Read by QxMD icon Read


Steven D Schwartzbach
Euglena can use light and CO2, photosynthesis, as well as a large variety of organic molecules as the sole source of carbon and energy for growth. Light induces the enzymes, in this case an entire organelle, the chloroplast, that is required to use CO2 as the sole source of carbon and energy for growth. Ethanol, but not malate, inhibits the photoinduction of chloroplast enzymes and induces the synthesis of the glyoxylate cycle enzymes that comprise the unique metabolic pathway leading to two carbon, ethanol and acetate, assimilation...
2017: Advances in Experimental Medicine and Biology
Shai Berlin, Ehud Y Isacoff
Membrane receptors and ion channels respond to various stimuli and relay that information across the plasma membrane by triggering specific and timed processes. These include activation of second messengers, allowing ion permeation, and changing cellular excitability, to name a few. Gaining control over equivalent processes is essential to understand neuronal physiology and pathophysiology. Recently, new optical techniques have emerged proffering new remote means to control various functions of defined neuronal populations by light, dubbed optogenetics...
April 10, 2017: EMBO Reports
Alexander A Bulychev, Anna V Komarova
Chloroplasts in vivo exposed to strong light export assimilates and excess reducing power to the cytoplasm for metabolic conversions and allocation to neighboring and distant organelles. The cytoplasmic streaming, being particularly fast in characean internodes, distributes the exported metabolites from brightly illuminated cell spots to light-limited regions, which is evident from the transient increase in chlorophyll fluorescence of shaded areas in response to illumination of distant cell regions situated upstream the liquid flow...
February 28, 2017: Biochimica et Biophysica Acta
Yangyang Yang, Ryu Tashiro, Yuki Suzuki, Tomoko Emura, Kumi Hidaka, Hiroshi Sugiyama, Masayuki Endo
Various DNA-based nanodevices have been developed on the nanometer scale using light as regulation input. However, the programmed controllability is still a major challenge for these artificial nanodevices. Herein, we demonstrate a rotary DNA nanostructure in which the rotations are controlled by light. A bar-shaped DNA rotor, fabricated as a stiff double-crossover molecule, was placed on the top of a rectangular DNA tile. The photoresponsive oligonucleotides modified with azobenzenes were employed as switching motifs to release/trap the rotor at specific angular position on DNA tile by switching photoirradiations between ultraviolet and visible light...
February 15, 2017: Chemistry: a European Journal
Xavier Gómez-Santacana, Silvia Pittolo, Xavier Rovira, Marc Lopez, Charleine Zussy, James A R Dalton, Adèle Faucherre, Chris Jopling, Jean-Philippe Pin, Francisco Ciruela, Cyril Goudet, Jesús Giraldo, Pau Gorostiza, Amadeu Llebaria
Phenylazopyridines are photoisomerizable compounds with high potential to control biological functions with light. We have obtained a series of phenylazopyridines with light dependent activity as negative allosteric modulators (NAM) of metabotropic glutamate receptor subtype 5 (mGlu5). Here we describe the factors needed to achieve an operational molecular photoisomerization and its effective translation into in vitro and in vivo receptor photoswitching, which includes zebrafish larva motility and the regulation of the antinociceptive effects in mice...
January 25, 2017: ACS Central Science
Anouk S Lubbe, Wiktor Szymanski, Ben L Feringa
There is a growing interest in the photoregulation of biological functions, due to the high level of spatiotemporal precision achievable with light. Additionally, light is non-invasive and waste-free. In particular, the photoregulation of oligonucleotide structure and function is a rapidly developing study field with relevance to biological, physical and material sciences. Molecular photoswitches have been incorporated in oligonucleotides for 20 years, and the field has currently grown beyond fundamental studies on photochemistry of the switches and DNA duplex stability, and is moving towards applications in chemical biology, nanotechnology and material science...
February 20, 2017: Chemical Society Reviews
Arnaud Tron, Isabelle Pianet, Alberto Martinez-Cuezva, James H R Tucker, Luca Pisciottani, Mateo Alajarin, Jose Berna, Nathan D McClenaghan
A molecular barbiturate messenger, which is reversibly released/captured by a photoswitchable artificial molecular receptor, is shown to act as an effector to control ring gliding on a distant hydrogen-bonding [2]rotaxane. Thus, light-driven chemical communication governing the operation of a remote molecular machine is demonstrated using an information-rich neutral molecule.
