WorldWideScience

Sample records for broccoli coq5 methyltransferase

  1. Targeting cancer stem cells with sulforaphane, a dietary component from broccoli and broccoli sprouts.

    Science.gov (United States)

    Li, Yanyan; Zhang, Tao

    2013-08-01

    Many studies have supported the protective effects of broccoli and broccoli sprouts against cancer. The chemopreventive properties of sulforaphane, which is derived from the principal glucosinolate of broccoli and broccoli sprouts, have been extensively studied. Recent research into the effects of sulforaphane on cancer stem cells (CSCs) has drawn lots of interest. CSCs are suggested to be responsible for initiating and maintaining cancer, and to contribute to recurrence and drug resistance. A number of studies have indicated that sulforaphane may target CSCs in different types of cancer through modulation of NF-κB, SHH, epithelial-mesenchymal transition and Wnt/β-catenin pathways. Combination therapy with sulforaphane and chemotherapy in preclinical settings has shown promising results. In this article, we focus on the effects of sulforaphane on CSCs and self-renewal pathways, as well as giving a brief review of recent human studies using broccoli sprout preparations.

  2. Identification of Resistance to Blackrot in Broccoli

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The screening for Black rot(Xanthomonas campestris PV.campestris)resistance in broccoli (Brassica oleracea L.Var.italica Planch) lines plays an important role in breeding for Black rot resistance and is of great value to practical utilization.The broccoli in bred line"91-9318-4"was used as the experimental material in the trial.X0-2 strain of Xanthomonas campestris PV.campestris was and purified from the infected broccoli plants in the field.The spraying method was adopted in the inoculation.The trial was designed as the randomized blocks of two factors with three replications.Factor A was the foliar age and factor B was the concetrations of inoculum.Factor A had three levels A1,A2 and A3 (the 2nd 4th and 6th true-leaf stage),factor B had three levels B1,B2 and B3(106 counts/mL,107 counts/mL and 108 counts/mL).26 breeding materials of broccoli were identified for resistance to Black rot by means of the acquired method.One resistant breeding material was obtained,the identifying results showed that this screening method is practical.

  3. Agronomy of strip intercropping broccoli with alyssum for biological control of aphids

    Science.gov (United States)

    Organic broccoli growers in California typically control aphids by intercropping broccoli with strips of alyssum (Lobularia maritima (L.) Desv.) which attracts hoverflies (Diptera: Syrphidae) that are important predators of aphids. A three year study with transplanted organic broccoli in Salinas, ...

  4. Therapeutic Potential of Brassica oleracea (Broccoli) - A Review

    OpenAIRE

    Chandini Ravikumar

    2015-01-01

    Broccoli is an edible green plant that is classified in the Italica cultivar group of the species Brassica oleracea. They are rich in vitamin C, dietary fiber and also contain glucoraphin, sulforaphane, selenium and isothiocyanates. Broccoli is also an excellent source of indole-3-carbinol. These constituents present in broccoli are known to be very popular since they possess several anti-cancer properties and benefits. These anti-carcinogenic compounds have a wide variety of uses and benefit...

  5. Novel concepts of broccoli sulforaphanes and disease: induction of phase II antioxidant and detoxification enzymes by enhanced-glucoraphanin broccoli.

    Science.gov (United States)

    James, Don; Devaraj, Sridevi; Bellur, Prasad; Lakkanna, Shantala; Vicini, John; Boddupalli, Sekhar

    2012-11-01

    Consumption of broccoli has long been considered to play a role in a healthy diet. Broccoli accumulates significant amounts of the phytonutrient glucoraphanin (4-methylsulfinylbutyl glucosinolate), which is metabolized in vivo to the biologically active sulforaphane. The preponderance of evidence available from in vitro, animal, and human studies supports the association of sulforaphane with phase II enzyme induction. This has provided impetus for developing varieties of broccoli, both sprouts and whole heads, that are rich in glucoraphanin. The cancer-preventive properties of cruciferous vegetables, especially broccoli, have been studied for decades. However, evidence of broccoli directly affecting cancer incidence or progression is ambiguous, in part because of the presence of substantial polymorphisms in enzymes that metabolize sulforaphane. Since broccoli sulforaphane is one of the most potent inducers of phase II enzymes, exploration into broccoli's impact on other areas of human health, such as cardiovascular health and upper airway immunity, has been suggested. This review provides an update on evidence supporting phase II enzyme induction by sulforaphanes, with implications for breeding broccoli varieties with enhanced amounts of glucoraphanin. Early-stage human studies of consumption of broccoli with enhanced glucoraphanin are also discussed.

  6. Anomalies in moisture transport during broccoli drying monitored by MRI?

    NARCIS (Netherlands)

    Jin, X.; Boxtel, van A.J.B.; Gerkema, E.; Vergeldt, F.J.; As, van H.; Straten, van G.; Boom, R.M.; Sman, van der R.G.M.

    2012-01-01

    Magnetic resonance imaging (MRI) offers unique opportunities to monitor moisture transport during drying or heating of food, which can render unexpected insights. Here, we report about MRI observations made during the drying of broccoli stalks indicating anomalous drying behaviour. In fresh broccoli

  7. Therapeutic Potential of Brassica oleracea (Broccoli - A Review

    Directory of Open Access Journals (Sweden)

    Chandini Ravikumar

    2015-05-01

    Full Text Available Broccoli is an edible green plant that is classified in the Italica cultivar group of the species Brassica oleracea. They are rich in vitamin C, dietary fiber and also contain glucoraphin, sulforaphane, selenium and isothiocyanates. Broccoli is also an excellent source of indole-3-carbinol. These constituents present in broccoli are known to be very popular since they possess several anti-cancer properties and benefits. These anti-carcinogenic compounds have a wide variety of uses and benefits for the treatment of various diseases and disorders. Broccoli is widely used in the treatment of several forms of cancer and also treats other neural disorders. The therapeutic potential of broccoli has been explained under its role in cancer, diabetes and other diseases. In the treatment of cancer, most of the constituents or the phytochemicals of broccoli such as brassinin, isothiocyanates, indole-3-carbinol etc. have been proved to be effectively beneficial. Even selenium plays a very important role in cancer prevention. The antioxidant activity of broccoli is induced by other phytochemicals such as glucosinolates, glucoraphin and sulforaphane. Sulforaphane in broccoli sprouts also has the potential to cure neural disorders such as Alzheimer’s disease and Parkinson’s disease. It is also used to bring about cure in asthma and diabetic patients. Flavonoids have the effect of reducing the risk of diabetes. Therefore sulforaphane is widely used to treat various diseases and disorders.

  8. Synthesis of Lysine Methyltransferase Inhibitors

    Directory of Open Access Journals (Sweden)

    Tao eYe

    2015-07-01

    Full Text Available Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

  9. Anomalies in moisture transport during broccoli drying monitored by MRI?

    Science.gov (United States)

    Jin, Xin; van Boxtel, Antonius J B; Gerkema, Edo; Vergeldt, Frank J; Van As, Henk; van Straten, Gerrit; Boom, Remko M; van der Sman, Ruud G M

    2012-01-01

    Magnetic resonance imaging (MRI) offers unique opportunities to monitor moisture transport during drying or heating of food, which can render unexpected insights. Here, we report about MRI observations made during the drying of broccoli stalks indicating anomalous drying behaviour. In fresh broccoli samples the moisture content in the core of the sample increases during drying, which conflicts with Fickian diffusion. We have put the hypothesis that this increase of moisture is due to the stress diffusion induced by the elastic impermeable skin. Pre-treatments that change skin and bulk elastic properties of broccoli show that our hypothesis of stress-diffusion is plausible.

  10. Histone methyltransferases in cancer

    DEFF Research Database (Denmark)

    Albert, Mareike; Helin, Kristian

    2009-01-01

    Cancer is perceived as a heterogeneous group of diseases that is characterized by aberrant patterns of gene expression. In the last decade, an increasing amount of data has pointed to a key role for epigenetic alterations in human cancer. In this review, we focus on a subclass of epigenetic...... regulators, namely histone methyltransferases (HMTs). Several HMTs have been linked to different types of cancer; however, in most cases we only have limited knowledge regarding the molecular mechanisms by which the HMTs contribute to disease development. We summarize the current knowledge regarding some...

  11. Health benefits and possible risks of broccoli - an overview.

    Science.gov (United States)

    Latté, Klaus Peter; Appel, Klaus-Erich; Lampen, Alfonso

    2011-12-01

    Chemopreventive effects of broccoli, a highly valued vegetable, have been known for a long time. Several studies have demonstrated that broccoli might be beneficial by reducing the risk for the development of certain forms of cancer. These effects are generally attributed to glucosinolate-derived degradation products like isothiocyanates and indoles which are formed by the hydrolytic action of plant myrosinase and/or glucosidases deriving from the human microbial flora. However, recent in vitro and experimental animal studies indicate that broccoli, its extracts and the glucosinolate-derived degradation products might also have undesirable effects, especially genotoxic activities. However, the relevance of the genotoxic activities to human health is not known yet. This paper gives an overview on genotoxic, anti-genotoxic/chemopreventive, nutritive and antinutritive properties of broccoli, its ingredients and their degradation products. A qualitative comparison of the benefit and risk of broccoli consumption benefit-risk assessment shows that the benefit from intake in modest quantities and in processed form outweighs potential risks. For other preparations (fortified broccoli-based dietary supplements, diets with extraordinary high daily intake, consumption as a raw vegetable) further studies both for potential risks and beneficial effects are needed in order to assess the benefit and risk in the future.

  12. Direct-Seeded Broccoli Responses to Reduced Nitrogen Application at Shoot-Tip Straightened Stage

    OpenAIRE

    LI Hong; Li, Tingxian; Robert J. Gordon; Asiedu, Samuel K.

    2009-01-01

    Broccoli (Brassica oleracea var. italica) is an important high-nutritional-value vegetable yet broccoli plant and nitrogen nutrition relations are not well understood. We conducted a study of broccoli plant response to nitrogen nutrient treatments in a commercial production field in Nova Scotia. The objectives were to quantify the effects of nitrogen nutrition on direct-seeded broccoli development and plant nitrogen uptake in different soils. The nitrogen treatments consisted of the rates of ...

  13. Production and postharvest quality maintenance of single unit and bunching broccoli in Virginia

    OpenAIRE

    Jett, Lewis W.

    1990-01-01

    Broccoli (Brassica oleracea L. var. italica) has become an increasingly popular vegetable with American consumers. Much of the attractiveness of fresh broccoli is derived from this vegetable's high nutrition and excellent organoleptic properties. In a consumer response survey, Virginia Master Gardeners indicated a preference for broccoli that has less stalk and more florets by weight. The objectives of this research were to produce single unit broccoli, and to examine vac...

  14. Influence of Extraction Method on Quality and Functionality of Broccoli Juice

    OpenAIRE

    Lee, Sung Gyu; Kim, Jin-Hee; Son, Min-Jung; Lee, Eun-Ju; Park, Woo-Dong; Kim, Jong-Boo; Lee, Sam-Pin; Lee, In-Seon

    2013-01-01

    This study was performed to compare the quality and functionality of broccoli juice as affected by extraction method. Broccoli juice was extracted using method I (NUC Kuvings silent juicer), method II (NUC centrifugal juicer), and method III (NUC mixer), and the quality properties of the broccoli juices were analyzed using three different methods. Additionally, the antioxidative, anticancer, and anti-hyperglycemic activities of broccoli juice prepared by the three different methods were inves...

  15. Selenium enrichment of broccoli sprout extract increases chemosensitivity and apoptosis of LNCaP prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Suzuki Kazuhiro

    2009-11-01

    Full Text Available Abstract Background Broccoli is a Brassica vegetable that is believed to possess chemopreventive properties. Selenium also shows promise as an anticancer agent. Thus, selenium enrichment of broccoli has the potential to enhance the anticancer properties of broccoli sprouts. Method Selenium-enriched broccoli sprouts were prepared using a sodium selenite solution. Their anticancer properties were evaluated in human prostate cancer cell lines and compared with those of a control broccoli sprout extract. Results Selenium-enriched broccoli sprouts were superior to normal broccoli sprouts in inhibiting cell proliferation, decreasing prostate-specific antigen secretion, and inducing apoptosis of prostate cancer cells. Furthermore, selenium-enriched broccoli sprouts but, not normal broccoli sprouts, induced a downregulation of the survival Akt/mTOR pathway. Conclusion Our results suggest that selenium-enriched broccoli sprouts could potentially be used as an alternative selenium source for prostate cancer prevention and therapy.

  16. Dielectric properties of tantalum powder with broccoli-like morphology

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Masahiko [Department of Energy Science and Technology, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Suzuki, Ryosuke O. [Department of Energy Science and Technology, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)]. E-mail: suzuki@energy.kyoto-u.ac.jp

    2005-04-19

    Metallic tantalum powder with broccoli-like morphology, consisting of spherical fine particles and of long rods or thin plates, was prepared in a hundred gram scale by calcium reduction of Ta{sub 2}O{sub 5} in molten CaCl{sub 2}. The properties as electrolytic capacitor were evaluated in comparison with commercial powder obtained by Na reduction and with powder consisting of only fine particles obtained by Ca reduction. The capacitance was larger than that of conventional powder with the same surface area, because the broccoli-like powder showed a strong resistance against shrinkage during high temperature annealing due to the framework of branches. The powder with new broccoli-like morphology can circumvent the conventional treatments for grain size control and gas removal.

  17. Food safety evaluation of broccoli and radish sprouts.

    Science.gov (United States)

    Martínez-Villaluenga, Cristina; Frías, Juana; Gulewicz, Piotr; Gulewicz, Krzysztof; Vidal-Valverde, Concepción

    2008-05-01

    Three cultivars of broccoli seeds (Brassica oleracea var. italica), cv. Tiburon, cv. Belstar and cv. Lucky, and two cultivars of radish seeds (Raphanus sativus), cv. Rebel and cv. Bolide, were germinated for three and five days and safety aspects such as microbiological counts and biogenic amines were investigated. Cytotoxicity evaluation was also carried out. Broccoli and radish sprouts contained numbers of mesophilic, psychrotrophic, total and faecal coliform bacteria which are the usual counts for minimally processed germinated seeds. Putrescine, cadaverine, histamine, tyramine, spermidine and spermine increased during sprout production although these levels were below those permitted by legislation (5 mg/100 g of edible food). Broccoli and radish sprouts demonstrated no toxic effects on proliferation and viability of HL-60 cells and should be included in our diets as healthy and safe fresh foods.

  18. Selenium enrichment of broccoli sprout extract increases chemosensitivity and apoptosis of LNCaP prostate cancer cells

    OpenAIRE

    Suzuki Kazuhiro; Ito Kazuto; Suradji Eka W; Yamazaki Chiho; Kobayashi Kenji; Faried Ahmad; Abdulah Rizky; Murakami Masami; Kuwano Hiroyuki; Koyama Hiroshi

    2009-01-01

    Abstract Background Broccoli is a Brassica vegetable that is believed to possess chemopreventive properties. Selenium also shows promise as an anticancer agent. Thus, selenium enrichment of broccoli has the potential to enhance the anticancer properties of broccoli sprouts. Method Selenium-enriched broccoli sprouts were prepared using a sodium selenite solution. Their anticancer properties were evaluated in human prostate cancer cell lines and compared with those of a control broccoli sprout ...

  19. No de novo sulforaphane biosynthesis in broccoli seedlings

    NARCIS (Netherlands)

    Gorissen, Antonie; Kraut, Nicolai U.; de Visser, Ries; de Vries, Marcel; Roelofsen, Han; Vonk, Roel J.

    2011-01-01

    The isothiocyanate sulforaphane, present in significant amounts in broccoli (Brassica oleracea L.) seedlings in the form of its precursor glucoraphanin, has been identified as an inducer of quinine reductase, a phase-II detoxification enzyme known for its anticarcinogenic properties. Its concentrati

  20. The Effect of Steaming on the Glucosinolate Content in Broccoli

    NARCIS (Netherlands)

    Verkerk, R.; Knol, J.J.; Dekker, M.

    2010-01-01

    Total and individual glucosinolates were measured after different duration of steaming broccoli (Brassica oleracea L. var. italica). During steaming, the temperature profile, cell lysis and inactivation of myrosinase were assessed as well. Steaming resulted in high retention of total aliphatic and i

  1. SOIL MULCHING WITH STRAW IN BROCCOLI CULTIVATION FOR EARLY HARVEST

    Directory of Open Access Journals (Sweden)

    Edyta Kosterna

    2014-04-01

    Full Text Available All treatments which protect soil from degradation and use of plant protection methods, other than chemicals are of great importance in the cultivation. This effect is attributed, among others, to organic mulches. By limiting the growth of weeds, maintaining proper moisture and reducing daily temperature fluctuations, mulch improves soil conditions for plant growth and development. The experiment was carried out between 2010 and 2012 at the Experimental Farm in Zawady as a split-block design with three replicates. The effect of the kind of straw (rye, corn, rape, buckwheat and its dose (10 and 20 t∙ha-1 applied as a mulch on the yield and quality of broccoli ‘Milady F1’ cultivated for early harvest was investigated. The effect of straw was compared to a control plot without mulch. Weather conditions in the successive years of the study had a significant influence on the yield and quality of broccoli. The highest yields with the best parameters were obtained in 2010 and 2012, which were characterized by sufficient rainfall for broccoli. It was not found significant differences in the yield level and weight of head between particular kinds of straw, however, all kinds of straw investigated in the experiment, irrespective of dose, contributed to a significant increase in the yield and favourably influenced the biometric features of broccoli compared to that achieved from cultivation without straw. Soil mulching with corn straw was most favourable to yield and its parameters.

  2. Innovative minimal processing of mini broccoli for keeping quality and safety and enhancing bioactive compounds

    OpenAIRE

    Martínez Hernández, Ginés Benito

    2012-01-01

    [ENG] Broccoli has been described as the ‘super–vegetable’ in the media after a great number of epidemiological and laboratory studies on this Brassica specie. These studies have shown numerous health–promoting properties of broccoli such as chemopreventive, antioxidant, antitumor, antimutagenicity, anti–inflammatory, antimicrobial, antiviral and reduction of coronary heart disease risk. These properties are related to the high content of broccoli in phenolic compounds, glucosinolates (isothi...

  3. THE INFLUENCE OF NUTRITION ON THE MAIN PRODUCTION OF BROCCOLI

    Directory of Open Access Journals (Sweden)

    Mădălina Doltu

    2013-07-01

    Full Text Available The research was realized in the unheated greenhouse of Horting Institute Bucharest, in 2012 year. It have aimed the influence of one phase of fertilization with ammonium nitrate (NH4NO3 on inflorescences of broccoli, at a hybrid F1 - Ironman. The fertilizer was used before the formation of main inflorescences, in different doses (100 kg/ha, 150 kg/ha, without fertilizer. Harvesting was done in 4 stages. A phase of fertilization with ammonium nitrate has influenced the main production of broccoli: the variant with fertilization 150 kg/ha has obtained the highest percentage of inflorescences formed, the average weight/inflorescence largest and superior production compared with other variants. Were obtained direct linear correlations between the doses of ammonium nitrate (NH4NO3 and the production aspects followed (percentage of main inflorescences harvested, average weight/inflorescence, total production, significances of the correlations very high.

  4. Broccoli, PTEN deletion and prostate cancer: where is the link?

    Directory of Open Access Journals (Sweden)

    Bardelli Alberto

    2010-12-01

    Full Text Available Abstract The concept that vegetables and fruits are relevant sources of cancer-preventive substances is strongly supported by population studies. Among others, cruciferous vegetables like broccoli, cabbage, cauliflower and Brussels sprouts are thought to affect the development of various types of cancers and especially prostate tumors. Yet, the identification of the molecular mechanisms by which the 'active' compounds contained in these vegetables mediate their anticancer activity has historically lagged behind. Accordingly, direct laboratory evidence of how individual nutrients affect cancer genes and the pathways they control remains the major obstacle to progress in this research field. Here we review a recent report investigating the interaction between sulforaphane, a dietary isothiocyanate derived from broccoli, and expression of the PTEN tumor suppressor gene in pre malignant prostate tissue.

  5. Polymer coating, germination and vigor of broccoli seeds

    OpenAIRE

    Almeida Celina de; Rocha Sandra Cristina dos Santos; Razera Luiz Fernandes

    2005-01-01

    Brassica oleracea var italica occupies a special place in the internal and external market of vegetables seeds. Vegetables producers demand seeds with high degree of purity, germination and vigor, since seeds' quality is the basis for the success of the production. In this work, broccoli seeds were coated in a spouted bed, by an aqueous suspension of hidroxy-ethyl-cellulose. Effects of the operating variables: spouting air temperature, atomizing air pressure and coating suspension flow rate o...

  6. Evaluation of genotypic variation of broccoli (brassica oleracea var. italic) in response to selenium treatment

    Science.gov (United States)

    Broccoli (Brassica oleracea var. italic) fortified with selenium (Se) has been promoted as a functional food. Here we evaluated 38 broccoli accessions for their capacity to accumulate Se and for their responses to selenate treatment in terms of nutritional qualities and sulfur gene expression. We fo...

  7. Influence of extraction method on quality and functionality of broccoli juice.

    Science.gov (United States)

    Lee, Sung Gyu; Kim, Jin-Hee; Son, Min-Jung; Lee, Eun-Ju; Park, Woo-Dong; Kim, Jong-Boo; Lee, Sam-Pin; Lee, In-Seon

    2013-06-01

    This study was performed to compare the quality and functionality of broccoli juice as affected by extraction method. Broccoli juice was extracted using method I (NUC Kuvings silent juicer), method II (NUC centrifugal juicer), and method III (NUC mixer), and the quality properties of the broccoli juices were analyzed using three different methods. Additionally, the antioxidative, anticancer, and anti-hyperglycemic activities of broccoli juice prepared by the three different methods were investigated in vitro. The broccoli juice made by method I contained the highest polyphenol and flavonoid contents at 1,226.24 mg/L and 1,018.32 mg/L, respectively. Particularly, broccoli juice prepared by method I showed higher DPPH and ABTS radical scavenging activities than those of the other samples. Additionally, broccoli juice made by method I showed the highest growth inhibitory effects against HeLa, A549, AGS, and HT-29 cancer cells. Broccoli juice prepared by method I had the highest α-glucosidase inhibitory effects. These results indicate that there are important differences in chemical and functional qualities between juice extraction techniques.

  8. Controlling rheology and structure of sweet potato starch noodles with high broccoli powder content by hydrocolloids

    NARCIS (Netherlands)

    Silva, E.; Birkenhake, M.; Scholten, E.; Sagis, L.M.C.; Linden, van der E.

    2013-01-01

    Incorporating high volume fractions of broccoli powder in starch noodle dough has a major effect on its shear modulus, as a result of significant swelling of the broccoli particles. Several hydrocolloids with distinct water binding capacity (locust bean gum (LBG), guar gum, konjac glucomannan (KG),

  9. High amounts of broccoli in pasta-like products: nutritional evaluation and sensory acceptability

    NARCIS (Netherlands)

    Silva, E.; Gerritsen, L.; Dekker, M.; Linden, van der E.; Scholten, E.

    2013-01-01

    Pasta and noodles were enriched with concentrations of broccoli powder (BP) up to 30% (v/v). To ensure the benefits from the broccoli nutrients, their leakage during cooking should be prevented. Such leakage is determined by the microstructure. In a previous study we have shown that the microstructu

  10. Bioavailability and kinetics of sulforaphane in humans after consumption of cooked versus raw broccoli

    NARCIS (Netherlands)

    Vermeulen, M.; Klöpping-Ketelaars, I.W.A.A.; Berg, R. van den; Vaes, W.H.J.

    2008-01-01

    The aim of this study was to determine the bioavailability and kinetics of the supposed anticarcinogen sulforaphane, the hydrolysis product of glucoraphanin, from raw and cooked broccoli. Eight men consumed 200 g of crushed broccoli, raw or cooked, with a warm meal in a randomized, free-living, open

  11. A research approach for quality based design of healthy foods: Dried broccoli as a case study

    NARCIS (Netherlands)

    Oliviero, T.; Verkerk, R.; Dekker, M.

    2013-01-01

    An approach for process design based on optimization of product quality attributes is presented. Adsorption drying of broccoli with retention of its health benefits is taken as an example to illustrate the approach. Related to its content of glucosinolates, broccoli has a high potential to reduce th

  12. Ozonated water and chlorine effects on the antioxidant properties of organic and conventional broccoli during postharvest

    Directory of Open Access Journals (Sweden)

    Giuseppina Pace Pereira Lima

    2014-04-01

    Full Text Available There is growing interest in studies on sanitizers other than chlorine that can maintain the quality of organic products without affecting their phytochemical content. The effects of using chlorinated and ozonized water treatments, as sanitizing procedures, on the post-harvest quality of organic and conventional broccoli (Brassica oleracea L. cv. Italica was evaluated. The biochemical parameters (chlorophyll, polyphenols, flavonoids, vitamin C and antioxidant capacity of the broccoli samples were analyzed at day 0 (arrival of the plant from the field, original features, and 1, 4 and 7 days after harvest. The polyamine analysis was performed on arrival of the plant from the field and on the first and seventh days. The cultivation procedure influenced polyphenol, vitamin C and total chlorophyll content, and the highest value was observed in organic broccoli after the fourth day. Flavenoid content was higher in organic broccoli. The use of ozone appears not to have had an influence on the amount of polyphenolic, flavonoids and vitamin C during storage. Total chlorophyll content was less affected by ozonized water than by the chlorine treatment as at the first and fourth days of storage. The highest content of putrescine was found in conventional broccoli, while the highest levels of spermidine and spermine were found in organic broccoli. Antioxidant capacity was highest in organic broccoli after day 4 of storage and was affected by the bioactive compounds analyzed. Methods of cultivation influenced natural antioxidant and chlorophyll contents in broccoli under cold storage.

  13. Differences in tolerance of broccoli and cabbage cultivars to clomazone herbicide

    Science.gov (United States)

    Clomazone herbicide is registered for cabbage in the U.S., but not for other cultivar groups within Brassica oleracea. Greenhouse and field experiments were designed to compare the tolerance of broccoli and cabbage cultivars to clomazone and assess its potential for weed management in broccoli. Fo...

  14. Effect of Hot Water Treatment on Postharvest Shelf Life and Quality of Broccoli

    Institute of Scientific and Technical Information of China (English)

    WU Ping; LI Wu

    2003-01-01

    Broccoli was stored at 0, 10, or 20℃ after immersion in hot water (38 -52℃ ) for 10 or 30min. Yellowing of broccoli was significantly slowed and shelf life significantly increased when broccoli wastreated with hot water at 42 -46℃ and then stored at 10 or 20℃. Heat injury occurred when treatment washigher than 46℃ in some varieties. Broccoli lasted 2 -3 days longer when stored at 10℃ and 1 -2 days longerwhen stored at 20℃ after hot water treatment at 46℃. There was no significant effect of treatment on shelflife after long time storage at 0℃. Weight loss was reduced by hot water treatment and the respiration behav-ior of the broccoli was also changed.

  15. Reproductive fitness of outcrossed hybrids between transgenic broccoli (brassica oleracea) carrying the ipt transgene and conventional varieties of kale, broccoli and cauliflower

    International Nuclear Information System (INIS)

    Pollens are potential carriers for genetically modified crops to transfer genetic materials horizontally to other plants. For phanerogams, pollen viability and cross-compatibility are critical factors for successful outcross hybridization. To evaluate this possibility, this project investigated pollen viability and pod setting rate by comparing broccoli (Brassica oleracea L. var. italica Planck) and broccoli transformed with the isopentenyl transferase (ipt) gene. Both served as pollen donors and four other varieties as pollen receptors to determine outcross rates. For pollen viability, F1 progeny was higher (p?0.05) for the cross of transgenic ipt broccoli with Li Syue significantly by FDA (fluorescein diacetate) assay. Higher successful hybrids were observed for transgenic ipt broccoli with Fu Yue, Li Syue and Green King. As pollen properties, number and grain diameter were significantly larger (p?0.05) in hybrid combinations of transgenic ipt broccoli with Li Syue and Green King significantly (p?0.05). The pod setting rates were higher while transgenic ipt broccoli served as donor plant. These results analyzing pollen properties between transgenic crops with possible outcross candidates would serve as one of those critical strategies for evaluating environmental biosafety issues for transgenic crops. (author)

  16. ADAPTABILITY, FERTILIZER EFFECT AND NUTRITION CONTENT OF VARIOUS BROCCOLI CULTIVAR (Brassica oleracea L. var. italica INTRODUCED IN KOPANG, CENTRAL LOMBOK

    Directory of Open Access Journals (Sweden)

    Zaenul Gafari

    2015-09-01

    Full Text Available This research was aimed to determine adaptability of eight introduced broccoli cultivars in the tropical climate, the effect of fertilizers, as well as determine the content of vitamin A, C and fiber owned by the cultivar. This research was using randomized complete block design ( RCBD with two factors. The first factorsare different broccoli cultivars namely Broccoli 'Lucky', Broccoli 'B - 106', Broccoli 'B-116', Broccoli 'B-112', Broccoli 'Green 2109' F1, Broccoli 'Green calabrase' and Broccoli 'Green Magic 'and Broccoli' Mujur'as a control. The second factors fertilizer of ZA, manure and urea. This research was performed in Kopang, Central Lombok, West Nusa Tenggara, for seven months from December 2014 to Juni 2015.Analysis of the nutrient content was done at the Laboratory of Analytical Chemistry, University of Mataram, Lombok. Parameters observed in this research were plant height, number and weight of leaves, and quality of curd. Data were analyzed by analysis of variance (ANOVA if significantly different then tested further by Duncan's Multiple Range Test (DMRT at 5% level. The results showed all the cultivars able to adapt. Broccoli 'B-106' is a cultivar that has the quality and quantity of curd most excellent and able to adapt to high temperatures. ZA fertilizer application will produce curd weight and diameter greater than that ofmanure or urea. The research also showed that cultivar B-112 has the highest content of vitamin A, B-116 has the highest vitamin C and Green 2109F1 has the highest fibers.

  17. Effect of NaCl treatments on glucosinolate metabolism in broccoli sprouts

    Institute of Scientific and Technical Information of China (English)

    Rong-fang GUO; Gao-feng YUAN; Qiao-mei WANG

    2013-01-01

    To understand the regulation mechanism of NaCl on glucosinolate metabolism in broccoli sprouts,the germination rate,fresh weight,contents of glucosinolates and sulforaphane,as well as myrosinase activity of broccoli sprouts germinated under 0,20,40,60,80,and 100 mmol/L of NaCl were investigated in our experiment.The results showed that glucoerucin,glucobrassicin,and 4-hydroxy glucobrassicin in 7-d-old broccoli sprouts were significantly enhanced and the activity of myrosinase was inhibited by 100 mmol/L of NaCl.However,the total glucosinolate content in 7-d-old broccoli sprouts was markedly decreased although the fresh weight was significantly increased after treatment with NaCl at relatively low concentrations(20,40,and 60 mmol/L).NaCl treatment at the concentration of 60 mmol/L for 5 d maintained higher biomass and comparatively higher content of glucosinolates in sprouts of broccoli with decreased myrosinase activity.A relatively high level of NaCl treatment(100 mmol/L)significantly increased the content of sulforaphane in 7-d-old broccoli sprouts compared with the control.These results indicate that broccoli sprouts grown under a suitable concentration of NaCl could be desirable for human nutrition.

  18. Broccoli consumption and chronic atrophic gastritis among Japanese males: an epidemiological investigation.

    Directory of Open Access Journals (Sweden)

    Sato K

    2004-06-01

    Full Text Available Previous in vitro and animal experiments have shown that sulforaphane, which is abundant in broccoli, inhibits Helicobacter pylori (H. pylori infection and blocks gastric tumor formation. This suggests that broccoli consumption prevents chronic atrophic gastritis (CAG introduced by H. pylori infection and, therefore, gastric cancer. For an epidemiological investigation of the relationship between the broccoli consumption and CAG, a cross-sectional study of 438 male employees, aged 39 to 60 years, of a Japanese steel company was conducted. CAG was serologically determined with serum cut-off values set at pepsinogen I < or = 70 ng/ml and a ratio of serum pepsinogen I/pepsinogen II < or = 3.0. Broccoli consumption (weekly frequency and diet were monitored by using a 31-item food frequency questionnaire. The prevalence of CAG among men who ate broccoli once or more weekly was twice as high as that among men who consumed a negligible amount (P < 0.05. Multiple logistic regression analysis indicated that broccoli consumption once or more weekly significantly increased the risk for CAG (odds ratio, 3.06; 95% confidence interval, 1.12-8.38; P < 0.05, after controlling for age, education, cigarette smoking, and alcohol consumption. The present study failed to show an expected association between frequent broccoli consumption and a low prevalence of CAG.

  19. Broccoli (Brassica oleracea var. italica head initiation under field conditions

    Directory of Open Access Journals (Sweden)

    Alina Kałużewicz

    2012-12-01

    Full Text Available A two–year study on the influence of temperature on broccoli head initiation was carried out at the ''Marcelin'' experimental station of the Poznań University of Life Sciences. In each year of the study, plants were planted in the field at four dates. The evaluation of the developmental phase of the broccoli shoot apex was based on the analysis of microscope slides. The date of head initiation was assumed as the day on which the first of the examined apices were found to be at the early generative phase. The plant characteristics (number of leaves, leaf area and stem diameter on the date of initiation were also determined. Variation in length of the period from planting to head initiation was found both between dates of planting and between experimental years. The shortest period from planting to initiation was when the plants were planted in April and June (17-18 days in the first year and the longest one for planting in April in the first year of the study (29 days. The length of the period from planting to head initiation depended on mean daily air temperature. The higher the temperature was, the shorter was the period.

