14:0, 16:0, 16:1, 18:0, 18:1, 18:2 and alpha 18:3 fatty acids.. ...

PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.

Synthetic biology is a highly interdisciplinary field, which combines biology, chemistry and physics with engineering. Its goal is to design molecular factories and synthetic cells with novel properties or functions for applications in healthcare, industry, or biological and medical research. Such artificial systems are in the nanometer scale and are built by combining and assembling existing, synthetic or engineered building blocks (e.g., proteins). Molecular systems have wide application ranges, e.g., for chemical compound synthesis, waste disposal, energy supply and medical diagnosis or treatment.. In this context, the NCCR Molecular Systems Engineering brings Swiss scientists from different disciplines together to stimulate innovation, and address existing and future challenges. The University of Bern is represented by the Fotiadis laboratory in the NCCR MSE.. Nanomachines for energy conversion. Energy-providing building blocks are essential to power molecular systems. Light-driven proton ...

Participants: 1) Peter Hegemann (PI; Humboldt University Berlin), coworker 2) Benjamin Rost (PI; Charité, Berlin), coworker: Abstract: Development and Application of New Optogenetic Tools Targeted to Intracellular Compartments The aim of our proposed work program is the development of novel optogenetic tools that allow investigations on subcellular compartments. We will combine optogenetic actuators and sensors with targeting motives for synaptic vesicles (SV) or lysosomes. The strategy will be based on our recently published work on optogenetic acidification of SV and lysosomes by organelle-specific expression of the light-driven proton pump Arch3. In order to achieve acute depletion of protons from SV and lysosomes we will use a proton channel derived from Arch3, which has been recently developed by the Hegemann lab by point-directed mutagenesis. For the manipulation of luminal chloride we will implement chloride-conductive channelrhodopsins or light-driven chloride pumps. The tetraspanin ...

A group of microbial retinal proteins most closely related to the proton pump xanthorhodopsin has a novel sequence motif and a novel function. Instead of, or in addition to, proton transport, they perform light-driven sodium ion transport, as reported for one representative of this group (KR2) from Krokinobacter. In this paper, we examine a similar protein, GLR from Gillisia limnaea, expressed in Escherichia coli, which shares some properties with KR2 but transports only Na +. The absorption spectrum of GLR is insensitive to Na + at concentrations of ≤3 M. However, very low concentrations of Na + cause profound differences in the decay and rise time of photocycle intermediates, consistent with a switch from a Na +-independent to a Na +-dependent photocycle (or photocycle branch) at ~60 μM Na +. The rates of photocycle steps in the latter, but not the former, are linearly dependent on Na + concentration. This suggests that a high-affinity Na + binding site is created transiently after ...

a.Gram-positive bacteria have a single cell wall formed from peptidoglycan. Anabaena, genus of nitrogen-fixing blue-green algae with beadlike or barrel-like cells and interspersed enlarged spores (heterocysts), found as plankton in shallow water and on moist soil. Gloeobacter violaceus is a rod-shape unicellular cyanobacterium that has been isolated from calcareous rocks in Switzerland [3]. A. bacteria and fungi ... D. bacteria and archaea. Thats right most cyanobacteria are gram negative. This makes them easy to identify. Cyanobacteria are the prokaryotic and gram-negative bacteria. into both cell halves, which in many bacteria is achieved by an active machinery that operates during DNA replication. Humans use of prokaryotes : This is a microscopic image of Bacillus subtilis (ATCC 6633) with a gram staining of magnification: 1,000. Cyanobacteria are among the easiest microfossils to recognize. During each cell cycle, chromosomes must be separated into future daughter cells, i.e. ... ...

RADIATION CURABLE INK COMPOSITION - A radiation curable ink composition has improved adhesion towards rigid recording media, good jetting behaviour and no or minimal health and safety risks. The radiation curable ink has a viscosity of 30 mPa·s, or less, at 50° C., has at least two monofunctional monomers, the two monofunctional monomers including a first monomer selected from an N-vinyl amide and a second monofunctional monomer being isobornyl acrylate, a difunctional acrylate monomer being propoxylated (or ethoxylated) neopentyl glycol di acrylate (SR 9003), at least one multifunctional monomer selected from the group consisting of a trifunctional acrylate monomer, a tetrafunctional acrylate monomer, a pentafunctional acrylate monomer, a trifunctional epoxide monomer, a tetrafunctional epoxide monomer, a pentafunctional epoxide monomer, a trifunctional oxetane monomer, a tetrafunctional oxetane monomer, a pentafunctional oxetane monomer, a trifunctional vinylether monomer, a tetrafunctional ...

The first half of this study focused on investigating the feasibility of introducing the optogenetic constructs Channelrhodopsin-2 (ChR2) and Halorhodopsin (eNpHR) into ARPE-19, an epithelial cell line derived from the human eye and routinely employed as an in vitro model of the RPE. Different approaches for the delivery of these opsin genes to the cells were evaluated and transfection was optimised both for ChR2 and eNpHR, following which the functionality of the channels, i.e. their ability to respond to light stimuli and drive the permeable ions through the membrane of the epithelial cells, was assessed. Activity of the optogenetic proteins was confirmed by the use of ion-sensitive fluorophores, in the case of ChR2 the calcium-sensitive Fura-2. Preliminary experiments performed using wild-type ChR2 (wtChR2), did not evidence major membrane ion permeability changes upon light exposure, as evaluated by calcium imaging. To overcome limitations of wtChR2, which is characterised by low channel ...

