Action and cooperation in alginate degradation by three enzymes from the human gut bacterium Bacteroides eggerthii DSM 20697.

Alginate is a polysaccharide consumed by humans in edible seaweed and different foods where it is applied as a texturizing hydrocolloid or in encapsulations of drugs and probiotics. While gut bacteria are found to utilize and ferment alginate to health-beneficial short-chain fatty acids, knowledge on the details of the molecular reactions is sparse. Alginates are composed of mannuronic acid (M) and its C-5 epimer guluronic acid (G).

Taylor Dispersion-Induced Phase Separation for the Efficient Characterisation of Protein Condensate Formation.

Biomolecular condensates have emerged as important structures in cellular function and disease, and are thought to form through liquid-liquid phase separation (LLPS). Thorough and efficient in vitro experiments are therefore needed to elucidate the driving forces of protein LLPS and the possibility to modulate it with drugs. Here we present Taylor dispersion-induced phase separation (TDIPS), a method to robustly measure condensation phenomena using a commercially available microfluidic platform.

H, C, N resonance assignment of the enzyme KdgF from Bacteroides eggerthii.

To fully utilize carbohydrates from seaweed biomass, the degradation of the family of polysaccharides known as alginates must be understood. A step in the degradation of alginate is the conversion of 4,5-unsaturated monouronates to 4-deoxy-L-erythro-5-hexoseulose catalysed by the enzyme KdgF. In this study BeKdgF from Bacteroides eggerthii from the human gut microbiota has been produced isotopically labelled in Escherichia coli.

Capillary flow experiments for thermodynamic and kinetic characterization of protein liquid-liquid phase separation.

Liquid-liquid phase separation or LLPS of proteins is a field of mounting importance and the value of quantitative kinetic and thermodynamic characterization of LLPS is increasingly recognized. We present a method, Capflex, which allows rapid and accurate quantification of key parameters for LLPS: Dilute phase concentration, relative droplet size distributions, and the kinetics of droplet formation and maturation into amyloid fibrils. The binding affinity between the polypeptide undergoing LLPS and LLPS-modulating compounds can also be determined.

Binding Sites for Oligosaccharide Repeats from Lactic Acid Bacteria Exopolysaccharides on Bovine β-Lactoglobulin Identified by NMR Spectroscopy.

Lactic acid bacterial exopolysaccharides (EPS) are used in the food industry to improve the stability and rheological properties of fermented dairy products. β-Lactoglobulin (BLG), the dominant whey protein in bovine milk, is well known to bind small molecules such as fatty acids, vitamins, and flavors, and to interact with neutral and anionic polysaccharides used in food and pharmaceuticals. While sparse data are available on the affinity of EPS-milk protein interactions, structural information on BLG-EPS complexes, including the EPS binding sites, is completely lacking.

Structural and functional aspects of mannuronic acid-specific PL6 alginate lyase from the human gut microbe .

Alginate is a linear polysaccharide from brown algae consisting of 1,4-linked β-d-mannuronic acid (M) and α-l-guluronic acid (G) arranged in M, G, and mixed MG blocks. Alginate was assumed to be indigestible in humans, but bacteria isolated from fecal samples can utilize alginate. Moreover, genomes of some human gut microbiome-associated bacteria encode putative alginate-degrading enzymes.

Alginate Trisaccharide Binding Sites on the Surface of β-Lactoglobulin Identified by NMR Spectroscopy: Implications for Molecular Network Formation.

β-lactoglobulin (BLG) is a promiscuous protein in terms of ligand interactions, having several binding sites reported for hydrophobic biomolecules such as fatty acids, lipids, and vitamins as well as detergents. BLG also interacts with neutral and anionic oligo- and polysaccharides for which the binding sites remain to be identified. The multivalency offered by these carbohydrate ligands is expected to facilitate coacervation, an electrostatically driven liquid-liquid phase separation.

Isoenergic modification of whey protein structure by denaturation and crosslinking using transglutaminase.