December 9, 2016: Organic Letters
Giorgio Perrella, Eirini Kaiserli
Light is a powerful stimulus regulating many aspects of plant development and phenotypic plasticity. Plants sense light through the action of specialized photoreceptor protein families that absorb different wavelengths and intensities of light. Recent discoveries in the area of photobiology have uncovered photoreversible changes in nuclear organization correlated with transcriptional regulation patterns that lead to de-etiolation and photoacclimation. Novel signalling components bridging photoreceptor activation with chromatin remodelling and regulation of gene expression have been discovered...
December 2016: New Phytologist
Yarra Venkatesh, Y Rajesh, S Karthik, A C Chetan, Mahitosh Mandal, Avijit Jana, N D Pradeep Singh
A new fluorescent photoremovable protecting group (FPRPG) based on acetylcarbazole framework has been explored for the first time release of single and dual (similar or different) substrates from single chromophore. Mechanistic studies of the photorelease process revealed that photorelease of two (similar or different) substrates from acetyl carbazole proceeds via a stepwise pathway. Further, we constructed photoresponsive dual drug delivery system (DDS) to release two different anticancer drugs (caffeic acid and chlorambucil, 1 equiv each)...
November 18, 2016: Journal of Organic Chemistry
Sampurna Garai, Naveen Chandra Joshi, Baishnab C Tripathy
Uroporphyrinogen III methyl transferase (UPM1) and Sirohydrochlorin ferrochelatase (SIRB) are the important genes involved in the biosynthesis of siroheme, the prosthetic group of nitrite reductases (NiR) and sulfite reductases (SiR) involved in nitrogen and sulfur assimilation. Both UPM1 and SIRB could be potential candidate genes targeted for sustainable agriculture especially in N-deficient soil. The phylogenetic analysis revealed that these genes are highly conserved among algae, bryophytes and vascular plants including dicots and monocots...
July 2016: Physiology and Molecular Biology of Plants: An International Journal of Functional Plant Biology
Wiktor S Bourée, Mathieu S Prévot, Xavier A Jeanbourquin, Néstor Guijarro, Melissa Johnson, Florian Le Formal, Kevin Sivula
Tunable ambipolar photoelectrochemical behavior emerges from microdomains of nanostructured p-type CuFeO2 and n-type Fe2 O3 that arise from a single facile solution-processed thin film. The switchable operation of this system is controlled by chemical, optical, or electronic inputs with a uniquely high photocurrent response (on the order of 1 mA cm(-2) ), suitable for robust practical application as an oxygen photoregulator.
November 2016: Advanced Materials
A V Budagovsky, N V Solovykh, M B Yankovskaya, M V Maslova, O N Budagovskaya, I A Budagovsky
The effect of the statistical properties of light on the value of the photoinduced reaction of the biological objects, which differ in the morphological and physiological characteristics, the optical properties, and the size of cells, was studied. The fruit of apple trees, the pollen of cherries, the microcuttings of blackberries in vitro, and the spores and the mycelium of fungi were irradiated by quasimonochromatic light fluxes with identical energy parameters but different values of coherence length and radius of correlation...
July 2016: Physical Review. E
Lei Cheng, Yao Jiang, Ni Yan, Shu-Feng Shan, Xiao-Qin Liu, Lin-Bing Sun
Selective adsorption and efficient regeneration are two crucial issues for adsorption processes; unfortunately, only one of them instead of both is favored by traditional adsorbents with fixed pore orifices. Herein, we fabricated a new generation of smart adsorbents through grafting photoresponsive molecules, namely, 4-(3-triethoxysilylpropyl-ureido)azobenzene (AB-TPI), onto pore orifices of the support mesoporous silica. The azobenzene (AB) derivatives serve as the molecular gates of mesopores and are reversibly opened and closed upon light irradiation...
September 7, 2016: ACS Applied Materials & Interfaces
Theocharis T Nazos, Emmanouel J Kokarakis, Demetrios F Ghanotakis
In the present work, the biodegradation of phenol by axenic cultures of the unicellular microalga Chlamydomonas reinhardtii was investigated. Biodegradation proved to be a dynamic bioenergetic process, affected by changes in the culture conditions. Microalgae biodegraded defined amounts of phenol, as a result of the induced stress caused at high concentrations, despite the fact that this process proved to be energy demanding and thus affected growth of the culture. High levels of biodegradation were observed both in the absence of an alternative carbon source and in the presence of acetate as a carbon source...