  20. Polymer coating, germination and vigor of broccoli seeds

    Directory of Open Access Journals (Sweden)

    Almeida Celina de

    2005-01-01

    Full Text Available Brassica oleracea var italica occupies a special place in the internal and external market of vegetables seeds. Vegetables producers demand seeds with high degree of purity, germination and vigor, since seeds' quality is the basis for the success of the production. In this work, broccoli seeds were coated in a spouted bed, by an aqueous suspension of hidroxy-ethyl-cellulose. Effects of the operating variables: spouting air temperature, atomizing air pressure and coating suspension flow rate over the dependent variables: seeds germination, seeds accelerated aging and the speed of seeds germination in soil, were investigated in a factorial scheme trial. The maximum processing time was 120 min. A totally randomized experiment evaluated and compared seeds germination and vigor of the coated and non-coated seeds. There was no identifiable, pronounced difference on germination of coated and non-coated seeds, accelerated aging of seeds, and speed of seeds germination in the soil. Coating with hidroxy-ethyl-cellulose in the spouted bed did not alter broccoli seeds physiologic quality. The surface of coated seeds presented satisfactory distribution and spreading of the polymer film, uniform and individual coating and homogeneous aspect.

  1. Heat Transfer during Blanching and Hydrocooling of Broccoli Florets.

    Science.gov (United States)

    Iribe-Salazar, Rosalina; Caro-Corrales, José; Hernández-Calderón, Óscar; Zazueta-Niebla, Jorge; Gutiérrez-Dorado, Roberto; Carrazco-Escalante, Marco; Vázquez-López, Yessica

    2015-12-01

    The objective of this work was to simulate heat transfer during blanching (90 °C) and hydrocooling (5 °C) of broccoli florets (Brassica oleracea L. Italica) and to evaluate the impact of these processes on the physicochemical and nutrimental quality properties. Thermophysical properties (thermal conductivity [line heat source], specific heat capacity [differential scanning calorimetry], and bulk density [volume displacement]) of stem and inflorescence were measured as a function of temperature (5, 10, 20, 40, 60, and 80 °C). The activation energy and the frequency factor (Arrhenius model) of these thermophysical properties were calculated. A 3-dimensional finite element model was developed to predict the temperature history at different points inside the product. Comparison of the theoretical and experimental temperature histories was carried out. Quality parameters (firmness, total color difference, and vitamin C content) and peroxidase activity were measured. The satisfactory validation of the finite element model allows the prediction of temperature histories and profiles under different process conditions, which could lead to an eventual optimization aimed to minimize the nutritional and sensorial losses in broccoli florets.

  2. Ozonated water and chlorine effects on the antioxidant properties of organic and conventional broccoli during postharvest

    OpenAIRE

    Giuseppina Pace Pereira Lima; Tatiana Marquini Machado; Luciana Manoel de Oliveira; Luciana da Silva Borges; Valber de Albuquerque Pedrosa; Paola Vanzani; Fabio Vianello

    2014-01-01

    There is growing interest in studies on sanitizers other than chlorine that can maintain the quality of organic products without affecting their phytochemical content. The effects of using chlorinated and ozonized water treatments, as sanitizing procedures, on the post-harvest quality of organic and conventional broccoli (Brassica oleracea L.) cv. Italica was evaluated. The biochemical parameters (chlorophyll, polyphenols, flavonoids, vitamin C and antioxidant capacity) of the broccoli sample...

  3. Bioactive glucosinolates and antioxidant properties of broccoli seeds cultivated in Thailand

    OpenAIRE

    Sarunya Chuanphongpanich; Sukon Phanichphant; Duang Bhuddasukh; Maitree Suttajit; Busaban Sirithunyalug

    2006-01-01

    One of the most significant health concerns of cruciferous vegetables is the presence of biologically active compounds, glucosinolates. Broccoli (Brassica oleracea var. italica) is a nutritionally important crop grown all over the world. Glucosinolates have been found to have anti-cancer properties. The primary purpose of this study was to evaluate glucosinolate content and antioxidant property in the seeds of broccoli cultivars widely grown in Thailand. Glucosinolates were analyzed with high...

  4. Broccoli yield in response to top-dressing fertilization with green manure and biofertilizer

    OpenAIRE

    Gilberto Bernardo de Freitas; Márcio Sousa Rocha; Ricardo Henrique Silva Santos; Letícia Monteiro da Silva Freitas; Leandro de Almeida Resende

    2011-01-01

    The objective of this work was to evaluate the productive performance of broccoli under different top-dressing organic fertilizations. The experiment was conducted under protected cultivation, in a completely randomized design with four replications, with two plants per experimental unit. Broccoli seedlings were produced in a commercial substrate in styrofoam trays. The seedlings were transplanted to plastic pots containing 10.0 L of substrate made up of subsoil and organic compost at the rat...

  5. Investigation on the influence of pre-treatments on drying behaviour of broccoli by MRI experiments

    OpenAIRE

    Jin, X.; Sman, van der, R.G.M.; Gerkema, E.; Vergeldt, F.J.; As, van, H.; Straten, van, FE; Boom, R.M.; Boxtel, van, C.

    2011-01-01

    Abstract: Magnetic Resonance Imaging (MRI) allows the monitoring of internal moisture content of food products during drying non-destructively. In an experimental set-up with continuous and controlled hot air supply, the internal moisture distribution of broccoli with different pre-treatments are measured during drying. Moisture distribution, drying rate and shrinkage are compared and analyzed quantitatively. MRI results indicated that for fresh broccoli stalks the moisture content in the cor...

  6. Cultivation conditions and selenium fertilization alter the phenolic profile, glucosinolate, and sulforaphane content of broccoli.

    Science.gov (United States)

    Robbins, Rebecca J; Keck, Anna-Sigrid; Banuelos, Gary; Finley, John W

    2005-01-01

    Broccoli is a food often consumed for its potential health-promoting properties. The health benefits of broccoli are partly associated with secondary plant compounds that have bioactivity; glucosinolates and phenolic acids are two of the most abundant and important in broccoli. In an effort to determine how variety, stress, and production conditions affect the production of these bioactive components broccoli was grown in the greenhouse with and without selenium (Se) fertilization, and in the field under conventional or organic farming procedures and with or without water stress. High-performance liquid chromatography/mass spectrometry was used to separate and identify 12 primary phenolic compounds. Variety had a major effect: There was a preponderance of flavonoids in the Majestic variety, but hydroxycinnamic esters were relatively more abundant in the Legacy variety. Organic farming and water stress decreased the overall production of phenolics. Se fertilization increased glucosinolates in general, and sulforaphane in particular, up to a point; above that Se fertilization decreased glucosinolate production. Organic farming and water stress also decreased glucosinolate production. These data show environmental and genetic variation in phenolics and glucosinolates in broccoli, and warn that not all broccoli may contain all health-promoting bioactive components. They further show that selection for one bioactive component (Se) may decrease the content of other bioactive components such as phenolics and glucosinolates. PMID:16117613

  7. Consumer acceptability and sensory profile of cooked broccoli with mustard seeds added to improve chemoprotective properties.

    Science.gov (United States)

    Ghawi, Sameer Khalil; Shen, Yuchi; Niranjan, Keshavan; Methven, Lisa

    2014-09-01

    Broccoli, a rich source of glucosinolates, is a commonly consumed vegetable of the Brassica family. Hydrolysis products of glucosinolates, isothiocyanates, have been associated with health benefits and contribute to the flavor of Brassica. However, boiling broccoli causes the myrosinase enzyme needed for hydrolysis to denature. In order to ensure hydrolysis, broccoli must either be mildly cooked or active sources of myrosinase, such as mustard seed powder, can be added postcooking. In this study, samples of broccoli were prepared in 6 different ways; standard boiling, standard boiling followed by the addition of mustard seeds, sous vide cooking at low temperature (70 °C) and sous vide cooking at higher temperature (100 °C) and sous vide cooking at higher temperature followed by the addition of mustard seeds at 2 different concentrations. The majority of consumers disliked the mildly cooked broccoli samples (70 °C, 12 min, sous vide) which had a hard and stringy texture. The highest mean consumer liking was for standard boiled samples (100 °C, 7 min). Addition of 1% mustard seed powder developed sensory attributes, such as pungency, burning sensation, mustard odor, and flavor. One cluster of consumers (32%) found mustard seeds to be a good complement to cooked broccoli; however, the majority disliked the mustard-derived sensory attributes. Where the mustard seeds were partially processed, doubling the addition to 2% led to only the same level of mustard and pungent flavors as 1% unprocessed seeds, and mean consumer liking remained unaltered. This suggests that optimization of the addition level of partially processed mustard seeds may be a route to enhance bioactivity of cooked broccoli without compromising consumer acceptability.

  8. Consumer acceptability and sensory profile of cooked broccoli with mustard seeds added to improve chemoprotective properties.

    Science.gov (United States)

    Ghawi, Sameer Khalil; Shen, Yuchi; Niranjan, Keshavan; Methven, Lisa

    2014-09-01

    Broccoli, a rich source of glucosinolates, is a commonly consumed vegetable of the Brassica family. Hydrolysis products of glucosinolates, isothiocyanates, have been associated with health benefits and contribute to the flavor of Brassica. However, boiling broccoli causes the myrosinase enzyme needed for hydrolysis to denature. In order to ensure hydrolysis, broccoli must either be mildly cooked or active sources of myrosinase, such as mustard seed powder, can be added postcooking. In this study, samples of broccoli were prepared in 6 different ways; standard boiling, standard boiling followed by the addition of mustard seeds, sous vide cooking at low temperature (70 °C) and sous vide cooking at higher temperature (100 °C) and sous vide cooking at higher temperature followed by the addition of mustard seeds at 2 different concentrations. The majority of consumers disliked the mildly cooked broccoli samples (70 °C, 12 min, sous vide) which had a hard and stringy texture. The highest mean consumer liking was for standard boiled samples (100 °C, 7 min). Addition of 1% mustard seed powder developed sensory attributes, such as pungency, burning sensation, mustard odor, and flavor. One cluster of consumers (32%) found mustard seeds to be a good complement to cooked broccoli; however, the majority disliked the mustard-derived sensory attributes. Where the mustard seeds were partially processed, doubling the addition to 2% led to only the same level of mustard and pungent flavors as 1% unprocessed seeds, and mean consumer liking remained unaltered. This suggests that optimization of the addition level of partially processed mustard seeds may be a route to enhance bioactivity of cooked broccoli without compromising consumer acceptability. PMID:25156799

  9. Investigation of functional properties and color changes of corn extrudates enriched with broccoli or olive paste.

    Science.gov (United States)

    Bisharat, Ghassan I; Katsavou, Ioanna D; Panagiotou, Nikolaos M; Krokida, Magdalini K; Maroulis, Zacharias B

    2015-12-01

    Following the tendency of replacing common food snacks with healthier food products, extruded snacks with corn flour and broccoli (4-10%) or olive paste (4-8%) were investigated in this study. The effect of material characteristics, including feed moisture content (14-19%), and broccoli or olive paste concentration, and extrusion conditions, including screw speed (150-250 r/min), and extrusion temperature (140-180 ℃), on the functional properties (water absorption index, water solubility index, and oil absorption index), as well as color change (ΔE) of the extruded snacks was studied. Regression analysis showed that screw speed did not significantly influence (p > 0.05) the properties. After mathematical modelling it was found that broccoli and olive paste concentration, as well as temperature increment, caused a decrease in water absorption index (minimum of 5.6 and 6.4 g/g sample, respectively) and an increase in water solubility index (maximum of 18.7 and 10.9 g/100 g sample, respectively), while feed moisture presented opposite tendency. Higher extrusion temperature led to an increment of oil absorption index (approximately to 1.2 and 1 mL/g sample) and decrement of color changes. Finally, feed moisture and broccoli concentration lowered oil absorption index and color of corn/broccoli extrudates, while olive paste concentration caused their increment.

  10. High amounts of broccoli in pasta-like products: nutritional evaluation and sensory acceptability.

    Science.gov (United States)

    Silva, E; Gerritsen, L; Dekker, M; van der Linden, E; Scholten, E

    2013-11-01

    Pasta and noodles were enriched with concentrations of broccoli powder (BP) up to 30% (v/v). To ensure the benefits from the broccoli nutrients, their leakage during cooking should be prevented. Such leakage is determined by the microstructure. In a previous study we have shown that the microstructure can change dramatically in such broccoli-enriched products. In this article we investigated the amount of nutrients retained within the product. As a representative of nutrients we have chosen glucosinolates (GLs). Therefore, we have investigated the concentration of these phytochemicals in dried and cooked pasta and noodles. We have found that glucosinolates present in the pasta and noodles increase linearly with the volume fraction of BP up to 20%. At 30% BP the retained amount of GLs was equal to that of 20% BP and did not increase further. Therefore incorporation of 30% BP does not lead to additional health benefits over incorporation of 20% BP. We conclude that the nutritional function of our pasta-like products can be improved by enrichment up to 20% broccoli. This value is much higher than that found in common commercial products (which is a few percent). In this article we also briefly address the sensory acceptability of such products. Up to 20% broccoli the products turned out to remain acceptable. Combining this with our results on texture analysis we conclude that the GLs release, sensory acceptability and textural properties are related via the microstructure.

  11. Growth and yield of broccoli fertilized with doses of velvet bean in greenhouse

    Directory of Open Access Journals (Sweden)

    Ellen Rúbia Diniz

    2015-06-01

    Full Text Available The dose effects of green manure in vegetable crops production are still poorly understood. There are few scientific studies indicate that increasing the dose may influence plants characteristics. The objectives were to evaluate the effect of doses of velvet bean green manure on growth and yield, the partitioning of dry matter and nitrogen (N in plants of broccoli, as well as determine the apparent recovery and physiological efficiency of use N. We established four treatments plus a control. The treatments consisted of four levels of green manure: 0, 3, 6, 9 t ha-1 on a dry matter basis, with the addition of 12 t ha-1 of compost. Doses of green manure applied influenced the growth and yield of broccoli. The distribution of dry matter between plant parts of broccoli is not influenced by the doses of green manure. Doses of green manure influenced the amount of N accumulated in the inflorescence and whole plant of broccoli. The apparent recovery of N from green manure and efficiency of N use by plants of broccoli are positively associated with the applied doses.

  12. The Propagation of Variation in Glucosinolate Levels as effected by Controlled Atmosphere and Temperature in a Broccoli Batch

    NARCIS (Netherlands)

    Schouten, R.E.; Zhang, X.; Tijskens, L.M.M.; Kooten, van O.

    2008-01-01

    Broccoli combines high levels of vitamins, fibres and glucosinolates (GLS) with a low calorie count. GLS are precursors for the characteristic broccoli flavour and have anti-carcinogenic properties. This study describes the effect of controlled atmo¬sphere (CA) and temperature on GLS concentrations

  13. Effect of matrix and particle type on rheological, textural and structural properties of broccoli pasta and noodles

    NARCIS (Netherlands)

    Silva, E.; Sagis, L.M.C.; Linden, van der E.; Scholten, E.

    2013-01-01

    Durum wheat semolina (DWS) pasta and sweet potato starch (SPS) noodles were incorporated with dif ferent volume fractions and types of broccoli powder (up to 20% v/v). The incorporation of high volume fractions of broccoli powder produced in-house in SPS noodles increases the modulus of the dough an

  14. Anticancer and Antioxidant Activity of Bread Enriched with Broccoli Sprouts

    Directory of Open Access Journals (Sweden)

    Urszula Gawlik-Dziki

    2014-01-01

    Full Text Available This study is focused on antioxidant and anticancer capacity of bread enriched with broccoli sprouts (BS in the light of their potential bioaccessibility and bioavailability. Generally, bread supplementation elevated antioxidant potential of product (both nonenzymatic and enzymatic antioxidant capacities; however, the increase was not correlated with the percent of BS. A replacement up to 2% of BS gives satisfactory overall consumers acceptability and desirable elevation of antioxidant potential. High activity was especially found for extracts obtained after simulated digestion, which allows assuming their protective effect for upper gastrointestinal tract; thus, the anticancer activity against human stomach cancer cells (AGS was evaluated. A prominent cytostatic response paralleled by the inhibition of AGS motility in the presence of potentially mastication-extractable phytochemicals indicates that phenolic compounds of BS retain their biological activity in bread. Importantly, the efficient phenolics concentration was about 12 μM for buffer extract, 13 μM for extracts after digestion in vitro, and 7 μM for extract after absorption in vitro. Our data confirm chemopreventive potential of bread enriched with BS and indicate that BS comprise valuable food supplement for stomach cancer chemoprevention.

  15. Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2011-03-01

    Full Text Available A simple solid-phase extraction (SPE method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998 for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1 was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.

  16. Effect of Different Growth State of Broccoli (Brassica oleracea var. italica) on Low Temperature Induction

    Institute of Scientific and Technical Information of China (English)

    JIANG Xin-mei; LI Yue-fang; YU Xi-hong

    2005-01-01

    In order to study the responding of different growth state on low temperature in Broccoli (Brassica oleracea var. italica), we took prematurity broccoli hybrid as the objects. It was found that growth state was varied under different sowing time , moreover, stem became wider with the increasing of light density at the same leaf age.Seedling age of responding to low temperature vernalization only when they grew five leaves above and with over 3.03± 0.07 centimeter stalk width in "Qingfeng Broccoli 103". The older leaf age was and the stronger plant was, the more sensitive and the shorter demanded duration time on low temperature was, and the shorter time required when the plants entered into critical period of floral bud differentiation.

  17. Pathogen detection, testing, and control in fresh broccoli sprouts

    Directory of Open Access Journals (Sweden)

    Fahey Jed W

    2006-04-01

    Full Text Available Abstract Background The recent increased interest in consuming green vegetable sprouts has been tempered by the fact that fresh sprouts can in some cases be vehicles for food-borne illnesses. They must be grown according to proper conditions of sanitation and handled as a food product rather than as an agricultural commodity. When sprouts are grown in accordance with the criteria proposed from within the sprout industry, developed by regulatory agencies, and adhered to by many sprouters, green sprouts can be produced with very low risk. Contamination may occur when these guidelines are not followed. Methods A one year program of microbial hold-and-release testing, conducted in concert with strict seed and facility cleaning procedures by 13 U.S. broccoli sprout growers was evaluated. Microbial contamination tests were performed on 6839 drums of sprouts, equivalent to about 5 million consumer packages of fresh green sprouts. Results Only 24 (0.75% of the 3191 sprout samples gave an initial positive test for Escherichia coli O157:H7 or Salmonella spp., and when re-tested, 3 drums again tested positive. Composite testing (e.g., pooling up to 7 drums for pathogen testing was equally sensitive to single drum testing. Conclusion By using a "test-and-re-test" protocol, growers were able to minimize crop destruction. By pooling drums for testing, they were also able to reduce testing costs which now represent a substantial portion of the costs associated with sprout growing. The test-and-hold scheme described herein allowed those few batches of contaminated sprouts to be found prior to packaging and shipping. These events were isolated, and only safe sprouts entered the food supply.

  18. The potential to intensify sulforaphane formation in cooked broccoli (Brassica oleracea var. italica) using mustard seeds (Sinapis alba).

    Science.gov (United States)

    Ghawi, Sameer Khalil; Methven, Lisa; Niranjan, Keshavan

    2013-06-01

    Sulforaphane, a naturally occurring cancer chemopreventive, is the hydrolysis product of glucoraphanin, the main glucosinolate in broccoli. The hydrolysis requires myrosinase isoenzyme to be present in sufficient activity; however, processing leads to its denaturation and hence reduced hydrolysis. In this study, the effect of adding mustard seeds, which contain a more resilient isoform of myrosinase, to processed broccoli was investigated with a view to intensify the formation of sulforaphane. Thermal inactivation of myrosinase from both broccoli and mustard seeds was studied. Thermal degradation of broccoli glucoraphanin was investigated in addition to the effects of thermal processing on the formation of sulforaphane and sulforaphane nitrile. Limited thermal degradation of glucoraphanin (less than 12%) was observed when broccoli was placed in vacuum sealed bag (sous vide) and cooked in a water bath at 100°C for 8 and 12 min. Boiling broccoli in water prevented the formation of any significant levels of sulforaphane due to inactivated myrosinase. However, addition of powdered mustard seeds to the heat processed broccoli significantly increased the formation of sulforaphane.

  19. The potential to intensify sulforaphane formation in cooked broccoli (Brassica oleracea var. italica) using mustard seeds (Sinapis alba).

    Science.gov (United States)

    Ghawi, Sameer Khalil; Methven, Lisa; Niranjan, Keshavan

    2013-06-01

    Sulforaphane, a naturally occurring cancer chemopreventive, is the hydrolysis product of glucoraphanin, the main glucosinolate in broccoli. The hydrolysis requires myrosinase isoenzyme to be present in sufficient activity; however, processing leads to its denaturation and hence reduced hydrolysis. In this study, the effect of adding mustard seeds, which contain a more resilient isoform of myrosinase, to processed broccoli was investigated with a view to intensify the formation of sulforaphane. Thermal inactivation of myrosinase from both broccoli and mustard seeds was studied. Thermal degradation of broccoli glucoraphanin was investigated in addition to the effects of thermal processing on the formation of sulforaphane and sulforaphane nitrile. Limited thermal degradation of glucoraphanin (less than 12%) was observed when broccoli was placed in vacuum sealed bag (sous vide) and cooked in a water bath at 100°C for 8 and 12 min. Boiling broccoli in water prevented the formation of any significant levels of sulforaphane due to inactivated myrosinase. However, addition of powdered mustard seeds to the heat processed broccoli significantly increased the formation of sulforaphane. PMID:23411305

  20. Ozone fumigation increases the abundance of nutrients in Brassica vegetables: broccoli (Brassica oleracea var. italica) and Chinese cabbage (Brassica pekinensis)

    OpenAIRE

    Rozpądek, Piotr; Nosek, Michał; Ślesak, Irenusz; Edward KUNICKI; Dziurka, Michał; Miszalski, Zbigniew

    2014-01-01

    B rassicaceae vegetables, among them broccoli and Chinese cabbage, are well recognized due to the nutritional properties. Four-week-old Chinese cabbage and broccoli seedlings were fumigated with O3 for 3 days before being transplanted into the field. The effect of O3 treatment was determined after reaching marketable quality (ca. 10 weeks). The inflorescences of O3-treated broccoli were enriched in vitamin E (α-tocopherol and γ-tocopherol), whereas Chinese cabbage heads had an increased conte...

  1. Biotechnological advancement in genetic improvement of broccoli (Brassica oleracea L. var. italica), an important vegetable crop.

    Science.gov (United States)

    Kumar, Pankaj; Srivastava, Dinesh Kumar

    2016-07-01

    With the advent of molecular biotechnology, plant genetic engineering techniques have opened an avenue for the genetic improvement of important vegetable crops. Vegetable crop productivity and quality are seriously affected by various biotic and abiotic stresses which destabilize rural economies in many countries. Moreover, absence of proper post-harvest storage and processing facilities leads to qualitative and quantitative losses. In the past four decades, conventional breeding has significantly contributed to the improvement of vegetable yields, quality, post-harvest life, and resistance to biotic and abiotic stresses. However, there are many constraints in conventional breeding, which can only be overcome by advancements made in modern biology. Broccoli (Brassica oleracea L. var. italica) is an important vegetable crop, of the family Brassicaceae; however, various biotic and abiotic stresses cause enormous crop yield losses during the commercial cultivation of broccoli. Thus, genetic engineering can be used as a tool to add specific characteristics to existing cultivars. However, a pre-requisite for transferring genes into plants is the availability of efficient regeneration and transformation techniques. Recent advances in plant genetic engineering provide an opportunity to improve broccoli in many aspects. The goal of this review is to summarize genetic transformation studies on broccoli to draw the attention of researchers and scientists for its further genetic advancement. PMID:26971329

  2. Broccoli glucosinolate degradation is reduced performing thermal treatment in binary systems with other food ingredients

    NARCIS (Netherlands)

    Giambanelli, E.; Verkerk, R.; Fogliano, V.; Capuano, E.; Antuono, D' L.F.; Oliviero, T.

    2015-01-01

    Glucosinolate (GL) stability has been widely studied in different Brassica species. However, the matrix effect determined by the presence of other ingredients occurred in many broccoli-based traditional recipes may affect GL thermal degradation. In this study, the matrix effect on GL thermal degrada

  3. Modelling the change in colour in broccoli and green beans during blanching

    NARCIS (Netherlands)

    Tijskens, L.M.M.; Schijvens, E.P.H.M.; Biekman, E.S.A.

    2001-01-01

    The green colour of vegetables changes considerably during heat treatments like blanching. Green beans from two different countries and growing seasons, and the stems and florets of broccoli were heat-treated from 40 up to 96 °C. The colour was monitored with the CIE-Lab system. Expressing the green

  4. Moisture Distribution in Broccoli: Measurements by MRI Hot Air Drying Experiments

    NARCIS (Netherlands)

    Jin, X.; Sman, van der R.G.M.; Gerkema, E.; Vergeldt, F.J.; As, van H.; Boxtel, van A.J.B.

    2011-01-01

    ABSTRACT The internal moisture distribution that arise in food products during drying, is a key factor for the retention of quality attributes. To reveal the course of moisture content in a product, internal moisture profiles in broccoli florets are measured by MRI imaging during drying experiments

  5. Moisture Sorption Isotherms of Broccoli Interpreted with the Flory-Huggins Free Volume Theory

    NARCIS (Netherlands)

    Jin, X.; Sman, R.G.M. van der; Maanen, J.F.C. van; Deventer, H.C. van; Straten, G. van; Boom, R.M.; Boxtel, A.J.B. van

    2014-01-01

    In this work, the Flory Huggins Free Volume theory is used to interpret the sorption isotherms of broccoli from its composition and using physical properties of the components. This theory considers the mixing properties of water, biopolymers and solutes and has the potential to describe the sorptio

  6. Koeling van bloemkool en broccoli op de veiling "De Tuinbouw" te Grootebroek

    NARCIS (Netherlands)

    Damen, P.M.M.; Hendriks, A.G.M.

    1980-01-01

    In een proef op de veiling "De Tuinbouw" in Grootebroek is zowel bloemkool als broccoli opgeslagen gedurende respectievelijk een en drie dagen bij 2 graden C en 95% r.v. Na koeling zijn de kolen geplaatst in een donkere ruimte met een temperatuur van 18 graden C en een r.v. van 90%. Beoordeeld is op

  7. Informatieblad Mineralen en Milieukwaliteit : nitraatuitspoeling uit gewasresten van broccoli, prei en suikerbiet

    NARCIS (Netherlands)

    Ruijter, de F.J.

    2008-01-01

    Om nitraatuitspoeling terug te dringen is het nodig om het N-overschot te verlagen. Bij sommige gewassen (bijv. broccoli en suikerbieten) zit het N-overschot grotendeels in de gewasresten. De vraag is in welke mate het N-overschot in de vorm van gewasresten bijdraagt aan nitraatuitspoeling, en in ho

  8. Moisture distribution in broccoli: measurements by MRI hot air drying experiments

    NARCIS (Netherlands)

    Jin, X.; Sman, van der R.G.M.; Gerkema, E.; Vergeldt, F.J.; As, van H.; Boxtel, van A.J.B.

    2011-01-01

    The internal moisture distribution that arise in food products during drying, is a key factor for the retention of quality attributes. To reveal the course of moisture content in a product, internal moisture profiles in broccoli florets are measured by MRI imaging during drying experiments with cont

  9. Effects of stir-fry cooking with different edible oils on the phytochemical composition of broccoli.

    Science.gov (United States)

    Moreno, Diego A; López-Berenguer, Carmen; García-Viguera, Cristina

    2007-01-01

    Numerous epidemiological studies indicate that Brassica vegetables in general and broccoli in particular protect humans against cancer; they are rich sources of glucosinolates and possess a high content on flavonoids, vitamins, and mineral nutrients. The contents of total intact glucosinolates, total phenolics, vitamin C, and minerals (potassium, sodium, calcium, magnesium, iron, manganese, zinc, and copper) in the edible portions of freshly harvested broccoli (florets), which was subjected to stir-frying treatments, were evaluated. In the present work, the stir-fry cooking experiments were carried out using different edible oils from plant origin (refined olive oil, extra virgin olive oil, sunflower oil, peanut oil, soyabean oil, and safflower oil) known and used worldwide. Results showed that during stir-frying, phenolics and vitamin C were more affected than glucosinolates and minerals. Stir-fry cooking with extra virgin olive, soybean, peanut, or safflower oil did not reduce the total glucosinolate content of the cooked broccoli compared with that of the uncooked sample. The vitamin C content of broccoli stir-fried with extra virgin olive or sunflower oil was similar to that of the uncooked sample, but greater than those samples stir-fried with other oils. PMID:17995900

  10. Broccoli consumption interacts with GSTM1 to perturb oncogenic signalling pathways in the prostate.

    Directory of Open Access Journals (Sweden)

    Maria Traka

    Full Text Available BACKGROUND: Epidemiological studies suggest that people who consume more than one portion of cruciferous vegetables per week are at lower risk of both the incidence of prostate cancer and of developing aggressive prostate cancer but there is little understanding of the underlying mechanisms. In this study, we quantify and interpret changes in global gene expression patterns in the human prostate gland before, during and after a 12 month broccoli-rich diet. METHODS AND FINDINGS: Volunteers were randomly assigned to either a broccoli-rich or a pea-rich diet. After six months there were no differences in gene expression between glutathione S-transferase mu 1 (GSTM1 positive and null individuals on the pea-rich diet but significant differences between GSTM1 genotypes on the broccoli-rich diet, associated with transforming growth factor beta 1 (TGFbeta1 and epidermal growth factor (EGF signalling pathways. Comparison of biopsies obtained pre and post intervention revealed more changes in gene expression occurred in individuals on a broccoli-rich diet than in those on a pea-rich diet. While there were changes in androgen signalling, regardless of diet, men on the broccoli diet had additional changes to mRNA processing, and TGFbeta1, EGF and insulin signalling. We also provide evidence that sulforaphane (the isothiocyanate derived from 4-methylsuphinylbutyl glucosinolate that accumulates in broccoli chemically interacts with TGFbeta1, EGF and insulin peptides to form thioureas, and enhances TGFbeta1/Smad-mediated transcription. CONCLUSIONS: These findings suggest that consuming broccoli interacts with GSTM1 genotype to result in complex changes to signalling pathways associated with inflammation and carcinogenesis in the prostate. We propose that these changes may be mediated through the chemical interaction of isothiocyanates with signalling peptides in the plasma. This study provides, for the first time, experimental evidence obtained in humans to

  11. DNA damage and repair activity after broccoli intake in young healthy smokers.

    Science.gov (United States)

    Riso, Patrizia; Martini, Daniela; Møller, Peter; Loft, Steffen; Bonacina, Gaia; Moro, Massimo; Porrini, Marisa

    2010-11-01

    Cruciferous vegetables contain compounds with antioxidant properties (e.g. carotenoids, vitamin C and folates) and can alter the activity of xenobiotic metabolism (i.e. isothiocyanates). These constituents may be particularly important for subjects who are exposed to free radicals and genotoxic compounds, including smokers. The aim of the study was to evaluate the effect of broccoli intake on biomarkers of DNA damage and repair. Twenty-seven young healthy smokers consumed a portion of steamed broccoli (250 g/day) or a control diet for 10 days each within a crossover design with a washout period. Blood was collected before and after each period. The level of oxidatively damaged DNA lesions (formamidopyrimidine DNA glycosylase-sensitive sites), resistance to ex vivo H(2)O(2) treatment and repair of oxidised DNA lesions were measured in peripheral blood mononuclear cells (PBMCs). We also measured mRNA expression levels of repair and defence enzymes: 8-oxoguanine DNA glycosylase (OGG1), nucleoside diphosphate linked moiety X-type motif 1 (NUDT1) and heme oxygenase 1 (HO-1). After broccoli consumption, the level of oxidised DNA lesions decreased by 41% (95% confidence interval: 10%, 72%) and the resistance to H(2)O(2)-induced DNA strand breaks increased by 23% (95% CI: 13%, 34%). Following broccoli intake, a higher protection was observed in subjects with glutathione S-transferase (GST) M1-null genotype. The expression level and activity of repair enzymes was unaltered. In conclusion, broccoli intake was associated with increased protection against H(2)O(2)-induced DNA strand breaks and lower levels of oxidised DNA bases in PBMCs from smokers. This protective effect could be related to an overall improved antioxidant status.

