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The importance of 1,5-anhydroglucitol (1,5-AG) as an intermediate biomarker for diabetic pregnancy is multi-fold: (1) it serves as a reliable indicator of moderate-level glycemic control, especially during early gestation; (2) it has been associated with increased risk of diabetes, independent of HbA1c and fasting glucose; and (3) it is an independent risk factor for the development of eclampsia during pregnancy. However, the clinical use of this biomarker during pregnancy has been underutilized due to physiological changes in glomerular filtration rate, plasma volume, and other hemodynamic parameters which have been hypothesized to bias gestational serum 1,5-AG concentrations. Here, we develop an in-silico model of gestational 1,5-AG by combining pre-existing physiological data in the literature with a two-compartment mathematical model, building off of a previous kinetic model described by Stickle and Turk (1997) Am. J. Physiol., 273, E821. Our model quantitatively characterizes how renal and hemodynamic factors impact measured 1,5-AG during normal pregnancy and during pregnancy with gestational diabetes and diabetes mellitus. During both normal and diabetic pregnancy, we find that a simple two-compartment model of 1,5-AG kinetics, with all parameters but reabsorption fraction adjusted for time in pregnancy, efficiently models 1,5-AG kinetics throughout the first two trimesters. Allowing reabsorption fraction to decrease after 25 weeks permits parameters closer to expected physiological values during the last trimester. Our quantitative model of 1,5-AG confirms the involvement of hypothesized renal and hemodynamic mechanisms during pregnancy, clarifying the expected trends in 1,5-AG to aid clinical interpretation. Further research and data may elucidate biological changes during the third trimester that account for the drop in 1,5-AG concentrations, and clarify physiological differences between diabetes subtypes during pregnancy. [ABSTRACT FROM AUTHOR]

This study aims to explore effects of 1,25( OH)2D3 and vitamin D receptor ( VDR) on peripheral CD4+/ CD8+ double-positive (DP) T lymphocytes in systemic lupus erythematosus ( SLE). MRL- LPr/ LPr mice with SLE ( n = 20) and normal MRL mice ( n = 20) were assigned into the control group (normal mice, without feeding with 1,25( OH)2D3), the 1,25( OH)2D3 group ( SLE mice, feeding with 1,25( OH)2D3), the VDR-knock-in + 1,25( OH)2D3 group ( SLE mice, VDR-knock-in, feeding with 1,25( OH)2D3) and the VDR-knockout group (normal mice, VDR-knockout, without feeding with 1,25( OH)2D3) ( n = 10 per group). Levels of T lymphocytes were measured by flow cytometry. The mRNA and proteins expressions of inflammatory factors were measured by qRT- PCR and ELISA. Extracellular signal-regulated kinase-1/2 ( ERK1/2) expression was measured by Western blotting. Compared with normal mice, SLE mice showed reduced levels of CD4+, CD4+/ CD8+ ratio, and DP lymphocytes. The levels of SLE-related indicators all increased significantly, followed with severe skin ulcers and urinary system infection. With the increase in time, skin ulcers and urinary system infection were significantly improved, levels of CD4+, CD4+/ CD8+ ratio, and DP lymphocytes increased, and levels of SLE-related indicators all decreased in the 1,25( OH)2D3 group. There were no significant changes in bioindicators in the control and the VDR-knock-in + 1,25( OH)2D3 groups. The symptoms of SLE gradually occurred in the VDR-knockout group. This study demonstrates that VDR and 1,25( OH)2D3 could elevate CD4+/ CD8+ DP T lymphocytes and reduce expressions of inflammatory factors, thus inhibiting the development and progression of SLE. [ABSTRACT FROM AUTHOR]

