Chiral Plasmonic Hydrogen Sensors.

In this article, a chiral plasmonic hydrogen-sensing platform using palladium-based nanohelices is demonstrated. Such 3D chiral nanostructures fabricated by nanoglancing angle deposition exhibit strong circular dichroism both experimentally and theoretically. The chiroptical properties of the palladium nanohelices are altered upon hydrogen uptake and sensitively depend on the hydrogen concentration.

Dynamic Color Displays Using Stepwise Cavity Resonators.

High-resolution multicolor printing based on pixelated optical nanostructures is of great importance for promoting advances in color display science. So far, most of the work in this field has been focused on achieving static colors, limiting many potential applications. This inevitably calls for the development of dynamic color displays with advanced and innovative functionalities.

Genome mining of ascomycetous fungi reveals their genetic potential for ergot alkaloid production.

Ergot alkaloids are important as mycotoxins or as drugs. Naturally occurring ergot alkaloids as well as their semisynthetic derivatives have been used as pharmaceuticals in modern medicine for decades. We identified 196 putative ergot alkaloid biosynthetic genes belonging to at least 31 putative gene clusters in 31 fungal species by genome mining of the 360 available genome sequences of ascomycetous fungi with known proteins.

Formyl migration product of chanoclavine-I aldehyde in the presence of the old yellow enzyme FgaOx3 from Aspergillus fumigatus: a NMR structure elucidation.

A previous study showed that together with the festuclavine synthase FgaFS, the old yellow enzyme FgaOx3 from Aspergillus fumigatus catalyzed the conversion of chanoclavine-I aldehyde to festuclavine in the biosynthesis of ergot alkaloids. In the absence of FgaFS, a mixture containing two compounds with a ratio of 7:3 was detected in the enzyme assay of FgaOx3. NMR experiments including (DQF)-COSY, HSQC, HMBC and NOESY identified their structures as E/Z isomers of N-methyl-N-[(5R,10R)-10-(2-oxo-propyl)-2,4,5,10-tetrahydrobenzo[cd]indol-5-yl]formamide and proved the migration of the formyl group at C-8 in chanoclavine I-aldehyde to N-6 in the identified products.

New insights into ergot alkaloid biosynthesis in Claviceps purpurea: an agroclavine synthase EasG catalyses, via a non-enzymatic adduct with reduced glutathione, the conversion of chanoclavine-I aldehyde to agroclavine.

Ergot alkaloids are indole derivatives with diverse structures and biological activities. They are produced by a wide range of fungi with Claviceps purpurea as the most important producer for medical use. Chanoclavine-I aldehyde is proposed as a branch point via festuclavine or pyroclavine to clavine-type alkaloids in Trichocomaceae and via agroclavine to ergoamides and ergopeptines in Clavicipitaceae.

Structure-function analysis of an enzymatic prenyl transfer reaction identifies a reaction chamber with modifiable specificity.

Fungal indole prenyltransferases participate in a multitude of biosynthetic pathways. Their ability to prenylate diverse substrates has attracted interest for potential use in chemoenzymatic synthesis. The fungal indole prenyltransferase FtmPT1 catalyzes the prenylation of brevianamide F in the biosynthesis of fumitremorgin-type alkaloids, which show diverse pharmacological activities and are promising candidates for the development of antitumor agents.

Ergot alkaloid biosynthesis in Aspergillus fumigatus: Conversion of chanoclavine-I aldehyde to festuclavine by the festuclavine synthase FgaFS in the presence of the old yellow enzyme FgaOx3.

Ergot alkaloids are toxins and important pharmaceuticals which are produced biotechnologically on an industrial scale. A putative gene fgaFS has been identified in the biosynthetic gene cluster of fumigaclavine C, an ergot alkaloid of the clavine-type. The deduced gene product FgaFS comprises 290 amino acids with a molecular mass of about 32.

Reconstruction of pyrrolo[2,3-b]indoles carrying an alpha-configured reverse C3-dimethylallyl moiety by using recombinant enzymes.