  12. BROCCOLI: Software for Fast fMRI Analysis on Many-Core CPUs and GPUs

    Directory of Open Access Journals (Sweden)

    Anders eEklund

    2014-03-01

    Full Text Available Analysis of functional magnetic resonance imaging (fMRI data is becoming ever more computationally demanding as temporal and spatial resolutions improve, and large, publicly available data sets proliferate. Moreover, methodological improvements in the neuroimaging pipeline, such as non-linear spatial normalization, non-parametric permutation tests and Bayesian Markov Chain Monte Carlo approaches, can dramatically increase the computational burden. Despite these challenges, there do not yet exist any fMRI software packages which leverage inexpensive and powerful graphics processing units (GPUs to perform these analyses. Here, we therefore present BROCCOLI, a free software package written in OpenCL (Open Computing Language that can be used for parallel analysis of fMRI data on a large variety of hardware configurations. BROCCOLI has, for example, been tested with an Intel CPU, an Nvidia GPU and an AMD GPU. These tests show that parallel processing of fMRI data can lead to significantly faster analysis pipelines. This speedup can be achieved on relatively standard hardware, but further, dramatic speed improvements require only a modest investment in GPU hardware. BROCCOLI (running on a GPU can perform non-linear spatial normalization to a 1 mm3 brain template in 4-6 seconds, and run a second level permutation test with 10,000 permutations in about a minute. These non-parametric tests are generally more robust than their parametric counterparts, and can also enable more sophisticated analyses by estimating complicated null distributions. Additionally, BROCCOLI includes support for Bayesian first-level fMRI analysis using a Gibbs sampler. The new software is freely available under GNU GPL3 and can be downloaded from github (https://github.com/wanderine/BROCCOLI/.

  13. Effects of broccoli rotation on lettuce drop caused by Sclerotinia minor and on the population density of sclerotia in soil

    OpenAIRE

    Hao, J J; Subbarao, K. V.; Koike, S T

    2003-01-01

    Field experiments were conducted at Spence Road site and at the Hartnell College East Campus site in Salinas, CA, to determine the effects of crop rotation with broccoli or a fallow period on lettuce drop caused by Sclerotinia minor and the density of pathogen sclerotia in the soil. Treatments at the Spence Road site with low inoculum density (cm(3) Of Soil) distributed randomly included: successive crops of lettuce (LLL), lettuce rotated with broccoli (LBL), and lettuce followed by a fallow ...

  14. Influence of different blanching methods on colour, ascorbic acid and phenolics content of broccoli.

    Science.gov (United States)

    Severini, C; Giuliani, R; De Filippis, A; Derossi, A; De Pilli, T

    2016-01-01

    Lack of nutrients in cooking water, high energetic costs, high water consumption and recycling are some drawbacks of vegetable blanching. Those disadvantages could be bypassed using microwave blanching. Three blanching methods (microwave, boiling water and steaming) were compared in this study in order to determine their effects on some functional properties of broccoli. In addition, the thermal damage on broccoli colour was evaluated. The effectiveness of each blanching process was performed measuring the lost of peroxidase activity, that results more rapidly in microwaves and steam treatments (50 and 60 s respectively) than in boiling water treatment (120 s). The colour indexes did not allow to discriminate a significant difference among treatments. The increase of treatment time caused a vitamin C decrease in samples blanched by boiling water and steam; this trend was not observed in microwaved samples. The phenols content did not significantly vary depending both on type and on time of treatment.

  15. Colorless chlorophyll catabolites in senescent florets of broccoli (Brassica oleracea var. italica).

    Science.gov (United States)

    Roiser, Matthias H; Müller, Thomas; Kräutler, Bernhard

    2015-02-11

    Typical postharvest storage of broccoli (Brassica oleracea var. italica) causes degreening of this common vegetable with visible loss of chlorophyll (Chl). As shown here, colorless Chl-catabolites are generated. In fresh extracts of degreening florets of broccoli, three colorless tetrapyrrolic Chl-catabolites accumulated and were detected by high performance liquid chromatography (HPLC): two "nonfluorescent" Chl-catabolites (NCCs), provisionally named Bo-NCC-1 and Bo-NCC-2, and a colorless 1,19-dioxobilin-type "nonfluorescent" Chl-catabolite (DNCC), named Bo-DNCC. Analysis by nuclear magnetic resonance spectroscopy and mass spectrometry of these three linear tetrapyrroles revealed their structures. In combination with a comparison of their HPL-chromatographic properties, this allowed their identification with three known catabolites from two other brassicacea, namely two NCCs from oil seed rape (Brassica napus) and a DNCC from degreened leaves of Arabidopsis thaliana.

  16. 出版业经济惨淡,Broccoli Books关门

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    据出版动画、漫画、游戏类图书的Broccoli Books有限公司总裁Kaname Tezuka披露,Broccoli国际出版美国公司,包括旗下的Broccoli Books出版社和Boysen berry出版社将于今年底关门。他表示,这是日本母公司的决定,“根据美国漫画图书市场和美国经济的整体状况,公司领导层决定最好暂时将力量集中在日本市场。”

  17. Effect of Nitrogen and Boron in Seed Yield and Yield Attributing Characters of Broccoli

    Directory of Open Access Journals (Sweden)

    A. Khanal

    2015-09-01

    Full Text Available Plant nutrient is one of the limiting factors affecting crop production. Nitrogen and boron are major nutrients in case of broccoli. So, an experiment was carried out to evaluate the effect of nitrogen and boron in seed yield and yield attributing characters of broccoli in Rampur, Chitwan during winter season. The experiment was laid out in factorial RCBD design with four levels of nitrogen and two levels of boron. Each plot consists of 25 plants which were separated by 60 * 60 cm spacing. There are altogether eight treatments replicates thrice. Local variety Calabrese was used. Significant effect of different dose of nitrogen and boron on yield attributing characters was found. Also interactive effect of nitrogen and boron in number of pods, pod length, seed yield and number of seeds per pod was found significantly different.

  18. Effects of different cooking methods on health-promoting compounds of broccoli

    Institute of Scientific and Technical Information of China (English)

    Gao-feng YUAN; Bo SUN; Jing YUAN; Qiao-mei WANG

    2009-01-01

    The effects of five domestic cooking methods, including steaming, microwaving, boiling, stir-frying, and stir-frying followed by boiling (stir-frying/boiling), on the nutrients and health-promoting compounds of broccoli were investigated. The results show that all cooking treatments, except steaming, caused significant losses of chlorophyll and vitamin C and significant decreases of total soluble proteins and soluble sugars. Total aliphatic and indole glucosinolates were significantly modified by all cooking treatments but not by steaming. In general, the steaming led to the lowest loss of total glucosinolates, while stir-frying and stir-frying/boiling presented the highest loss. Stir-frying and stir-frying/boiling, the two most popular methods for most homemade dishes in China, cause great losses of chlorophyll, soluble protein, soluble sugar, vitamin C, and glucosinolates, but the steaming method appears the best in retention of the nutrients in cooking broccoli.

  19. Broccoli yield in response to top-dressing fertilization with green manure and biofertilizer

    Directory of Open Access Journals (Sweden)

    Gilberto Bernardo de Freitas

    2011-10-01

    Full Text Available The objective of this work was to evaluate the productive performance of broccoli under different top-dressing organic fertilizations. The experiment was conducted under protected cultivation, in a completely randomized design with four replications, with two plants per experimental unit. Broccoli seedlings were produced in a commercial substrate in styrofoam trays. The seedlings were transplanted to plastic pots containing 10.0 L of substrate made up of subsoil and organic compost at the ratio of 3:1 (v/v, respectively, which is equivalent to about 20.0 t ha-1 of organic compost at planting. After seedling establishment, the top-dressing fertilization treatments were applied: gliricidia biomass associated or not with liquid biofertilizer of cattle manure to the soil and bokashi. Two control treatments were established: one with mineral fertilization recommended for the crop and the other without top-dressing fertilization. The broccoli production was evaluated (commercial standard. Plants that received mineral fertilizer were more productive, however, they were not significantly different (p>0.05, by Dunnet test, from the plants fertilized with 2.5 t ha-1 gliricidiabiomass (dry mass associated with liquid biofertilizer (2.0 L m-2 applied to soil. Top-dressing fertilizations with only gliricidia, at 2.5 and 5.0 t ha-1 of biomass (dry mass, resulted in no significant increase in production of broccoli inflorescence. The use of bokashi in addition to gliricidia biomass and liquid biofertilizer reduced the efficiency of the fertilization compared with plants that received only gliricidia and liquid biofertilizer.

  20. Ozone effects on yield quality of spring oilseed rape and broccoli

    Science.gov (United States)

    Vandermeiren, Karine; De Bock, Maarten; Horemans, Nele; Guisez, Yves; Ceulemans, Reinhart; De Temmerman, Ludwig

    2012-02-01

    The impact of elevated tropospheric ozone (O 3) on the quality of spring oilseed rape ( Brassica napus cv Ability) and broccoli ( Brassica oleracea L. cv Italic cv Monaco) was assessed during a three year Open - Top Chamber (OTC) experiment. Current ambient O 3 levels were compared to an increase of 20 and 40 ppb during 8 h per day over the entire growing season. The qualitative responses were expressed as a function of the accumulated hourly O 3 concentrations over a threshold of 40 ppb (AOT40) and the phytotoxic O 3 dose above a threshold of 6 nmol s -1 m -2 projected leaf area (POD 6). Our results provide clear evidence that O 3 has an influence on the qualitative attributes of the harvested products of these Brassica species. The responses were comparable whether they were expressed as a function of the accumulated O 3 concentrations or of the modelled O 3 uptake. The protein concentration of oilseed rape seeds and broccoli heads was significantly increased in response to O 3. There was also a shift in the fatty acid composition of the vegetable oil derived from seeds of oilseed rape. Oleic acid (18:1) declined significantly ( p broccoli an important shift occurred from indolic to aliphatic GSLs although the total GSL concentration was not changed. The increase in the aliphatic/indolic GSL ratio ( p properties of these vegetables. The vitamin C (ascorbate - ASC) and α-TOC concentrations of broccoli were not influenced by O 3; glutathione (GSH) was slightly increased in response to a higher O 3 uptake ( p < 0.05). The consequences of these changes with regard to food and feed quality and human health are discussed.

  1. On the Strains of Erwinia carotouora subsp. carotouora Isolated from Radish Seedlings and Broccoli Plants

    OpenAIRE

    Tsuchiya, Kenichi; Karnjanarat, Surang; Hayashi, Mitsunori; Umeno, Masayoshi; Wakimoto, Satoshi

    1987-01-01

    Twenty bacterial strains isolated from edible radish seedlings (Kaiware-daikon : Raphunus sativus L.) and broccoli plants (Brassica oleracea var. italica Plen.) showing soft rot were compared on the basis of pathogenicity and physiological, biochemical and serological properties. Ten strains isolated from each host were homogeneous and they were identical in being positive for the following properties : rod shaped cells with peritrichous flagellation, anaerobic growth, fermentative metabolism...

  2. Dark-chilling of Seedlings Affects Initiation and Morphology of Broccoli Inflorescence

    Directory of Open Access Journals (Sweden)

    Aneta GRABOWSKA

    2013-05-01

    Full Text Available The constant supply of broccoli heads for a vegetable market can be kept by the differentiation of sowing time and the age of seedlings. Dark-chilling of young seedlings can also modify the time of transplanting, subsequent plant development, yield and inflorescence quality. The aim of the present study was to analyze the influence of seedling dark-chilling on the inflorescence initiation and the morphological quality of broccoli heads. The experiment was carried out at the University of Agriculture in Krakow (South Poland in the years 2009 and 2010, with broccoli (Brassica oleracea L. var. italica Plenck medium late cultivar ‘Monaco’ F1. The examined factors were the age of seedlings (4-, 6-, 8-, and 10-week-old and dark-chilling (2°C/2 weeks and non-chilled control. Microscopic analysis of the apex sections was performed to determine the time of the inflorescence differentiation in chilled and non-chilled seedlings of different age. Chosen morphological features of the mature heads were also described as depended on age and chilling of seedlings. The inflorescence initiation was observed between 4 and 6 week of the plant ontogeny. Especially 4-week-old seedlings, chilled by two weeks, were more advanced in the generative development in comparison to non-chilled control. Low temperature applied in the seedling stage did not cause the head buttoning. Inflorescences developed by broccoli planted from 4 and 6-week-old seedlings, both chilled and control, were characterized by the best visual quality, determined by a convex head shape, tight branching angle, small and uniform size and regular form of flower buds. Chilling of oldest, 8- and 10-week-old seedlings negatively affected the inflorescence quality, through planed and spread shape of heads and non-uniform shape of flower buds.

  3. Multiwalled carbon nanotubes enter broccoli cells enhancing growth and water uptake of plants exposed to salinity

    OpenAIRE

    Martínez-Ballesta, Mª Carmen; Zapata, Lavinia; Chalbi, Najla; Carvajal, Micaela

    2016-01-01

    Background Carbon nanotubes have been shown to improve the germination and growth of some plant species, extending the applicability of the emerging nano-biotechnology field to crop science. Results In this work, exploitation of commercial multiwalled carbon nanotubes (MWCNTs) in control and 100 mM NaCl-treated broccoli was performed. Transmission electron microscopy demonstrated that MWCNTs can enter the cells in adult plants with higher accumulation under salt stress. Positive effect of MWC...

  4. Organic broccoli production on transition soils: Comparing cover crops, tillage and sidedress N

    OpenAIRE

    Schellenberg, D.L.; Morse, R.D.; Welbaum, G.E.

    2009-01-01

    Metadata only record Little information is available about how farmers in transition to organic practices should manage short- and long-term N fertility. The objectives of this research were (1) to evaluate the leguminous cover crops lablab (Dolichos lablab L.), soybean (Glycine max L.), sunn hemp (Crotalaria juncea L.) and a mixture of sunn hemp and cowpea (Vigna sinensis Endl.) as N sources; (2) to compare N availability and broccoli yield when cover crops were incorporated with conventi...

  5. Post Harvest Treatment Effects on Crown-Cut Broccoli Shelf Life

    OpenAIRE

    Ramesh, Reddy Yettella Venkata

    2004-01-01

    The effects of packaging treatments, post harvest cooling delay and storage duration on color, texture, ascorbic acid content, weight loss and glucosinolate retention in crown-cut heads of broccoli were studied. Oxygen and CO2 levels inside shrink wrap packages were also monitored. Shrink wrap packaging had a significant positive effect on hue angle (p<0.05). Packaging and post harvest cooling delay had no effect on hue difference and total color difference. While post harvest cooling dela...

  6. Untargeted Metabolomics Reveals Predominant Alterations in Lipid Metabolism Following Light Exposure in Broccoli Sprouts.

    Science.gov (United States)

    Maldini, Mariateresa; Natella, Fausta; Baima, Simona; Morelli, Giorgio; Scaccini, Cristina; Langridge, James; Astarita, Giuseppe

    2015-01-01

    The consumption of vegetables belonging to the family Brassicaceae (e.g., broccoli and cauliflower) is linked to a reduced incidence of cancer and cardiovascular diseases. The molecular composition of such plants is strongly affected by growing conditions. Here we developed an unbiased metabolomics approach to investigate the effect of light and dark exposure on the metabolome of broccoli sprouts and we applied such an approach to provide a bird's-eye view of the overall metabolic response after light exposure. Broccoli seeds were germinated and grown hydroponically for five days in total darkness or with a light/dark photoperiod (16 h light/8 h dark cycle). We used an ultra-performance liquid-chromatography system coupled to an ion-mobility, time-of-flight mass spectrometer to profile the large array of metabolites present in the sprouts. Differences at the metabolite level between groups were analyzed using multivariate statistical analyses, including principal component analysis and correlation analysis. Altered metabolites were identified by searching publicly available and in-house databases. Metabolite pathway analyses were used to support the identification of subtle but significant changes among groups of related metabolites that may have gone unnoticed with conventional approaches. Besides the chlorophyll pathway, light exposure activated the biosynthesis and metabolism of sterol lipids, prenol lipids, and polyunsaturated lipids, which are essential for the photosynthetic machinery. Our results also revealed that light exposure increased the levels of polyketides, including flavonoids, and oxylipins, which play essential roles in the plant's developmental processes and defense mechanism against herbivores. This study highlights the significant contribution of light exposure to the ultimate metabolic phenotype, which might affect the cellular physiology and nutritional value of broccoli sprouts. Furthermore, this study highlights the potential of an

  7. Untargeted Metabolomics Reveals Predominant Alterations in Lipid Metabolism Following Light Exposure in Broccoli Sprouts

    Directory of Open Access Journals (Sweden)

    Mariateresa Maldini

    2015-06-01

    Full Text Available The consumption of vegetables belonging to the family Brassicaceae (e.g., broccoli and cauliflower is linked to a reduced incidence of cancer and cardiovascular diseases. The molecular composition of such plants is strongly affected by growing conditions. Here we developed an unbiased metabolomics approach to investigate the effect of light and dark exposure on the metabolome of broccoli sprouts and we applied such an approach to provide a bird’s-eye view of the overall metabolic response after light exposure. Broccoli seeds were germinated and grown hydroponically for five days in total darkness or with a light/dark photoperiod (16 h light/8 h dark cycle. We used an ultra-performance liquid-chromatography system coupled to an ion-mobility, time-of-flight mass spectrometer to profile the large array of metabolites present in the sprouts. Differences at the metabolite level between groups were analyzed using multivariate statistical analyses, including principal component analysis and correlation analysis. Altered metabolites were identified by searching publicly available and in-house databases. Metabolite pathway analyses were used to support the identification of subtle but significant changes among groups of related metabolites that may have gone unnoticed with conventional approaches. Besides the chlorophyll pathway, light exposure activated the biosynthesis and metabolism of sterol lipids, prenol lipids, and polyunsaturated lipids, which are essential for the photosynthetic machinery. Our results also revealed that light exposure increased the levels of polyketides, including flavonoids, and oxylipins, which play essential roles in the plant’s developmental processes and defense mechanism against herbivores. This study highlights the significant contribution of light exposure to the ultimate metabolic phenotype, which might affect the cellular physiology and nutritional value of broccoli sprouts. Furthermore, this study highlights the

  8. Bioactive glucosinolates and antioxidant properties of broccoli seeds cultivated in Thailand

    Directory of Open Access Journals (Sweden)

    Sarunya Chuanphongpanich

    2006-03-01

    Full Text Available One of the most significant health concerns of cruciferous vegetables is the presence of biologically active compounds, glucosinolates. Broccoli (Brassica oleracea var. italica is a nutritionally important crop grown all over the world. Glucosinolates have been found to have anti-cancer properties. The primary purpose of this study was to evaluate glucosinolate content and antioxidant property in the seeds of broccoli cultivars widely grown in Thailand. Glucosinolates were analyzed with high performance liquid chromatography (HPLC. Total and individual glucosinolate levels varied significantly among cultivars. In all broccoli seeds, 4-methylsulfinylbutylglucosinolate (glucoraphanin was the predominant glucosinolate. The highest total glucosinolates was 65.5 µmol/g DW in ‘Top Green #067’ cultivar, followed by ‘Packman’ (58.6, ‘Green Queen’ (51.2, ‘Pak Ging’ (25.5 and ‘Rod Fai’ (20.3. The antioxidant capacities, including ABTS radical scavenging activity and ferrous ion chelating ability in the methanol and water extracts, were found to be high.

  9. A liquid chromatography-mass spectrometry approach to study "glucosinoloma" in broccoli sprouts.

    Science.gov (United States)

    Maldini, Mariateresa; Baima, Simona; Morelli, Giorgio; Scaccini, Cristina; Natella, Fausta

    2012-09-01

    Glucosinolates are an important class of secondary plant metabolites, possessing health-promoting properties. Young broccoli plants are a very good source of glucosinolates with concentrations several times greater than in mature plants. The aim of our study was to develop a liquid chromatography-mass spectrometry and liquid chromatography/tandem mass spectrometry qualitative and quantitative method for the measure of glucosinolates in broccoli sprouts. The described method provides high sensitivity and specificity, allowing a rapid and simultaneous determination of 14 glucosinolates. The proposed method has been validated for eight glucosinolates: glucobrassicin, glucoraphanin, glucoiberin, glucoerucin, progoitrin, gluconapin, sinigrin and glucocheirolin. The linear range was 1-150 µg ml(-1), the intra-day and inter-day precision values are within 6% and 8% at the lower limit of quantification, while the overall recovery of the eight glucosinolates was 99 ± 9%. This validated method was used successfully for analysis of glucosinolates content of broccoli sprouts grown in different conditions.

  10. Validation of the Analytical Method for the Determination of Flavonoids in Broccoli

    Directory of Open Access Journals (Sweden)

    Tuszyńska Magdalena

    2014-09-01

    Full Text Available A simple, accurate and selective HPLC method was developed and validated for determination of quercetin and kaempferol, which are the main flavonols in broccoli. The separation was achieved on a reversed-phase C18 column using a mobile phase composed of methanol/water (60/40 and phosphoric acid 0.2% at a flow rate of 1.0 ml min-1. The detection was carried out on a DAD detector at 370 nm. This method was validated according to the requirements for new methods, which include selectivity, linearity, precision, accuracy, limit of detection and limit of quantitation. The current method demonstrates good linearity, with R2 > 0.99. The recovery is within 98.07-102.15% and 97.92-101.83% for quercetin and kaempferol, respectively. The method is selective, in that quercetin and kaempferol are well separated from other compounds of broccoli with good resolution. The low limit of detection and limit of quantitation of quercetin and kaempferol enable the detection and quantitation of these flavonoids in broccoli at low con–centrations.

  11. Utility of the broccoli sign in the distinction of prolapsed uterine tumor from cervical tumor

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Priyanka; Chang, Stephanie T. [Department of Radiology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628 (United States); Rabban, Joseph T. [Department of Anatomic Pathology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628 (United States); Chen, Lee-may [Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628 (United States); Yeh, Benjamin M. [Department of Radiology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628 (United States); Coakley, Fergus V., E-mail: Fergus.Coakley@radiology.ucsf.edu [Department of Radiology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628 (United States)

    2012-08-15

    Objective: To describe the utility, histopathological basis, and clinical correlates of the broccoli sign. Methods: The committee on human research approved this HIPAA compliant study and waived written informed consent. Based on the records of the senior author and our multidisciplinary Gynecologic Oncology Tumor Board, we retrospectively identified thirteen women (mean age of 48.8 years; range, 34-74) with a cervical mass seen at MR imaging (n = 13) or CT (n = 5) that demonstrated the previously reported broccoli sign (i.e., a soft tissue stalk connecting the cervical mass to the uterine cavity) on one or other modality. All available clinical, imaging, and histopathological records were reviewed, with particular emphasis on initially suspected diagnosis, final proven diagnosis, and outcome. Results: Cervical cancer was the initial clinically suspected diagnosis in 6 of 13 patients. Surgical resection demonstrated prolapsed uterine tumor in all patients, consisting of endometrioid adenocarcinoma (n = 7), carcinosarcoma (n = 2), adenosarcoma (n = 1), and leiomyoma (n = 3). Excluding the three patients with leiomyomas, currently, 7 patients with malignant tumors are disease free after a mean interval of 15 months (range, 3-45) and 3 patients have been lost to follow-up. Conclusion: A stalk connecting an apparent cervical mass seen at CT or MR imaging to the endometrial cavity ('broccoli sign') favors the diagnosis of a prolapsed uterine tumor; these prolapsed uterine tumors can often be malignant but appear to have a good prognosis.

  12. Exergetic performance analyses of drying of broccoli florets in a tray drier

    International Nuclear Information System (INIS)

    At present, the drying process is one of the major procedures of food preservation and an important unit operation in a wide variety of food industries. Recently, drying of vegetables is of a particular interest because it is added to various ready-to-eat meals in order to improve their nutritional quality due to health benefit compounds present in vegetables (vitamins, phytochemicals, dietary fibers). Broccoli has been described as a vegetable with a high nutritional value due to its important content of vitamins, antioxidants and anti-carcinogenic compounds. Broccoli dehydration has not been investigated to a great extent and a few data are available in the open literature. In this study, broccoli florets were dried in a tray drier at a temperature range of 50-70 deg C with an air velocity range of 0.5-1.5 m/s. The performance of the process and system was evaluated using the exergy analysis method. Based on the experimental data, effects of the drying air temperature and the velocity on the performance of the drying process were discussed. It was obtained that the exergy evaporation rate and the exergetic efficiency of the process were obtained to vary between 0.0006-0.0029 kW and 0.27-1.16%, respectively. They increased as the drying air temperature increased, while the exergetic efficiency decreased with the rise in the drying air velocity. (author)

  13. Detection of the Diversity of Cytoplasmic Male Sterility Sources in Broccoli (Brassica Oleracea var. Italica) Using Mitochondrial Markers

    Science.gov (United States)

    Shu, Jinshuai; Liu, Yumei; Li, Zhansheng; Zhang, Lili; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao

    2016-01-01

    Broccoli (Brassica oleracea var. italica) is an important commercial vegetable crop. As part of an efficient pollination system, cytoplasmic male sterility (CMS) has been widely used for broccoli hybrid production. Identifying the original sources of CMS in broccoli accessions has become an important part of broccoli breeding. In this study, the diversity of the CMS sources of 39 broccoli accessions, including 19 CMS lines and 20 hybrids, were analyzed using mitochondrial markers. All CMS accessions contained the ogu orf138-related DNA fragment and the key genes of nap CMS, pol CMS, and tour CMS were not detected. The 39 CMS accessions were divided into five groups using six orf138-related and two simple sequence repeat markers. We observed that ogu CMS R3 constituted 79.49% of the CMS sources. CMS6 and CMS26 were differentiated from the other accessions using a specific primer. CMS32 was distinguished from the other accessions based on a 78-nucleotide deletion at the same locus as the orf138-related sequence. When the coefficient was about 0.90, five CMS accessions (13CMS6, 13CMS23, 13CMS24, 13CMS37, and 13CMS39) exhibiting abnormal floral organs with poor seed setting were grouped together. The polymerase chain reaction amplification profiles for these five accessions differed from those of the other accessions. We identified eight useful molecular markers that can be used to detect CMS types during broccoli breeding. Our data also provide important information relevant to future studies on the possible origins and molecular mechanisms of CMS in broccoli. PMID:27446156

  14. Detection of the Diversity of Cytoplasmic Male Sterility Sources in Broccoli (Brassica Oleracea var. Italica) Using Mitochondrial Markers.

    Science.gov (United States)

    Shu, Jinshuai; Liu, Yumei; Li, Zhansheng; Zhang, Lili; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao

    2016-01-01

    Broccoli (Brassica oleracea var. italica) is an important commercial vegetable crop. As part of an efficient pollination system, cytoplasmic male sterility (CMS) has been widely used for broccoli hybrid production. Identifying the original sources of CMS in broccoli accessions has become an important part of broccoli breeding. In this study, the diversity of the CMS sources of 39 broccoli accessions, including 19 CMS lines and 20 hybrids, were analyzed using mitochondrial markers. All CMS accessions contained the ogu orf138-related DNA fragment and the key genes of nap CMS, pol CMS, and tour CMS were not detected. The 39 CMS accessions were divided into five groups using six orf138-related and two simple sequence repeat markers. We observed that ogu CMS R3 constituted 79.49% of the CMS sources. CMS6 and CMS26 were differentiated from the other accessions using a specific primer. CMS32 was distinguished from the other accessions based on a 78-nucleotide deletion at the same locus as the orf138-related sequence. When the coefficient was about 0.90, five CMS accessions (13CMS6, 13CMS23, 13CMS24, 13CMS37, and 13CMS39) exhibiting abnormal floral organs with poor seed setting were grouped together. The polymerase chain reaction amplification profiles for these five accessions differed from those of the other accessions. We identified eight useful molecular markers that can be used to detect CMS types during broccoli breeding. Our data also provide important information relevant to future studies on the possible origins and molecular mechanisms of CMS in broccoli. PMID:27446156

  15. Dietary chemoprevention of PhIP induced carcinogenesis in male Fischer 344 rats with tomato and broccoli.

    Directory of Open Access Journals (Sweden)

    Kirstie Canene-Adams

    Full Text Available The heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-B]pyridine (PhIP, found in meats cooked at high temperatures, has been implicated in epidemiological and rodent studies for causing breast, prostate, and colorectal cancers. A previous animal study using a xenograft model has shown that whole tomato and broccoli, when eaten in combination, exhibit a marked effect on tumor reduction compared to when eaten alone. Our aim was to determine if PhIP-induced carcinogenesis can be prevented by dietary consumption of whole tomato + broccoli powders. Male Fischer 344 rats (n = 45 were randomized into the following treatment groups: control (AIN93G diet, PhIP (200 ppm in AIN93G diet for the first 20 weeks of the study, or tomato + broccoli + PhIP (mixed in AIN93G diet at 10% each and fed with PhIP for 20 weeks, and then without PhIP for 32 weeks. Study animals were monitored for 52 weeks and were euthanized as necessary based on a set of criteria for health status and tumor burden. Although there appeared to be some hepatic and intestinal toxicity due to the combination of PhIP and tomato + broccoli, these rodents had improved survival and reduced incidence and/or severity of PhIP-induced neoplastic lesions compared to the PhIP-alone treated group. Rats eating tomato + broccoli exhibited a marked decrease in the number and size of cribiform prostatic intraepitheilial neoplasia/carcinoma in situ (cribiform PIN/CIS lesions and in the incidence of invasive intestinal adenocarcinomas and skin carcinomas. Although the apparent toxic effects of combined PhIP and tomato + broccoli need additional study, the results of this study support the hypothesis that a diet rich in tomato and broccoli can reduce or prevent dietary carcinogen-induced cancers.

  16. Dietary chemoprevention of PhIP induced carcinogenesis in male Fischer 344 rats with tomato and broccoli.

    Science.gov (United States)

    Canene-Adams, Kirstie; Sfanos, Karen S; Liang, Chung-Tiang; Yegnasubramanian, Srinivasan; Nelson, William G; Brayton, Cory; De Marzo, Angelo M

    2013-01-01

    The heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-B]pyridine (PhIP), found in meats cooked at high temperatures, has been implicated in epidemiological and rodent studies for causing breast, prostate, and colorectal cancers. A previous animal study using a xenograft model has shown that whole tomato and broccoli, when eaten in combination, exhibit a marked effect on tumor reduction compared to when eaten alone. Our aim was to determine if PhIP-induced carcinogenesis can be prevented by dietary consumption of whole tomato + broccoli powders. Male Fischer 344 rats (n = 45) were randomized into the following treatment groups: control (AIN93G diet), PhIP (200 ppm in AIN93G diet for the first 20 weeks of the study), or tomato + broccoli + PhIP (mixed in AIN93G diet at 10% each and fed with PhIP for 20 weeks, and then without PhIP for 32 weeks). Study animals were monitored for 52 weeks and were euthanized as necessary based on a set of criteria for health status and tumor burden. Although there appeared to be some hepatic and intestinal toxicity due to the combination of PhIP and tomato + broccoli, these rodents had improved survival and reduced incidence and/or severity of PhIP-induced neoplastic lesions compared to the PhIP-alone treated group. Rats eating tomato + broccoli exhibited a marked decrease in the number and size of cribiform prostatic intraepitheilial neoplasia/carcinoma in situ (cribiform PIN/CIS) lesions and in the incidence of invasive intestinal adenocarcinomas and skin carcinomas. Although the apparent toxic effects of combined PhIP and tomato + broccoli need additional study, the results of this study support the hypothesis that a diet rich in tomato and broccoli can reduce or prevent dietary carcinogen-induced cancers. PMID:24312188

  17. Evolution of novel O-methyltransferases from the Vanilla planifolia caffeic acid O-methyltransferase.

    Science.gov (United States)

    Li, Huaijun Michael; Rotter, David; Hartman, Thomas G; Pak, Fulya E; Havkin-Frenkel, Daphna; Belanger, Faith C

    2006-06-01

    The biosynthesis of many plant secondary compounds involves the methylation of one or more hydroxyl groups, catalyzed by O-methyltransferases (OMTs). Here, we report the characterization of two OMTs, Van OMT-2 and Van OMT-3, from the orchid Vanilla planifolia Andrews. These enzymes catalyze the methylation of a single outer hydroxyl group in substrates possessing a 1,2,3-trihydroxybenzene moiety, such as methyl gallate and myricetin. This is a substrate requirement not previously reported for any OMTs. Based on sequence analysis these enzymes are most similar to caffeic acid O-methyltransferases (COMTs), but they have negligible activity with typical COMT substrates. Seven of 12 conserved substrate-binding residues in COMTs are altered in Van OMT-2 and Van OMT-3. Phylogenetic analysis of the sequences suggests that Van OMT-2 and Van OMT-3 evolved from the V. planifolia COMT. These V. planifolia OMTs are new instances of COMT-like enzymes with novel substrate preferences.

  18. Distinction between the Cfr Methyltransferase Conferring Antibiotic Resistance and the Housekeeping RlmN Methyltransferase

    DEFF Research Database (Denmark)

    Atkinson, Gemma C; Hansen, Lykke H; Tenson, Tanel;

    2013-01-01

    The cfr gene encodes the Cfr methyltransferase that primarily methylates C-8 in A2503 of 23S rRNA in the peptidyl transferase region of bacterial ribosomes. The methylation provides resistance to six classes of antibiotics of clinical and veterinary importance. The rlmN gene encodes the Rlm......N methyltransferase that methylates C-2 in A2503 in 23S rRNA and A37 in tRNA, but RlmN does not significantly influence antibiotic resistance. The enzymes are homologous and use the same mechanism involving radical S-adenosyl methionine to methylate RNA via an intermediate involving a methylated cysteine....... The differentiation between the two classes is supported by previous and new experimental evidence from antibiotic resistance, primer extensions, and mass spectrometry. Finally, evolutionary aspects of the distribution of Cfr- and RlmN-like enzymes are discussed....