Microbial nitrification in soils is a major contributor to nitrogen (N) loss in agricultural systems. Some plants can secrete organic substances that act as biological nitrification inhibitors ( BNIs), and a small number of BNIs have been identified and characterized. However, virtually no research has focused on the important food crop, rice ( Oryza sativa)., Here, 19 rice varieties were explored for BNI potential on the key nitrifying bacterium Nitrosomonas europaea. Exudates from both indica and japonica genotypes were found to possess strong BNI potential. Older seedlings had higher BNI abilities than younger ones; Zhongjiu25 ( ZJ25) and Wuyunjing7 ( WYJ7) were the most effective genotypes among indica and japonica varieties, respectively., A new nitrification inhibitor, 1,9-decanediol, was identified, shown to block the ammonia monooxygenase ( AMO) pathway of ammonia oxidation and to possess an 80% effective dose ( ED80) of 90 ng μl−1. Plant N-use efficiency ( NUE) was determined using a 15N-labeling method. Correlation analyses indicated that both BNI abilities and 1,9-decanediol amounts of root exudates were positively correlated with plant ammonium-use efficiency and ammonium preference., These findings provide important new insights into the plant-bacterial interactions involved in the soil N cycle, and improve our understanding of the BNI capacity of rice in the context of NUE. [ABSTRACT FROM AUTHOR]

In this study, novel polyester diols of 2000 molecular weight (MW) were synthesized by reacting azelaic acid (AZ) with 1,3-propanediol (1,3-PDO) and diethylene glycol (DEG) in the esterification reaction catalyzed with a small amount of butyltintris(2-ethylhexanoate). As a reference, polyester polyols of 2000 MW were synthesized from adipic acid (AA) with 1,3-PDO and DEG. The properties of polyester polyols were evaluated. The polyester polyol based on AZ and 1,3-PDO is 100 % renewable polyol; 1,3-PDO used in the syntheses is renewable product produced by fermentation process of sugar. Both 1,3-PDO-polyester polyols exhibited crystalline transition above room temperature, while DEG-polyester polyols were liquid at room temperature. The polyester polyols were chain-extended with 4,4′-diphenylmethane diisocyanate (Mondur M) and 1,4-butanediol (BDO) to form thermoplastic polyurethanes (TPU). TPU were evaluated for mechanical and water resistance properties, and their morphology were studied via differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and atomic force microscope (AFM). TPU based on azelate and adipate polyols were relatively soft elastomeric materials with high melting temperatures. AFM analyses of TPU indicated better phase separation in 1,3-PDO polyester polyols with the highest phase separation observed in TPU based on 1,3-PDO/azelaic acid polyols. Water resistance of TPU based on azelate polyols was improved as compared to TPU based on adipate polyols. [ABSTRACT FROM AUTHOR]

The 1,3-dicarbonyl compounds are important building blocks to obtain products with various biological activities and technological applications. In this work, we used a simple transesterification method to develop fatty acetoacetates in a solvent-free medium using a green catalyst, sulfamic acid (NHSOH), under microwave irradiation. The experimental results demonstrate good yields in a short reaction time (13 min), which makes this method an efficient approach to synthesize fatty acetoacetates from a wide range of saturated, unsaturated, and polyunsaturated long chain fatty alcohols, and ricinoleic derivatives. Experiments of recycling of the catalyst were performed and no decrease in catalytic activity of sulfamic acid was observed. [ABSTRACT FROM AUTHOR]

The fungus Verticillium longisporum is a soil-borne plant pathogen of increasing economic importance, and information on plant responses to it is limited. To identify the genes and components involved in the early stages of infection, transcripts in roots of V. longisporum-challenged Arabidopsis Col-0 and the susceptible NON- RACE SPECIFIC DISEASE RESISTANCE 1 ( ndr1-1) mutant were compared using ATH1 gene chips. The analysis revealed altered transcript levels of several terpene biosynthesis genes, including the monoterpene synthase TPS23/27. When transgenic 35S: TPS23/27 and TPS23/27-ami RNA plants were monitored the over-expresser line showed enhanced fungal colonization whereas the silenced genotype was indistinguishable from Col-0. Transcript analysis of terpene biosynthesis genes suggested that only the TPS23/27 pathway is affected in the two transgenic genotypes. To confirm changes in monoterpene production, emitted volatiles were determined using solid-phase microextraction and gas chromatography-mass spectrometry. Levels of all identified TPS23/27 monoterpene products were significantly altered in the transgenic plants. A stimulatory effect on conidial germination and hyphal growth of V. longisporum was also seen in co-cultivation with 35S: TPS23/27 plants and upon exposure to 1,8-cineole, the main product of TPS23/27. Methyl jasmonate treatments of myc2-1 and myc2-2 mutants and analysis of TPS23/27:uidA in the myc2-2 background suggested a dependence on jasmonic acid mediated by the transcription factor MYC2. Taken together, our results show that TPS23/27-produced monoterpenes stimulate germination and subsequent invasion of V. longisporum in Arabidopsis roots. [ABSTRACT FROM AUTHOR]

