dChitin, a major component of fungal cell walls and invertebrate cuticles, is an exceedingly abundant polysaccharide, ranking next to cellulose. Industrial demand for chitin and its degradation products as raw materials for fine chemical products is increasing. A bacterium with high chitin-decomposing activity, Paenibacillus sp. strain FPU-7, was isolated from soil by using a screening medium containing ␣-chitin powder. Although FPU-7 secreted several extracellular chitinases and thoroughly digested the powder, the extracellular fluid alone broke them down incompletely. Based on expression cloning and phylogenetic analysis, at least seven family 18 chitinase genes were found in the FPU-7 genome. Interestingly, the product of only one gene (chiW) was identified as possessing three S-layer homology (SLH) domains and two glycosyl hydrolase family 18 catalytic domains. Since SLH domains are known to function as anchors to the Gram-positive bacterial cell surface, ChiW was suggested to be a novel multimodular surface-expressed enzyme and to play an important role in the complete degradation of chitin. Indeed, the ChiW protein was localized on the cell surface. Each of the seven chitinase genes (chiA to chiF and chiW) was cloned and expressed in Escherichia coli cells for biochemical characterization of their products. In particular, ChiE and ChiW showed high activity for insoluble chitin. The high chitinolytic activity of strain FPU-7 and the chitinases may be useful for environmentally friendly processing of chitin in the manufacture of food and/or medicine.
Curcumin is a yellow dye in the crude drug "Turmeric" (Curcumae Rhizoma) from the rhizome of Curcuma longa L. (Zingiberaceae). Curcumin is reported to have anti-inflammatory, 1) anti-oxidative, 2) liver protective, 3) anti-spastic 4) and anti-tumor effects. 5) We reported that curcumin had an antiallergic effect using the type I and IV allergy model animals 6) and also that curcumin had an inhibitory effect on histamine release from rat peritoneal mast cells. 7)Several curcumin-related compounds occur in plants or biometabolites. Curcuminoids such as curcumin, monodemethoxycurcumin and bis-demethoxycurcumin are contained in the crude drug "Turmeric".2) Tetrahydrocurcumin (THC) is known to be an active metabolite of curcumin. 8,9) Curcuminoids are pharmacologically active agents of the crude drug "Turmeric" for multiple pharmacological activities.10) However, few, if any, reports have so far been concerned with which action of curcuminoids may be fundamental for exerting a variety of actions. Therefore, we focused our attention on the anti-oxidative and anti-allergic activities of curcumin-related compounds in order to see if the anti-allergic activities originate in anti-oxidative activities. Furthermore, we were very interested in the chemical features of curcumin or THC for exerting the anti-oxidative and anti-allergic activities.In the present study, we investigated anti-allergic and antioxidative effects of curcumin-related compounds (glycosides, reductants and bis-demethoxy analogs) in order to elucidate the chemical structural features of curcumin. The anti-allergic activities were assessed by measurement of histamine release from rat basophilic leukemia (RBL-2H3) cells. The anti-oxidative activities were evaluated by measurement of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals in cell-free solution and superoxide anion in cells. Finally, we discussed the underlying mechanisms on anti-allergic activities of curcumin-related compounds with special reference to their anti-oxidative activities. MATERIALS AND METHODSMaterials Curcumin, concanavalin A (Con A) and phosphatidyl serine were purchased from Sigma Japan Co. (Tokyo, Japan). Histamine · 2HCl, 2,2-diphenyl-1-picrylhydrazyl (DPPH), phorbol-12-myristate-13-acetate (PMA), cytochrome c (from bovine heart), superoxide dismutase (SOD) and o-phthalaldehyde were purchased from Wako Pure Chemical Co. (Osaka, Japan). Calcium ionophore A23187 was purchased from Calbiochem Co. (CA, U.S.A.).0.05% BSA-Tyrode buffer (pH 7.4) was prepared in distilled water and consisted of NaCl (137 mM), KCl (2.7 mM), N-(2-hydroxyethyl)piperazine-NЈ-ethanesulfonic acid (HEPES) (10 mM), glucose (5.6 mM), CaCl 2 (1.0 mM), MgCl 2 (1.0 mM), NaH 2 PO 4 · 2H 2 O (0.4 mM) and bovine serum albumin (BSA) (0.05%). Phosphate buffer saline (PBS) (pH 6.8) was prepared in distilled water and consisted of NaCl (137 mM), KCl (2.7 mM), Na 2 HPO 4 · 12H 2 O (8.0 mM) and KH 2 PO 4 (1.5 mM). Preparation of Curcumin-Related CompoundsWe prepared fifteen curcumin-related compounds by chemical modification o...