  19. Structures of NS5 Methyltransferase from Zika Virus.

    Science.gov (United States)

    Coloma, Javier; Jain, Rinku; Rajashankar, Kanagalaghatta R; García-Sastre, Adolfo; Aggarwal, Aneel K

    2016-09-20

    The Zika virus (ZIKV) poses a major public health emergency. To aid in the development of antivirals, we present two high-resolution crystal structures of the ZIKV NS5 methyltransferase: one bound to S-adenosylmethionine (SAM) and the other bound to SAM and 7-methyl guanosine diphosphate (7-MeGpp). We identify features of ZIKV NS5 methyltransferase that lend to structure-based antiviral drug discovery. Specifically, SAM analogs with functionalities on the Cβ atom of the methionine portion of the molecules that occupy the RNA binding tunnel may provide better specificity relative to human RNA methyltransferases.

  20. Structures of NS5 Methyltransferase from Zika Virus

    Directory of Open Access Journals (Sweden)

    Javier Coloma

    2016-09-01

    Full Text Available The Zika virus (ZIKV poses a major public health emergency. To aid in the development of antivirals, we present two high-resolution crystal structures of the ZIKV NS5 methyltransferase: one bound to S-adenosylmethionine (SAM and the other bound to SAM and 7-methyl guanosine diphosphate (7-MeGpp. We identify features of ZIKV NS5 methyltransferase that lend to structure-based antiviral drug discovery. Specifically, SAM analogs with functionalities on the Cβ atom of the methionine portion of the molecules that occupy the RNA binding tunnel may provide better specificity relative to human RNA methyltransferases.

  1. Structures of NS5 Methyltransferase from Zika Virus.

    Science.gov (United States)

    Coloma, Javier; Jain, Rinku; Rajashankar, Kanagalaghatta R; García-Sastre, Adolfo; Aggarwal, Aneel K

    2016-09-20

    The Zika virus (ZIKV) poses a major public health emergency. To aid in the development of antivirals, we present two high-resolution crystal structures of the ZIKV NS5 methyltransferase: one bound to S-adenosylmethionine (SAM) and the other bound to SAM and 7-methyl guanosine diphosphate (7-MeGpp). We identify features of ZIKV NS5 methyltransferase that lend to structure-based antiviral drug discovery. Specifically, SAM analogs with functionalities on the Cβ atom of the methionine portion of the molecules that occupy the RNA binding tunnel may provide better specificity relative to human RNA methyltransferases. PMID:27633330

  2. Monolignol 4-O-methyltransferases and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang-Jun; Bhuiya, Mohammad-Wadud; Zhang, Kewei

    2014-11-18

    Modified (iso)eugenol 4-O-methyltransferase enzymes having novel capacity for methylation of monolignols and reduction of lignin polymerization in plant cell wall are disclosed. Sequences encoding the modified enzymes are disclosed.

  3. Sulforaphane formation and bioaccessibility are more affected by steaming time than meal composition during in vitro digestion of broccoli.

    Science.gov (United States)

    Sarvan, I; Kramer, E; Bouwmeester, H; Dekker, M; Verkerk, R

    2017-01-01

    Broccoli is a rich source of the glucosinolate glucoraphanin (GR). After hydrolysis of GR by the endogenous enzyme myrosinase, sulforaphane (SF) or sulforaphane nitrile (SFN) are produced, depending on environmental conditions. How the conversion of GR and bioaccessibility of released breakdown products are affected by steaming (raw, 1min, 2min and 3min steamed) and meal composition (protein or lipid addition) was studied with an in vitro digestion model (mouth, stomach, intestine, but not colonic digestion). The main formation of SF and SFN occurred during in vitro chewing. The contents of GR, SF and SFN did not change after further digestion, as the irreversible inactivated myrosinase under gastric conditions caused no further GR hydrolysis. SF concentrations were up to 10 times higher in raw and 1min steamed broccoli samples after digestion compared to longer-steamed broccoli. Protein or lipid addition had no influence on the formation and bioaccessibility of SF or SFN. PMID:27507513

  4. Effects of industrial pre-freezing processing and freezing handling on glucosinolates and antioxidant attributes in broccoli florets.

    Science.gov (United States)

    Cai, Congxi; Miao, Huiying; Qian, Hongmei; Yao, Leishuan; Wang, Bingliang; Wang, Qiaomei

    2016-11-01

    The effects of industrial pre-freezing processing and freezing handling on the contents of glucosinolates and antioxidants (vitamin C, polyphenols, carotenoid and chlorophyll), as well as the antioxidant capacity in broccoli (Brassica oleracea L. var. italica) florets were investigated in the present study. Our results showed that the glucosinolate accumulations were significantly decreased after pre-freezing processing, whereas elevated levels of phenols, carotenoids, chlorophyll, and also antioxidant capacity were observed in frozen broccoli florets. The contents of vitamin C remained constant during above mentioned processing. In conclusion, the current industrial freezing processing method is a good practice for the preservation of main antioxidant nutrients in broccoli florets, although some improvements in pre-freezing processing, such as steam blanching and ice-water cooling, are needed to attenuate the decrease in glucosinolate content. PMID:27211670

  5. IDENTIFICATION OF ANTAGONISTS OF Xanthomonas campestris ISOLATED FROM RHIZOSPHERE ZONE OF BROCCOLI FARM AT KEMBANG MERTA VILLAGE, TABANAN, BALI

    Directory of Open Access Journals (Sweden)

    Nadya Treesna Wulansari

    2015-03-01

    Full Text Available The main objectives of this research were to isolate and identify antagonists of Xanthomonas campestris from rhizosphere zone of broccoli plants. Soil samples were collected from broccoli farm located at Kembang Merta village, Tabanan, Bali. Isolation and identification of the antagonists were conducted at the Laboratory of Microbiology, Udayana University. Two fungal (Trichoderma harzianum and Trichoderma viride and two bacterial (Bacillus sp. and Pseudomonas sp. antagonists potentially to be developed as biocontrol agents of Xanthomonas campestris were successfully identified in this research

  6. Growth and yield responses of broccoli cultivars to different rates of nitrogen at western Chitwan, Nepal

    DEFF Research Database (Denmark)

    Giri, Raj Kumar; Sharma, Moha Datta; Shakya, Santa Man;

    2013-01-01

    A field experiment was conducted with the objective to determine the optimum rate of nitrogen (N) fertilizer for effective growth and yield of two varieties of broccoli in southern plain of Nepal. The experiment was laid out with two-factorial completely random block design (RCBD) comprising two......% higher total curd than Calabrese. Similarly, curd production increased N rate up to 200 kg ha-1 reaching a maximum of 14.47 t ha-1. This indicated that optimum level of N could be beyond the rates tested in this study, which needs further experimentation....

  7. Isolation of DNA methyltransferase from plants

    International Nuclear Information System (INIS)

    DNA methyltransferases (DMT) were isolated from nuclei of cauliflower, soybean, and pea by extraction with 0.35 M NaCl. Assays were performed on hemimethylated Micrococcus luteus DNA or on M. luteus DNA to test for maintenance or de novo methylase activity, respectively. Fully methylated DNA was used as a substrate to determine background levels of methylation. Based on these tests, yields of maintenance DMT activity in the crude extract from pea hypocotyl, soybean hypocotyl, and cauliflower inflorescence were 2.8, 0.9, and 1.6 units per g wet tissue (one unit equals 1 pmol of methyl from [3H]AdoMet incorporated into acid precipitable material per h at 300). Two peaks of DMT activity were detected in the soybean nuclear extract following phosphocellulose chromatography. One eluted at 0.4 M and the other at 0.8 M KCl. With both fractions maintenance activity was approximately 2 times that of the de novo activity. Using gel filtration the DMT eluted at 220,000 Daltons. The optimal pH for activity was between 6.5 and 7.0, and the optimal temperature was 300

  8. Purification and properties of thioether methyltransferase

    International Nuclear Information System (INIS)

    A method to assay activity was developed which measures acceptance of methyl groups from [methyl-3H]-S-adenosylmethionine by dimethyl selenide. The product, [3H]trimethylselenonium ion, is separated by HPLC and quantitated by scintillation counting. Thioether methyltransferase from mouse liver and lung resides primarily in the cytosol. In terms of specific activity the enzyme is most active in the lung and liver. Purification from lung cytosol requires a three-step process of DEAE and gel filtration column chromatographies followed by chromatofocusing. SDS-Polyacrylamide gel electrophoresis shows a single homogeneous band with a molecular mass of 28,000 daltons. Vmax and Km values for dimethyl selenide as a substrate are 15. 7 pmol/min and 0.44 μM, respectively. Our studies have also shown that this purified enzyme is capable of methylating a wide range of compounds. To further test the enzyme's role in detoxification, in vivo studies were performed by injecting mice with substrate and [methyl-3H]methionine and analyzing tissue extracts and urine for [methyl-3H]sulfonium

  9. Systematic Comparisons of Orthologous Selenocysteine Methyltransferase and Homocysteine Methyltransferase Genes from Seven Monocots Species

    Directory of Open Access Journals (Sweden)

    De-yong ZHAO

    2015-06-01

    Full Text Available Identifying and manipulating genes underlying selenium metabolism could be helpful for increasing selenium content in crop grain, which is an important way to overcome diseases resulted from selenium deficiency. A reciprocal smallest distance algorithm (RSD approach was applied using two experimentally confirmed Homocysteine S-Methyltransferases genes (HMT1 and HMT2 and a putative Selenocysteine Methyltransferase (SMT from dicots plant Arabidopsis thaliana, to explore their orthologs in seven sequenced diploid monocot species: Oryza sativa, Zea mays, Sorghum bicolor, Brachypodium distachyon, Hordeum vulgare, Aegilops tauschii (the D-genome donor of common wheat and Triticum urartu (the A-genome donor of common wheat. HMT1 was apparently diverged from HMT2 and most of SMT orthologs were the same with that of HMT2 in this study, leading to the hypothesis that SMT and HMT originate from one common ancestor gene. Identifying orthologs provide candidates for further experimental confirmation; also it could be helpful in designing primers to clone SMT or HMT orthologs in other crops.

  10. Optimization of a blanching step to maximize sulforaphane synthesis in broccoli florets.

    Science.gov (United States)

    Pérez, Carmen; Barrientos, Herna; Román, Juan; Mahn, Andrea

    2014-02-15

    A blanching step was designed to favor sulforaphane synthesis in broccoli. Blanching was optimised through a central composite design, and the effects of temperature (50-70 °C) and immersion time in water (5-15 min) on the content of total glucosinolates, glucoraphanin, sulforaphane, and myrosinase activity were determined. Results were analysed by ANOVA and the optimal condition was determined through response surface methodology. Temperature between 50 and 60 °C significantly increased sulforaphane content (pblanching at 70 and 74 °C diminished significantly this content, compared to fresh broccoli. The optimal blanching conditions given by the statistical model were immersion in water at 57 °C for 13 min; coinciding with the minimum glucosinolates and glucoraphanin content, and with the maximum myrosinase activity. In the optimal conditions, the predicted response of 4.0 μmol sulforaphane/g dry matter was confirmed experimentally. This value represents a 237% increase with respect to the fresh vegetable.

  11. Phenotypic and genotypic characterization of Xanthomonas campestris strains isolated from cabbage, kale and broccoli

    Directory of Open Access Journals (Sweden)

    Popović Tatjana

    2013-01-01

    Full Text Available Thirty-six strains of Xanthomonas campestris pv. campestris (Xcc isolated from cabbage, kale and broccoli were identified according to their pathogenicity, phenotypic and genotypic characterization. Pathogenicity was confirmed by the injection method with a hypodermic syringe into the mesophilic tissue of cabbage leaves. All strains were Gramnegative, aerobic, catalase-positive, oxidase-negative, grew at 35°C, produced levan, H2S and indole, did not reduce nitrate, hydrolyzed Tween 80, starch, gelatin and esculin and did not show tolerance to 0.1 and 0.02% TTC. The strains produced acid from d-arabinose, arginine, dulcitol, galactose, d-glucose, maltose, mannose, sorbitol, sucrose and xylose. The genetic characterization was based on the sequence analyses of 16S rDNA and ERIC and BOX PCR. Strains of different pathovars were also used to compare PCR resulting patterns. BOX-PCR of the strains from kale and broccoli, obtained using (GTG5 primer, yielded patterns with a high similarity level to pathovar reference strain Xcc. The strains from cabbage yielded BOX and ERIC product patterns, distinguishing them from the other tested strains and reference strains. 16S rDNA of the representative strains was closely related to Xcc strain ATCC 33913. ERIC PCR and BOX using (GTG5 primer generated different Xcc patterns and were effective in distinguishing strains from different plant hosts. [Projekat Ministarstva nauke Republike Srbije, br. III43010 i br. III46007

  12. Stingless bees damage broccoli inflorescences when collecting fibers for nest building

    Directory of Open Access Journals (Sweden)

    Adriano Jorge Nunes dos Santos

    2012-01-01

    Full Text Available The stingless bee Trigona spinipes (Fabricius, 1793 (Hymenoptera: Apidae is an important pollinator for various crops, but constitutes an occasional pest of other plant species since it causes injury to leaves, stems, flowers and fruits while collecting nest materials. The aim of the present study was to determine the damage caused by T. spinipes to a broccoli (Brassica oleracea L. var. italica, Brassicaceae growing on an organic farm. A significant number of plants (72.5 % presented damaged inflorescences, while 39% of all of the inflorescences suffered some degree of injury. The activities of T. spinipes caused scarifications on the stems of the inflorescences, and these typically evolved to epidermal cicatrices up to 10 mm wide. In some cases, the lesions were sufficiently deep to cause partial destruction of the vascular tissues, and this lead to thinner (< 5 mm diameter floral stems that may collapse. To the best of our knowledge, this is the first report concerning the attack of broccoli plants by T. spinipes. The results obtained should serve to highlight the possibility that stingless bees could be responsible for direct and/or indirect damage to vegetable crops, and to stimulate the development of control strategies for these incidental pests.

  13. Optimizing elicitation and seed priming to enrich broccoli and radish sprouts in glucosinolates.

    Science.gov (United States)

    Baenas, Nieves; Villaño, Debora; García-Viguera, Cristina; Moreno, Diego A

    2016-08-01

    Elicitation is a cheaper and socially acceptable tool for improving plant food functionality. Our objective was to optimize the treatment doses of the elicitors: methyl jasmonate (MeJA), jasmonic acid (JA) and DL-methionine (MET), in order to find a successful and feasible treatment to produce broccoli and radish sprouts with enhanced levels of health-promoting glucosinolates. Also a priming of seeds as a novel strategy to trigger the glucosinolates content was carried out with water (control), MeJA (250μM), JA (250μM) and MET (10mM) before the elicitor exogenous treatment. The results showed that almost all treatments could enhance effectively the total glucosinolates content in the sprouts, achieving the most significant increases from 34% to 100% of increase in broccoli and from 45% to 118% of increase in radish sprouts after MeJA priming and treatments. Consequently, our work demonstrates the feasibility of using elicitors, such as plant stress hormones, by priming and exogenously, as a way of increase the phytochemical profile of these sprouts to enhance their consumption in the diet. PMID:26988507

  14. Pure phosphine fumigation treatment at low temperature for postharvest control of western flower thrips on lettuce, broccoli, asparagus, and strawberries

    Science.gov (United States)

    U.S. exported lettuce, broccoli, asparagus, and strawberries often harbor western flower thrips (Frankliniella occidentalis), a quarantined pest in Taiwan, and therefore require quarantine treatment. Pure phosphine fumigation at a low temperature of 2°C was studied as an alternative fumigant to meth...

  15. Biotechnological applications in in vitro plant regeneration studies of broccoli (Brassica oleracea L. var. italica), an important vegetable crop.

    Science.gov (United States)

    Kumar, Pankaj; Srivastava, Dinesh Kumar

    2016-04-01

    Biotechnology holds promise for genetic improvement of important vegetable crops. Broccoli (Brassica oleracea L. var. italica) is an important vegetable crop of the family Brassicaceae. However, various biotic and abiotic stresses cause enormous crop yield losses during commercial cultivation of broccoli. Establishment of a reliable, reproducible and efficient in vitro plant regeneration system with cell and tissue culture is a vital prerequisite for biotechnological application of crop improvement programme. An in vitro plant regeneration technique refers to culturing, cell division, cell multiplication, de-differentiation and differentiation of cells, protoplasts, tissues and organs on defined liquid/solid medium under aseptic and controlled environment. Recent progress in the field of plant tissue culture has made this area one of the most dynamic and promising in experimental biology. There are many published reports on in vitro plant regeneration studies in broccoli including direct organogenesis, indirect organogenesis and somatic embryogenesis. This review summarizes those plant regeneration studies in broccoli that could be helpful in drawing the attention of the researchers and scientists to work on it to produce healthy, biotic and abiotic stress resistant plant material and to carry out genetic transformation studies for the production of transgenic plants. PMID:26721234

  16. Persistence of Indicator and Pathogenic Microorganisms in Broccoli following Manure Spreading and Irrigation with Fecally Contaminated Water: Field Experiment.

    Science.gov (United States)

    Généreux, Mylène; Breton, Marie Jo; Fairbrother, John Morris; Fravalo, Philippe; Côté, Caroline

    2015-10-01

    In 2011 and 2012, trials consisting of experimental plots were carried out to evaluate the presence of pathogenic (Listeria monocytogenes, Salmonella) and prevalence of indicator (Escherichia coli) microorganisms in broccoli fertilized with liquid hog manure or mineral fertilizers and irrigated zero, one, or two times with E. coli-contaminated water. In 2011, results showed that E. coli contamination in broccoli heads was affected by the interval between irrigation and sampling (P = 0.0236), with a significant decrease between the first and third day following irrigation (P = 0.0064). In 2012, irrigation frequency significantly increased E. coli prevalence in broccoli samples (P = 0.0499). In 2012, E. coli counts in the soil were significantly influenced by the type of fertilizer applied, as plots receiving liquid hog manure showed higher bacterial counts (P = 0.0006). L. monocytogenes was recovered in one broccoli sample, but geno-serogrouping differentiated the isolate from those recovered in manure and irrigation water. The L. monocytogenes serogroup IIA, pulsotype 188 strain was found in six soil samples and in irrigation water applied 5 days before soil sampling. This study highlights the link between E. coli levels in irrigation water, irrigation frequency, and interval between irrigation and harvest on produce contamination. It also demonstrates that L. monocytogenes introduced into the soil following irrigation can persist for up to 5 days.

  17. An overview of health-promoting compounds of broccoli (Brassica oleracea var. italica) and the effect of processing.

    Science.gov (United States)

    Mahn, Andrea; Reyes, Alejandro

    2012-12-01

    Broccoli offers many heath-promoting properties owing to its content of antioxidant and anticarcinogenic compounds. The concentration and bioavailability of polyphenols, glucosinolates, sulforaphane and selenium depend on plant biochemistry, cultivation strategy and type of processing. In this article, the main biochemical properties of broccoli are reviewed regarding their health-promoting effects. Additionally, the way these properties are affected by processing is discussed. Steaming and drying result in an apparent increment of sulforaphane content as well as antioxidant activity, most likely due to an increase of the extractability of antioxidants and sulforaphane. Freezing and boiling diminish polyphenols concentration, mainly due to volatilization and leaching into the cooking water. In view of these results, the optimization of broccoli processing in order to maximize the content of bioactive compounds should be possible. The effect of processing on selenium compounds has been poorly studied so far, and therefore this topic should be investigated in the future. Finally, the effect of operating conditions in different drying processes on the content of bioactive compounds in broccoli should be investigated in a greater depth.

  18. Discriminating between cultivars and treatments of broccoli using mass spectral fingerprinting and analysis of variance-principal component analysis

    Science.gov (United States)

    Metabolite fingerprints, obtained with direct injection mass spectrometry (MS) with both positive and negative ionization, were used with analysis of variance-principal components analysis (ANOVA-PCA) to discriminate between cultivars and growing treatments of broccoli. The sample set consisted of ...

  19. Variation in Broccoli Cultivar Phytochemical Content under Organic and Conventional Management Systems: Implications in Breeding for Nutrition

    NARCIS (Netherlands)

    Renaud, E.N.C.; Lammerts Van Bueren, E.; Myers, J.R.; Caldas Paulo, M.J.; Eeuwijk, van F.A.; Zhu, N.; Juvik, J.A.

    2014-01-01

    Organic agriculture requires cultivars that can adapt to organic crop management systems without the use of synthetic pesticides as well as genotypes with improved nutritional value. The aim of this study encompassing 16 experiments was to compare 23 broccoli cultivars for the content of phytochemic

  20. Alterations in Chlorophyll a Fluorescence and Pigments Concentration in the Leaves of Cauliflower and Broccoli Transplants Subjected to Chilling

    Directory of Open Access Journals (Sweden)

    Renata WOJCIECHOWSKA

    2016-06-01

    Full Text Available Chlorophyll a fluorescence parameters and photosynthetic pigments content in leaves of broccoli (Brassica oleracea L. var. italica cv. ‘Monaco’ F1 and cauliflower (Brassica oleracea L. var. botrytis cv. ‘Bruce’ F1 transplants were analyzed to investigate the effects of chilling temperatures (6 and 10 °C and the exposure length (1 or 2 weeks on the photosynthetic apparatus condition in 3-year experiment. Data were compared to control plants exposed to 14 °C for 1 and 2 weeks. The lowest values of maximum quantum efficiency of photosystem II (Fv/Fm and the performance index (PI were observed in cauliflower chilled at 6 °C for 2 weeks. This was not accompanied by any substantial reduction in chlorophylls concentration, however, significant correlations between Fv/Fm or PI and chlorophylls content in cauliflower leaves were found. There was no negative effects of chilling on photosynthetic activity and chlorophyll content in broccoli leaves, the amount of carotenoids significantly increased in the broccoli chilled for 2 weeks in 6 °C. The chlorophyll a fluorescence indices and accelerated carotenoids synthesis showed that broccoli had less vulnerable photosynthetic apparatus to stress-induced temperatures and more efficient protection mechanisms in comparison to cauliflower transplants.

  1. Sulforaphane formation and bioaccessibility are more affected by steaming time than meal composition during in vitro digestion of broccoli

    NARCIS (Netherlands)

    Sarvan-Kruse, Irmela; Kramer, E.; Bouwmeester, H.; Dekker, M.; Verkerk, R.

    2017-01-01

    Broccoli is a rich source of the glucosinolate glucoraphanin (GR). After hydrolysis of GR by the endogenous enzyme myrosinase, sulforaphane (SF) or sulforaphane nitrile (SFN) are produced, depending on environmental conditions. How the conversion of GR and bioaccessibility of released breakdown p

  2. The Impact of Broccoli II & Tomato II on European patents in conventional breeding, GMO’s and Synthetic Biology:

    DEFF Research Database (Denmark)

    Minssen, Timo; Nordberg, Ana

    2015-01-01

    On 25 March 2015, the Enlarged Board of Appeal of the European Patent Office (EBA) finally delivered its’ much awaited decisions on the consolidated referrals G2/12 (“Tomato II”) and G2/13 (“Broccoli II”). The EBA affirmed that products, namely plants or parts thereof, obtained by essentially bio...

  3. Biotechnological applications in in vitro plant regeneration studies of broccoli (Brassica oleracea L. var. italica), an important vegetable crop.

    Science.gov (United States)

    Kumar, Pankaj; Srivastava, Dinesh Kumar

    2016-04-01

    Biotechnology holds promise for genetic improvement of important vegetable crops. Broccoli (Brassica oleracea L. var. italica) is an important vegetable crop of the family Brassicaceae. However, various biotic and abiotic stresses cause enormous crop yield losses during commercial cultivation of broccoli. Establishment of a reliable, reproducible and efficient in vitro plant regeneration system with cell and tissue culture is a vital prerequisite for biotechnological application of crop improvement programme. An in vitro plant regeneration technique refers to culturing, cell division, cell multiplication, de-differentiation and differentiation of cells, protoplasts, tissues and organs on defined liquid/solid medium under aseptic and controlled environment. Recent progress in the field of plant tissue culture has made this area one of the most dynamic and promising in experimental biology. There are many published reports on in vitro plant regeneration studies in broccoli including direct organogenesis, indirect organogenesis and somatic embryogenesis. This review summarizes those plant regeneration studies in broccoli that could be helpful in drawing the attention of the researchers and scientists to work on it to produce healthy, biotic and abiotic stress resistant plant material and to carry out genetic transformation studies for the production of transgenic plants.

  4. DNA Methyltransferases Inhibitors from Natural Sources.

    Science.gov (United States)

    Zwergel, Clemens; Valente, Sergio; Mai, Antonello

    2016-01-01

    DNA methyltransferases (DNMTs) catalyze the methylation at cytosine-C5 mainly in a CpG dinucleotide context. Although DNA methylation is essential for fundamental processes like embryonic development or differentiation, aberrant expression and/or activities of DNMTs are involved in several pathologies, from neurodegeneration to cancer. DNMTs inhibition can arrest tumor growth, cells invasiveness and induce differentiation, whereas their increased expression is shown in numerous cancer types. Moreover, hypermethylated promoters of tumor suppressor genes lead to their silencing. Hence, the use of specific inhibitors of DNMT might reactivate those genes and stop or even reverse the aberrant cell processes. To date, the only approved DNMTs inhibitors for therapy belong to the nucleoside-based family of drugs, but they display relevant side effects as well as high chemical instability. Thus, there is a keen interest actually exists to develop novel, potent and safe inhibitors possessing a nonnucleoside structure. Increasing literature evidence is highlighting that natural sources could help the researchers to achieve this goal. Indeed, several polyphenols, flavonoids, antraquinones, and others are described able to inhibit DNMTs activity and/or expression, thus decreasing the methylation/silencing of different genes involved in tumorigenesis. These events can lead to re-expression of such genes and to cell death in diverse cancer cell lines. Epigallocatechin-3-gallate (1) and laccaic acid A (11) resulted the most effective DNMT1 inhibitors with submicromolar IC50 values, acting as competitive inhibitors. Compound 1 and 11 both displayed gene demethylation and re-activation in several cancers. However, all of the natural compounds described in this review showed important results, from gene reactivation to cell growth inhibition. Moreover, some of them displayed interesting activity even in rodent cancer models and very recently entered clinical trials. PMID:26303417

  5. Characterization of a multifunctional methyltransferase from the orchid Vanilla planifolia.

    Science.gov (United States)

    Pak, F E; Gropper, S; Dai, W D; Havkin-Frenkel, D; Belanger, F C

    2004-07-01

    The final enzymatic step in the synthesis of the flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde) is believed to be methylation of 3,4-dihydroxybenzaldehyde. We have isolated and functionally characterized a cDNA that encodes a multifunctional methyltransferase from Vanilla planifolia tissue cultures that can catalyze the conversion of 3,4-dihydroxybenzaldehyde to vanillin, although 3,4-dihydroxybenzaldehyde is not the preferred substrate. The higher catalytic efficiency of the purified recombinant enzyme with the substrates caffeoyl aldehyde and 5-OH-coniferaldehyde, and its tissue distribution, suggest this methyltransferase may primarily function in lignin biosynthesis. However, since the enzyme characterized here does have 3,4-dihydroxybenzaldehyde-O-methyltransferase activity, it may be useful in engineering strategies for the synthesis of natural vanillin from alternate sources.

  6. Enhanced antimicrobial effect of organic acid washing against foodborne pathogens on broccoli by vacuum impregnation.

    Science.gov (United States)

    Kang, Jun-Won; Kang, Dong-Hyun

    2016-01-18

    This study was undertaken to evaluate the effect of vacuum impregnation applied to the washing process for removal of Salmonella Typhimurium and Listeria monocytogenes from broccoli surfaces. Broccoli was inoculated with the two foodborne pathogens and treated with simple dipping washing or with vacuum impregnation in 2% malic acid for 5, 10, 20, or 30 min. There were two methods of vacuum impregnation: continuous and intermittent. After 30 min of 101.3 kPa (=14.7 psi, simple dipping), 61.3 kPa (=8.9 psi), and 21.3 kPa (=3.1 psi) of continuous vacuum impregnation treatment, there were 1.6, 2.0, and 2.4 log 10 CFU/g reductions of S. Typhimurium and 1.5, 1.7, and 2.3 log 10 CFU/g reductions of L. monocytogenes, respectively. After 30 min of 101.3, 61.3, and 21.3 kPa of intermittent vacuum impregnation treatment, there were 1.5, 2.3, and 3.7 log 10 CFU/g reductions of S. Typhimurium and 1.6, 2.1, and 3.2 log 10 CFU/g reductions of L. monocytogenes, respectively. Scanning electron photomicrographs showed that bacteria tend to attach to or become entrapped in protective sites after simple wash processing (dipping). However, most bacteria were washed out of protective sites after intermittent treatment. Direct treatment of cell suspensions with vacuum impregnation showed that it had no inactivation capacity in itself since there were no significant differences (P ≥ 0.05) between the reduction rates of non- and vacuum impregnation treatment. These results demonstrate that the increased antimicrobial effect of vacuum impregnation can be attributed to increased accessibility of sanitizer and an enhanced washing effect in protected sites on produce. Color, texture and titratable acidity values of broccoli treated with intermittent vacuum impregnation in 2% malic acid for 30 min were not significantly (P ≥ 0.05) different from those of untreated samples even though a storage interval was needed for titratable acidity values to be reduced to levels comparable to those of

  7. Effect of cooking on the concentration of bioactive compounds in broccoli (Brassica oleracea var. Avenger) and cauliflower (Brassica oleracea var. Alphina F1) grown in an organic system.

    Science.gov (United States)

    Dos Reis, Luzia Caroline Ramos; de Oliveira, Viviani Ruffo; Hagen, Martine Elisabeth Kienzle; Jablonski, André; Flôres, Simone Hickmann; de Oliveira Rios, Alessandro

    2015-04-01

    Brassica vegetables have been shown to have antioxidant capacities due to the presence of carotenoids, flavonoids and vitamins. This study evaluates the influence of different processing conditions (boiling, steaming, microwaving and sous vide) on the stability of flavonoids, carotenoids and vitamin A in broccoli and cauliflower inflorescences grown in an organic system. Results indicated that sous vide processing resulted in greater antioxidant capacity and that all processes contributed in some way to an increased content of antioxidant compounds in both cauliflower and broccoli.

  8. Diversity in mechanism and function of tRNA methyltransferases

    Science.gov (United States)

    Swinehart, William E; Jackman, Jane E

    2015-01-01

    tRNA molecules undergo extensive post-transcriptional processing to generate the mature functional tRNA species that are essential for translation in all organisms. These processing steps include the introduction of numerous specific chemical modifications to nucleotide bases and sugars; among these modifications, methylation reactions are by far the most abundant. The tRNA methyltransferases comprise a diverse enzyme superfamily, including members of multiple structural classes that appear to have arisen independently during evolution. Even among closely related family members, examples of unusual substrate specificity and chemistry have been observed. Here we review recent advances in tRNA methyltransferase mechanism and function with a particular emphasis on discoveries of alternative substrate specificities and chemistry associated with some methyltransferases. Although the molecular function for a specific tRNA methylation may not always be clear, mutations in tRNA methyltransferases have been increasingly associated with human disease. The impact of tRNA methylation on human biology is also discussed. PMID:25626150

  9. Yorkie Promotes Transcription by Recruiting a Histone Methyltransferase Complex

    Directory of Open Access Journals (Sweden)

    Hyangyee Oh

    2014-07-01

    Full Text Available Hippo signaling limits organ growth by inhibiting the transcriptional coactivator Yorkie. Despite the key role of Yorkie in both normal and oncogenic growth, the mechanism by which it activates transcription has not been defined. We report that Yorkie binding to chromatin correlates with histone H3K4 methylation and is sufficient to locally increase it. We show that Yorkie can recruit a histone methyltransferase complex through binding between WW domains of Yorkie and PPxY sequence motifs of NcoA6, a subunit of the Trithorax-related (Trr methyltransferase complex. Cell culture and in vivo assays establish that this recruitment of NcoA6 contributes to Yorkie’s ability to activate transcription. Mammalian NcoA6, a subunit of Trr-homologous methyltransferase complexes, can similarly interact with Yorkie’s mammalian homolog YAP. Our results implicate direct recruitment of a histone methyltransferase complex as central to transcriptional activation by Yorkie, linking the control of cell proliferation by Hippo signaling to chromatin modification.

  10. Chromosomal replication incompatibility in Dam methyltransferase deficient Escherichia coli cells

    DEFF Research Database (Denmark)

    Freiesleben, Ulrik Von

    1996-01-01

    Dam methyltransferase deficient Escherichia coli cells containing minichromosomes were constructed. Free plasmid DNA could not be detected in these cells and the minichromosomes were found to be integrated in multiple copies in the origin of replication (oriC) region of the host chromosome...