Earlier findings on the nutritional benefits of diacylglycerols (DAGs) have attracted much attention on the synthesis of DAGs. In this study, we reported an improved method for the lipase-catalyzed synthesis of 1,3-diolein by the irreversible glycerolysis of vinyl oleate with glycerol. The effects of reaction system, lipase loading, molar ratio of vinyl oleate to glycerol, reaction temperature and time on 1,3-diolein content in crude reaction mixture were investigated. When the reaction was conducted in a solvent-free system at 30 °C for 8 h by reacting 2 mmol vinyl oleate with 1 mmol glycerol with 8 % (w/w, relative to total reactants) Lipozyme RM IM (Novozymes, Beijing, China) as catalyst, there were 90.5 ± 2.9 % (area/area) 1,3-diolein and (3.3 ± 0.3) % 1,2-diolein produced. After purification, 1,3-diolein was obtained at 81.4 % yield with 98.2 % purity. The lipase-catalyzed synthesis of 1,3-diolein using vinyl oleate as acyl donor by glycerolysis was also conducted using a medium with 50 mmol of glycerol and 100 mmol vinyl oleate. Compared to enzymatic esterification in a solvent, enzymatic glycerolysis for the synthesis 1,3-diolein is more effective due to the irreversible reaction, mild due to the low reaction temperature, and environmentally benign due to the use of solvent-free reaction system. [ABSTRACT FROM AUTHOR]

Positional-species composition (PSC) of 1,2,3-triacyl- sn-glycerols (TAG) from the arils of mature fruits of 13 species of Euonymus L. genus was established. The residues of six major fatty acids (FA), palmitic, stearic, hexadecenoic (H), octadecenoic (O), linoleic (L), and linolenic, were present in the TAG. PSC of TAG was determined by their partial lipase hydrolysis. By using hierarchical cluster and principal component analyses, it was definitely demonstrated that separate taxonomic units forming this genus were significantly distinguished as regards PSC of TAG. In particular, the Euonymus subgenus greatly exceeded the Kalonymus subgenus in both total content of L in TAG and in the rate of its incorporation into their mid-position, while TAG of Kalonymus were marked by a prevalence of O-TAG and sn-2-O isomers. Thus, these subgenera were significantly distinct in the rate of incorporation of O and L residues in the sn-2 position of TAG molecules. Meanwhile, the TAG from the Euonymus section species were marked by an enhanced concentration of H and the incorporation of H in UUU TAG was much more active than in other TAG types. As for positional-type composition of TAG, saturated FA were always virtually absent in the sn-2 position of Euonymus aril TAG. [ABSTRACT FROM AUTHOR]

Virgin olive oil has high levels of phenolic compounds that are highly bioavailable; these compounds are receiving considerable attention for their antioxidant activity, closely related to the prevention of non-communicable chronic diseases. The aim of this work was to characterize the phenolic profile and antioxidant capacity of monovarietal olive oils cvs. Arauco, Arbequina, Farga and Empeltre produced in Argentina. This study focused on the relationship between the single molecules or classes of molecules quantified by SPE-CZE, the corresponding Folin-Ciocalteu results, and antioxidant capacity using three different tests. Fifteen compounds were simultaneously determined: tyrosol, vinylphenol, oleuropein, hydroxytyrosol, rutin, catechin, naringenin, cinnamic acid, chlorogenic acid, syringic acid, luteolin, apigenin, vanillin acid, quercetin, and caffeic acid. The phenolic contents of the monovarietal olive oils show significant diffe rences between different varieties ( p < 0.05), with positive and significant Pearson's correlation found between Folin-Ciocalteu and CZE. Besides, the correlation between the content of total polyphenols and antioxidant capacity was high for all the antioxidant assays performed. When analyzing the correlation coefficients of the different families of phenolic compounds studied, simple phenols and cinnamic acid derivatives show a higher correlation with antioxidant capacity. Thus, findings obtained in this study demonstrated that Arauco olive oil, autochthonous for Argentina, possesses the highest antioxidant/free-radical scavenging properties, which are very likely due to the presence of high contents of phenolic compounds. [ABSTRACT FROM AUTHOR]