Nine reversely C3-prenylated pyrrolo[2,3-b]indoles were successfully prepared by using two recombinant enzymes involved in the biosynthesis of acetylaszonalenin from Neosartorya fischeri. The prenyltransferase AnaPT catalysed the conversion of six tryptophan-containing cyclic dipeptides to reversely C3-prenylated indoline derivatives. Using cyclo-L-Trp-L-Trp as substrate, both mono- and diprenylated indolines were obtained.

Ergot alkaloid biosynthesis in Aspergillus fumigatus: conversion of chanoclavine-I to chanoclavine-I aldehyde catalyzed by a short-chain alcohol dehydrogenase FgaDH.

Ergot alkaloids are toxins and important pharmaceuticals which are produced biotechnologically on an industrial scale. A putative gene fgaDH has been identified in the biosynthetic gene cluster of fumigaclavine C, an ergot alkaloid of the clavine-type. The deduced gene product FgaDH comprises 261 amino acids with a molecular mass of about 27.

Metabolic interactions of AGE inhibitor pyridoxamine and antioxidant alpha-lipoic acid following 22 weeks of treatment in obese Zucker rats.

Aims: The advanced glycation end product inhibitor pyridoxamine (PYR) and the antioxidant alpha-lipoic acid (LA) interact to ameliorate insulin resistance in obese Zucker rats following short-term (6-week) treatment. This study was designed to ascertain whether these unique interactive effects of PYR and LA remain manifest following longer-term (22-week) treatment.

Main Methods: Female obese Zucker rats received vehicle (OV), PYR (OP, 60 mg/kg body wt), racemic LA (rac-LA; OM, 92 mg/kg), the R-(+)-enantiomer of LA (R-LA; OR, 92 mg/kg), or combined treatments with PYR and rac-LA (OPM) or PYR and R-LA (OPR), daily for 22 weeks.

Interactions of the advanced glycation end product inhibitor pyridoxamine and the antioxidant alpha-lipoic acid on insulin resistance in the obese Zucker rat.

Oxidative stress and protein glycation can contribute to the development of insulin resistance and complications associated with type 2 diabetes mellitus. The antioxidant alpha-lipoic acid (ALA) reduces oxidative stress and the formation of advanced glycation end products (AGEs) and improves insulin sensitivity in skeletal muscle and liver. The AGE inhibitor pyridoxamine (PM) prevents irreversible protein glycation, thereby reducing various diabetic complications.

The jejunum is the main site of absorption for anthocyanins in mice.

Intestinal absorption of anthocyanins (ACNs) was studied in vitro by comparing ACN disappearance from the mucosal solution of Ussing chambers not containing any tissue (controls) and that of Ussing chambers containing segments of mouse duodenum, jejunum, ileum or colon. The tissues were mounted in the chambers and bathed with Ringer's solution (RS) adjusted to a pH representative of the respective segments in vivo. The chambers were kept at 37 degrees C and RS was perfused continuously with carbogen (95% O(2)/5% CO(2)).

Analysis of mating-dependent transcription of Blakeslea trispora carotenoid biosynthesis genes carB and carRA by quantitative real-time PCR.

The zygomycete fungus Blakeslea trispora is used commercially as natural source of beta-carotene. beta-Carotene production is strongly induced during mating of two strains of the opposite sex and results in the production of the pheromone trisporic acid, which in turn stimulates enhanced beta-carotene biosynthesis. beta-Carotene production is due to the enzymatic activity of phytoene synthase, lycopene cyclase and phytoene dehydrogenase.

Initial in vitro toxicity testing of functional foods rich in catechins and anthocyanins in human cells.

Functional foods need to be assessed for beneficial effects to support claims, but also for toxic effects. This report describes two examples of how complex food samples are initially characterized in human cells in vitro. Water extracts of green tea (GT) and black carrots (BC) were analyzed for key ingredients (catechins and anthocyanidins, respectively).

Duplicated dockerin subdomains of Clostridium thermocellum endoglucanase CelD bind to a cohesin domain of the scaffolding protein CipA with distinct thermodynamic parameters and a negative cooperativity.

Mutagenized dockerin domains of endoglucanase CelD (type I) and of the cellulosome-integrating protein CipA (type II) were constructed by swapping residues 10 and 11 of the first or the second duplicated segment between the two polypeptides. These residues have been proposed to determine the specificity of cohesin-dockerin interactions. The dockerin domain of CelD still bound to the seventh cohesin domain of CipA (CohCip7), provided that mutagenesis occurred in one segment only.