  11. Label-free electrochemical detection of human methyltransferase from tumors.

    Science.gov (United States)

    Furst, Ariel L; Muren, Natalie B; Hill, Michael G; Barton, Jacqueline K

    2014-10-21

    The role of abnormal DNA methyltransferase activity in the development and progression of cancer is an essential and rapidly growing area of research, both for improved diagnosis and treatment. However, current technologies for the assessment of methyltransferase activity, particularly from crude tumor samples, limit this work because they rely on radioactivity or fluorescence and require bulky instrumentation. Here, we report an electrochemical platform that overcomes these limitations for the label-free detection of human DNA(cytosine-5)-methyltransferase1 (DNMT1) methyltransferase activity, enabling measurements from crude cultured colorectal cancer cell lysates (HCT116) and biopsied tumor tissues. Our multiplexed detection system involving patterning and detection from a secondary electrode array combines low-density DNA monolayer patterning and electrocatalytically amplified DNA charge transport chemistry to measure selectively and sensitively DNMT1 activity within these complex and congested cellular samples. Based on differences in DNMT1 activity measured with this assay, we distinguish colorectal tumor tissue from healthy adjacent tissue, illustrating the effectiveness of this two-electrode platform for clinical applications. PMID:25288757

  12. Changes in SeMSC, Glucosinolates and Sulforaphane Levels, and in Proteome Profile in Broccoli (Brassica oleracea var. Italica Fertilized with Sodium Selenate

    Directory of Open Access Journals (Sweden)

    Alejandra Moenne

    2013-05-01

    Full Text Available The aim of this work was to analyze the effect of sodium selenate fortification on the content of selenomethyl selenocysteine (SeMSC, total glucosinolates and sulforaphane, as well as the changes in protein profile of the inflorescences of broccoli (Brassica oleracea var. Italica. Two experimental groups were considered: plants treated with 100 mmol/L sodium selenate (final concentration in the pot and control plants treated with water. Fortification began 2 weeks after transplantation and was repeated once a week during 10 weeks. Broccoli florets were harvested when they reached appropriate size. SeMSC content in broccoli florets increased significantly with sodium selenate fortification; but total glucosinolates and sulforaphane content as well as myrosinase activity were not affected. The protein profile of broccoli florets changed due to fortification with sodium selenate. Some proteins involved in general stress-responses were up-regulated, whereas down-regulated proteins were identified as proteins involved in protection against pathogens. This is the first attempt to evaluate the physiological effect of fortification with sodium selenate on broccoli at protein level. The results of this work will contribute to better understanding the metabolic processes related with selenium uptake and accumulation in broccoli.

  13. On the evolutionary origin of eukaryotic DNA methyltransferases and Dnmt2.

    Directory of Open Access Journals (Sweden)

    Tomasz P Jurkowski

    Full Text Available The Dnmt2 enzymes show strong amino acid sequence similarity with eukaryotic and prokaryotic DNA-(cytosine C5-methyltransferases. Yet, Dnmt2 enzymes from several species were shown to methylate tRNA-Asp and had been proposed that eukaryotic DNA methyltransferases evolved from a Dnmt2-like tRNA methyltransferase ancestor [Goll et al., 2006, Science, 311, 395-8]. It was the aim of this study to investigate if this hypothesis could be supported by evidence from sequence alignments. We present phylogenetic analyses based on sequence alignments of the methyltransferase catalytic domains of more than 2300 eukaryotic and prokaryotic DNA-(cytosine C5-methyltransferases and analyzed the distribution of DNA methyltransferases in eukaryotic species. The Dnmt2 homologues were reliably identified by an additional conserved CFT motif next to motif IX. All DNA methyltransferases and Dnmt2 enzymes were clearly separated from other RNA-(cytosine-C5-methyltransferases. Our sequence alignments and phylogenetic analyses indicate that the last universal eukaryotic ancestor contained at least one member of the Dnmt1, Dnmt2 and Dnmt3 families of enzymes and additional RNA methyltransferases. The similarity of Dnmt2 enzymes with DNA methyltransferases and absence of similarity with RNA methyltransferases combined with their strong RNA methylation activity suggest that the ancestor of Dnmt2 was a DNA methyltransferase and an early Dnmt2 enzyme changed its substrate preference to tRNA. There is no phylogenetic evidence that Dnmt2 was the precursor of eukaryotic Dnmts. Most likely, the eukaryotic Dnmt1 and Dnmt3 families of DNA methyltransferases had an independent origin in the prokaryotic DNA methyltransferase sequence space.

  14. Effect of blanching temperature and dipping time on drying time of broccoli.

    Science.gov (United States)

    Doymaz, Ibrahim

    2014-03-01

    Drying characteristics of broccoli was experimentally studied in cabinet-type convective dryer. Experiments were conducted using constant air velocity of 2 m/s and air temperature of 60 . Drying rate increased with increasing blanching temperature and thus reduced the drying time. The experimental drying data were used to fit twelve drying models and drying rate constants and coefficients of the models were determined by non-linear regression analysis. Estimations by the Midilli et al. model were in good agreement with the experimental data obtained. Fick's second law was used to calculate the effective moisture diffusivity, which varied from 1.987 to 3.577 × 10(-8) m(2)/s for the given blanching temperature range. The rehydration ratio was observed to increase with increasing blanching temperature.

  15. Ingestion of broccoli sprouts does not improve endothelial function in humans with hypertension

    DEFF Research Database (Denmark)

    Christiansen, Buris; Bellostas Muguerza, Natalia; Petersen, Atheline Major;

    2010-01-01

    UNLABELLED: Ingestion of glucosinolates has previously been reported to improve endothelial function in spontaneously hypertensive rats, possibly because of an increase in NO availability in the endothelium due to an attenuation of oxidative stress; in our study we tried to see if this also would...... be the case in humans suffering from essential hypertension. METHODS: 40 hypertensive individuals without diabetes and with normal levels of cholesterol were examined. The participants were randomized either to ingest 10 g dried broccoli sprouts, a natural donor of glucosinolates with high in vitro...... antioxidative potential, for a 4 week period or to continue their ordinary diet and act as controls. Blood pressure, endothelial function measured by flow mediated dilation (FMD) and blood samples were obtained from the participants every other week and the content of glucosinolates was measured before...

  16. 秋花椰菜引种试验%Trial of introducing autumn broccoli

    Institute of Scientific and Technical Information of China (English)

    蔡文注; 叶明鑫; 陈艺婷; 颜慧莹; 陈龙杰

    2012-01-01

    Trial test of 13 introduced broccoli varieties has been carried out in Xiang' an district of Xiamen city in autumn of 2011. Two qualified and resistant varieties SWONSEA and SUPER FORMEN were screened by comparison of plant chacteristicrs, resistance, corm pattern, single corm weight, yield and quality.%2011年秋季在厦门市翔安区对引入的13个花椰菜品种进行试种,通过植株性状、抗逆性、球型、单球重、产量及品质的比较,初步筛选出优质、抗性好的秋花椰菜品种SWONSEA和SUPERFORMEN。

  17. Effect of blanching temperature and dipping time on drying time of broccoli.

    Science.gov (United States)

    Doymaz, Ibrahim

    2014-03-01

    Drying characteristics of broccoli was experimentally studied in cabinet-type convective dryer. Experiments were conducted using constant air velocity of 2 m/s and air temperature of 60 . Drying rate increased with increasing blanching temperature and thus reduced the drying time. The experimental drying data were used to fit twelve drying models and drying rate constants and coefficients of the models were determined by non-linear regression analysis. Estimations by the Midilli et al. model were in good agreement with the experimental data obtained. Fick's second law was used to calculate the effective moisture diffusivity, which varied from 1.987 to 3.577 × 10(-8) m(2)/s for the given blanching temperature range. The rehydration ratio was observed to increase with increasing blanching temperature. PMID:23744113

  18. Structure and Function of Flavivirus NS5 Methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Zhou,Y.; Ray, D.; Zhao, Y.; Dong, H.; Ren, S.; Li, Z.; Guo, Y.; Bernard, K.; Shi, P.; Li, H.

    2007-01-01

    The plus-strand RNA genome of flavivirus contains a 5' terminal cap 1 structure (m{sup 7}GpppAmG). The flaviviruses encode one methyltransferase, located at the N-terminal portion of the NS5 protein, to catalyze both guanine N-7 and ribose 2'-OH methylations during viral cap formation. Representative flavivirus methyltransferases from dengue, yellow fever, and West Nile virus (WNV) sequentially generate GpppA {yields} m{sup 7}GpppA {yields} m{sup 7}GpppAm. The 2'-O methylation can be uncoupled from the N-7 methylation, since m{sup 7}GpppA-RNA can be readily methylated to m{sup 7}GpppAm-RNA. Despite exhibiting two distinct methylation activities, the crystal structure of WNV methyltransferase at 2.8 {angstrom} resolution showed a single binding site for S-adenosyl-L-methionine (SAM), the methyl donor. Therefore, substrate GpppA-RNA should be repositioned to accept the N-7 and 2'-O methyl groups from SAM during the sequential reactions. Electrostatic analysis of the WNV methyltransferase structure showed that, adjacent to the SAM-binding pocket, is a highly positively charged surface that could serve as an RNA binding site during cap methylations. Biochemical and mutagenesis analyses show that the N-7 and 2'-O cap methylations require distinct buffer conditions and different side chains within the K{sub 61}-D{sub 146}-K{sub 182}-E{sub 218} motif, suggesting that the two reactions use different mechanisms. In the context of complete virus, defects in both methylations are lethal to WNV; however, viruses defective solely in 2'-O methylation are attenuated and can protect mice from later wild-type WNV challenge. The results demonstrate that the N-7 methylation activity is essential for the WNV life cycle and, thus, methyltransferase represents a novel target for flavivirus therapy.

  19. Vegetative and reproductive plasticity of broccoli at three levels of incident photosynthetically active radiation

    International Nuclear Information System (INIS)

    To study the effects of shading on the growth, development, dry matter partitioning, and plant architecture of broccoli, ‘Legacy’ hybrid plants were grown in pots in a greenhouse under black shading meshes to generate different levels of photosynthetically active radiation (PAR). The average incident PAR was 23 mol PPF m–2 d–1 under control conditions, 15.2 under a 35% mesh, and 6.7 under a 70% mesh. The air temperature was within the range 15-22°C. As shading increased so did the duration of the growth cycle and the leaf area (LA). Shading did not affect the number of leaves, although the upper ones were more erect. The stem length and the accumulated intercepted PAR (IPAR) were negatively related. Inflorescence diameter and commercial fresh weight decreased only with the 70% mesh. Shading did not affect stem dry weight (DW) but altered dry matter allocation in the root and spear. The DW of the leaves maintained an average 45.7% of the total DW despite the greater LA developed under shade. The net assimilation rate diminished with the reduction of IPAR, and the LA increased; the plant relative growth rate was therefore practically constant. With increased shading, the leaves and the stem became the dominant photosynthate sinks. The commercial fresh weight achieved with 15.2 mol photosynthetic photon flux (PPF) m–2 d–1 was equivalent to that obtained with 23 mol PPF m–2 d–1, but the cycle was extended for 4.5 days. With 6.7 mol PPF m–2 d–1, yield diminished because of the lower DW produced in a cycle extended by 15 days, and because more dry matter was allocated to the stem than to the spear. Based on these results, broccoli could be considered a shade-tolerant plant. (author)

  20. Ozone dose-response relationships for spring oilseed rape and broccoli

    Science.gov (United States)

    De Bock, Maarten; Op de Beeck, Maarten; De Temmerman, Ludwig; Guisez, Yves; Ceulemans, Reinhart; Vandermeiren, Karine

    2011-03-01

    Tropospheric ozone is an important air pollutant with known detrimental effects for several crops. Ozone effects on seed yield, oil percentage, oil yield and 1000 seed weight were examined for spring oilseed rape ( Brassica napus cv. Ability). For broccoli ( Brassica oleracea L. cv. Italica cv. Monaco) the effects on fresh marketable weight and total dry weight were studied. Current ozone levels were compared with an increase of 20 and 40 ppb during 8 h per day, over the entire growing season. Oilseed rape seed yield was negatively correlated with ozone dose indices calculated from emergence until harvest. This resulted in an R2 of 0.24 and 0.26 ( p crops (UNECE, Mills, 2004), can indeed be applied for spring oilseed rape. The reduction of oilseed rape yield showed the highest correlation with the ozone uptake during the vegetative growth stage: when only the first 47 days after emergence were used to calculate POD 6, R2 values increased up to 0.476 or even 0.545 when the first 23 days were excluded. The highest ozone treatments, corresponding to the future ambient level by 2100 (IPCC, Meehl et al., 2007), led to a reduction of approximately 30% in oilseed rape seed yield in comparison to the current ozone concentrations. Oil percentage was also significantly reduced in response to ozone ( p oil yield was even more severely affected by elevated ozone exposure compared to seed yield: critical levels for oil yield dropped to 3.2 ppm h and 3.9 mmol m -2. For broccoli the applied ozone doses had no effect on yield.

  1. Molecular identification of carnosine N-methyltransferase as chicken histamine N-methyltransferase-like protein (hnmt-like.

    Directory of Open Access Journals (Sweden)

    Jakub Drozak

    Full Text Available Anserine (beta-alanyl-N(Pi-methyl-L-histidine, a naturally occurring derivative of carnosine (beta-alanyl-L-histidine, is an abundant constituent of skeletal muscles and brain of many vertebrates. Although it has long been proposed to serve as a proton buffer, radicals scavenger and transglycating agent, its physiological function remains obscure. The formation of anserine is catalyzed by carnosine N-methyltransferase which exhibits unknown molecular identity. In the present investigation, we have purified carnosine N-methyltransferase from chicken pectoral muscle about 640-fold until three major polypeptides of about 23, 26 and 37 kDa coeluting with the enzyme were identified in the preparation. Mass spectrometry analysis of these polypeptides resulted in an identification of histamine N-methyltransferase-like (HNMT-like protein as the only meaningful candidate. Analysis of GenBank database records indicated that the hnmt-like gene might be a paralogue of histamine N-methyltransferase gene, while comparison of their protein sequences suggested that HNMT-like protein might have acquired a new activity. Chicken HNMT-like protein was expressed in COS-7 cells, purified to homogeneity, and shown to catalyze the formation of anserine as confirmed by both chromatographic and mass spectrometry analysis. Both specificity and kinetic studies carried out on the native and recombinant enzyme were in agreement with published data. Particularly, several compounds structurally related to carnosine, including histamine and L-histidine, were tested as potential substrates for the enzyme, and carnosine was the only methyl group acceptor. The identification of the gene encoding carnosine N-methyltransferase might be beneficial for estimation of the biological functions of anserine.

  2. Influence of sous vide processing, steaming and boiling on vitamin retention and sensory quality in broccoli florets.

    Science.gov (United States)

    Petersen, M A

    1993-10-01

    In this study the effect of sous vide processing, steaming and traditional boiling of broccoli florets on retention of ascorbic acid, vitamin B6 and folacin was investigated. Freshly prepared samples were also sensorily evaluated. In all heat treatments ascorbic acid was found to have the highest retention, and was therefore judged not to be suitable as an indicator for vitamin retention in general. When the three types of heat treatment were compared, boiling showed lowest retention of all the vitamins examined (45-64% in 5 min), whereas sous-vide processing gave the highest retentions (97-100% in 5 min). Retentions during steaming were a little lower (83-100% in 5 min). Sensory evaluation showed that sous-vide cooked and steamed broccoli florets generally had higher acceptability than boiled. PMID:8249480

  3. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata.

    Science.gov (United States)

    Bañuelos, Gary S; Arroyo, Irvin S; Dangi, Sadikshya R; Zambrano, Maria C

    2016-01-01

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0-30 cm) were 1.65 mg kg(-1) and 88 μg L(-1), and 0.92 mg kg(-1) and 48.6 μg L(-1) at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg(-1) and 3.15 to 6.25 mg kg(-1) in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0-5 and 0-30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions. PMID:27602038

  4. Methyl jasmonate and 1-methylcyclopropene treatment effects on quinone reductase inducing activity and post-harvest quality of broccoli.

    Directory of Open Access Journals (Sweden)

    Kang Mo Ku

    Full Text Available Effect of pre-harvest methyl jasmonate (MeJA and post-harvest 1-methylcyclopropene (1-MCP treatments on broccoli floret glucosinolate (GS concentrations and quinone reductase (QR, an in vitro anti-cancer biomarker inducing activity were evaluated two days prior to harvest, at harvest and at 10, 20, and 30 days of post-harvest storage at 4 °C. MeJA treatments four days prior to harvest of broccoli heads was observed to significantly increase floret ethylene biosynthesis resulting in chlorophyll catabolism during post-harvest storage and reduced product quality. Post-harvest treatment with 1-methylcyclopropene (1-MCP, which competitively binds to protein ethylene receptors, maintained post-harvest floret chlorophyll concentrations and product visual quality in both control and MeJA-treated broccoli. Transcript abundance of BoPPH, a gene which is responsible for the synthesis of pheophytinase, the primary enzyme associated with chlorophyll catabolism in broccoli, was reduced by 1-MCP treatment and showed a significant, negative correlation with floret chlorophyll concentrations. The GS, glucobrassicin, neoglucobrassicin, and gluconasturtiin were significantly increased by MeJA treatments. The products of some of the GS from endogenous myrosinase hydrolysis [sulforaphane (SF, neoascorbigen (NeoASG, N-methoxyindole-3-carbinol (NI3C, and phenethyl isothiocyanate (PEITC] were also quantified and found to be significantly correlated with QR. Sulforaphane, the isothiocyanate hydrolysis product of the GS glucoraphanin, was found to be the most potent QR induction agent. Increased sulforaphane formation from the hydrolysis of glucoraphanin was associated with up-regulated gene expression of myrosinase (BoMyo and the myrosinase enzyme co-factor gene, epithiospecifier modifier1 (BoESM1. This study demonstrates the combined treatment of MeJA and 1-MCP increased QR activity without post-harvest quality loss.

  5. Effect of vetch wheat mixture and broccoli as preceding crops on organic summer vegetables: on farm trial in western Turkey

    OpenAIRE

    ASLAN, Burcay

    2011-01-01

    Organic farming requires the use of practices such as crop rotation, green manure and compost application instead of chemical compounds to enhance farm productivity. In this study, effects of two pre-crops (vetch-wheat mixture and broccoli) and additional fertilization (AF) strategy (compost and commercial fertilizer) were tested on organic production of two main crops (tomato and zucchini) and on soil fertility. The main aim of this on-farm trial is to evaluate the applicability of the resul...

  6. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata

    Science.gov (United States)

    Bañuelos, Gary S.; Arroyo, Irvin S.; Dangi, Sadikshya R.; Zambrano, Maria C.

    2016-01-01

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0–30 cm) were 1.65 mg kg-1 and 88 μg L-1, and 0.92 mg kg-1 and 48.6 μg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0–5 and 0–30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions. PMID:27602038

  7. Continued selenium biofortification of carrots and broccoli grown in soils once amended with Se-enriched S. pinnata

    Directory of Open Access Journals (Sweden)

    Gary S. Bañuelos

    2016-08-01

    Full Text Available Selenium (Se biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton three and four years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0-30 cm were 1.65 mg kg-1 and 88 µg L-1, and 0.92 mg kg-1 and 48.6 µg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid analyses (PLFA showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi, actinomycetes and Gram-positive and bacterial PLFA at both 0-5 and 0-30 cm, respectively, three years later. Successfully producing Se-enriched broccoli and carrots three and four years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions.

  8. Fall and spring broccoli yields and weed control under no-till and conventional tillage with overseeded legume living mulches

    OpenAIRE

    Infante, Michelle Louise

    1994-01-01

    Experiments were conducted with 'BigSur' broccoli (Brassica oleracea var. italica Plenck) at two sites in fall of 1993 and at two sites in the spring of 1994 on a Hayter loam in southwestern Virginia. Objectives were to determine the tillage main-plot (CT = conventional tillage, and NT = no-tillage) and weed-control subplot (C = no overseeding or preemergent herbicide; HB = oxyfluorfen; RC = red clover (Trifolium pratense L.); WC = Dutch white clover (Trifolium repens L.); and ...

  9. Potential efficacy of broccoli sprouts as a unique supplement for management of type 2 diabetes and its complications.

    Science.gov (United States)

    Bahadoran, Zahra; Mirmiran, Parvin; Azizi, Fereidoun

    2013-05-01

    Functional foods and their nutraceutical components are now considered as supplementary treatments in type 2 diabetes and prevention of its long-term complications. Young broccoli sprouts as a functional food contain many bioactive compounds specially sulforaphane. In hyperglycemic and oxidative conditions, sulforaphane has the potential to activate the NF-E2-related factor-2 (Nrf2)-dependent antioxidant response-signaling pathway, induces phase 2 enzymes, attenuates oxidative stress, and inactivates nuclear factor kappa-B (NF-κB), a key modulator of inflammatory pathways. Interestingly, sulforaphane induces some peroxisome proliferator-activated receptors, which contribute to lipid metabolism and glucose homeostasis. In animal and in vitro models, sulforaphane also shows antihypertensive, anticancer, cardioprotective, and hypocholesterolemic capacity, and has bactericidal properties against Helicobacter pylori. Supplementation of type 2 diabetics with high sulforaphane content broccoli sprouts resulted in increased total antioxidant capacity of plasma and in decreased oxidative stress index, lipid peroxidation, serum triglycerides, oxidized low-density lipoprotein (LDL)/LDL-cholesterol ratio, serum insulin, insulin resistance, and serum high-sensitive C-reactive protein. Sulforaphane could prevent nephropathy, diabetes-induced fibrosis, and vascular complications. Potential efficacy of sulforaphane and probably other bioactive components of young broccoli sprouts makes it as an excellent choice for supplementary treatment in type 2 diabetes.

  10. Effects of broccoli extract on biodistribution and labeling blood components with {sup 99m}Tc-GH

    Energy Technology Data Exchange (ETDEWEB)

    Cekic, Betul; Muftuler, Fazilet Zumrut Biber; Kilcar, Ayfer Yurt; Ichedef, Cigdem; Unak, Perihan [Ege University, Izmir (Turkey). Inst. of Nuclear Sciences. Dept. of Nuclear Applications

    2011-09-15

    Purpose: people consume vegetables without the knowledge of the side effects of the biological and chemical contents and interactions between radiopharmaceuticals and herbal extract. To this end, current study is focused on the effects of broccoli extract on biodistribution of radiolabeled glucoheptonate ({sup 99m}Tc-GH) and radiolabeling of blood components. Methods: GH was labeled with {sup 99m}Tc. Quality control studies were done utilizing TLC method. Biodistribution studies were performed on male rats which were treated via gavage with either broccoli extract or SF as control group for 15 days. Blood samples were withdrawn from rats' heart. Radiolabeling of blood constituents performed incubating with GH, SnCl{sub 2} and {sup 99m} Tc. Results: radiochemical yield of {sup 99m}Tc-GH is 98.46{+-}1.48 % (n=8). Biodistribution studies have shown that according to the control, the treated group with broccoli has approximately 10 times less uptake in kidney. The percentage of the radioactivity ratios of the blood components is found to be same in both groups. Conclusions: although there is no considerable effect on the radiolabeling of blood components, there is an outstanding change on the biodistribution studies especially on kidneys. The knowledge of this change on kidney uptake may contribute to reduce the risk of misdiagnosis and/or repetition of the examinations in Nuclear Medicine. (author)

  11. EFFECT OF SHADING ON INCIDENCE OF BLACK ROT DISEASE AND YIELD QUALITY OF BROCCOLI IN HUMID TROPICAL REGIONS OF THAILAND

    Directory of Open Access Journals (Sweden)

    Karistsapol Nooprom

    2013-08-01

    Full Text Available The study was carried out in the experimental location of Department of Plant Science, Faculty of Natural Resources, Prince of Songkla University, Thailand, from April to June, 2012. Split-plot in randomized complete block design was used in this experiment with four replications. The broccoli plants under the shading had the lowest incidence of black rot disease (14.48% which was significantly lower than the full sunlight (76.91%. There was a positive impact of the shading on yield quality of the broccoli. The Yok Kheo had the highest head length and diameter (39.13 cm and 12.11 cm, respectively when planting under the shading. These results consistent with broccoli total yield, the highest total yield was obtained from the Yok Kheo under the both shading and full sunlight (10.92 t.ha-1 and 8.29 t.ha-1, respectively, followed by the Green Queen under the shading (6.21 t.ha-1. Therefore, the appropriate variety for planting during dry season in humid tropical regions of Thailand was the Yok Kheo and Green Queen because its total yield per hectare was higher than of the Top Green and they also had higher quality of head.

  12. Plant isoflavone and isoflavanone O-methyltransferase genes

    Science.gov (United States)

    Broeckling, Bettina E.; Liu, Chang-Jun; Dixon, Richard A.

    2014-08-19

    The invention provides enzymes that encode O-methyltransferases (OMTs) from Medicago truncatula that allow modification to plant (iso)flavonoid biosynthetic pathways. In certain aspects of the invention, the genes encoding these enzymes are provided. The invention therefore allows the modification of plants for isoflavonoid content. Transgenic plants comprising such enzymes are also provided, as well as methods for improving disease resistance in plants. Methods for producing food and nutraceuticals, and the resulting compositions, are also provided.

  13. Structural characterization of the mitomycin 7-O-methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Shanteri; Chang, Aram; Goff, Randal D.; Bingman, Craig A.; Grüschow, Sabine; Sherman, David H.; Phillips, Jr., George N.; Thorson, Jon S. (Michigan); (UW)

    2014-10-02

    Mitomycins are quinone-containing antibiotics, widely used as antitumor drugs in chemotherapy. Mitomycin-7-O-methyltransferase (MmcR), a key tailoring enzyme involved in the biosynthesis of mitomycin in Streptomyces lavendulae, catalyzes the 7-O-methylation of both C9{beta}- and C9{alpha}-configured 7-hydroxymitomycins. We have determined the crystal structures of the MmcR-S-adenosylhomocysteine (SAH) binary complex and MmcR-SAH-mitomycin A (MMA) ternary complex at resolutions of 1.9 and 2.3 {angstrom}, respectively. The study revealed MmcR to adopt a common S-adenosyl-L-methionine-dependent O-methyltransferase fold and the presence of a structurally conserved active site general acid-base pair is consistent with a proton-assisted methyltransfer common to most methyltransferases. Given the importance of C7 alkylation to modulate mitomycin redox potential, this study may also present a template toward the future engineering of catalysts to generate uniquely bioactive mitomycins.

  14. DNA repair methyltransferase (Mgmt) knockout mice are sensitive to the lethal effects of chemotherapeutic alkylating agents.

    OpenAIRE

    Glassner, Brian; Weeda, Geert; Allan, James; Broekhof, Jose'; Carls, Nick; Donker, Ingrid; Engelward, Bevin; Hampson, Richard; Hersmus, Remko; Hickman, Mark; Roth, Richard; Warren, Henry; Wu, Mavis; Hoeijmakers, Jan; Samson, Leona

    1999-01-01

    textabstractWe have generated mice deficient in O6-methylguanine DNA methyltransferase activity encoded by the murine Mgmt gene using homologous recombination to delete the region encoding the Mgmt active site cysteine. Tissues from Mgmt null mice displayed very low O6-methylguanine DNA methyltransferase activity, suggesting that Mgmt constitutes the major, if not the only, O6-methylguanine DNA methyltransferase. Primary mouse embryo fibroblasts and bone marrow cells from Mgmt -/- mice were s...

  15. Comparation of Salt Stress Resistance between Broccoli and Cauliflower%盐胁迫下西兰花和花椰菜抗逆性比较

    Institute of Scientific and Technical Information of China (English)

    蒋海燕

    2015-01-01

    Comparation of salt stress resistance between Broccoli and cauliflower was studied in this paper. The results showed that the concentration of NaCl that significantly inhibited seedling growth of broccoli and cauliflower was 300 mmol/L and 100 mmol/L, respectively. Under the salt stress, the proline content, SOD activity and POD activity of broccoli were higher than that of cauliflower, while the MDA content of broccoli were lower than that of cauliflower, which showed the physiological basis of higher salt resistance in broccoli.%研究比较盐胁迫下西兰花和花椰菜的抗盐性大小。结果表明,NaCl胁迫显著(P<0.05)抑制西兰花幼苗生长的浓度为300 mmol/L;显著抑制花椰菜幼苗生长的浓度为100 mmol/L。盐胁迫下,西兰花脯氨酸含量和SOD、POD活性均较花椰菜高,而丙二醛含量较花椰菜低。结果表明盐胁迫下保护酶活性增强和脯氨酸积累是西兰花具有较强抗盐能力的重要生理学基础。

  16. Detecting 16S rRNA Methyltransferases in Enterobacteriaceae by Use of Arbekacin.

    Science.gov (United States)

    McGann, Patrick; Chahine, Sarah; Okafor, Darius; Ong, Ana C; Maybank, Rosslyn; Kwak, Yoon I; Wilson, Kerry; Zapor, Michael; Lesho, Emil; Hinkle, Mary

    2016-01-01

    16S rRNA methyltransferases confer resistance to most aminoglycosides, but discriminating their activity from that of aminoglycoside-modifying enzymes (AMEs) is challenging using phenotypic methods. We demonstrate that arbekacin, an aminoglycoside refractory to most AMEs, can rapidly detect 16S methyltransferase activity in Enterobacteriaceae with high specificity using the standard disk susceptibility test. PMID:26537447

  17. Detecting 16S rRNA Methyltransferases in Enterobacteriaceae by Use of Arbekacin

    OpenAIRE

    McGann, Patrick; Chahine, Sarah; Okafor, Darius; Ong, Ana C; Maybank, Rosslyn; Kwak, Yoon I.; Wilson, Kerry; Zapor, Michael; Lesho, Emil; Hinkle, Mary

    2015-01-01

    16S rRNA methyltransferases confer resistance to most aminoglycosides, but discriminating their activity from that of aminoglycoside-modifying enzymes (AMEs) is challenging using phenotypic methods. We demonstrate that arbekacin, an aminoglycoside refractory to most AMEs, can rapidly detect 16S methyltransferase activity in Enterobacteriaceae with high specificity using the standard disk susceptibility test.

  18. DNA methyltransferase 1 and DNA methylation patterning contribute to germinal center B-cell differentiation

    DEFF Research Database (Denmark)

    Shaknovich, Rita; Cerchietti, Leandro; Tsikitas, Lucas;

    2011-01-01

    cells. Among DNA methyltransferases (DNMTs), only DNMT1 was significantly up-regulated in GC B cells. Dnmt1 hypomorphic mice displayed deficient GC formation and treatment of mice with the DNA methyltransferase inhibitor decitabine resulted in failure to form GCs after immune stimulation. Notably...

  19. Effect of cooking on the concentration of bioactive compounds in broccoli (Brassica oleracea var. Avenger) and cauliflower (Brassica oleracea var. Alphina F1) grown in an organic system.

    Science.gov (United States)

    Dos Reis, Luzia Caroline Ramos; de Oliveira, Viviani Ruffo; Hagen, Martine Elisabeth Kienzle; Jablonski, André; Flôres, Simone Hickmann; de Oliveira Rios, Alessandro

    2015-04-01

    Brassica vegetables have been shown to have antioxidant capacities due to the presence of carotenoids, flavonoids and vitamins. This study evaluates the influence of different processing conditions (boiling, steaming, microwaving and sous vide) on the stability of flavonoids, carotenoids and vitamin A in broccoli and cauliflower inflorescences grown in an organic system. Results indicated that sous vide processing resulted in greater antioxidant capacity and that all processes contributed in some way to an increased content of antioxidant compounds in both cauliflower and broccoli. PMID:25442619

  20. A SABATH Methyltransferase from the moss Physcomitrella patens catalyzes

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Nan [ORNL; Ferrer, Jean-Luc [Universite Joseph Fourier, France; Moon, Hong S [Department of Plant Sciences, University of Tennessee; Kapteyn, Jeremy [Institute of Biological Chemistry, Washington State University; Zhuang, Xiaofeng [Department of Plant Sciences, University of Tennessee; Hasebe, Mitsuyasu [Laboratory of Evolutionary Biology, National Institute for Biology, 38 Nishigounaka; Stewart, Neal C. [Department of Plant Sciences, University of Tennessee; Gang, David R. [Institute of Biological Chemistry, Washington State University; Chen, Feng [University of Tennessee, Knoxville (UTK)

    2012-01-01

    Known SABATH methyltransferases, all of which were identified from seed plants, catalyze methylation of either the carboxyl group of a variety of low molecular weight metabolites or the nitrogen moiety of precursors of caffeine. In this study, the SABATH family from the bryophyte Physcomitrella patens was identified and characterized. Four SABATH-like sequences (PpSABATH1, PpSABATH2, PpSABATH3, and PpSABATH4) were identified from the P. patens genome. Only PpSABATH1 and PpSABATH2 showed expression in the leafy gametophyte of P. patens. Full-length cDNAs of PpSABATH1 and PpSABATH2 were cloned and expressed in soluble form in Escherichia coli. Recombinant PpSABATH1 and PpSABATH2 were tested for methyltransferase activity with a total of 75 compounds. While showing no activity with carboxylic acids or nitrogen-containing compounds, PpSABATH1 displayed methyltransferase activity with a number of thiols. PpSABATH2 did not show activity with any of the compounds tested. Among the thiols analyzed, PpSABATH1 showed the highest level of activity with thiobenzoic acid with an apparent Km value of 95.5 lM, which is comparable to those of known SABATHs. Using thiobenzoic acid as substrate, GC MS analysis indicated that the methylation catalyzed by PpSABATH1 is on the sulfur atom. The mechanism for S-methylation of thiols catalyzed by PpSABATH1 was partially revealed by homology-based structural modeling. The expression of PpSABATH1 was induced by the treatment of thiobenzoic acid. Further transgenic studies showed that tobacco plants overexpressing PpSABATH1 exhibited enhanced tolerance to thiobenzoic acid, suggesting that PpSABATH1 have a role in the detoxification of xenobiotic thiols.