Faced with declining soil-water potential, plants synthesize abscisic acid ( ABA), which then triggers stomatal closure to conserve tissue moisture. Closed stomates, however, also create several physiological dilemmas. Among these, the large CO2 influx required for net photosynthesis will be disrupted. Depleting CO2 in the plant will in turn bias stomatal opening by suppressing ABA sensitivity, which then aggravates transpiration further. We have investigated the molecular basis of how C3 plants resolve this H2O- CO2 conflicting priority created by stomatal closure. Here, we have identified in Arabidopsis thaliana an early drought-induced spermidine spermine- N1 -acetyltransferase homolog, which can slow ABA-mediated stomatal closure. Evidence from genetic, biochemical and physiological analyses has revealed that this protein does so by acetylating the metabolite 1,3-diaminopropane ( DAP), thereby turning on the latter's intrinsic activity. Acetylated DAP triggers plasma membrane electrical and ion transport properties in an opposite way to those by ABA. Thus in adapting to low soil-water availability, acetyl- DAP could refrain stomates from complete closure to sustain CO2 diffusion to photosynthetic tissues. [ABSTRACT FROM AUTHOR]

During the ethoxylation of fatty alcohol, 1,4-dioxane, a toxic by-product may be formed. A simple and rapid method using gas chromatography with a flame ionization detector was developed for detection of 1,4-dioxane in commercial palm-based fatty alcohol ethoxylate (FAEO). The method involved spiking the 1,4-dioxane into FAEO samples, and directly injecting the spiked samples into GC with no clean-up steps. The method was validated in terms of linearity, accuracy, intra-day precision and inter-day precision, selectivity, limit of detection and limit of quantification. In terms of linearity, a calibration curve with a correlation coefficient of 0.9999 was obtained. The accuracy of the method was indicated by recovery obtained for spiked 1,4-dioxane samples at 5 levels of spiking, i.e. at 30, 60, 100, 200 and 500 μg/g, where recoveries were within 99-105 % with relative standard deviation (RSD) of <4.0 %. The RSD values of the intra-day and inter-day precision were <1.0 %. The limit of detection and quantification was 10 and 30 μg/g, respectively. The selectivity of the method was indicated by its ability to analyze commercial FAEO samples with different average moles of ethylene oxide (EO). The GC profiles of these FAEO with varying numbers of moles of EO were similar, and there were no other peaks interfering with the 1,4-dioxane peak. [ABSTRACT FROM AUTHOR]

The multi-stage treatment of stable oil-in-water emulsions produced during non-enzymatic aqueous processing of dehulled yellow mustard flour with cyclic ethers [tetrahydrofuran (THF) and 1,4-dioxane] was investigated to produce a single-phase oil-solvent-water miscella suitable for biodiesel production. While the single-stage treatment of yellow mustard emulsion recovered 97 % and 95 % of the oil by using 4:1 THF:oil and 9:1 dioxane:oil weight ratios, respectively, miscella phases containing more than 7 % water formed, which made them unsuitable as biodiesel feedstock. Multi-stage treatments of the emulsion using lower THF:oil and dioxane:oil weight ratios were further developed to produce oil-solvent-water miscella phases with low water content. While three-stage extraction of emulsions using 0.5:1, 1:1, 1.5:1, and 2:1 dioxane:oil weight ratios did not destabilize the emulsion, three-stage extraction using 0.5:1 and 0.75:1 THF:oil weight ratios effectively recovered over 97 % of the oil, resulting in the production of oil-rich miscella phases containing only 1 % and 1.5 % water, respectively. These miscella phases were analyzed for free fatty acid and phosphorus contents and proved to be excellent feedstocks for the preparation of high-purity methyl esters through single-phase base-catalyzed transmethylation. [ABSTRACT FROM AUTHOR]

