Single mutation in a novel bacterial LOV protein yields a singlet oxygen generator.

Mr4511 from Methylobacterium radiotolerans is a 164 amino acid protein built of a flavin mononucleotide (FMN) binding, blue-light responsive LOV (Light, Oxygen, Voltage) core domain plus flanking regions. In contrast to the majority of LOV domains, Mr4511 lacks a tryptophan residue that was previously identified as a major quencher for the FMN triplet state in photosensitizers for singlet oxygen (SO) engineered from these photoreceptors. Here we show that for Mr4511 it is sufficient to only mutate the reactive cysteine responsible for the photocycle (Cys71) in the native protein to generate an efficient SO photosensitizer: both C71S and C71G variants exhibit SO quantum yields of formation, Φ, around 0.

Hexamethoxymethylmelamine - A precursor of persistent and mobile contaminants in municipal wastewater and the water cycle.

Hexamethoxymethylmelamine (HMMM) is a crosslinker of melamine resins and widely used in the production of coatings and plastics, e.g. for cans, coils and automobiles.

Relationship between Discharge and River Plastic Concentrations in a Rural and an Urban Catchment.

Rivers play a major role in the transport of plastic debris from inland sources such as urban areas into the marine environment. The present study examined plastic particle concentrations and loads (>500 μm) upstream and downstream of an urban subcatchment over 15 months and investigated the relationship between river water discharge () and plastic concentration (). The plastic particle concentration increases by 0.

Improved Intestinal Mucus Permeation of Vancomycin via Incorporation Into Nanocarrier Containing Papain-Palmitate.

The aim of this study was to improve intestinal mucus permeation of a peptide antibiotic via incorporation into papain-palmitate-modified self-emulsifying drug delivery systems (SEDDS) as nanocarrier. Vancomycin as a peptide antibiotic was lipidized by hydrophobic ion pair formation using sodium bis-2-ethylhexyl-sulphosuccinate before incorporation in SEDDS comprising Capmul MCM, propylenglycol, and Kolliphor EL (2:1:2). As mucolytic agent, 0.

NMR-Based Metabolic Profiles of Intact Zebrafish Embryos Exposed to Aflatoxin B1 Recapitulates Hepatotoxicity and Supports Possible Neurotoxicity.

Aflatoxin B1 (AFB1) is a widespread contaminant of grains and other agricultural crops and is globally associated with both acute toxicity and carcinogenicity. In the present study, we utilized nuclear magnetic resonance (NMR), and specifically high-resolution magic angle spin (HRMAS) NMR, coupled to the zebrafish () embryo toxicological model, to characterize metabolic profiles associated with exposure to AFB1. Exposure to AFB1 was associated with dose-dependent acute toxicity (i.

Deactivation of redox mediators in lithium-oxygen batteries by singlet oxygen.

Non-aqueous lithium-oxygen batteries cycle by forming lithium peroxide during discharge and oxidizing it during recharge. The significant problem of oxidizing the solid insulating lithium peroxide can greatly be facilitated by incorporating redox mediators that shuttle electron-holes between the porous substrate and lithium peroxide. Redox mediator stability is thus key for energy efficiency, reversibility, and cycle life.

Analysis of Food by High Performance Liquid Chromatography Coupled with Coulometric Detection and Related Techniques: A Review.

The development of single coulometric cells in combination with high performance liquid chromatography to dual cells and to the coulometric electrode array detector is described. An overview is given about the application of these methods in food chemistry. Easily oxidizable compounds, such as phenolic substances, pesticides, or vitamins, can be determined, as well as substances with high oxidation potentials or electroinactive compounds.

DABCOnium: An Efficient and High-Voltage Stable Singlet Oxygen Quencher for Metal-O Cells.

Singlet oxygen ( O ) causes a major fraction of the parasitic chemistry during the cycling of non-aqueous alkali metal-O batteries and also contributes to interfacial reactivity of transition-metal oxide intercalation compounds. We introduce DABCOnium, the mono alkylated form of 1,4-diazabicyclo[2.2.

PhenoMeNal: processing and analysis of metabolomics data in the cloud.

Background: Metabolomics is the comprehensive study of a multitude of small molecules to gain insight into an organism's metabolism. The research field is dynamic and expanding with applications across biomedical, biotechnological, and many other applied biological domains. Its computationally intensive nature has driven requirements for open data formats, data repositories, and data analysis tools.

Publisher Correction: Detection of antibiotics synthetized in microfluidic picolitre-droplets by various actinobacteria.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Far-red acclimating cyanobacterium as versatile source for bright fluorescent biomarkers.

Far-red and near-infrared emitting chromophores extend applications of fluorescent proteins to regions of maximal transmission of most tissues, but present considerable engineering challenges. Far-red adapting cyanobacteria generate a novel set of biliproteins. One of them, ApcF2, from a thermophilic cyanobacterium was subjected to structure-guided, site-directed random and specific mutagenesis, and was screened for bright far-red emission.

Insulin Mimetic Properties of Extracts Prepared from .

Diabetes mellitus (DM) and consequential cardiovascular diseases lead to millions of deaths worldwide each year; 90% of all people suffering from DM are classified as Type 2 DM (T2DM) patients. T2DM is linked to insulin resistance and a loss of insulin sensitivity. It leads to a reduced uptake of glucose mediated by glucose transporter 4 (GLUT4) in muscle and adipose tissue, and finally hyperglycemia.

Chromophorylation of cyanobacteriochrome Slr1393 from sp. PCC 6803 is regulated by protein Slr2111 through allosteric interaction.