  1. Coordinate regulation of DNA methyltransferase expression during oogenesis

    Directory of Open Access Journals (Sweden)

    Bestor Timothy H

    2007-04-01

    Full Text Available Abstract Background Normal mammalian development requires the action of DNA methyltransferases (DNMTs for the establishment and maintenance of DNA methylation within repeat elements and imprinted genes. Here we report the expression dynamics of Dnmt3a and Dnmt3b, as well as a regulator of DNA methylation, Dnmt3L, in isolated female germ cells. Results Our results indicate that these enzymes are coordinately regulated and that their expression peaks during the stage of postnatal oocyte development when maternal methylation imprints are established. We find that Dnmt3a, Dnmt3b, Dnmt3L and Dnmt1o transcript accumulation is related to oocyte diameter. Furthermore, DNMT3L deficient 15 dpp oocytes have aberrantly methylated Snrpn, Peg3 and Igf2r DMRs, but normal IAP and LINE-1 methylation levels, thereby highlighting a male germ cell specific role for DNMT3L in the establishment of DNA methylation at repeat elements. Finally, real-time RT-PCR analysis indicates that the depletion of either DNMT3L or DNMT1o in growing oocytes results in the increased expression of the de novo methyltransferase Dnmt3b, suggesting a potential compensation mechanism by this enzyme for the loss of one of the other DNA methyltransferases. Conclusion Together these results provide a better understanding of the developmental regulation of Dnmt3a, Dnmt3b and Dnmt3L at the time of de novo methylation during oogenesis and demonstrate that the involvement of DNMT3L in retrotransposon silencing is restricted to the male germ line. This in turn suggests the existence of other factors in the oocyte that direct DNA methylation to transposons.

  2. Effects of combined treatments of irradiation and antimicrobial coatings on reduction of food pathogens in broccoli florets

    Energy Technology Data Exchange (ETDEWEB)

    Takala, P.N.; Salmieri, S.; Vu, K.D. [INRS-Institut Armand-Frappier, Research Laboratories in Sciences Applied to Food, Canadian Irradiation Centre, 531, Blvd des Prairies, Laval, QC, H7V 1B7 (Canada); Lacroix, M., E-mail: Monique.Lacroix@iaf.inrs.ca [INRS-Institut Armand-Frappier, Research Laboratories in Sciences Applied to Food, Canadian Irradiation Centre, 531, Blvd des Prairies, Laval, QC, H7V 1B7 (Canada)

    2011-12-15

    The effect of combined treatment of antimicrobial coatings and {gamma}-radiation on reduction of food pathogens such as Listeria monocytogenes, Escherichia coli, and Salmonella Typhimurium was evaluated in broccoli florets. Broccoli florets were inoculated with pathogenic bacteria at 10{sup 6} CFU/g. Inoculated florets were then coated with methylcellulose-based coating containing various mixtures of antimicrobial agents: organic acids (OAs) plus lactic acid bacteria metabolites (LABs), OA plus citrus extract (CE), OA plus CE plus spice mixture (SM), and OA plus rosemary extract (RE). Coated florets were irradiated with various doses (0-3.3 kGy), and microbial analyses were used to calculate the D{sub 10} value and radiosensitive relative. The coating containing OA plus CE was the most effective formulation for increasing the sensitization of Escherichia coli by 2.4 times as compared to the control without the antimicrobial coating. For Salmonella Typhimurium, coating containing OA plus LAB was the most effective formulation, increasing radiosensitivity by 2.4 times as well. All antimicrobial coatings had almost the same effect of increasing the sensitivity of Listeria monocytogenes (from 1.31 to 1.45 times) to {gamma}-irradiation. - Highlights: > Demonstrate scientifically the synergistic effect of the combined treatment of gamma-irradiation and natural antimicrobial coating in reduction of food pathogens in broccoli. > The coating containing organic acids plus citrus extract was the most efficient formulation for increasing the sensitization of E. coli by 2.40 times as compared to the control. > The coating containing organic acids plus lactic acid bacteria metabolites was the most effective formulation causing the sensitization of S. Typhimurium to {gamma}-irradiation by 2.4 times. > Potential in application of developed formulations to protect food products against food pathogens.

  3. Effects of combined treatments of irradiation and antimicrobial coatings on reduction of food pathogens in broccoli florets

    International Nuclear Information System (INIS)

    The effect of combined treatment of antimicrobial coatings and γ-radiation on reduction of food pathogens such as Listeria monocytogenes, Escherichia coli, and Salmonella Typhimurium was evaluated in broccoli florets. Broccoli florets were inoculated with pathogenic bacteria at 106 CFU/g. Inoculated florets were then coated with methylcellulose-based coating containing various mixtures of antimicrobial agents: organic acids (OAs) plus lactic acid bacteria metabolites (LABs), OA plus citrus extract (CE), OA plus CE plus spice mixture (SM), and OA plus rosemary extract (RE). Coated florets were irradiated with various doses (0-3.3 kGy), and microbial analyses were used to calculate the D10 value and radiosensitive relative. The coating containing OA plus CE was the most effective formulation for increasing the sensitization of Escherichia coli by 2.4 times as compared to the control without the antimicrobial coating. For Salmonella Typhimurium, coating containing OA plus LAB was the most effective formulation, increasing radiosensitivity by 2.4 times as well. All antimicrobial coatings had almost the same effect of increasing the sensitivity of Listeria monocytogenes (from 1.31 to 1.45 times) to γ-irradiation. - Highlights: → Demonstrate scientifically the synergistic effect of the combined treatment of gamma-irradiation and natural antimicrobial coating in reduction of food pathogens in broccoli. → The coating containing organic acids plus citrus extract was the most efficient formulation for increasing the sensitization of E. coli by 2.40 times as compared to the control. → The coating containing organic acids plus lactic acid bacteria metabolites was the most effective formulation causing the sensitization of S. Typhimurium to γ-irradiation by 2.4 times. → Potential in application of developed formulations to protect food products against food pathogens.

  4. Effect of broccoli sprouts on nasal response to live attenuated influenza virus in smokers: a randomized, double-blind study.

    Directory of Open Access Journals (Sweden)

    Terry L Noah

    Full Text Available Smokers have increased susceptibility and altered innate host defense responses to influenza virus infection. Broccoli sprouts are a source of the Nrf2 activating agentsulforaphane, and short term ingestion of broccoli sprout homogenates (BSH has been shown to reduce nasal inflammatory responses to oxidant pollutants.Assess the effects of BSH on nasal cytokines, virus replication, and Nrf2-dependent enzyme expression in smokers and nonsmokers.We conducted a randomized, double-blind, placebo-controlled trial comparing the effects of BSH on serially sampled nasal lavage fluid (NLF cytokines, viral sequence quantity, and Nrf2-dependent enzyme expression in NLF cells and biopsied epithelium. Healthy young adult smokers and nonsmokers ingested BSH or placebo (alfalfa sprout homogenate for 4 days, designated Days -1, 0, 1, 2. On Day 0 they received standard vaccine dose of live attenuated influenza virus (LAIV intranasally. Nasal lavage fluids and nasal biopsies were collected serially to assess response to LAIV.In area under curve analyses, post-LAIV IL-6 responses (P = 0.03 and influenza sequences (P = 0.01 were significantly reduced in NLF from BSH-treated smokers, whilequinoneoxidoreductasein NLF cells was significantly increased. In nonsmokers, a similar trend for reduction in virus quantity with BSH did not reach statistical significance.In smokers, short term ingestion of broccoli sprout homogenates appears to significantly reduce some virus-induced markers of inflammation, as well as reducing virus quantity. Nutritional antioxidant interventions have promise as a safe, low-cost strategy for reducing influenza risk among smokers and other at risk populations.ClinicalTrials.gov NCT01269723.

  5. Purification and characterization of DNA methyltransferases from Neisseria gonorrhoeae.

    OpenAIRE

    Piekarowicz, A; Yuan, R.; Stein, D C

    1988-01-01

    Three DNA methyltransferases, M.NgoAI, and M.NgoBI and M.NgoBII, free of any nuclease activities were isolated from Neisseria gonorrhoeae strains WR220 and MUG116 respectively. M.NgoAI recognizes the sequence 5' GGCC 3' and methylates the first 5' cytosine on both strands. M.NgoBI and M.NgoBII recognize 5' TCACC 3' and 5' GTAN5CTC 3' respectively. M.NgoBII methylates cytosine on only one strand to produce 5' GTAN5mCTC 3'.

  6. High level expression and purification of HhaI methyltransferase.

    OpenAIRE

    Wu, J. C.; Santi, D V

    1988-01-01

    A cloning system for the DNA-(cytosine-5)-methyltransferase MHhaI and high level expression of the enzyme are described. A parent plasmid was constructed from fragments of the MHhaI gene and synthetic oligonucleotides. The construct permits introduction of various restriction sites for cloning at precise positions near the initiation codon, and beyond the termination codon. The entire MHhaI coding sequence was introduced as a 1042 b.p. NdeI-XbaI fragment into the vector pAR3040 which contains...

  7. Catalytic site remodelling of the DOT1L methyltransferase by selective inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Wenyu [Univ. of Toronto, ON (Canada); Chory, Emma J. [Dana-Farber Cancer Inst., Boston, MA (United States); Northeastern Univ., Boston, MA (United States); Wernimont, Amy K. [Univ. of Toronto, ON (Canada); Tempel, Wolfram [Univ. of Toronto, ON (Canada); Scopton, Alex [Univ. of Toronto, ON (Canada); Federation, Alexander [Dana-Farber Cancer Inst., Boston, MA (United States); Marineau, Jason J. [Dana-Farber Cancer Inst., Boston, MA (United States); Qi, Jun [Dana-Farber Cancer Inst., Boston, MA (United States); Barsyte-Lovejoy, Dalia [Univ. of Toronto, ON (Canada); Yi, Joanna [Dana-Farber Cancer Inst., Boston, MA (United States); Marcellus, Richard [Ontario Inst. for Cancer Research, Toronto, ON (Canada); Iacob, Roxana E. [Northeastern Univ., Boston, MA (United States); Engen, John R. [Northeastern Univ., Boston, MA (United States); Griffin, Carly [Ontario Inst. for Cancer Research, Toronto, ON (Canada); Aman, Ahmed [Ontario Inst. for Cancer Research, Toronto, ON (Canada); Wienholds, Erno [Univ. of Toronto, ON (Canada); Li, Fengling [Univ. of Toronto, ON (Canada); Pineda, Javier [Dana-Farber Cancer Inst., Boston, MA (United States); Univ. of Notre Dame, IN (United States); Estiu, Guillermina [Univ. of Notre Dame, IN (United States); Shatseva, Tatiana [Univ. of Toronto, ON (Canada); Hajian, Taraneh [Univ. of Toronto, ON (Canada); Al-awar, Rima [Ontario Inst. for Cancer Research, Toronto, ON (Canada); Dick, John E. [Univ. of Toronto, ON (Canada); Vedadi, Masoud [Univ. of Toronto, ON (Canada); Brown, Peter J. [Univ. of Toronto, ON (Canada); Arrowsmith, Cheryl H. [Univ. of Toronto, ON (Canada); Bradner, James E. [Dana-Farber Cancer Inst., Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Schapira, Matthieu [Univ. of Toronto, ON (Canada)

    2012-12-18

    Selective inhibition of protein methyltransferases is a promising new approach to drug discovery. An attractive strategy towards this goal is the development of compounds that selectively inhibit binding of the cofactor, S-adenosylmethionine, within specific protein methyltransferases. Here we report the three-dimensional structure of the protein methyltransferase DOT1L bound toEPZ004777, the first S-adenosylmethionine-competitive inhibitor of a protein methyltransferase with in vivo efficacy. This structure and those of four new analogues reveal remodelling of the catalytic site. EPZ004777 and a brominated analogue, SGC0946, inhibit DOT1L in vitro and selectively kill mixed lineage leukaemia cells, in which DOT1L is aberrantly localized via interaction with an oncogenic MLL fusion protein. These data provide important new insight into mechanisms of cell-active S-adenosylmethionine-competitive protein methyltransferase inhibitors, and establish a foundation for the further development of drug-like inhibitors of DOT1L for cancer therapy.

  8. Improved synthesis methods of standards used for quantitative determination of total isothiocyanates from broccoli in human urine

    DEFF Research Database (Denmark)

    Kristensen, Mette; Krogholm, Kirstine Suszkiewicz; Frederiksen, Hanne;

    2007-01-01

    A well-known method for quantification of isothiocyanates (ITCs) and their metabolites is the condensation reaction with 1,2-benzenedithiole to produce 1,3-benzodithiole-2-thione, which can be quantified by high-performance liquid chromatography. Standards of an ITC metabolite and 1,3-benzodithio...... excretion of ITCs from 10 healthy subjects who consumed 350 g broccoli. The excretion was investigated throughout 48 h showing a cumulative urinary ITC excretion of 49.1 +/- 25.2% of the dose....

  9. Dietary Chemoprevention of PhIP Induced Carcinogenesis in Male Fischer 344 Rats with Tomato and Broccoli

    OpenAIRE

    Kirstie Canene-Adams; Sfanos, Karen S; Chung-Tiang Liang; Srinivasan Yegnasubramanian; Nelson, William G.; Cory Brayton; Marzo, Angelo M. De

    2013-01-01

    The heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-B]pyridine (PhIP), found in meats cooked at high temperatures, has been implicated in epidemiological and rodent studies for causing breast, prostate, and colorectal cancers. A previous animal study using a xenograft model has shown that whole tomato and broccoli, when eaten in combination, exhibit a marked effect on tumor reduction compared to when eaten alone. Our aim was to determine if PhIP-induced carcinogenesis can be prevente...

  10. The broccoli-born isothiocyanate sulforaphane impairs nucleotide excision repair: XPA as one potential target.

    Science.gov (United States)

    Piberger, Ann Liza; Köberle, Beate; Hartwig, Andrea

    2014-03-01

    The isothiocyanate sulforaphane (SFN), the major hydrolysis product of glucosinolates present in broccoli, has frequently been proposed to exert anticarcinogenic properties, mainly due to the induction of the nrf2/Keap1/ARE-signaling pathway. As potential underlying mechanism, a SFN-dependent zinc release from Keap1, the negative regulator of nrf2, has been described. This raises the question whether SFN is able to interfere with other zinc binding structures as well, for example those essential for DNA repair. Within this study, a SFN-induced deliberation of zinc from a synthesized peptide resembling the zinc binding domain of the xeroderma pigmentosum A (XPA) protein was observed starting at 50 μM SFN. Since XPA is absolutely required for nucleotide excision repair, the impact of SFN on the repair of (+)-anti-benzo[a]pyrene 7,8-diol-9,10-epoxide ((+)-anti-BPDE)-induced DNA adducts in HCT 116 cells was investigated. While preincubation with SFN did not affect initial lesion levels, a dose-dependent repair inhibition of (+)-anti-BPDE-induced DNA damage during the first 12 h after lesion induction was observed, starting at 1 μM SFN. In contrast, the later phase of DNA repair was not impaired by SFN. In support of an inactivation of XPA also in cells, SFN increased the (+)-anti-BPDE-induced cytotoxicity XPA dependently in XP12RO cells. Comparison of p53-proficient and p53-deficient cells revealed no difference in SFN-induced DNA repair inhibition, indicating that p53 is no cellular target of SFN. Since DNA repair processes are required to maintain DNA integrity, the presented data suggest a potential impairment of genomic stability by SFN.

  11. Growth of lowland broccoli coconut coir dust and peat based growing media using fertigation system

    International Nuclear Information System (INIS)

    A study was carried out inside the greenhouse to determine the response of lowland broccoli (Brassica oleracea) plants grown in five mixtures of coconut coir dust and peat as the growing media. The growing mixes were prepared in the following ratios (% by vol): 100% coconut coir dust, 75% coconut coir dust + 25% peat, 50% coconut coir dust + 50% peat, 25% coconut coir dust + 75% peat and 100% peat. The plants were supplied with 200 mg 1-1 nitrogen using a computerized fertigation system developed at MINT Plants grown on 100% peat exhibited reduced plant growth and yield compared to plants grown on mixes containing coconut coir dust. Plants growth and yield were increased on growing media contained > 50% coconut coir dust; however, the highest total plant dry weight, plant height and yield were obtained from plants grown on 100% coconut coir dust. Total nitrogen concentration in the leaves and stems was not significantly different in all mixture of the growing media regardless of whether coconut coir dust or peat was used. In general, nitrate -nitrogen concentrations were lowest in the floret than in the leaves and stem tissues of plants grown on all growing media used in the study. However, nitrate-nitrogen concentrations in the leaves, stems and florets were lowest in the plants grown on 100% peat compared to the plants grown on growing media containing coconut coir dust. The concentrations of nitrate-nitrogen in the florets, which ranged from 290 to 450 mg N kg-l/dry weight, are considered to be under permissible levels by European standards. (Author)

  12. Lipid substrate specificity of phosphatidylethanolamine N-methyltransferase of Tetrahymena

    International Nuclear Information System (INIS)

    The ciliate protozoan Tetrahymena thermophila forms about 60% of its phosphatidylcholine by methylation of phosphatidylethanolamine with S-adenosylmethionine using the enzyme phosphatidylethanolamine N-methyltransferase. Analogues of ethanolamine or of ethanolamine phosphate are incorporated into the phospholipids of Tetrahymena when cells are cultured in their presence. These compounds, 3-amino-1-propanol, 2-aminoethylphosphonate, 3-aminopropylphosphonate and N,N-dimethylaminoethylphosphonate replace from 50 to 75% of the ethanolamine phosphate in phosphatidylethanolamine. However, analysis of the phospholipids of lipid-altered Tetrahymena showed that none of the phosphatidylethanolamine analogues had been converted to the corresponding phosphatidylcholine analogue. No incorration of [14C-CH3]methionine into the phosphatidylcholine analogues could be demonstrated in vivo, nor was label from [3H-CH3]S-adenosylmethionine incorporated in virto. Thus, only phosphatidylethanolamine and its monomethyl and dimethyl derivatives have been found to be substrates for the phosphatidylethanoiamine N-methyltransferase. The enzyme therefore requires a phospholipid substrate containing an ester linkage between the alkylamine and phosphorus, with the amino group required to be β to the alcohol

  13. An allosteric inhibitor of protein arginine methyltransferase 3.

    Science.gov (United States)

    Siarheyeva, Alena; Senisterra, Guillermo; Allali-Hassani, Abdellah; Dong, Aiping; Dobrovetsky, Elena; Wasney, Gregory A; Chau, Irene; Marcellus, Richard; Hajian, Taraneh; Liu, Feng; Korboukh, Ilia; Smil, David; Bolshan, Yuri; Min, Jinrong; Wu, Hong; Zeng, Hong; Loppnau, Peter; Poda, Gennadiy; Griffin, Carly; Aman, Ahmed; Brown, Peter J; Jin, Jian; Al-Awar, Rima; Arrowsmith, Cheryl H; Schapira, Matthieu; Vedadi, Masoud

    2012-08-01

    PRMT3, a protein arginine methyltransferase, has been shown to influence ribosomal biosynthesis by catalyzing the dimethylation of the 40S ribosomal protein S2. Although PRMT3 has been reported to be a cytosolic protein, it has been shown to methylate histone H4 peptide (H4 1-24) in vitro. Here, we report the identification of a PRMT3 inhibitor (1-(benzo[d][1,2,3]thiadiazol-6-yl)-3-(2-cyclohexenylethyl)urea; compound 1) with IC50 value of 2.5 μM by screening a library of 16,000 compounds using H4 (1-24) peptide as a substrate. The crystal structure of PRMT3 in complex with compound 1 as well as kinetic analysis reveals an allosteric mechanism of inhibition. Mutating PRMT3 residues within the allosteric site or using compound 1 analogs that disrupt interactions with allosteric site residues both abrogated binding and inhibitory activity. These data demonstrate an allosteric mechanism for inhibition of protein arginine methyltransferases, an emerging class of therapeutic targets.

  14. Structural biology of human H3K9 methyltransferases.

    Directory of Open Access Journals (Sweden)

    Hong Wu

    Full Text Available UNLABELLED: SET domain methyltransferases deposit methyl marks on specific histone tail lysine residues and play a major role in epigenetic regulation of gene transcription. We solved the structures of the catalytic domains of GLP, G9a, Suv39H2 and PRDM2, four of the eight known human H3K9 methyltransferases in their apo conformation or in complex with the methyl donating cofactor, and peptide substrates. We analyzed the structural determinants for methylation state specificity, and designed a G9a mutant able to tri-methylate H3K9. We show that the I-SET domain acts as a rigid docking platform, while induced-fit of the Post-SET domain is necessary to achieve a catalytically competent conformation. We also propose a model where long-range electrostatics bring enzyme and histone substrate together, while the presence of an arginine upstream of the target lysine is critical for binding and specificity. ENHANCED VERSION: This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1.

  15. Evaluation of Image Analysis to Determine the N-Fertilizer Demand of Broccoli Plants (Brassica oleracea convar. botrytis var. italica

    Directory of Open Access Journals (Sweden)

    Simone Graeff

    2008-01-01

    Full Text Available Numerous models have been developed for calculating optimum decision rules for nitrogen fertilization based on remote sensing techniques. New technologies related to digital image analysis may provide an alternative method to estimate nutrient status faster and more efficiently than current techniques. A series of field studies was conducted to determine the applicability of digital image analysis for nitrogen demand estimates in broccoli plants. Digital images were taken under constant light conditions in various wavelength ranges (380–1300 nm using a digital imager. Images were processed for the parameters ∗ and ∗ in the ∗∗∗ color system. The image analysis showed a close correlation between the nitrogen status of broccoli plants and the parameter ∗ of the ∗∗∗ color system especially in the wavelength ranges 510780 and 516780 nm. The relationship between nutrient concentration in leaf dry matter and the parameters ∗ was used to determine the N fertilizer demand within the cultivation period. Estimated N amounts were applied as top dressing four weeks after setting and were 100 kg ha−1 lower than the standard fertilizer rate. Calculated N balances indicated a total uptake of applied N amounts in the image-based N treatments without considerable yield loss. Thus, digital image analysis proved to be an effective means of determining nitrogen status and adjusting fertilizer applications to preserve or enhance crop quality and yield considering sustainability.

  16. Effects of combined treatments of irradiation and antimicrobial coatings on reduction of food pathogens in broccoli florets

    Science.gov (United States)

    Takala, P. N.; Salmieri, S.; Vu, K. D.; Lacroix, M.

    2011-12-01

    The effect of combined treatment of antimicrobial coatings and γ-radiation on reduction of food pathogens such as Listeria monocytogenes, Escherichia coli, and Salmonella Typhimurium was evaluated in broccoli florets. Broccoli florets were inoculated with pathogenic bacteria at 10 6 CFU/g. Inoculated florets were then coated with methylcellulose-based coating containing various mixtures of antimicrobial agents: organic acids (OAs) plus lactic acid bacteria metabolites (LABs), OA plus citrus extract (CE), OA plus CE plus spice mixture (SM), and OA plus rosemary extract (RE). Coated florets were irradiated with various doses (0-3.3 kGy), and microbial analyses were used to calculate the D10 value and radiosensitive relative. The coating containing OA plus CE was the most effective formulation for increasing the sensitization of Escherichia coli by 2.4 times as compared to the control without the antimicrobial coating. For Salmonella Typhimurium, coating containing OA plus LAB was the most effective formulation, increasing radiosensitivity by 2.4 times as well. All antimicrobial coatings had almost the same effect of increasing the sensitivity of Listeria monocytogenes (from 1.31 to 1.45 times) to γ-irradiation.

  17. Differential responses of two broccoli (Brassica oleracea L. var Italica) cultivars to salinity and nutritional quality improvement.

    Science.gov (United States)

    Zaghdoud, Chokri; Alcaraz-López, Carlos; Mota-Cadenas, César; Martínez-Ballesta, María del Carmen; Moreno, Diego A; Ferchichi, Ali; Carvajal, Micaela

    2012-01-01

    The comparative responses of two broccoli cultivars (Brassica oleracea var. Italica, cv. Parthenon and cv. Naxos) to a 15 d exposure to different NaCl levels were investigated. Salinity led to increased concentrations of Na(+) and Cl(-) ions in both cultivars, a disruption of the endogenous minerals levels in the shoots and roots-that varied with the cultivar and salt concentration-and decreases in the osmotic potential (Ψ(π)), root hydraulic conductance (L(0)), and stomatal conductance (G(s)). The reduced biomass of Naxos at moderate NaCl indicates greater sensitivity to salinity, compared with Parthenon. Parthenon accumulated more soluble sugars, for osmotic adjustment, whereas Naxos accumulated proline, which gave the two cultivars differing nutritional characteristics. The total glucosinolates (GSLs) content was not affected by salinity in Parthenon while it decreased significantly in Naxos as a consequence of the decrease in the indole GSL. However, Naxos accumulated more aliphatic GSLs under salt stress than Parthenon, which confers on this cultivar a greater nutritional value when cultivated under salinity.These results suggest that, at distinct salinity levels, each broccoli cultivar adopts a specific strategy, indicating the crucial role of the genetic background on the organoleptic and nutritional properties that each cultivar acquires.

  18. Differential Responses of Two Broccoli (Brassica oleracea L. var Italica Cultivars to Salinity and Nutritional Quality Improvement

    Directory of Open Access Journals (Sweden)

    Chokri Zaghdoud

    2012-01-01

    Full Text Available The comparative responses of two broccoli cultivars (Brassica oleracea var. Italica, cv. Parthenon and cv. Naxos to a 15 d exposure to different NaCl levels were investigated. Salinity led to increased concentrations of Na+ and Cl− ions in both cultivars, a disruption of the endogenous minerals levels in the shoots and roots—that varied with the cultivar and salt concentration—and decreases in the osmotic potential (Ψπ, root hydraulic conductance (L0, and stomatal conductance (Gs. The reduced biomass of Naxos at moderate NaCl indicates greater sensitivity to salinity, compared with Parthenon. Parthenon accumulated more soluble sugars, for osmotic adjustment, whereas Naxos accumulated proline, which gave the two cultivars differing nutritional characteristics. The total glucosinolates (GSLs content was not affected by salinity in Parthenon while it decreased significantly in Naxos as a consequence of the decrease in the indole GSL. However, Naxos accumulated more aliphatic GSLs under salt stress than Parthenon, which confers on this cultivar a greater nutritional value when cultivated under salinity.These results suggest that, at distinct salinity levels, each broccoli cultivar adopts a specific strategy, indicating the crucial role of the genetic background on the organoleptic and nutritional properties that each cultivar acquires.

  19. Gold nanoparticles synthesized by Brassica oleracea (Broccoli) acting as antimicrobial agents against human pathogenic bacteria and fungi

    Science.gov (United States)

    Piruthiviraj, Prakash; Margret, Anita; Krishnamurthy, Poornima Priyadharsani

    2016-04-01

    Production of antimicrobial agents through the synthesis of gold nanoparticles using green technology has been extensively made consistent by various researchers; yet, this study uses the flower bud's aqueous extracts of Brassica oleracea (Broccoli) as a reducing agent for chloroauric acid (1 mM). After 30 min of incubation, synthesis of gold nanoparticles (AuNps) was observed by a change in extract color from pale yellow to purple color. Synthesis of AuNps was confirmed in UV-visible spectroscopy at the range of approximately 560 nm. The SEM analysis showed the average nanoparticles size of 12-22 nm. The antimicrobial activity of AuNps was analyzed by subjecting it to human pathogenic bacteria (Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumonia) and fungi (Aspergillus flavus, Aspergillus niger and Candida albicans) using disc diffusion method. The broccoli-synthesized AuNps showed the efficient antibacterial and antifungal activity of above-mentioned microbes. It was confirmed that AuNps have the best antimicrobial agent compared to the standard antibiotics (Gentamicin and Fluconazole). When the concentrations of AuNps were increased (10, 25, and 50 µg/ml), the sensitivity zone also increased for all the tested microbes. The synthesized AuNps are capable of rendering high antimicrobial efficacy and, hence, have a great potential in the preparation of drugs used against major bacterial and fungal diseases in humans.

  20. Enhanced resistance to Botrytis cinerea and Rhizoctonia solani in transgenic broccoli with a Trichoderma viride endochitinase gene

    Institute of Scientific and Technical Information of China (English)

    YU Ya; REN Shu-xin; GUO Yang-dong; ZHANG Lei; LIAN Wei-ran; XU Feng-feng; LI Shuang-tao; XIANG Juan; ZHANG Guo-zhen; HU Zan-min; ZHAO Bing

    2015-01-01

    A endochitinase gene (Tch ) from the fungus Trichoderma viride was introduced into broccoli (Brassica oleracea var. italica) by Agrobacterium-mediated transformation. Sixty-eight putative transformants were obtained and the presence of the Tch gene was conifrmed by both PCR and Southern blot analysis. RT-PCR analysis showed an accumulation of the transcript encoding the endochitinase protein in the transgenic plants. Using real-time quantitative PCR, the expression proifling of endochitinase gene was analyzed. Primary transformants and selfed progeny were examined for expression of the endo-chitinase using a lfuorometric assay and for their resistance to the pathogenic fungi Botrytis cinerea and Rhizoctonia solani. The endochitinase activities in T0 in vitro plants, T0 mature plants and T1 mature plants were correlated with leaf lesions, and the transgenic line T618 had high endochitinse activities of 102.68, 114.53 and 120.27 nmol L–1 MU min–1 mg–1 protein in the three kinds of plants, respectively. The endochitinase activity showed a positive correlation with the resistance to the pathogens. Most transgenic T0 broccoli had increased resistance to the pathogens of B. cinerea and R. solani in leaf assays and this resistance was conifrmed to be inheritable. These ifndings suggested that expression of the Tch gene from T. viride could enhance resistance to pathogenic fungi in Brassica species.

  1. Discriminating between cultivars and treatments of broccoli using mass spectral fingerprinting and analysis of variance-principal component analysis.

    Science.gov (United States)

    Luthria, Devanand L; Lin, Long-Ze; Robbins, Rebecca J; Finley, John W; Banuelos, Gary S; Harnly, James M

    2008-11-12

    Metabolite fingerprints, obtained with direct injection mass spectrometry (MS) with both positive and negative ionization, were used with analysis of variance-principal components analysis (ANOVA-PCA) to discriminate between cultivars and growing treatments of broccoli. The sample set consisted of two cultivars of broccoli, Majestic and Legacy, the first grown with four different levels of Se and the second grown organically and conventionally with two rates of irrigation. Chemical composition differences in the two cultivars and seven treatments produced patterns that were visually and statistically distinguishable using ANOVA-PCA. PCA loadings allowed identification of the molecular and fragment ions that provided the most significant chemical differences. A standardized profiling method for phenolic compounds showed that important discriminating ions were not phenolic compounds. The elution times of the discriminating ions and previous results suggest that they were common sugars and organic acids. ANOVA calculations of the positive and negative ionization MS fingerprints showed that 33% of the variance came from the cultivar, 59% from the growing treatment, and 8% from analytical uncertainty. Although the positive and negative ionization fingerprints differed significantly, there was no difference in the distribution of variance. High variance of individual masses with cultivars or growing treatment was correlated with high PCA loadings. The ANOVA data suggest that only variables with high variance for analytical uncertainty should be deleted. All other variables represent discriminating masses that allow separation of the samples with respect to cultivar and treatment.

  2. VEGETATIVE GROWTH AND PRODUCTIVITY OF A NUMBER OF INTRODUCED BROCCOLI CULTIVARS (Brassica oleracea L. var. italica Plenck. IN BATUR VILLAGE, KINTAMANI DISTRICT, BANGLI REGENCY, BALI

    Directory of Open Access Journals (Sweden)

    Ni Kadek Raleni

    2015-09-01

    Full Text Available Broccoli (Brassica oleracea L. var. italica Plenck. is a vegetable crop belongs to Brassicaceae family. Broccoli has high nutrition, high in fiber and contains isotiacyanate that has anticancer activity. Broccoli market in Indonesia, particularly in modern supermarkets, increases 15-20% per year, however, productivity was still low, therefore effort to increase broccoli production in Indonesia need to be investigated. Field trial was conducted at Batur Village, Kintamani District, Bangli Regency, Bali, to find out cultivars that were adapted in tropical region. Introduced cultivars being trialed were ‘Alborada’, ‘Belstar’, ‘Fiesta’, ‘Sarasota’, ‘Bay Meadows’, ‘Castle Dome’, ‘Liutenant’, ‘Iron Man’, ‘Marathon’, ‘Green Gold’, ‘Imperial’, ‘Green Magic’ and ‘Lucky’ as control. Variable observed were vegetative growth, curding period, and productivity of each cultivar. This study employed Randomized Completely Block Design with 3 replicates (plots and 8 plants each plot. Data were analyzed using ANOVA (Analysis of variance on Costat program, followed by Duncan’s Multiple Range Test (DMRT on 1% level. Results show that each cultivar varied in adaptability in tropical region. ‘Castle Dome’ has the highest productivity, while ‘Fiesta’ was the lowest.