Transglutaminase (TG) catalyzes formation of covalent bonds between lysine and glutamine side chains and has applications in manipulation of food structure. Physical properties of a whey protein mixture (SPC) denatured either at elevated pH or by heat-treatment and followed by TG catalyzed crosslinking, have been characterised using dynamic light scattering, size exclusion chromatography, flourescence spectroscopy and atomic force microscopy. The degree of enzymatic crosslinking appeared higher for pH- than for heat-denatured SPC.

Subgroup-specific intrinsic disorder profiles of Arabidopsis NAC transcription factors: Identification of functional hotspots.

Protein intrinsic disorder (ID), referring to the lack of a fixed tertiary structure, is significant in signaling and transcription. We recently characterized ID in 6 phylogenetically representative Arabidopsis thaliana NAC transcription factors. Their transcription regulatory domains are mostly disordered but contain short, functionally important regions with structure propensities known as molecular recognition features.

Effect of thermocycling with or without 1 year of water storage on retentive strengths of luting cements for zirconia crowns.

Statement Of Problem: Bond stability between zirconia crowns and luting cement and between cement and dentin is a main concern; however, only limited evidence is available as to its longevity.

Purpose: The purpose of this in vitro study was to measure the retentive strengths of 7 self-adhesive cements (RelyX Unicem Aplicap, RelyX Unicem Clicker, RelyX Unicem 2 Automix, iCEM, Maxcem Elite, Bifix SE, SpeedCem), 2 adhesive cements with self-etch primers (Panavia 21, SEcure), 1 glass ionomer cement (Ketac Cem), 1 resin-modified glass ionomer cement (Meron Plus), and 1 zinc phosphate cement for luting zirconia crowns (LAVA) to extracted teeth after thermocycling with or without 1 year of water storage.

Material And Methods: Two-hundred-forty extracted human molars (2 treatments; n=10 per cement) were prepared in a standardized manner.

Protein intrinsic disorder in Arabidopsis NAC transcription factors: transcriptional activation by ANAC013 and ANAC046 and their interactions with RCD1.

Protein ID (intrinsic disorder) plays a significant, yet relatively unexplored role in transcription factors (TFs). In the present paper, analysis of the transcription regulatory domains (TRDs) of six phylogenetically representative, plant-specific NAC [no apical meristem, ATAF (Arabidopsis transcription activation factor), cup-shaped cotyledon] TFs shows that the domains are present in similar average pre-molten or molten globule-like states, but have different patterns of order/disorder and MoRFs (molecular recognition features). ANAC046 (Arabidopsis NAC 046) was selected for further studies because of its simple MoRF pattern and its ability to interact with RCD1 (radical-induced cell death 1).

Primary stability of a hybrid self-tapping implant compared to a cylindrical non-self-tapping implant with respect to drilling protocols in an ex vivo model.

Background: Modifications of implant design have been intending to improve primary stability. However, little is known about investigation of a hybrid self-tapping implant on primary stability.

Purposes: The aims of this study were to evaluate the primary stability of two hybrid self-tapping implants compared to one cylindrical non-self-tapping implant, and to elucidate the relevance of drilling protocols on primary stability in an ex vivo model.

Influence of different luting concepts on long term retentive strength of zirconia crowns.

Purpose: To evaluate the retentive strength of a resin cement in combination with a conventional adhesive (Variolink II/Syntac Classic), two resin cements with self-etching adhesives (Panavia F 2.0/ED Primer, Multilink/Multilink Primer A/B), two self-adhering cements (RelyX Unicem Aplicap, Maxcem), and a resin-modified glass-ionomer cement (FujiCem) after cementation of zirconium-oxide ceramic crowns (LAVA) on extracted human teeth.

Methods: 160 extracted teeth (n=20) were prepared in a standardized manner (10 degrees, h=3 mm).

Minimal exposure time of different LED-curing devices.

Objectives: The purpose of the study was to investigate the shortest possible exposure time of different LED-curing devices for five different resin composites in a clinically relevant in vitro-model, where a 7 mm distance from the light guide tip to the bottom side of the cavity was compiled.