Cyanobacteriochromes (CBCRs) are photochromic proteins in cyanobacteria that act as photosensors. CBCRs bind bilins as chromophores and sense nearly the entire visible spectrum of light, but the regulation of the chromophorylation of CBCRs is unknown. Slr1393 from sp.

Optimization of an innovative vinylimidazole-based monolithic stationary phase and its use for pressured capillary electrochromatography.

A novel polymer monolith based on the dicationic crosslinker 3,3'-(hexane-1,6-diyl)bis(1-vinylimidazolium) bromide, the monomer 1-vinylimidazole and a ternary porogen mixture (1-propanol, decan-1-ol and water) was developed and optimized for capillary electrochromatography. This aim was accomplished by adjusting the composition of individual constituents in the polymerization mixture and monitored based on several relevant parameters (e.g.

Detection of antibiotics synthetized in microfluidic picolitre-droplets by various actinobacteria.

The natural bacterial diversity is regarded as a treasure trove for natural products. However, accessing complex cell mixtures derived from environmental samples in standardized high-throughput screenings is challenging. Here, we present a droplet-based microfluidic platform for ultrahigh-throughput screenings able to directly harness the diversity of entire microbial communities.

Development and application of a method for ivory dating by analyzing radioisotopes to distinguish legal from illegal ivory.

The age determination of elephant ivory provides necessary and crucial information for all criminal prosecution authorities enforcing the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The knowledge of the age of ivory allows to distinguish between pre-convention, hence legal material and ivory deriving from recent, illegal poaching incidents. The commonly applied method to determine the age of ivory is radiocarbon dating in the form of bomb pulse dating, which however will fade out soon.

The Red-/Green-Switching GAF3 of Cyanobacteriochrome Slr1393 from Synechocystis sp. PCC6803 Regulates the Activity of an Adenylyl Cyclase.

Cyanobacteriochromes (CBCRs) are photoreceptors in cyanobacteria that present a bilin chromophore-binding GAF domain as a photochromic element to control the activity of a downstream enzyme or regulator. CBCR Slr1393 from Synechocystis PCC 6803 carries three GAF domains, but only the third one binds phycocyanobilin covalently. Slr1393 shows photochromicity between red and green absorbing states and regulates a C-terminally located histidine kinase.

Expanding the Rubterolone Family: Intrinsic Reactivity and Directed Diversification of PKS-derived Pyrans.

We characterized two key biosynthetic intermediates of the intriguing rubterolone family (tropolone alkaloids) that contain a highly reactive pyran moiety (in equilibrium with the hydrolyzed 1,5-dione form) and undergo spontaneous pyridine formation in the presence of primary amines. We exploited the intrinsic reactivity of the pyran moiety and isolated several new rubterolone derivatives, two of which contain a unique thiazolidine moiety. Three rubterolone derivatives were chemically modified with fluorescence and biotin tags using peptide coupling and click reaction.

In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava (Psidium Guajava) Extracts.

Scope: Known pharmacological activities of guava (Psidium guajava) include modulation of blood glucose levels. However, mechanistic details remain unclear in many cases.

Methods And Results: This study investigated the effects of different guava leaf and fruit extracts on intestinal glucose transport in vitro and on postprandial glucose levels in vivo.

Immunomodulatory Effects of Diterpene Quinone Derivatives from the Roots of in Human PBMC.

Several phytochemicals were shown to interfere with redox biology in the human system. Moreover, redox biochemistry is crucially involved in the orchestration of immunological cascades. When screening for immunomodulatory compounds, the two interferon gamma- (IFN--) dependent immunometabolic pathways of tryptophan breakdown via indoleamine 2,3-dioxygenase-1 (IDO-1) and neopterin formation by GTP-cyclohydrolase 1 (GTP-CH-I) represent prominent targets, as IFN--related signaling is strongly sensitive to oxidative triggers.

Stable Europium(III) Complexes with Short Linkers for Site-Specific Labeling of Biomolecules.

In this study, two new terpyridine-based Eu complexes were synthesized, the structures of which were optimized for luminescence resonance energy-transfer (LRET) experiments. The complexes showed high quantum yields (32 %); a single long lifetime (1.25 ms), which was not influenced by coupling to protein; very high stability in the presence of chelators such as ethylenediamine-,,','-tetraacetate and ethylene glycol-bis(2-aminoethylether)-,,','-tetraacetic acid; and no interaction with cofactors such as adenosine triphosphate and guanosine triphosphate.

Structures and enzymatic mechanisms of phycobiliprotein lyases CpcE/F and PecE/F.

The light-harvesting phycobilisome in cyanobacteria and red algae requires the lyase-catalyzed chromophorylation of phycobiliproteins. There are three functionally distinct lyase families known. The heterodimeric E/F type is specific for attaching bilins covalently to α-subunits of phycocyanins and phycoerythrins.

Mucus permeating self-emulsifying drug delivery systems (SEDDS): About the impact of mucolytic enzymes.

This study aimed to improve the mucus permeating properties of self-emulsifying drug delivery systems (SEDDS) by anchoring lipidized bromelain, papain and trypsin using palmitoyl chloride. SEDDS containing enzyme-palmitate conjugates were characterized regarding droplet size and zeta potential. Their mucus permeating properties were evaluated by Transwell diffusion and rotating tube method using fluorescein diacetate (FDA) as marker.

Singlet Oxygen during Cycling of the Aprotic Sodium-O Battery.

Aprotic sodium-O batteries require the reversible formation/dissolution of sodium superoxide (NaO ) on cycling. Poor cycle life has been associated with parasitic chemistry caused by the reactivity of electrolyte and electrode with NaO , a strong nucleophile and base. Its reactivity can, however, not consistently explain the side reactions and irreversibility.