Monosaccharides are simple sugars with only one sachharide unit. These cannot be hydrolysed into simpler forms. A monosaccharide containing an aldehydic group (-CHO) in its molecule is called aldose. The glucose and galactose are aldoses. A monosaccharide which contains a keto group (| C = O) in its molecule is called ketose. Fructose is a ketose.

In addition to inversion of the stereochemistry of the 15S-hydroxyl group of PGD2, various other modifications of the substituents at C15 of PGD2 have little effect on DP2-mediated responses. For example, oxidation of the hydroxyl group to a keto group, as in 13,14-dihydro-15-keto-PGD2, only slightly reduces DP2 agonist activity but completely abolishes DP1 agonist activity (Gervais et al., 2001; Hirai et al., 2001; Monneret et al., 2001). Likewise, removal of the 15-hydroxyl group coupled with the addition of a double bond to the alkyl side chain of PGD2 (15-deoxy-Δ12,14-PGD2) does not affect DP2 activity (Monneret et al., 2002) but dramatically reduces DP1-mediated responses (Bundy et al., 1983). As noted above, inversion of the stereochemistry at C15 coupled with addition of a methyl group increases potency at the DP2 receptor and nearly completely eliminates it at the DP1 receptor (Monneret et al., 2003). These findings might be interpreted to suggest that the alkyl side chain of PGD2 does ...

PatriciaIzquierdo DelgadoOptometrista Equipo de la Dra. Isabel Garabito Cociña Especialidad: Oftalmología Especialidades: Optometrista 91 387 52 76 Hosp...

By Tim Stephens. Optogenetics techniques, which allow scientists to map and control nerve cells using light stimulation, are being used to study neural circuits in the brain with unprecedented precision. This revolutionary technology relies on light-sensitive proteins such as channelrhodopsins, and researchers at UC Santa Cruz have now determined the molecular mechanism involved in the light-induced activation of one of these proteins.. Little was known about the functional mechanism of these proteins even though they are widely used in optogenetics, Kliger said.. The researchers used fast laser spectroscopy to study the function of Channelrhodopsin-2, which is found in a type of marine algae and is widely used in optogenetics experiments. Channelrhodopsins are ion channels that control the flow of ions across cell membranes. There are many kinds of ion channels that serve different purposes in different types of cells. Nerve signals involve ion flow across the membranes of nerve cells, and ...

Rhodopsins are the major photopigments in the fruit fly Drosophila melanogaster. Drosophila express six well-characterized Rhodopsins (Rh1-Rh6) with distinct absorption maxima and expression pattern. In 2000, when the Drosophila genome was published, a novel Rhodopsin gene was discovered: Rhodopsin 7 (Rh7). Rh7 is highly conserved among the Drosophila genus and is also found in other arthropods. Phylogenetic trees based on protein sequences suggest that the seven Drosophila Rhodopsins cluster in three different groups. While Rh1, Rh2 and Rh6 form a

Chemical exchange of hydrogen atoms is the basis for many biological processes, including energy conversion from light into chemical potentials. In a recent collaborative study of the SFB 1078 under the direction of Hartmut Oschkinat (B1), Peter Hegemann (B1, B2) and Roland R. Netz (C1), proton exchange was detected and characterized in the light-driven proton pump bacteriorhodopsin, a well-established model system for protonation dynamics studies. The work, published in the new open access journal Communications Biology of the Nature Publishing Group, revealed that reversible proton translocation occurs even in the dark-state of the protein, involving the retinal Schiff base and D85 exchanging protons with H2O. The authors find evidence of an active site proton cage and possible proton transfer via R82. The experimental observations have been corroborated by theoretical approaches, further extending the general understanding of proton exchange in proteins.. Friedrich, D., Brünig, F. N., ...

MAcrolides can differ in their macrocyclic ring (modified to create clarithromycin (Biaxin©) and azithromycin (Zithromax©) with improved pharmacokinetic properties) and sugars. For telithromycin (Ketek®), the sugar at the 3-position was removed and replaced with a keto group - hence the class name of ketolides - and an additional modification allowed for binding to a secondary site on the bacterial ribosome, resulting in enhanced activity against resistant strains. ...

R-COOHH- J? -CHzCOOH. (By dfav^e OiCt-C^wif). +. R-CHzCOOH +R -COOH. (j5T ■: lMV15* of Cj - Cjiw*J). In case of unsymmetrical ketones cleavage occurs in such a way that keto group stays with ...

Channelrhodopsin-2 (ChR2) has quickly gained popularity as a powerful tool for eliciting genetically targeted neuronal activation. However, little has been reported on the response kinetics of optogenetic stimulation across different neuronal subtypes. With excess stimulation, neurons can be driven …

The vivid colours make Centranthus ruber welcome in all but the most snobbish of town gardens, until it gets too invasive. But the classic location is on the outside of garden walls. Throughout the summer the plants narrow the streets on both sides, leaning inwards like arsenals of soft weaponry drawn up for a massacre of love. Then masses of fluffy seeds get blown into stony crevices and develop into even more of these tough, vigorous plants ...

Download this stock image: centranthus ruber,red valerian - X9M2G5 from Alamys library of millions of high resolution stock photos, illustrations and vectors.

How we see things around us without noticing it! We know the peculiar habit of the sunflower. How it moves with the movement of the sun everyday. But if

ウサギ・ポリクローナル抗体 ab3424 交差種: Ms,Cow 適用: WB,IHC-Fr…Rhodopsin抗体一覧…画像、プロトコール、文献などWeb上の情報が満載のアブカムの Antibody 製品。国内在庫と品質保証制度も充実。