  3. 冰温贮藏对西兰花保鲜的影响%Effect of ice-temperature storage on the freshness retaining of broccolis

    Institute of Scientific and Technical Information of China (English)

    林本芳; 鲁晓翔; 李江阔; 陈绍慧

    2012-01-01

    研究冰温贮藏对西兰花保鲜效果的影响。将西兰花分为两组,一组存于冰温库中(-0.7~-0.4)℃,另一组存于普通冷库中(-1~1)℃。每14d取样测定其理化指标及营养成分。实验结果表明:冰温贮藏对于延缓西兰花可溶性固形物含量、可溶性糖浓度和VC含量的下降具有明显的效果,可显著抑制西兰花贮藏期间乙烯生成率,延迟乙烯高峰的出现,但对呼吸的抑制效果不大;冰温贮藏提高了西兰花POD、SOD和CAT等的活性,降低了PPO的活性,延缓了西兰花的衰老。这说明西兰花适于冰温贮藏,且冰温贮藏的效果优于普通冷藏的效果。%In order to investigate the effect of ice-temperature storage on the results of freshness retaining of broccolis,the broccolis were stored under two different storage temperatures.One was-0.7~-0.4℃,and the other was-1~1℃.The physicochemical indexes and nutrition components were measured for 14 days.The research results showed that the soluble solids content,soluble sugar and vitamine C of the broccolis by ice-temperature storage decreased less than that of ordinary storage.Ice-temperature storage could significantly inhibit the ethylene generation rate of the broccolis,but the inhibition effect on respiration of the broccolis was not obvious.The activities of peroxidase(POD),superoxide dismutase(SOD)and catalase(CAT)were promoted and the activity of polyphenol oxidas(PPO)was reduced,in turn,the ripening of broccolis was delayed.Therefore,the storage effect of broccolis by ice-temperature storage is superior to that by ordinary storage.

  4. Substrate recognition and modification by the nosiheptide resistance methyltransferase.

    Directory of Open Access Journals (Sweden)

    Sitao Yin

    Full Text Available The proliferation of antibiotic resistant pathogens is an increasing threat to the general public. Resistance may be conferred by a number of mechanisms including covalent or mutational modification of the antibiotic binding site, covalent modification of the drug, or the over-expression of efflux pumps. The nosiheptide resistance methyltransferase (NHR confers resistance to the thiazole antibiotic nosiheptide in the nosiheptide producer organism Streptomyces actuosus through 2'O-methylation of 23S rRNA at the nucleotide A1067. Although the crystal structures of NHR and the closely related thiostrepton-resistance methyltransferase (TSR in complex with the cofactor S-Adenosyl-L-methionine (SAM are available, the principles behind NHR substrate recognition and catalysis remain unclear.We have analyzed the binding interactions between NHR and model 58 and 29 nucleotide substrate RNAs by gel electrophoresis mobility shift assays (EMSA and fluorescence anisotropy. We show that the enzyme binds to RNA as a dimer. By constructing a hetero-dimer complex composed of one wild-type subunit and one inactive mutant NHR-R135A subunit, we show that only one functional subunit of the NHR homodimer is required for its enzymatic activity. Mutational analysis suggests that the interactions between neighbouring bases (G1068 and U1066 and A1067 have an important role in methyltransfer activity, such that the substitution of a deoxy sugar spacer (5' to the target nucleotide achieved near wild-type levels of methylation. A series of atomic substitutions at specific positions on the substrate adenine show that local base-base interactions between neighbouring bases are important for methylation.Taken together these data suggest that local base-base interactions play an important role in aligning the substrate 2' hydroxyl group of A1067 for methyl group transfer. Methylation of nucleic acids is playing an increasingly important role in fundamental biological processes

  5. Chromosome Doubling of Microspore-Derived Plants from Cabbage (Brassica oleracea var. capitata L.) and Broccoli (Brassica oleracea var. italica L.)

    Science.gov (United States)

    Yuan, Suxia; Su, Yanbin; Liu, Yumei; Li, Zhansheng; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao; Sun, Peitian

    2015-01-01

    Chromosome doubling of microspore-derived plants is an important factor in the practical application of microspore culture technology because breeding programs require a large number of genetically stable, homozygous doubled haploid plants with a high level of fertility. In the present paper, 29 populations of microspore-derived plantlets from cabbage (Brassica oleracea var. capitata) and broccoli (Brassica oleracea var. italica) were used to study the ploidy level and spontaneous chromosome doubling of these populations, the artificial chromosome doubling induced by colchicine, and the influence of tissue culture duration on the chromosomal ploidy of the microspore-derived regenerants. Spontaneous chromosome doubling occurred randomly and was genotype dependent. In the plant populations derived from microspores, there were haploids, diploids, and even a low frequency of polyploids and mixed-ploidy plantlets. The total spontaneous doubling in the 14 cabbage populations ranged from 0 to 76.9%, compared with 52.2 to 100% in the 15 broccoli populations. To improve the rate of chromosome doubling, an efficient and reliable artificial chromosome doubling protocol (i.e., the immersion of haploid plantlet roots in a colchicine solution) was developed for cabbage and broccoli microspore-derived haploids. The optimal chromosome doubling of the haploids was obtained with a solution of 0.2% colchicine for 9–12 h or 0.4% colchicine for 3–9 h for cabbage and 0.05% colchicine for 6–12 h for broccoli. This protocol produced chromosome doubling in over 50% of the haploid genotypes for most of the populations derived from cabbage and broccoli. Notably, after 1 or more years in tissue culture, the chromosomes of the haploids were doubled, and most of the haploids turned into doubled haploid or mixed-ploidy plants. This is the first report indicating that tissue culture duration can change the chromosomal ploidy of microspore-derived regenerants. PMID:26734028

  6. Plants as biofactories: Postharvest Stress-Induced Accumulation of Phenolic Compounds and Glucosinolates in Broccoli Subjected to Wounding Stress and Exogenous Phytohormones

    Directory of Open Access Journals (Sweden)

    Daniel eVillarreal-García

    2016-02-01

    Full Text Available Broccoli contains high levels of bioactive molecules and is considered a functional food. In this study, postharvest treatments to enhance the concentration of glucosinolates and phenolic compounds were evaluated. Broccoli whole heads were wounded to obtain florets and wounded florets (florets cut into four even pieces and stored for 24 h at 20 ºC with or without exogenous ethylene (ET, 1000 ppm or methyl jasmonate (MeJA, 250 ppm. Whole heads were used as a control for wounding treatments. Regarding glucosinolate accumulation, ET selectively induced the 4-hydroxylation of glucobrassicin in whole heads, resulting in ~223% higher 4-hydroxyglucobrassicin than time 0 h samples. Additionally, glucoraphanin was increased by ~53% in whole heads treated with ET, while neoglucobrassicin was greatly accumulated in wounded florets treated with ET or MeJA, showing increases of ~193% and ~286%, respectively. On the other hand, although only whole heads stored without phytohormones showed higher concentrations of phenolic compounds, which was reflected in ~33%, ~30%, and 46% higher levels of 1,2,2-trisinapoylgentiobose, 1,2-diferulolylgentiobiose, and 1,2-disinapoyl-2-ferulolylgentiobiose, respectively; broccoli florets stored under air control conditions showed enhanced concentrations of 3-O-caffeoylquinic acid, 1,2-disinapoylgentiobiose, and 1,2-disinapoyl-2-ferulolylgentiobiose (~22%, ~185%, and ~65% more, respectively. However, exogenous ET and MeJA impeded individual phenolics accumulation. Results allowed the elucidation of simple and effective postharvest treatment to enhance the content of individual glucosinolates and phenolic compounds in broccoli. The stressed-broccoli tissue could be subjected to downstream processing in order to extract and purify bioactive molecules with applications in the dietary supplements, agrochemical and cosmetics markets.

  7. 西兰花干燥过程中还原型Vc与氧化型Vc的变化%Changes of ascorbic acid in processes of dehydrated broccoli

    Institute of Scientific and Technical Information of China (English)

    杨霞; 司俊娜; 樊振江; 高愿军

    2012-01-01

    The changes of L-ascorbic acid and I. dehydroascorbic acid during the processes of dehydrated broccoli were studied. The results showed that;the saving of ascorbic acid dealed with steam blanching were higher than treated by hot water, and treaed broccoli 2 mm with hot water in 80℃ had the thinkable result . Broccolis cooling wsth ice-water were better than natural cooling to the saving of ascorbic acid. The ascorbic acid could be saving to the maximize retention treated with vacuum freeze dried, which wass better than treated with microwave drying and hot air drying, and could maintain the shape and the color of broccoli. And treated broccoli 6 h in -25℃ was the best method.%研究西兰花脱水加工过程中还原型Vc和氧化型Vc的变化.结果表明:经过蒸汽热烫的西兰花,其还原型Vc和氧化型Vc的保存率高于热水热烫的保存率,其中80℃蒸汽热烫处理2 min效果最好;热烫后冰水冷却的西兰花还原型Vc和氧化型Vc.保存率高于自然冷却;真空冷冻干燥能将西兰花中还原型Vc和氧化型Vc.最大程度的保留.西兰花脱水加工过程中氧化型Vc的保存率高于还原型Vc,说明西兰花中的还原型Vc更易被破坏.

  8. 聚乳酸薄膜对西兰花的保鲜效果分析%Effect of Polylactic Acid Film Packaging on Preservation of Broccoli

    Institute of Scientific and Technical Information of China (English)

    李伟; 张一珠; 付正义; 张伟阳; 程树军

    2016-01-01

    Polylactic acid (PLA) film was applied to preserve broccoli with polyethylene (PE) film packaging and without packaging as controls. The effect of PLA film on preservation of broccoli quality was investigated by periodically recording quality changes during storage at a constant temperature of (20 ± 3) ℃. The results showed that the vitamin C and chlorophyll contents of broccoli were declined, while the relative conductivity and peroxidase (POD) activity were increased during storage under all three packaging conditions. The broccoli packaged in PLA film showed minimum changes. From the above results it is clear that PLA film can preserve broccoli quality obviously and effectively prolong its shelf life at normal temperature.%用聚乳酸(polylactic acid,PLA)薄膜包装西兰花,以聚乙烯(polyethylene,PE)薄膜包装和无膜包装为对照组,在(20±3)℃条件下对西兰花的相关指标进行定期测定,研究PLA薄膜对西兰花的保鲜效果。结果表明:在PLA薄膜、PE薄膜和无膜包装贮藏过程中,西兰花的VC、叶绿素含量均呈下降趋势,且前者含量明显高于后两者,而相对电导率、过氧化物酶活性均呈上升趋势,前者明显低于后两者。可见,PLA薄膜包装处理对常温条件下的西兰花有明显的保鲜效果,能有效地延长西兰花的常温货架期。

  9. Proteome identification of proteins interacting with histone methyltransferase SET8

    Institute of Scientific and Technical Information of China (English)

    Yi Qin; Huafang Ouyang; Jing Liu; Youhua Xie

    2013-01-01

    SET8 (also known as PR-Set7/9,SETD8,KMT5A),a member of the SET domain containing methyltransferase family,which specifically catalyzes mono-methylation of K20 on histone H4 (H4K20me1),has been implicated in multiple biological processes,such as gene transcriptional regulation,cell cycle control,genomic integrity maintenance and development.In this study,we used GST-SET8 fusion protein as bait to search for SET8 interaction partners to elucidate physiological functions of SET8.In combination with mass spectrometry,we identified 40 proteins that potentially interact with SET8.DDX21,a nucleolar protein,was further confirmed to associate with SET8.Furthermore,we discovered a novel function of SET8 in the regulation of rRNA transcription.

  10. Clinical utility of thiopurine S-methyltransferase genotyping.

    Science.gov (United States)

    Corominas, Hèctor; Baiget, Montserrat

    2004-01-01

    Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme that plays a major role in the metabolism of thiopurine drugs such as mercaptopurine and azathioprine. The interindividual differences in response to thiopurine administration is in part due to the presence of genetic polymorphisms in the gene that regulates TPMT activity. TPMT genotype correlates well with the in vivo enzyme activity within erythrocytes. Patients with genetically determined decreased TPMT activity develop severe myelosuppression when treated with standard doses of thiopurine drugs because an excess of thioguanine nucleotides accumulates in hematopoietic tissues. TPMT genotyping provides clinicians with a reliable method for identifying TPMT-deficient patients who can benefit from low doses of thiopurine drugs in order to reduce the risk of developing adverse effects. Moreover, the administration of higher doses of the drug could improve therapeutic response in patients in whom the TPMT genotyping demonstrates the absence of mutated alleles.

  11. Betaine-homocysteine methyltransferase (BHMT) : genomic sequencing and relevance to hyperhomocysteinemia and vascular disease in humans

    NARCIS (Netherlands)

    Heil, S.G.; Lievers, K.J.A.; Boers, G.H.; Verhoef, P.; Heijer, den M.; Trijbels, F.J.M.; Blom, H.J.

    2000-01-01

    Elevated homocysteine levels have been associated with arteriosclerosis and thrombosis. Hyperhomocysteinemia is caused by altered functioning of enzymes of its metabolism due to either inherited or acquired factors. Betaine-homocysteine methyltransferase (BHMT) serves, next to methionine synthase, a

  12. An audit of thiopurine methyltransferase genotyping and phenotyping before intended azathioprine treatment for dermatological conditions

    DEFF Research Database (Denmark)

    Vestergaard, T; Bygum, A

    2009-01-01

    Summary Background. Determining thiopurine methyltransferase (TPMT) genotype and phenotype before azathioprine treatment predicts which patients are most likely to develop myelosuppression. Aim. To evaluate the course of azathioprine treatment in people with TPMT heterozygosity and whether this d...

  13. Arsenic (+3 oxidation state) methyltransferase and the methylation of arsenicals in the invertebrate chordate Ciona intestinalis

    Science.gov (United States)

    Biotransformation of inorganic arsenic (iAs) involves methylation catalyzed by arsenic (+3 oxidation state) methyltransferase (As3mt), yielding mono- , di- , and trimethylated arsenicals. To investigate the evolution of molecular mechanisms that mediate arsenic biotransformation,...

  14. “MGMT for pt mgmt”: Is Methylguanine-DNA Methyltransferase Testing Ready for Patient Management?

    OpenAIRE

    Iafrate, A. John; Louis, David N.

    2008-01-01

    This Commentary reports on a robust quantitative assay for the interpretation of O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation assays that should facilitate the comparison and implementation of such assays across laboratories.

  15. Molecular Basis for the Regulation of the H3K4 Methyltransferase Activity of PRDM9

    Directory of Open Access Journals (Sweden)

    Hong Wu

    2013-10-01

    Full Text Available PRDM9, a histone lysine methyltransferase, is a key determinant of the localization of meiotic recombination hot spots in humans and mice and the only vertebrate protein known to be involved in hybrid sterility. Here, we report the crystal structure of the PRDM9 methyltransferase domain in complex with a histone H3 peptide dimethylated on lysine 4 (H3K4me2 and S-adenosylhomocysteine (AdoHcy, which provides insights into the methyltransferase activity of PRDM proteins. We show that the genuine substrate of PRDM9 is histone H3 lysine 4 (H3K4 and that the enzyme possesses mono-, di-, and trimethylation activities. We also determined the crystal structure of PRDM9 in its autoinhibited state, which revealed a rearrangement of the substrate and cofactor binding sites by a concerted action of the pre-SET and post-SET domains, providing important insights into the regulatory mechanisms of histone lysine methyltransferase activity.

  16. Structure–function analysis of vaccinia virus mRNA cap (guanine-N7) methyltransferase

    OpenAIRE

    Zheng, Sushuang; Shuman, Stewart

    2008-01-01

    The guanine-N7 methyltransferase domain of vaccinia virus mRNA capping enzyme is a heterodimer composed of a catalytic subunit and a stimulatory subunit. Structure–function analysis of the catalytic subunit by alanine scanning and conservative substitutions (49 mutations at 25 amino acids) identified 12 functional groups essential for methyltransferase activity in vivo, most of which were essential for cap methylation in vitro. Defects in cap binding were demonstrated for a subset of lethal m...

  17. The RNA–Methyltransferase Misu (NSun2) Poises Epidermal Stem Cells to Differentiate

    OpenAIRE

    Sandra Blanco; Agata Kurowski; Jennifer Nichols; Watt, Fiona M.; Salvador Aznar Benitah; Michaela Frye

    2011-01-01

    Homeostasis of most adult tissues is maintained by balancing stem cell self-renewal and differentiation, but whether post-transcriptional mechanisms can regulate this process is unknown. Here, we identify that an RNA methyltransferase (Misu/Nsun2) is required to balance stem cell self-renewal and differentiation in skin. In the epidermis, this methyltransferase is found in a defined sub-population of hair follicle stem cells poised to undergo lineage commitment, and its depletion results in e...

  18. Ribosomal protein methyltransferases in the yeast Saccharomyces cerevisiae: Roles in ribosome biogenesis and translation.

    Science.gov (United States)

    Al-Hadid, Qais; White, Jonelle; Clarke, Steven

    2016-02-12

    A significant percentage of the methyltransferasome in Saccharomyces cerevisiae and higher eukaryotes is devoted to methylation of the translational machinery. Methylation of the RNA components of the translational machinery has been studied extensively and is important for structure stability, ribosome biogenesis, and translational fidelity. However, the functional effects of ribosomal protein methylation by their cognate methyltransferases are still largely unknown. Previous work has shown that the ribosomal protein Rpl3 methyltransferase, histidine protein methyltransferase 1 (Hpm1), is important for ribosome biogenesis and translation elongation fidelity. In this study, yeast strains deficient in each of the ten ribosomal protein methyltransferases in S. cerevisiae were examined for potential defects in ribosome biogenesis and translation. Like Hpm1-deficient cells, loss of four of the nine other ribosomal protein methyltransferases resulted in defects in ribosomal subunit synthesis. All of the mutant strains exhibited resistance to the ribosome inhibitors anisomycin and/or cycloheximide in plate assays, but not in liquid culture. Translational fidelity assays measuring stop codon readthrough, amino acid misincorporation, and programmed -1 ribosomal frameshifting, revealed that eight of the ten enzymes are important for translation elongation fidelity and the remaining two are necessary for translation termination efficiency. Altogether, these results demonstrate that ribosomal protein methyltransferases in S. cerevisiae play important roles in ribosome biogenesis and translation.

  19. EFFECT OF SOIL SULFUR FERTILIZER AND SOME FOLIAR FERTILIZERS ON GROWTH AND YIELD OF BROCCOLI IN SALINE SOIL

    Directory of Open Access Journals (Sweden)

    Ali Husain JASIM

    2015-12-01

    Full Text Available Factorial experiment was conducted in the open fields of Agricultural College, Al-Qasim Green University during the agricultural seasons of 2013/2014 and 2014/2015 to study the effect of adding two levels of agricultural sulfur (control and add 100 kg.ha-1 and four levels of nutrient spray (without spray, high-potash fertilizer, high-phosphorus fertilizer and humic acid on growth and yield of broccoli under drip irrigation and polyethylene soil mulching in saline soil (9.6 dS.m-1. Randomized complete block design with three replicates was used. The results showed that agricultural sulfur led to increase number of leaves, leaf area, leaves chlorophyll content, diameter and weight of flower head compared to control. Spraying foliar fertilizer and its interaction with sulfur fertilizer also led to increase all of parameters above (except leaves chlorophyll content significantly compared to control treatment.

  20. Cultivation Technique for Broccoli in Plateau Conditions%西兰花高原栽培技术

    Institute of Scientific and Technical Information of China (English)

    孟平红

    2000-01-01

    @@ 西兰花(broccoli)又名青花菜、绿花菜等,因其色泽碧绿、脆嫩爽口、营养丰富而深受消费者和生产者青睐.但西兰花在我国栽培历史较短,贵州更是栽培较少,远远不能满足市场需求.笔者根据贵州高原的气候特点,经过对西兰花的品种选择、播种期、育苗方法等进行了试验研究,初步摸索出一套适合海拔1 100 m左右的西兰花高原栽培技术.

  1. Influence of cooking conditions on organoleptic and health-related properties of artichokes, green beans, broccoli and carrots.

    Science.gov (United States)

    Guillén, Sofía; Mir-Bel, Jorge; Oria, Rosa; Salvador, María L

    2017-02-15

    Colour, pigments, total phenolic content and antioxidant activity were investigated in artichokes, green beans, broccoli and carrots cooked under different conditions. Domestic induction hobs with temperature control were used to evaluate the effect of boiling, sous-vide cooking and water immersion cooking at temperatures below 100°C on the properties of each vegetable. Sous-vide cooking preserved chlorophyll, carotenoids, phenolic content and antioxidant activity to a greater extent than boiling for all of the vegetables tested and retained colour better, as determined by a(∗). A reduction of only 10-15°C in the cooking temperature was enough to improve the properties of the samples cooked by water immersion, except for green beans. Artichokes and carrots suffered pronounced losses of antioxidant activity during boiling (17.0 and 9.2% retention, respectively), but the stability of this parameter significantly increased with sous-vide cooking (84.9 and 55.3% retention, respectively).

  2. Yield and Quality Components of Broccoli Cultivars (Brassica oleracea L. convar. botrytis (L. Alef. var. italica Plenck

    Directory of Open Access Journals (Sweden)

    Nina Toth

    1998-12-01

    According to total yield in the three investigation years it was not possible to point out any cultivar. The highest yield and average weight of top inflorescences was achieved with cultivars Fiesta, Bolivia, Platini and Viking (6.3, 6.2, 6.2 and 6.0 t×ha -1 , resp. 169, 168, 168 and 162 g. Evaluation of the compactness of these inflorescences suggest an exceptional strength. Cultivars Citation and Cruiser excel as regards the production and yield of side inflorescences (2.2 and 2.4 t×ha -1 . For the broccoli production in north-west Croatia during the summer-autumn period recommended cultivars for fresh consumption are Bolivia, Fiesta, Platini and Viking and for processing industries Citation and Cruser.

  3. Effects of Organic and Waste-Derived Fertilizers on Yield, Nitrogen and Glucosinolate Contents, and Sensory Quality of Broccoli (Brassica oleracea L. var. italica).

    Science.gov (United States)

    Øvsthus, Ingunn; Breland, Tor Arvid; Hagen, Sidsel Fiskaa; Brandt, Kirsten; Wold, Anne-Berit; Bengtsson, Gunnar B; Seljåsen, Randi

    2015-12-23

    Organic vegetable production attempts to pursue multiple goals concerning influence on environment, production resources, and human health. In areas with limited availability of animal manure, there is a need for considering various off-farm nutrient resources for such production. Different organic and waste-derived fertilizer materials were used for broccoli production at two latitudes (58° and 67°) in Norway during two years. The fertilizer materials were applied at two rates of total N (80 and 170 kg ha(-1)) and compared with mineral fertilizer (170 kg ha(-1)) and no fertilizer. Broccoli yield was strongly influenced by fertilizer materials (algae meal fertilizer). Yield, but not glucosinolate content, was linearly correlated with estimated potentially plant-available N. However, extruded shrimp shell and mineral NPK fertilizer gave higher glucosinolate contents than sheep manure and no fertilizer. Sensory attributes were less affected by fertilizer material and plant-available N.

  4. Effects of Organic and Waste-Derived Fertilizers on Yield, Nitrogen and Glucosinolate Contents, and Sensory Quality of Broccoli (Brassica oleracea L. var. italica).

    Science.gov (United States)

    Øvsthus, Ingunn; Breland, Tor Arvid; Hagen, Sidsel Fiskaa; Brandt, Kirsten; Wold, Anne-Berit; Bengtsson, Gunnar B; Seljåsen, Randi

    2015-12-23

    Organic vegetable production attempts to pursue multiple goals concerning influence on environment, production resources, and human health. In areas with limited availability of animal manure, there is a need for considering various off-farm nutrient resources for such production. Different organic and waste-derived fertilizer materials were used for broccoli production at two latitudes (58° and 67°) in Norway during two years. The fertilizer materials were applied at two rates of total N (80 and 170 kg ha(-1)) and compared with mineral fertilizer (170 kg ha(-1)) and no fertilizer. Broccoli yield was strongly influenced by fertilizer materials (algae meal fertilizer). Yield, but not glucosinolate content, was linearly correlated with estimated potentially plant-available N. However, extruded shrimp shell and mineral NPK fertilizer gave higher glucosinolate contents than sheep manure and no fertilizer. Sensory attributes were less affected by fertilizer material and plant-available N. PMID:26553169

  5. Characterization of the phospholipid methyltransferase in RBC ghost preparations

    International Nuclear Information System (INIS)

    The activity of the phospholipid methyltransferase from human RBC ghosts was studied using radio-HPLC techniques to analyze the products. Both monomethyl phosphatidyl ethanolamine (MMPE) and dimethyl phosphatidyl ethanolamine (DMPE) were used as substrated. The reaction rate was linear for 45 min. Apparent K/sub M/s of 24-28 uM and 19-21 uM were measured for these two substrates, respectively. The reaction rate was not linear with protein. It appeared to increase logarithmic. An apparent K/sub M/ for S-adenosylmethionine was 36-45 uM. These K/sub M/ values are similar to those reported by others for liver. As the concentration of MMPE was increased, the ratio of DMPE/PC also increased due largely to a greater increase in DMPE formation. Optimal reaction rates for the formation of DMPE were 0.9-1.3 pmol/mg/min, and an optimal rate of about 1.7-2.4 pmol/min/mg was measured for the conversion of DMPE to phosphatidyl choline (PC). Freezing the ghost preparation did not affect the activity of the enzyme. When no exogenous phospholipid was added to the incubation, the sum of the formation rates of all three methylated products was about 26 pmol/mg/hr. The relative amount of each product was 46% MMPE, 32% DMPE and 22% PC. When either MMPE or DMPE was added as substrate, the formation of MMPE was reduced to less than 1%

  6. Methyltransferase and demethylase profiling studies during brown adipocyte differentiation.

    Science.gov (United States)

    Son, Min Jeong; Kim, Won Kon; Oh, Kyoung-Jin; Park, Anna; Lee, Da Som; Han, Baek Soo; Lee, Sang Chul; Bae, Kwang-Hee

    2016-07-01

    Although brown adipose tissue is important with regard to energy balance, the molecular mechanism of brown adipocyte differentiation has not been extensively studied. Specifically, regulation factors at the level of protein modification are largely unknown. In this study, we examine the changes in the expression level of enzymes which are involved in protein lysine methylation during brown adipocyte differentiation. Several enzymes, in this case SUV420H2, PRDM9, MLL3 and JHDM1D, were found to be up-regulated. On the other hand, Set7/9 was significantly down-regulated. In the case of SUV420H2, the expression level increased sharply during brown adipocyte differentiation, whereas the expression of SUV420H2 was marginally enhanced during the white adipocyte differentiation. The knock-down of SUV420H2 caused the suppression of brown adipocyte differentiation, as compared to a scrambled control. These results suggest that SUV420H2, a methyltransferase, is involved in brown adipocyte differentiation, and that the methylation of protein lysine is important in brown adipocyte differentiation. [BMB Reports 2016; 49(7): 388-393].

  7. Identification and functional characterization of lysine methyltransferases of Entamoeba histolytica.

    Science.gov (United States)

    Borbolla-Vázquez, Jessica; Orozco, Esther; Medina-Gómez, Christian; Martínez-Higuera, Aarón; Javier-Reyna, Rosario; Chávez, Bibiana; Betanzos, Abigail; Rodríguez, Mario A

    2016-07-01

    Lysine methylation of histones, a posttranslational modification catalyzed by lysine methyltransferases (HKMTs), plays an important role in the epigenetic regulation of transcription. Lysine methylation of non-histone proteins also impacts the biological function of proteins. Previously it has been shown that lysine methylation of histones of Entamoeba histolytica, the protozoan parasite that infects 50 million people worldwide each year and causing up to 100,000 deaths annually, is implicated in the epigenetic machinery of this microorganism. However, the identification and characterization of HKMTs in this parasite had not yet been determined. In this work we identified four HKMTs in E. histolytica (EhHKMT1 to EhHKMT4) that are expressed by trophozoites. Enzymatic assays indicated that all of them are able to transfer methyl groups to commercial histones. EhHKMT1, EhHKMT2 and EhHKMT4 were detected in nucleus and cytoplasm of trophozoites. In addition EhHKMT2 and EhHKMT4 were located in vesicles containing ingested cells during phagocytosis, and they co-immunoprecipitated with EhADH, a protein involved in the phagocytosis of this parasite. Results suggest that E. histolytica uses its HKMTs to regulate transcription by epigenetic mechanisms, and at least two of them could also be implicated in methylation of proteins that participate in phagocytosis. PMID:27062489

  8. Theoretical insights into catalytic mechanism of protein arginine methyltransferase 1.

    Directory of Open Access Journals (Sweden)

    Ruihan Zhang

    Full Text Available Protein arginine methyltransferase 1 (PRMT1, the major arginine asymmetric dimethylation enzyme in mammals, is emerging as a potential drug target for cancer and cardiovascular disease. Understanding the catalytic mechanism of PRMT1 will facilitate inhibitor design. However, detailed mechanisms of the methyl transfer process and substrate deprotonation of PRMT1 remain unclear. In this study, we present a theoretical study on PRMT1 catalyzed arginine dimethylation by employing molecular dynamics (MD simulation and quantum mechanics/molecular mechanics (QM/MM calculation. Ternary complex models, composed of PRMT1, peptide substrate, and S-adenosyl-methionine (AdoMet as cofactor, were constructed and verified by 30-ns MD simulation. The snapshots selected from the MD trajectory were applied for the QM/MM calculation. The typical SN2-favored transition states of the first and second methyl transfers were identified from the potential energy profile. Deprotonation of substrate arginine occurs immediately after methyl transfer, and the carboxylate group of E144 acts as proton acceptor. Furthermore, natural bond orbital analysis and electrostatic potential calculation showed that E144 facilitates the charge redistribution during the reaction and reduces the energy barrier. In this study, we propose the detailed mechanism of PRMT1-catalyzed asymmetric dimethylation, which increases insight on the small-molecule effectors design, and enables further investigations into the physiological function of this family.

  9. The Role of Protein Arginine Methyltransferases in Inflammatory Responses

    Directory of Open Access Journals (Sweden)

    Ji Hye Kim

    2016-01-01

    Full Text Available Protein arginine methyltransferases (PRMTs mediate the methylation of a number of protein substrates of arginine residues and serve critical functions in many cellular responses, including cancer development, progression, and aggressiveness, T-lymphocyte activation, and hepatic gluconeogenesis. There are nine members of the PRMT family, which are divided into 4 types (types I–IV. Although most PRMTs do not require posttranslational modification (PTM to be activated, fine-tuning modifications, such as interactions between cofactor proteins, subcellular compartmentalization, and regulation of RNA, via micro-RNAs, seem to be required. Inflammation is an essential defense reaction of the body to eliminate harmful stimuli, including damaged cells, irritants, or pathogens. However, chronic inflammation can eventually cause several types of diseases, including some cancers, atherosclerosis, rheumatoid arthritis, and periodontitis. Therefore, inflammation responses should be well modulated. In this review, we briefly discuss the role of PRMTs in the control of inflammation. More specifically, we review the roles of four PRMTs (CARM1, PRMT1, PRMT5, and PRMT6 in modulating inflammation responses, particularly in terms of modulating the transcriptional factors or cofactors related to inflammation. Based on the regulatory roles known so far, we propose that PRMTs should be considered one of the target molecule groups that modulate inflammatory responses.

  10. DNA methyltransferase inhibitor CDA-II inhibits myogenic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zirong [State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060 (China); Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610 (United States); Jin, Guorong [State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060 (China); Lin, Shuibin [Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610 (United States); Lin, Xiumei [Department of Hematology, Guangzhou First Municipal People' s Hospital, Guangzhou 510180 (China); Gu, Yumei [Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610 (United States); Zhu, Yujuan; Hu, Chengbin; Zhang, Qingjiong [State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060 (China); Wu, Lizi [Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610 (United States); Shen, Huangxuan, E-mail: shenhx@mail.sysu.edu.cn [State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060 (China)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer CDA-II inhibits myogenic differentiation in a dose-dependent manner. Black-Right-Pointing-Pointer CDA-II repressed expression of muscle transcription factors and structural proteins. Black-Right-Pointing-Pointer CDA-II inhibited proliferation and migration of C2C12 myoblasts. -- Abstract: CDA-II (cell differentiation agent II), isolated from healthy human urine, is a DNA methyltransferase inhibitor. Previous studies indicated that CDA-II played important roles in the regulation of cell growth and certain differentiation processes. However, it has not been determined whether CDA-II affects skeletal myogenesis. In this study, we investigated effects of CDA-II treatment on skeletal muscle progenitor cell differentiation, migration and proliferation. We found that CDA-II blocked differentiation of murine myoblasts C2C12 in a dose-dependent manner. CDA-II repressed expression of muscle transcription factors, such as Myogenin and Mef2c, and structural proteins, such as myosin heavy chain (Myh3), light chain (Mylpf) and MCK. Moreover, CDA-II inhibited C1C12 cell migration and proliferation. Thus, our data provide the first evidence that CDA-II inhibits growth and differentiation of muscle progenitor cells, suggesting that the use of CDA-II might affect skeletal muscle functions.