The content and fatty acid (FA) composition of FA neutral acylglycerols (NAG), a mixture of 1,2,3-triacyl- sn-glycerols (TAG) and 3-acetyl-1,2-diacyl- sn-glycerols ( acDAG), were determined in the seeds and arils of fruits of 14 Euonymus L. species. On the average, the seeds exceeded the arils in the absolute and relative dry matter content 2.9- and 1.9-fold, respectively, and separate plant species greatly differed in NAG composition. The proportions of TAG in the NAG of seeds and arils were 4-5 and ~98 %, respectively. The degree of FA unsaturation in aril NAG was higher than in the seed NAG, and in acDAG-higher, than in TAG. In the NAG, 14 major FA molecular species (excluding minor FA) were found, and linoleic, oleic, palmitic, and linolenic acids were predominant. NAG of separate taxonomic units of the genus Euonymus L. differed from each other in the concentration of major FA as well as other FA. So, by using statistical analysis, it was definitely established that the species from the subgenus Euonymus were characterized by an increased content of linoleic acid, while those from the subgenus Kalonymus, by the predominance of oleic acid. Meanwhile, the species of the section Euonymus were marked by an enhanced concentration of a number of hexa- and octadecenoic FA positional isomers. [ABSTRACT FROM AUTHOR]

The effect of storage conditions (light, temperature, container types) and time on the quality of natural olive oils from different cultivars and Australian regions were studied. The oils' changing quality was monitored through several physico-chemical methods (free fatty acids, peroxide value, UV-spectrometry (K, K and Δ K), induction time, total polyphenol content, bitterness, pyropheophytin a and 1,2-diacyl-glycerol content) and sensory analysis over 24 months. Pyropheophytins a and 1,2-diacyl-glycerols criteria showed very good performance as indicators of overall olive oil quality and freshness as well as highlighting any problems during the storage of the product. Pyropheophytin a increment averaged 7 % per year and the 1,2-diacyl-glycerols decreased at an average of 23 % per year at normal storage conditions over time. [ABSTRACT FROM AUTHOR]

An efficient solvent-free synthesis of a variety of highly pure 1,3- sn-diglycerides (1,3- sn-diacylglycerols) in a two-step one pot process is described. Heating glycerol carbonate (4-hydroxymethyl-1,3-dioxolan-2-one) with fatty acid anhydrides 2a-d affords 1:1 mixtures of glycerol carbonate fatty esters 3a-3d and the corresponding fatty acids. Further heating the reaction mixtures in the presence of catalytic amounts of 1,4-diazabicyclo[2.2.2]octane (DABCO) at 195-200 °C yields highly pure 1,3- sn-diglycerides 4a-4d. [ABSTRACT FROM AUTHOR]

Metabolic engineering aimed at monoterpene production has become an intensive research topic in recent years, although most studies have been limited to herbal plants including model plants such as Arabidopsis. The genus Eucalyptus includes commercially important woody plants in terms of essential oil production and the pulp industry. This study attempted to modify the production of monoterpenes, which are major components of Eucalyptus essential oil, by introducing two expression constructs containing Perilla frutescens limonene synthase ( PFLS) cDNA, whose gene products were designed to be localized in either the plastid or cytosol, into Eucalyptus camaldulensis. The expression of the plastid-type and cytosol-type PFLS cDNA in transgenic E. camaldulensis was confirmed by real-time polymerase chain reaction (PCR). Gas chromatography with a flame ionization detector analyses of leaf extracts revealed that the plastidic and cytosolic expression of PFLS yielded 2.6- and 4.5-times more limonene than that accumulated in wild-type E. camaldulensis, respectively, while the ectopic expression of PFLS had only a small effect on the emission of limonene from the leaves of E. camaldulensis. Surprisingly, the high level of PFLS in Eucalyptus was accompanied by a synergistic increase in the production of 1,8-cineole and α-pinene, two major components of Eucalyptus monoterpenes. This genetic engineering of monoterpenes demonstrated a new potential for molecular breeding in woody plants. [ABSTRACT FROM AUTHOR]

The article reports on the results of research which was done in an effort to define a serum 25(OH)D calcium level below which the serum 1,25(OH)D can no longer be sustained. researchers found that vitamin D deficiency does not reduce serum 1,25(OH)D or calcium absorption until the serum falls to the -10nM level.