Cell wall of Thermoanaerobacterium thermosulfurigenes EM1: isolation of its components and attachment of the xylanase XynA.

Thermoanaerobacterium thermosulfurigenes EM1 has a gram-positive type cell wall completely covered by a surface layer (S-layer) with hexagonal lattice symmetry. The components of the cell envelope were isolated, and the S-layer protein was purified and characterized. S-layer monomers assembled in vitro into sheets with the same hexagonal symmetry as in vivo.

Distinct affinity of binding sites for S-layer homologous domains in Clostridium thermocellum and Bacillus anthracis cell envelopes.

Binding parameters were determined for the SLH (S-layer homologous) domains from the Clostridium thermocellum outer layer protein OlpB, from the C. thermocellum S-layer protein SlpA, and from the Bacillus anthracis S-layer proteins EA1 and Sap, using cell walls from C. thermocellum and B.

Molecular characterization of genes encoding a novel ABC transporter in Thermoanaerobacterium thermosulfurigenes EM1.

The nucleotide sequence of two open reading frames (ORFs) from Thermoanaerobacterium thermosulfurigenes EM1 was determined that encode proteins with similarity to components of ATP-binding cassette (ABC) transport systems. Sequence analysis suggests that the deduced proteins AbcA and AbcB consist of an NH2-terminal membrane-spanning domain and a COOH-terminal ATP-binding domain. The deduced proteins AbcA and AbcB showed highest similarity to proteins of the MsbA subfamily of ABC transporters.

Functions of S-layers.

Although S-layers are being increasingly identified on Bacteria and Archaea, it is enigmatic that in most cases S-layer function continues to elude us. In a few instances, S-layers have been shown to be virulence factors on pathogens (e.g.

Characterization of genes from Thermoanaerobacterium thermosulfurigenes EM1 that encode two glycosyl hydrolases with conserved S-layer-like domains.

Two genes from Thermoanaerobacterium thermosulfurigenes EM1 were identified which are predicted to encode a xylanase (XynA) and a polygalacturonate hydrolase (Pg1A). The xynA gene has the potential to encode a 1234-amino acid product consisting of a signal peptide followed by a repeated domain, a xylanase family F domain, two cellulose-binding domains and a triplicated sequence at its C-terminus. The gene pglA is predicted to encode a product of 1148 amino acids consisting of a signal sequence followed by a fibronectin type III-like domain (Fn3 domain), the catalytic domain, a Gly/Thr/Ser/Asn-rich segment and a triplicated domain.

Cloning, sequencing, and expression of the gene encoding a large S-layer-associated endoxylanase from Thermoanaerobacterium sp. strain JW/SL-YS 485 in Escherichia coli.

The gene (xynA) encoding a surface-exposed, S-layer-associated endoxylanase from Thermoanaerobacterium sp. strain JW/SL-YS 485 was cloned and expressed in Escherichia coli. A 3.

Molecular analysis of the amy gene locus of Thermoanaerobacterium thermosulfurigenes EM1 encoding starch-degrading enzymes and a binding protein-dependent maltose transport system.

A gene of Thermoanaerobacterium thermosulfurigenes EM1 encoding a protein with similarity to the maltose-binding protein of Escherichia coli was cloned and sequenced. It was located in the amy gene region of the chromosome downstream of the pullulanase-encoding amyB gene and upstream of amyDC, encoding membrane components of an ABC transport system, and the alpha-amylase gene amyA. The gene was designated amyE.

Pullulanase of Thermoanaerobacterium thermosulfurigenes EM1 (Clostridium thermosulfurogenes): molecular analysis of the gene, composite structure of the enzyme, and a common model for its attachment to the cell surface.

The complete pullulanase gene (amyB) from Thermoanaerobacterium thermosulfurigenes EM1 was cloned in Escherichia coli, and the nucleotide sequence was determined. The reading frame of amyB consisted of 5,586 bp encoding an exceptionally large enzyme of 205,991 Da. Sequence analysis revealed a composite structure of the pullulanase consisting of catalytic and noncatalytic domains.