January 2017: Photosynthesis Research
Yusuke Nakasone, Hideaki Ooi, Yukiko Kamiya, Hiroyuki Asanuma, Masahide Terazima
Photoresponsive DNA modified with azobenzene is an attractive design molecule for efficient photoregulation of DNA hybridization, which may be used for controlling DNA functions. Although the essential step of photocontrolling DNA is the initial isomerization of the azobenzene, the dissociation/association kinetics remain unknown. Here, the time-resolved diffusion method was used to trace the dissociation/association processes of photoresponsive DNA. Although the isomerization of azobenzene occurs in picoseconds, the dissociation of the double-stranded DNA to single-stranded DNA triggered by the trans to cis isomerization takes place ∼10(7) times slower, with a time constant of 670 μs at 200 μM...
July 27, 2016: Journal of the American Chemical Society
Per J Hansen, Karin Ojamäe, Terje Berge, Erik C L Trampe, Lasse T Nielsen, Inga Lips, Michael Kühl
Some phagotrophic organisms can retain chloroplasts of their photosynthetic prey as so-called kleptochloroplasts and maintain their function for shorter or longer periods of time. Here we show for the first time that the dinoflagellate Dinophysis acuta takes control over "third-hand" chloroplasts obtained from its ciliate prey Mesodinium spp. that originally ingested the cryptophyte chloroplasts. With its kleptochloroplasts, D. acuta can synthesize photosynthetic as well as photoprotective pigments under long-term starvation in the light...
2016: Frontiers in Microbiology
Ammathnadu S Amrutha, K R Sunil Kumar, Kazuya Matsuo, Nobuyuki Tamaoki
Recently we demonstrated the photoregulation of the activity of kinesin-1 using an azobenzene-tethered peptide (azo-peptide: Azo-Ile-Pro-Lys-Ala-Ile-Gln-Ala-Ser-His-Gly-Arg-OH). To understand the mechanism behind this photoswitchable inhibition, here we studied the structure-property relationships of a range of azo-peptides through systematic variations in the structures of the peptide and azobenzene units. The vital peptide sequence for kinesin inhibition-mediated through electrostatic, hydrophobic and C-Hπ interactions-was the same as that for the self-inhibition of kinesin...
July 26, 2016: Organic & Biomolecular Chemistry
Xiaojie Lin, Kyoko Fukazawa, Kazuhiko Ishihara
UNLABELLED: Nile blue (NB)-tagged DNA helix-targeting amphiphilic photoreactive 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, poly(MPC-co-3-methacryloyloxy-2-hydroxypropyl-4-oxybenzophenone-co-2-trimethylammonium ethyl methacrylate chloride) (PMHT-NB), containing a cationic group to facilitate cell membrane penetration and a benzophenone (BP) group to promote photoinduced conjugation with DNA helix was synthesized using radical polymerization method. Ultraviolet light (UV)-visible light absorption spectra of PMHT-NB showed absorption peaks at wavelengths 254, 289, and 600nm, suggesting successful incorporation of BP and NB groups...
August 2016: Acta Biomaterialia
Karl Gruber, Bernhard Kräutler
Old cofactor, new tricks: In enzymes, coenzyme B12 has a well-known function as a radical initiator through homolysis of the Co-C bond. It has recently been shown that nature has repurposed this cofactor as a photosensitive switch for the regulation of bacterial carotenoid biosynthesis. Co-C bond breakage is again the key event in this process, triggering huge conformational changes in the B12 -binding protein.
May 4, 2016: Angewandte Chemie
Shinzi Ogasawara
Several methods for controlling gene expression by light illumination have been reported. Most of these methods control transcription by regulating the interaction between DNA and transcription factors. The use of a photolabile protecting compound (cage compound) is another promising approach for controlling gene expression, although typically in an irreversible manner. We here describe a new approach for reversibly controlling translation using a photoresponsive 8-styryl cap (8ST-cap) that can be reversibly isomerized by illumination with light of a specific wavelength...
2016: Methods in Molecular Biology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"