The article focuses on the physiological role of fibroblast growth factor (FGF)23 in the regulation of phosphate and vitamin D in metabolism. The discussion includes the structural characteristics of FGF23, the use of anti-FGF23 monoclonal antibodies to inhibit the FGF23 mechanism of action in vitro and in vivo, the results of the Klotho-dependent reporter assay in a mouse model, and the masking of FGF receptor-binding sites in the N-terminal and C-terminal domains.

Background and purpose:Vascular endothelial cells play a role in the physiological response to mechanical stress. Transforming growth factor β1 (TGFβ1) induces morphological changes in endothelial cells, and this may alter their mechanosensitive responses. The aim of this study was to examine the effects of TGFβ1 on hypotonic stress (HTS)-induced responses in bovine aortic endothelial cells (BAECs).Experimental approach:Cultured BAECs were treated with 3 ng ml-1 TGFβ1 for 24 h (24h-TGFβ1) or 7 days (7d-TGFβ1). Cytosolic actin fibres were stained with rhodamine-phalloidin. Intracellular Ca2+ concentration was measured using fura2. Tyrosine phosphorylation and RhoA expression were assessed by Western blotting. Expression of RhoA mRNA was assessed by real-time PCR.Key results:BAECs developed pseudopod-like processes within 24 h and showed a fibroblast-like appearance after 7 days. HTS induced Ca2+ transients via endogenous ATP release in both control and 24h-TGFβ1 BAECs but not in 7d-TGFβ1 BAECs. We have previously shown that HTS-induced ATP release is mediated by sequential activation of RhoA and tyrosine kinases. The basal amount of membrane-bound RhoA was significantly lower in 7d-TGFβ1 than in 24h-TGFβ1 or control BAECs. HTS increased the membrane-bound RhoA to the same fractional level in 24h-TGFβ1 and control BAECs, but its net maximal amount was significantly lower in 7d-TGFβ1. HTS-induced downstream signals of RhoA activation, i.e. the tyrosine phosphorylation of FAK and paxillin, were markedly suppressed in 7d-TGFβ1 BAECs.Conclusions and Implications:These results indicate that long-term treatment with TGFβ1 does not impair mechanoreception in BAECs but impairs mechanotransduction by affecting RhoA membrane translocation.British Journal of Pharmacology (2007) 150, 424–433. doi:10.1038/sj.bjp.0707123; published online 15 January 2007 [ABSTRACT FROM AUTHOR]

Background and purpose:Inhibition of hepatic glycogen phosphorylase is a potential treatment for glycaemic control in type 2 diabetes. Selective inhibition of the liver phosphorylase isoform could minimize adverse effects in other tissues. We investigated the potential selectivity of two indole site phosphorylase inhibitors, GPi688 and GPi819.Experimental approach:The activity of glycogen phosphorylase was modulated using the allosteric effectors glucose or caffeine to promote the less active T state, and AMP to promote the more active R state. In vitro potency of indole site inhibitors against liver and muscle glycogen phosphorylase a was examined at different effector concentrations using purified recombinant enzymes. The potency of GPi819 was compared with its in vivo efficacy at raising glycogen concentrations in liver and muscle of Zucker (fa/fa) rats.Key results:In vitro potency of indole site inhibitors depended upon the activity state of phosphorylase a. Both inhibitors showed selectivity for liver phosphorylase a when the isoform specific activities were equal. After 5 days dosing of GPi819 (37.5 μmol kg−1), where free compound levels in plasma and tissue were at steady state, glycogen elevation was 1.5-fold greater in soleus muscle than in liver (P<0.05).Conclusions and implications:The in vivo selectivity of GPi819 did not match that seen in vitro when the specific activities of phosphorylase a isoforms are equal. This suggests T state promoters may be important physiological regulators in skeletal muscle. The greater efficacy of indole site inhibitors in skeletal muscle has implications for the overall safety profile of such drugs.British Journal of Pharmacology (2006) 149, 775–785. doi:10.1038/sj.bjp.0706925; published online 3 October 2006 [ABSTRACT FROM AUTHOR]