Methods: Resin composite samples (Tetric EvoCeram A3, Filtek Supreme XT A3B, Premise A3, CeramX Mono M5, QuiXfil) were filled in three increments of 2mm thickness each in stainless steel moulds (Ø=5 mm, h=6 mm, n=9). The samples were incrementally exposed to different blue LED-curing devices (Bluephase, Bluephase C8, Bluephase 16i/Ivoclar Vivadent, L.

Primary stability of a conical implant and a hybrid, cylindric screw-type implant in vitro.

Purpose: The differences with respect to primary stability between 2 Camlog implants, a conical implant, and a hybrid cylindric screw-type implant, were investigated in vitro. The effect of underdimensioned implant bed preparation was also studied for both implant designs.

Materials And Methods: In an in vitro model the stability of different implants in fresh porcine iliac bone blocks was measured using torque moment values, the Periotest, resonance frequency analysis, and push-out testing.

In vitro retentive strength of zirconium oxide ceramic crowns using different luting agents.

Statement Of Problem: In contrast to gold crowns, in vitro determination of the retentive strength of all-ceramic crowns is more difficult because components allowing connection to testing apparatus are not as easily integrated into the all-ceramic material. Nevertheless, retentive strength data are crucial for obtaining information about the potential clinical performance of luting cements for all-ceramic restorations. Therefore, a new in vitro model was necessary to evaluate the retentive strength of all-ceramic crowns.

Depth of cure of LED vs QTH light-curing devices at a distance of 7 mm.

Purpose: To determine the depth of cure of 5 blue LED curing devices compared to that obtained with 3 QTH curing devices.

Materials And Methods: The LED curing devices tested were 1) e-Light: 40 s; 2) Elipar FreeLight: 40 s; 3) Elipar FreeLight 2: 20 s and 40 s; 4) Ultra-Lume LED 2: 20 s and 40 s; 5) LEDemetron 1: 20 s and 40 s. The QTH curing devices tested were 1) Optilux 501: standard light guide 20 s and 40 s, turbo light guide 20 s; 2) Elipar TriLight: 40 s; 3) Astralis 10: 20 s.

Comparison of the efficacy of chemomechanical caries removal (Carisolv) with that of conventional excavation in reducing the cariogenic flora.

Objectives: The usage of minimally invasive procedures and attention to patient comfort are of great importance, especially for dental treatment in small children. This has led to the development of chemomechanical methods for caries removal. The aim of this study was to compare the efficacy of chemomechanical caries removal with that of conventional excavation in reducing the count of the cariogenic flora.

Effect of diode laser irradiation on the attachment rate of periodontal ligament cells: an in vitro study.

Background: The present study is part of a basic research program investigating the cellular effects of an 810 nm GaAlAs-diode laser on human periodontal tissues. The aim of the investigation was to evaluate the effects of laser treatment of root surface specimens on the attachment of periodontal ligament (PDL) cells in vitro.

Methods: Root specimens were prepared from periodontally diseased teeth.

In vitro colonisation of acrylic resin denture base materials by Streptococcus oralis and Actinomyces viscosus.

Aim: The aim of the study was to compare the attachment of two typical strains of oral bacteria to four denture base materials.

Design: In vitro study.

Method: Discs of acrylic resin denture base materials (Paladon 65, polished and unpolished; Palapress; Microbase, polished and unpolished, and Triad VLC) were placed into Petri dishes with Schaedler's medium, inoculated with Streptococcus oralis 34 or Actinomyces viscosus T14V.

The influence of oral bacteria on the surfaces of resin-based dental restorative materials--an in vitro study.

Three tooth-coloured, resin-based restorative materials (Charisma, Dyract, and Pertac) were exposed to typical oral bacteria (S. mutans, S. oralis and A.

Retentive strengths of cast gold crowns using glass ionomer, compomer, or resin cement.

Purpose: The retention forces of a newly developed compomer cement (Dyract Cem), a glass ionomer cement (Ketac Cem Aplicap), and a resin cement (F21) were examined.

Material And Methods: Cemented cast gold crowns were removed along the path of insertion with a Zwick universal testing device. The impact of both a cured and a noncured additional bonding layer that were applied to the inner surface of the crowns was examined across the Dyract Cem group.