Several cationic dyes were evaluated as reagents for the spectrophotometrlc determination of anionic surfactants. Of the dyes examined, ethyl violet was the most useful reagent. By use of this dye, trace amounts of anionic surfactants could be extracted Into benzene and toluene In a single extraction and determined spectrophotometrlcally at 615 nm; the molar absorptivity was about 1 X 10s L mol-1 cm-1 and the absorbance of the reagent blank was 0.01. The method could be applied to the determination of parts-per-bllllon amounts of anionic surfactants In waters with satisfactory results.
The direct approach: A new high‐throughput screening system for analyzing the asymmetric induction in catalytic enantioselective synthesis couples solid‐phase reactions with a circular dichroism detection system (see picture). Thus, direct monitoring of asymmetric induction without the need for purification or chromatographic analysis is obtained.
Plasma NP levels in fetuses with CHD and/or arrhythmia are correlated with the severity of fetal heart failure. Elevated NP levels are attributed mainly to an increase in central venous pressure secondary to arrhythmia or atrioventricular valve regurgitation due to CHD, rather than to the morphological abnormality itself. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
The Gram-positive bacterium Paenibacillus sp. str. FPU-7 effectively hydrolyzes chitin by using a number of chitinases. A unique chitinase with two catalytic domains, ChiW, is expressed on the cell surface of this bacterium and has high activity towards various chitins, even crystalline chitin. Here, the crystal structure of ChiW at 2.1 Å resolution is presented and describes how the enzyme degrades chitin on the bacterial cell surface. The crystal structure revealed a unique multi-modular architecture composed of six domains to function efficiently on the cell surface: a right-handed β-helix domain (carbohydrate-binding module family 54, CBM-54), a Gly-Ser-rich loop, 1st immunoglobulin-like (Ig-like) fold domain, 1st β/α-barrel catalytic domain (glycoside hydrolase family 18, GH-18), 2nd Ig-like fold domain and 2nd β/α-barrel catalytic domain (GH-18). The structure of the CBM-54, flexibly linked to the catalytic region of ChiW, is described here for the first time. It is similar to those of carbohydrate lyases but displayed no detectable carbohydrate degradation activities. The CBM-54 of ChiW bound to cell wall polysaccharides, such as chin, chitosan, β-1,3-glucan, xylan and cellulose. The structural and biochemical data obtained here also indicated that the enzyme has deep and short active site clefts with endo-acting character. The affinity of CBM-54 towards cell wall polysaccharides and the degradation pattern of the catalytic domains may help to efficiently decompose the cell wall chitin through the contact surface. Furthermore, we clarify that other Gram-positive bacteria possess similar cell-surface-expressed multi-modular enzymes for cell wall polysaccharide degradation.
Direkter Zugang: Ein neues Hochdurchsatz‐Screening‐System für die Analyse der asymmetrischen Induktion in einer katalytischen enantioselektiven Synthese koppelt Festphasenreaktionen mit einem Circulardichroismus‐Detektionssystem (siehe Bild). Damit kann die asymmetrische Induktion direkt verfolgt werden, ohne dass ein Reinigungsschritt oder eine chromatographische Analyse erforderlich ist.
BackgroundEarly detection for worsening renal function (WRF) is indispensable in patients with acute decompensated heart failure (HF). We tested the hypothesis that the difference in the circulating levels of each B‐type or brain natriuretic peptide (BNP) molecular form is associated with the occurrence of WRF.Methods and ResultsCirculating levels of proBNP, the NT‐proBNP (N‐terminal proBNP), and total BNP (proBNP+mature BNP) were prospectively measured in patients with acute decompensated HF using specific and sensitive enzyme immunochemiluminescent assays. An estimated mature BNP (emBNP) concentration was calculated by subtracting proBNP levels from total BNP levels. WRF was defined as a >20% decrease in the estimated glomerular filtration rate during the hospitalization. One‐way repeated‐measures ANOVA was used to compare the changes of variables between the patients with and without WRF. In patients with acute decompensated HF (New York Heart Association class III–IV; 96%) hospitalized for HF, NT‐proBNP levels did not differ during the hospitalization between patients with and without WRF (n=42 and 140, respectively). By contrast, emBNP levels were lower in patients with WRF than in those without WRF on day 3 after admission. NT‐proBNP/emBNP molar ratios were elevated on day 3 after admission in the patients with WRF, before estimated glomerular filtration rate declined, but were unchanged in patients without WRF. On day 3 after hospital admission, NT‐proBNP/emBNP ratios were strongly associated with percentage decreases in estimated glomerular filtration rate.ConclusionsThese findings suggest that elevation of NT‐proBNP/emBNP ratio precedes WRF in patients with acute HF and can be a potentially useful biomarker for risk stratification of cardiorenal syndrome.
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