A novel elicitor that induces chitinases in tobacco BY-2 cells was isolated from Alternaria alternata 102. Six other fungi, including A. alternata IFO 6587, could not induce, or weakly induce chitinase activity. The purified elicitor was soluble in 75% methanol and showed the chitinase-inducing activity when applied at concentrations of as low as 25 ng·mL−1. Structural determination by methylation analysis, reducing-end analysis, MALDI-TOF/MS, and NMR spectroscopy indicated that the elicitor was a mixture of β-1,3-, 1,6-oligoglucans mostly with a degree of polymerization of between 8 and 17. Periodate oxidation of the elicitor suggested that the 1,6-linked and nonreducing terminal residues are essential for the elicitor activity. Further analysis of the elicitor responses in BY-2 cells indicated that the activity of this β-1,3-, 1,6-glucan elicitor was about 1000 times more potent than that of laminarin, which is a known elicitor of defense responses in tobacco. Analyzing the expression of defense-related genes indicated that a phenylalanine ammonia-lyase gene and a coumaroyl-CoA O-methyltransferase gene were transiently expressed by this β-1,3-, 1,6-glucan elicitor. The elicitor induced a weak oxidative burst but did not induce cell death in the BY-2 cells. In the tissue of tobacco plants, this β-1,3-, 1,6-glucan elicitor induced the expression of basic PR-3 genes, the phenylpropanoid pathway genes, and the sesquiterpenoid pathway genes. In comparison with laminarin and laminarin sulfate, which are reported to be potent elicitors of defense responses in tobacco, the expression pattern of genes induced by the purified β-1,3-, 1,6-glucan elicitor was more similar to that induced by laminarin than to that induced by laminarin sulfate. [ABSTRACT FROM AUTHOR]

Abstract. Salomaa V, Pankow J, Heiss G, Cakir B, Eckfeldt JH, Ellison RC, Myers RH, Hiller KM, Brantley KR, Morris TL, Weston BW (National Public Health Institute, Helsinki, Finland, University of North Carolina, University of Minnesota, Boston University School of Medicine, USA). Genetic background of Lewis negative blood group phenotype and its association with atherosclerotic disease in the NHLBI Family Heart Study, J Intern Med 2000; 247: 689–698. Objectives. To examine the prevalence of four mutations, T59G, T1067A, T202C and C314T, of the human α(1,3/1,4) fucosyltransferase 3 (FUT 3) gene amongst persons with Lewis negative and those with Lewis positive blood group phenotype. An additional objective was to explore the hypothesis that these mutations are associated with coronary heart disease and inflammatory reaction. Design. A population-based cross-sectional study. Setting. Analysis of samples and data from the National Heart Lung and Blood Institute Family Heart Study. Subjects. All Lewis (a–b–) participants (n = 136) and a sample of Lewis positive participants (n = 136) of the Family Heart Study; all were of Caucasian ethnicity. Main outcome measures. The prevalence of examined mutations by Lewis phenotype. Results. The examined mutations were common and strongly associated with the Lewis (a–b–) phenotype. Accordingly, 90–95% of Lewis (a–b–) individuals amongst Caucasians can be identified by screening for these four mutations. Exploratory analyses suggested that with the exception of T59G, all examined mutations were positively associated with prevalent coronary heart disease, although not statistically significantly, perhaps due to the small number of prevalent coronary heart disease cases. C-reactive protein tended to be higher amongst persons with a TC or CC genotype at position 202 (3.07 ± 0.41 vs. 2.08 ± 0.32 mg L–1, P = 0.06). Conclusions. Four specific mutations of fucosyltransferase 3 gene are responsible for the vast majority of Lewis (a–b–) phenotypes in Caucasians. These mutations are common in the population at large and may be associated with increased risk of coronary heart disease. Further studies using larger samples are warranted. [ABSTRACT FROM AUTHOR]

The presence of very low concentrations of the widely used denaturant urea induces structural changes in the monomeric heme-containing enzyme, horseradish peroxidase (HRP). Structural alterations in the protein were reflected in quenching studies of tryptophan fluorescence using the widely used quencher acrylamide. Stern–Volmer quenching constants measured in presence of urea, even in concentrations below 100 mm, were higher than those measured in absence of the denaturant. The fluorescence emission maximum of 1,8-ANS, used as a probe for monitoring conformational changes in the enzyme, was blue-shifted from 530 nm in aqueous buffer to 518 nm when incorporated in native HRP. This blue shift increased further by 3 nm in presence of HRP preincubated with 100 mm urea, whereupon it steadily decreased with increasing urea concentration to become zero at 8 m urea. The mean fluorescence lifetime of 1,8-ANS incorporated in HRP was much higher than that of ANS in aqueous buffer, and showed continuous variation with the concentration of urea in which the enzyme was incubated. Systematic changes in the microenvironment of the heme moiety in HRP were also reflected in the visible CD spectra of the enzyme incubated with low concentrations of urea. These results are consistent with those of our earlier studies performed with the denaturant guanidinium chloride and indicate structural relaxation of HRP, with retention of enzymatic activity and native-like secondary structure, in presence of millimolar concentrations of urea. [ABSTRACT FROM AUTHOR]

The fructan-β-fructosidase activity (1 -FEH; EC 3 . 2. 1 . 80) that degrades inulin in tubers of Helianthus tuberosus L. appears to be developmentally regulated; it was low in growing tubers but increased during dormancy and sprouting. In spite of relatively high 1-FEH activity in vitro, fructose concentration was very low in developing and dormant tubers and increased markedly only during sprouting. A fructan-β-fructosidase from such sprouting tubers was purified 41-fold to a single protein band on one-dimensional sodium dodecylsulphate-polyacrylamide gels. The purification procedure included ammonium sulphate precipitation, lectin-affinity chromatography on concanavalin A, anion-exchange and cation-exchange chromatography. The enzyme had an apparent molecular mass of 75000 measured by size-exclusion chromatography, and 79000 measured by one-dimensional sodium dodecylsulphate-polyacrylamide gel electrophoresis. It exhibited a high substrate specificity, hydrolysing terminal β-(2-1)-fructosyl-fructose-linkages in linear and branched fructan oligomers; β-(2-6)-linkages were hardly hydrolysed. Hydrolysis of inulin oligomers followed normal saturation kinetics: Km values for 1,1 -kestotetraose and 1,1,1-kestopentaose were 8.3 mM and 12 mM, respectively. Fructosyl residues were hydrolysed from inulin oligomers by a multi-chain mechanism. The fructan-β-fructosidase showed optimal enzyme activity at pH 5.2, and it retained its full activity after pre-incubation for 1 h at up to 40 °C. The release of fructose from 5 mM 1,1- kestotetraose was reduced by 25% when 1-FEH was assayed in the presence of 10 mM sucrose. It is proposed that the inhibition of 1-FEH activity by sucrose is a mechanism for controlling fructan degradation in planta. [ABSTRACT FROM AUTHOR]

Fructan pentasaccharides were purified, in quantities suitable for use as substrates for enzyme assays, from Neosugar-P (Meiji Seika Kaisha Ltd., Japan), tubers of Helianthus tuberosus L., and stems and leaf sheaths of Triticum aestivum L. by a combination of gel-filtration and RP-HPLC. Fructan of higher molecular mass (mean DP - 30) was purified from leaves of Lolium rigidum Gaud. that had been induced to accumulate fructan and characterized along with the commercially available fructan from Cichorium intybus L. (Sigma, St Louis, USA) (mean DP = 33). The fructan pentasaccharide purified from H. tuberosus was found to contain exclusively 2,1- linked fructose and terminal fructose and terminal glucose, and was identified as (1,1,1)-kestopentaose. The fructan pentasaccharide purified from Neosugar-P also contained (1,1,1)-kestopentaose, although the presence of 3% 1,6-linked glucose and 1% 2,6-linked fructose indicated that a small proportion of other kestopentaoses were present. The fructan pentasaccharide purified from T. aestivum consisted of almost exclusively 2,6-linked fructose and terminal glucose and terminal fructose and was considered to contain predominantly (6,6,6)-kestopentaose. The presence of 1% 2,1,6-linked fructose indicated the sample also contained a small proportion of branched kestopentaose. The high molecular mass fructan from C. intybus was found to comprise linear molecules containing only 2,1-linked fructose, terminal glucose and terminal fructose. High molecular mass fructan from L. rigidum contained predominantly 2,6-linked fructose, had predominantly internal glucose, indicated by 2% 1,6-linked glucose, low levels of branching, indicated by 2% 2,1,6-linked fructose residues and 1% of the residues were 2,1-linked fructose. [ABSTRACT FROM AUTHOR]