  11. Euchromatin histone methyltransferase 1 regulates cortical neuronal network development

    Science.gov (United States)

    Bart Martens, Marijn; Frega, Monica; Classen, Jessica; Epping, Lisa; Bijvank, Elske; Benevento, Marco; van Bokhoven, Hans; Tiesinga, Paul; Schubert, Dirk; Nadif Kasri, Nael

    2016-01-01

    Heterozygous mutations or deletions in the human Euchromatin histone methyltransferase 1 (EHMT1) gene cause Kleefstra syndrome, a neurodevelopmental disorder that is characterized by autistic-like features and severe intellectual disability (ID). Neurodevelopmental disorders including ID and autism may be related to deficits in activity-dependent wiring of brain circuits during development. Although Kleefstra syndrome has been associated with dendritic and synaptic defects in mice and Drosophila, little is known about the role of EHMT1 in the development of cortical neuronal networks. Here we used micro-electrode arrays and whole-cell patch-clamp recordings to investigate the impact of EHMT1 deficiency at the network and single cell level. We show that EHMT1 deficiency impaired neural network activity during the transition from uncorrelated background action potential firing to synchronized network bursting. Spontaneous bursting and excitatory synaptic currents were transiently reduced, whereas miniature excitatory postsynaptic currents were not affected. Finally, we show that loss of function of EHMT1 ultimately resulted in less regular network bursting patterns later in development. These data suggest that the developmental impairments observed in EHMT1-deficient networks may result in a temporal misalignment between activity-dependent developmental processes thereby contributing to the pathophysiology of Kleefstra syndrome. PMID:27767173

  12. Sensitivity of produce respiration models used in the MAP-DESIGN software on the shelf life simulation of broccoli in the modified atmosphere package

    OpenAIRE

    Weerasak Lertsiriyothin

    2009-01-01

    Optimization for the designing of modified atmosphere packaging (MAP) for broccoli was made by the MAP-DESIGN software (author’s own code). The software is capable of dealing with all parameters required for the designing of MAP for fresh produce, namely packaging materials, package dimensions, storage conditions, and plant respiratory models. Computational algorithms were carefully designed based upon widely-used theories of living plant respiration, gas permeability through packaging film...

  13. A Picrinine N-Methyltransferase Belongs to a New Family of γ-Tocopherol-Like Methyltransferases Found in Medicinal Plants That Make Biologically Active Monoterpenoid Indole Alkaloids.

    Science.gov (United States)

    Levac, Dylan; Cázares, Paulo; Yu, Fang; De Luca, Vincenzo

    2016-04-01

    Members of the Apocynaceae plant family produce a large number of monoterpenoid indole alkaloids (MIAs) with different substitution patterns that are responsible for their various biological activities. A novel N-methyltransferase involved in the vindoline pathway in Catharanthus roseus showing distinct similarity to γ-tocopherol C-methyltransferases was used in a bioinformatic screen of transcriptomes from Vinca minor, Rauvolfia serpentina, and C. roseus to identify 10 γ-tocopherol-like N-methyltransferases from a large annotated transcriptome database of different MIA-producing plant species (www.phytometasyn.ca). The biochemical function of two members of this group cloned from V. minor (VmPiNMT) and R. serpentina (RsPiNMT) have been characterized by screening their biochemical activities against potential MIA substrates harvested from the leaf surfaces of MIA-accumulating plants. The approach was validated by identifying the MIA picrinine from leaf surfaces of Amsonia hubrichtii as a substrate of VmPiNMT and RsPiNMT. Recombinant proteins were shown to have high substrate specificity and affinity for picrinine, converting it to N-methylpicrinine (ervincine). Developmental studies with V. minor and R. serpentina showed that RsPiNMT and VmPiNMT gene expression and biochemical activities were highest in younger leaf tissues. The assembly of at least 150 known N-methylated MIAs within members of the Apocynaceae family may have occurred as a result of the evolution of the γ-tocopherol-like N-methyltransferase family from γ-tocopherol methyltransferases. PMID:26848097

  14. Change of related isoenzyme during vernalization in broccoli%青花菜绿体春化过程中同工酶变化研究

    Institute of Scientific and Technical Information of China (English)

    刘生财; 蒋欣梅; 于锡宏

    2009-01-01

    试验以青花菜早熟品种"清风103"为试材,对青花菜绿体春化过程中植株中春化相关的酶进行研究.结果表明,青花菜植株在低温春化处理过程中,NR、EST和α-淀粉酶及ASP的活性都呈增加趋势.对EST、α-淀粉酶和POD同工酶分析发现,经过低温春化处理后既有新谱带的产生,也有谱带的消失,产生或消失的谱带可能与青花菜春化有关.%The experiment took early maturing variety broccoli Qingfeng 103 as experimental material. Related isoenzyme during vernalization in broccoli was studied in this research. The results showed that NR, EST, α-amylase and ASP activity were significantly increased during vernalization. After the analyse of EST, α-amylase and POD isoenzyme, some new bands appeared but some disappeared. Perhaps these bands were associated with vernalization in broccoli.

  15. Assessing Competence of Broccoli Consumption on Inflammatory and Antioxidant Pathways in Restraint-Induced Models: Estimation in Rat Hippocampus and Prefrontal Cortex

    Directory of Open Access Journals (Sweden)

    Leila Khalaj

    2013-01-01

    Full Text Available A growing body of evidence advocated the protective and therapeutic potential of natural compounds and phytochemicals used in diets against pathological conditions. Herein, the outcome of dietary whole broccoli consumption prior to restraint stress has been investigated in the hippocampus and prefrontal cortex of male rats, two important regions involved in the processing of responses to stressful events. Interestingly, a region-specific effect was detected regarding some of antioxidant defense system factors: nuclear factor erythroid-derived 2-related factor 2 (Nrf-2 antioxidant pathway, mitochondrial prosurvival proteins involved in mitochondrial biogenesis, and apoptotic cell death proteins. Dietary broccoli supplementation modulated the restraint-induced changes towards a consistent overall protection in the hippocampus. In the prefrontal cortex, however, despite activation of most of the protective factors, presumably as an attempt to save the system against the stress insult, some detrimental outcomes such as induced malate dehydrogenase (MDA level and cleaved form of caspase-3 were detectable. Such diversity may be attributed in one hand to the different basic levels and/or availability of defensive mechanisms within the two studied cerebral regions, and on the other hand to the probable dose-dependent and hormetic effects of whole broccoli. More experiments are essential to demonstrate these assumptions.

  16. 不同贮藏条件对青花菜品质的影响%Effects of Storage Conditions on the Quality of Broccolis

    Institute of Scientific and Technical Information of China (English)

    杨佩; 侯军; 石英

    2011-01-01

    Effects of such conditions as temperature, relative humidity and light on storage quality of broccoli were studied. The results showed that, in the three combinations of temperature and relative humidity, the weight and L-ascorbic acid of broccoli and hardness of stem could be maintained by the condition of 15 ℃ and 75% relative humidity. Under the lighting conditions (at the temperature of 20±2 ℃ ), the soluble solids contents (SSC) of buds and the weight of broccoli were decreased slowly. But L-ascorbic acid and hardness decreased more quickly under the lighting conditions.%研究了不同温湿度及光照条件对青花菜采后贮藏品质的影响.结果表明,在三种温湿度组合处理中,以15℃温度、75%相对湿度的条件可有效减少青花菜的失重,保持花茎的硬度和还原型抗坏血酸含量,延长贮藏期;室温(20±2℃)光照条件有利于减少青花菜的失重和可溶性固形物含量的下降速率,但不利于硬度及还原型抗坏血酸的保持.

  17. 青花菜气相色谱指纹图谱研究%Study on Gas Chromatographic Fingerprint of Broccoli

    Institute of Scientific and Technical Information of China (English)

    王冬群; 胡寅侠

    2014-01-01

    With FPD as detector , the fingerprint features of broccoli were studied by gas chromatographic method using DB-1701 and HP-5 capillary column respectively .The results showed that the broccoli had 2 peaks in both 2 columns, and their retention times were all very stable .The peak areas among different sam-ples were obviously different , and there was no obvious proportional relation between 2 peaks of the same sam-ple.The GC fingerprint could be used as one of the bases of broccoli quality assessment .%采用气相色谱法,分别利用DB-1701和HP-5毛细管柱,以FPD为检测器,研究了青花菜的指纹图谱特点。结果显示,青花菜在2种柱子中均表现为2个峰,且其保留时间均非常稳定,但不同样品间峰面积差异较大;同一样品中2个峰的峰面积没有明显的比例关系。气相色谱指纹图谱可作为青花菜质量控制的依据之一。

  18. 西兰花甜玉米复合蔬菜纸的研制%Study on Compound Vegetable Paper of Broccoli and Sweet Corn

    Institute of Scientific and Technical Information of China (English)

    汤慧民; 尚海英

    2015-01-01

    With broccoli and sweet corn as raw material, sodium alginate, carrageenan,starch as adhesive, based on single factor experiment, the production process conditions of vegetable paper of broccoli and sweet corn was optimized through orthogonal experiment.The result showed that the acquired vegetable paper was best in color, flavor, taste and texture adopting the condition of the quality ratio of broccoli slurry and sweet corn pulp was 2:1,sodium alginate 0.5%, carrageenan 0.6%, starch 8%, film thickness 1.5 mm, drying 4 h at 65℃.%以西兰花和甜玉米为原料,海藻酸钠、卡拉胶、淀粉为胶黏剂,在单因素的基础上,采用正交试验法确定西兰花甜玉米复合蔬菜纸的最佳生产工艺条件:西兰花浆和甜玉米浆的质量比例是2:1、0.5%的海藻酸钠、0.6%卡拉胶、8%淀粉,涂膜厚度1.5 mm,65℃干燥4 h.所制得的蔬菜纸色、香、味、形俱佳.

  19. Effects of the 3D-clinorotation on endogenous substances of broccoli sprout (Brassica oleracea var. italica) and its food safety

    Science.gov (United States)

    Hiraishi, K.; Tomita-Yokotani, K.; Wakabayashi, K.; Hashimoto, H.; Miyagawa, T.; Yamashita, M.

    Habitation in outer space is one of our challenges in this century We are studying on space agriculture to provide foods for space living people However careful assessment should be made on the effects of exotic environment on the endogenous production of biologically active substances and food safety of plants cultivated in space Broccoli sprout Brassica oleracea var italica is known to produce sulforaphane 4-methylsulfinybutyl isothiocyanate which is effective to function as an antioxidant and enhance immunity Because of such substance it is recognized to be good food materials Broccoli sprouts were then cultivated for 3 days under the 3D-clinorotation The amount of sulforaphane produced by this treatment showed no significant difference compared to the ground control Secondly we examined population of microorganisms adhered on the surface of sprout cultivated under the 3D-clinorotation Number of the microorganisms colony formed was statistically higher than the control Mold species was identified to penicillium sp based on the microscopic observation Poor construction of plant cell wall elements cellulose lignin etc is well known effects of microgravity Defense function of the broccoli plant cells might be weakened against microorganism We also speculate other possible causes for the high rate of contamination such as photosynthetic activity of the plant or microclimate air flow heat transport and humidity around the seedling affected by pseudo-microgravity or the 3D-clinorotation Those factors may relate to the difference in proliferation

  20. Research of Natamycin on the Freshness Retaining of Broccolis%纳他霉素对西兰花的保鲜效果

    Institute of Scientific and Technical Information of China (English)

    林本芳; 鲁晓翔; 李江阔; 陈绍慧

    2012-01-01

    研究纳他霉素处理对西兰花冷藏保鲜品质的影响。纳他霉素处理浓度分别为800mg/L、1200mg/L,在(0±1)℃冷藏期间每10d取样测定西兰花理化指标及营养成分。结果表明:与冷藏对照相比,纳他霉素处理对于延缓西兰花可溶性固形物含量、Vc含量及叶绿素含量的下降均有明显效果,并可抑制西兰花贮藏期间的呼吸强度;纳他霉素处理可提高西兰花SOD的活性和降低PPO活性,延缓了细胞膜相对透性的升高。说明冷藏结合纳他霉素处理对西兰花的成熟衰老有抑制作用,其中经1200mg/L处理的西兰花保鲜效果较好。%This paper investigated the effect of different concentrations (800mg/L,1200mg/L) of natamycin on the quality of Broccolis stored at -1 ℃ - 1 ℃. The physicochemical indexes and nutrition components of Broccolis were detected every 10days. The results showed that the soluble solids, vitamine C and chlorophyll content of broccolis by natamycin treatment decreased less than that just by cold storage. Natamycin could inhibit the increase of respiratory intensity, increased superoxide dismutase (SOD) activities and slowed down polyphenol oxidase(PPO) activity and de- creased cell membrane permeability. These results showed that cold storage combined with natamycin treatment could delay ripening of Broccoli, wherein the storage effect of Broccolis with 1200 mg/L natamycin treatment was better than that with 800mg/L.

  1. Mechanistic studies on transcriptional coactivator protein arginine methyltransferase 1.

    Science.gov (United States)

    Rust, Heather L; Zurita-Lopez, Cecilia I; Clarke, Steven; Thompson, Paul R

    2011-04-26

    Protein arginine methyltransferases (PRMTs) catalyze the transfer of methyl groups from S-adenosylmethionine (SAM) to the guanidinium group of arginine residues in a number of important cell signaling proteins. PRMT1 is the founding member of this family, and its activity appears to be dysregulated in heart disease and cancer. To begin to characterize the catalytic mechanism of this isozyme, we assessed the effects of mutating a number of highly conserved active site residues (i.e., Y39, R54, E100, E144, E153, M155, and H293), which are believed to play key roles in SAM recognition, substrate binding, and catalysis. The results of these studies, as well as pH-rate studies, and the determination of solvent isotope effects (SIEs) indicate that M155 plays a critical role in both SAM binding and the processivity of the reaction but is not responsible for the regiospecific formation of asymmetrically dimethylated arginine (ADMA). Additionally, mutagenesis studies on H293, combined with pH studies and the lack of a normal SIE, do not support a role for this residue as a general base. Furthermore, the lack of a normal SIE with either the wild type or catalytically impaired mutants suggests that general acid/base catalysis is not important for promoting methyl transfer. This result, combined with the fact that the E144A/E153A double mutant retains considerably more activity then the single mutants alone, suggests that the PRMT1-catalyzed reaction is primarily driven by bringing the substrate guanidinium into the proximity of the S-methyl group of SAM and that the prior deprotonation of the substrate guanidinium is not required for methyl transfer.

  2. Structural Basis of Substrate Recognition in Thiopurine S-Methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yi; Feng, Qiping; Wilk, Dennis; Adjei, Araba A.; Salavaggione, Oreste E.; Weinshilboum, Richard M.; Yee, Vivien C. (Case Western); (MCCM)

    2008-09-23

    Thiopurine S-methyltransferase (TPMT) modulates the cytotoxic effects of thiopurine prodrugs such as 6-mercaptopurine by methylating them in a reaction using S-adenosyl-l-methionine as the donor. Patients with TPMT variant allozymes exhibit diminished levels of protein and/or enzyme activity and are at risk for thiopurine drug-induced toxicity. We have determined two crystal structures of murine TPMT, as a binary complex with the product S-adenosyl-l-homocysteine and as a ternary complex with S-adenosyl-l-homocysteine and the substrate 6-mercaptopurine, to 1.8 and 2.0 {angstrom} resolution, respectively. Comparison of the structures reveals that an active site loop becomes ordered upon 6-mercaptopurine binding. The positions of the two ligands are consistent with the expected S{sub N}2 reaction mechanism. Arg147 and Arg221, the only polar amino acids near 6-mercaptopurine, are highlighted as possible participants in substrate deprotonation. To probe whether these residues are important for catalysis, point mutants were prepared in the human enzyme. Substitution of Arg152 (Arg147 in murine TPMT) with glutamic acid decreases V{sub max} and increases K{sub m} for 6-mercaptopurine but not K{sub m} for S-adenosyl-l-methionine. Substitution at this position with alanine or histidine and similar substitutions of Arg226 (Arg221 in murine TPMT) result in no effect on enzyme activity. The double mutant Arg152Ala/Arg226Ala exhibits a decreased V{sub max} and increased K{sub m} for 6-mercaptopurine. These observations suggest that either Arg152 or Arg226 may participate in some fashion in the TPMT reaction, with one residue compensating when the other is altered, and that Arg152 may interact with substrate more directly than Arg226, consistent with observations in the murine TPMT crystal structure.

  3. Negative in vitro selection identifies the rRNA recognition motif for ErmE methyltransferase

    DEFF Research Database (Denmark)

    Nielsen, A K; Douthwaite, S; Vester, B

    1999-01-01

    Erm methyltransferases modify bacterial 23S ribosomal RNA at adenosine 2058 (A2058, Escherichia coli numbering) conferring resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics. The motif that is recognized by Erm methyltransferases is contained within helix 73 of 23S r......RNA and the adjacent single-stranded region around A2058. An RNA transcript of 72 nt that displays this motif functions as an efficient substrate for the ErmE methyltransferase. Pools of degenerate RNAs were formed by doping 34-nt positions that extend over and beyond the putative Erm recognition motif within the 72......-mer RNA. The RNAs were passed through a series of rounds of methylation with ErmE. After each round, RNAs were selected that had partially or completely lost their ability to be methylated. After several rounds of methylation/selection, 187 subclones were analyzed. Forty-three of the subclones...

  4. Discovery of a Potent Class I Protein Arginine Methyltransferase Fragment Inhibitor.

    Science.gov (United States)

    Ferreira de Freitas, Renato; Eram, Mohammad S; Szewczyk, Magdalena M; Steuber, Holger; Smil, David; Wu, Hong; Li, Fengling; Senisterra, Guillermo; Dong, Aiping; Brown, Peter J; Hitchcock, Marion; Moosmayer, Dieter; Stegmann, Christian M; Egner, Ursula; Arrowsmith, Cheryl; Barsyte-Lovejoy, Dalia; Vedadi, Masoud; Schapira, Matthieu

    2016-02-11

    Protein methyltransferases (PMTs) are a promising target class in oncology and other disease areas. They are composed of SET domain methyltransferases and structurally unrelated Rossman-fold enzymes that include protein arginine methyltransferases (PRMTs). In the absence of a well-defined medicinal chemistry tool-kit focused on PMTs, most current inhibitors were identified by screening large and diverse libraries of leadlike molecules. So far, no successful fragment-based approach was reported against this target class. Here, by deconstructing potent PRMT inhibitors, we find that chemical moieties occupying the substrate arginine-binding site can act as efficient fragment inhibitors. Screening a fragment library against PRMT6 produced numerous hits, including a 300 nM inhibitor (ligand efficiency of 0.56) that decreased global histone 3 arginine 2 methylation in cells, and can serve as a warhead for the development of PRMT chemical probes.

  5. The RNA-methyltransferase Misu (NSun2 poises epidermal stem cells to differentiate.

    Directory of Open Access Journals (Sweden)

    Sandra Blanco

    2011-12-01

    Full Text Available Homeostasis of most adult tissues is maintained by balancing stem cell self-renewal and differentiation, but whether post-transcriptional mechanisms can regulate this process is unknown. Here, we identify that an RNA methyltransferase (Misu/Nsun2 is required to balance stem cell self-renewal and differentiation in skin. In the epidermis, this methyltransferase is found in a defined sub-population of hair follicle stem cells poised to undergo lineage commitment, and its depletion results in enhanced quiescence and aberrant stem cell differentiation. Our results reveal that post-transcriptional RNA methylation can play a previously unappreciated role in controlling stem cell fate.

  6. Properly substituted analogues of BIX-01294 lose inhibition of G9a histone methyltransferase and gain selective anti-DNA methyltransferase 3A activity.

    Directory of Open Access Journals (Sweden)

    Dante Rotili

    Full Text Available Chemical manipulations performed on the histone H3 lysine 9 methyltransferases (G9a/GLP inhibitor BIX-01294 afforded novel desmethoxyquinazolines able to inhibit the DNA methyltransferase DNMT3A at low micromolar levels without any significant inhibition of DNMT1 and G9a. In KG-1 cells such compounds, when tested at sub-toxic doses, induced the luciferase re-expression in a stable construct controlled by a cytomegalovirus (CMV promoter silenced by methylation (CMV-luc assay. Finally, in human lymphoma U-937 and RAJI cells, the N-(1-benzylpiperidin-4-yl-2-(4-phenylpiperazin-1-ylquinazolin-4-amine induced the highest proliferation arrest and cell death induction starting from 10 µM, in agreement with its DNMT3A inhibitory potency.

  7. Influence of cooking conditions on organoleptic and health-related properties of artichokes, green beans, broccoli and carrots.

    Science.gov (United States)

    Guillén, Sofía; Mir-Bel, Jorge; Oria, Rosa; Salvador, María L

    2017-02-15

    Colour, pigments, total phenolic content and antioxidant activity were investigated in artichokes, green beans, broccoli and carrots cooked under different conditions. Domestic induction hobs with temperature control were used to evaluate the effect of boiling, sous-vide cooking and water immersion cooking at temperatures below 100°C on the properties of each vegetable. Sous-vide cooking preserved chlorophyll, carotenoids, phenolic content and antioxidant activity to a greater extent than boiling for all of the vegetables tested and retained colour better, as determined by a(∗). A reduction of only 10-15°C in the cooking temperature was enough to improve the properties of the samples cooked by water immersion, except for green beans. Artichokes and carrots suffered pronounced losses of antioxidant activity during boiling (17.0 and 9.2% retention, respectively), but the stability of this parameter significantly increased with sous-vide cooking (84.9 and 55.3% retention, respectively). PMID:27664628

  8. Broccoli sprout extract prevents diabetic cardiomyopathy via Nrf2 activation in db/db T2DM mice

    Science.gov (United States)

    Xu, Zheng; Wang, Shudong; Ji, Honglei; Zhang, Zhiguo; Chen, Jing; Tan, Yi; Wintergerst, Kupper; Zheng, Yang; Sun, Jian; Cai, Lu

    2016-01-01

    To develop a clinic-relevant protocol for systemic up-regulation of NFE2-related factor 2 (Nrf2) to prevent diabetic cardiomyopathy (DCM), male db/db and age-matched wild-type (WT) mice were given sulforaphane (SFN, an Nrf2 activator) and its natural source, broccoli sprout extract (BSE) by gavage every other day for 3 months, with four groups: vehicle (0.1 ml/10 g), BSE-low dose (estimated SFN availability at 0.5 mg/kg), BSE-high dose (estimated SFN availability at 1.0 mg/kg), and SFN (0.5 mg/kg). Cardiac function and pathological changes (hypertrophy, fibrosis, inflammation and oxidative damage) were assessed by echocardiography and histopathological examination along with Western blot and real-time PCR, respectively. Both BSE and SFN significantly prevented diabetes-induced cardiac dysfunction, hypertrophy and fibrosis. Mechanistically, BSE, like SFN, significantly up-regulated Nrf2 transcriptional activity, evidenced by the increased Nrf2 nuclear accumulation and its downstream gene expression. This resulted in a significant prevention of cardiac oxidative damage and inflammation. For all these preventive effects, BSE at high dose provided a similar effect as did SFN. These results indicated that BSE at high dose prevents DCM in a manner congruent with SFN treatment. Therefore, it suggests that BSE could potentially be used as a natural and safe treatment against DCM via Nrf2 activation. PMID:27457280

  9. Structural and evolutionary bioinformatics of the SPOUT superfamily of methyltransferases

    Directory of Open Access Journals (Sweden)

    Purta Elzbieta

    2007-03-01

    Full Text Available Abstract Background SPOUT methyltransferases (MTases are a large class of S-adenosyl-L-methionine-dependent enzymes that exhibit an unusual alpha/beta fold with a very deep topological knot. In 2001, when no crystal structures were available for any of these proteins, Anantharaman, Koonin, and Aravind identified homology between SpoU and TrmD MTases and defined the SPOUT superfamily. Since then, multiple crystal structures of knotted MTases have been solved and numerous new homologous sequences appeared in the databases. However, no comprehensive comparative analysis of these proteins has been carried out to classify them based on structural and evolutionary criteria and to guide functional predictions. Results We carried out extensive searches of databases of protein structures and sequences to collect all members of previously identified SPOUT MTases, and to identify previously unknown homologs. Based on sequence clustering, characterization of domain architecture, structure predictions and sequence/structure comparisons, we re-defined families within the SPOUT superfamily and predicted putative active sites and biochemical functions for the so far uncharacterized members. We have also delineated the common core of SPOUT MTases and inferred a multiple sequence alignment for the conserved knot region, from which we calculated the phylogenetic tree of the superfamily. We have also studied phylogenetic distribution of different families, and used this information to infer the evolutionary history of the SPOUT superfamily. Conclusion We present the first phylogenetic tree of the SPOUT superfamily since it was defined, together with a new scheme for its classification, and discussion about conservation of sequence and structure in different families, and their functional implications. We identified four protein families as new members of the SPOUT superfamily. Three of these families are functionally uncharacterized (COG1772, COG1901, and COG4080

  10. Transformation of Broccoli with KTI Gene and the Bioassay for Diamondback Moth Resistance%抗虫相关基因KTI对青花菜的转化及其对小菜蛾抗性的分析

    Institute of Scientific and Technical Information of China (English)

    江汉民; 宋文芹; 刘莉莉; 文正华; 姚星伟; 单晓政; 孙德岭

    2013-01-01

    KTI gene was transformed into broccoli (Brassica oleracea L. ssp. italica) genome via Agrobacterium mediated transformation method using broccoli lines '09LR-11' as explants. Thirteen kanamycin resistant broccoli plants were obtained. PCR analysis with primers specific to KTI gene identified 8 KTI positive plants. Southern blotting analysis with KTI gene as probes showed that the KTI gene was integrated into broccoli genome. RT-PCR analysis indicated that the KTI gene was expressed in transgenic broccoli. Both laboratory and field tests proved that the transgenic broccoli plants were resistant to diamondback moth (Plutella xylostella larvae) .%以青花菜(Brassica oleraceaL.ssp.italica)下胚轴为外植体,通过农杆菌介导的遗传转化方法将来源于杨树的Kunitz型丝氨酸胰蛋白酶抑制剂(KTI)基因导入青花菜品系‘09LR-11’中,获得13株卡那霉素抗性植株.以KTI特异引物对转基因植株进行PCR检测,其中8株为KTI阳性植株.Southernblot分析进一步表明,基因KTI已成功整合到青花菜基因组中.RT-PCR检测表明,KTI在转基因青花菜中已成功表达.通过室内叶片离体试验和田间观察,初步证明转KTI青花菜对小菜蛾幼虫具有一定抗性.

  11. A NOVEL S-ADENOSYL-L-METHIONINE: ARSENIC (III) METHYLTRANSFERASE FROM RAT LIVER CYTOSOL

    Science.gov (United States)

    A Novel S-Adenosyl-L-methionine: Arsenic(III) Methyltransferase from Rat Liver CytosolShan Lin, Qing Shi, F. Brent Nix, Miroslav Styblo, Melinda A. Beck, Karen M. Herbin-Davis, Larry L. Hall, Josef B. Simeonsson, and David J. Thomas S-adenosyl-L-methionine (AdoMet): ar...

  12. CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC (III) METHYLTRANSFERASE (CYT19)

    Science.gov (United States)

    CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC(III) METHYLTRANSFERASE (cyt19)Stephen B. Waters1 , Felicia Walton1 , Miroslav Styblo1 , Karen Herbin-Davis2, and David J. Thomas2 1 School of Medicine, University of North Carolina at Chape...

  13. Structural basis for S-adenosylmethionine binding and methyltransferase activity by mitochondrial transcription factor B1.

    Science.gov (United States)

    Guja, Kip E; Venkataraman, Krithika; Yakubovskaya, Elena; Shi, Hui; Mejia, Edison; Hambardjieva, Elena; Karzai, A Wali; Garcia-Diaz, Miguel

    2013-09-01

    Eukaryotic transcription factor B (TFB) proteins are homologous to KsgA/Dim1 ribosomal RNA (rRNA) methyltransferases. The mammalian TFB1, mitochondrial (TFB1M) factor is an essential protein necessary for mitochondrial gene expression. TFB1M mediates an rRNA modification in the small ribosomal subunit and thus plays a role analogous to KsgA/Dim1 proteins. This modification has been linked to mitochondrial dysfunctions leading to maternally inherited deafness, aminoglycoside sensitivity and diabetes. Here, we present the first structural characterization of the mammalian TFB1 factor. We have solved two X-ray crystallographic structures of TFB1M with (2.1 Å) and without (2.0 Å) its cofactor S-adenosyl-L-methionine. These structures reveal that TFB1M shares a conserved methyltransferase core with other KsgA/Dim1 methyltransferases and shed light on the structural basis of S-adenosyl-L-methionine binding and methyltransferase activity. Together with mutagenesis studies, these data suggest a model for substrate binding and provide insight into the mechanism of methyl transfer, clarifying the role of this factor in an essential process for mitochondrial function. PMID:23804760

  14. Association of Catechol-O-Methyltransferase (COMT) Polymorphism and Academic Achievement in a Chinese Cohort

    Science.gov (United States)

    Yeh, Ting-Kuang; Chang, Chun-Yen; Hu, Chung-Yi; Yeh, Ting-Chi; Lin, Ming-Yeh

    2009-01-01

    Catechol-O-methyltransferase (COMT) is a methylation enzyme that catalyzes the degradation pathway and inactivation of dopamine. It is accepted widely as being involved in the modulation of dopaminergic physiology and prefrontal cortex (PFC) function. The COMT Val158Met polymorphism is associated with variation in COMT activity. COMT 158Met allele…

  15. Effect of alternative temozolomide schedules on glioblastoma O 6-methylguanine-DNA methyltransferase activity and survival

    OpenAIRE

    Robinson, C G; Palomo, J M; Rahmathulla, G; McGraw, M; Donze, J; L. Liu; Vogelbaum, M A

    2010-01-01

    Background: O 6-methylguanine-DNA methyltransferase (MGMT) expression in glioblastoma correlates with temozolomide resistance. Dose-intense temozolomide schedules deplete MGMT activity in peripheral blood mononuclear cells; however, no published data exist evaluating the effect of temozolomide schedules on intracranial tumour MGMT activity. Methods: Human glioblastoma cells (GBM43) with an unmethylated MGMT promoter were implanted intracranially in immunodeficient rodents. Three weeks later, ...

  16. rmtA, encoding a putative anginine methyltransferase, regulates secondary metabolism and development in Aspergillus flavus

    Science.gov (United States)

    Aspergillus flavus is found colonizing numerous oil seed crops such as corn, peanuts, sorghum, treenuts and cotton worldwide, contaminating them with aflatoxin and other harmful potent toxins. In the phylogenetically related model fungus Aspergillus nidulans, the methyltransferase, RmtA, has been de...

  17. Catechol-O-methyltransferase gene methylation and substance use in adolescents : the TRAILS study

    NARCIS (Netherlands)

    van der Knaap, L. J.; Schaefer, J. M.; Franken, I. H. A.; Verhulst, F. C.; van Oort, F. V. A.; Riese, H.

    2014-01-01

    Substance use often starts in adolescence and poses a major problem for society and individual health. The dopamine system plays a role in substance use, and catechol-O-methyltransferase (COMT) is an important enzyme that degrades dopamine. The Val(108/158)Met polymorphism modulates COMT activity an

  18. Super-resolution optical DNA Mapping via DNA methyltransferase-directed click chemistry

    DEFF Research Database (Denmark)

    Vranken, Charlotte; Deen, Jochem; Dirix, Lieve;

    2014-01-01

    We demonstrate an approach to optical DNA mapping, which enables near single-molecule characterization of whole bacteriophage genomes. Our approach uses a DNA methyltransferase enzyme to target labelling to specific sites and copper-catalysed azide-alkyne cycloaddition to couple a fluorophore to ...

  19. SABATH Methyltransferases from White Spruce (Picea glauca [Moench] Voss): Gene Cloning, Functional Characterization and Structural Analysis

    Science.gov (United States)

    Known members of the plant SABATH family of methyltransferases have important biological functions by methylating hormones, signaling molecules and other metabolites. While all previously characterized SABATH genes were isolated from angiosperms, in this article, we report on the isolation and funct...

  20. Catechol-O-methyltransferase gene methylation and substance use in adolescents: The TRAILS study

    NARCIS (Netherlands)

    L.J. van der Knaap (Lisette); J.M. Schäfer (Johanna); I.H.A. Franken (Ingmar); F.C. Verhulst (Frank); F.V.A. van Oort (Floor); H. Riese (Harriëtte)

    2014-01-01

    textabstractSubstance use often starts in adolescence and poses a major problem for society and individual health. The dopamine system plays a role in substance use, and catechol-O-methyltransferase (COMT) is an important enzyme that degrades dopamine. The Val108/158Met polymorphism modul

  1. Cations modulate the substrate specificity of bifunctional class I O-methyltransferase from Ammi majus.

    Science.gov (United States)

    Lukacin, Richard; Matern, Ulrich; Specker, Silvia; Vogt, Thomas

    2004-11-19

    Caffeoyl-coenzyme A O-methyltransferase cDNA was cloned from dark-grown Ammi majus L. (Apiaceae) cells treated with a crude fungal elicitor and the open reading frame was expressed in Escherichia coli. The translated polypeptide of 27.1-kDa shared significant identity to other members of this highly conserved class of proteins and was 98.8% identical to the corresponding O-methyltransferase from parsley. For biochemical characterization, the recombinant enzyme could be purified to apparent homogeneity by metal-affinity chromatography, although the recombinant enzyme did not contain any affinity tag. Based on sequence analysis and substrate specificity, the enzyme classifies as a cation-dependent O-methyltransferase with pronounced preference for caffeoyl coenzyme A, when assayed in the presence of Mg2+-ions. Surprisingly, however, the substrate specificity changed dramatically, when Mg2+ was replaced by Mn2+ or Co2+ in the assays. This effect could point to yet unknown functions and substrate specificities in situ and suggests promiscuous roles for the lignin specific cluster of plant O-methyltransferases.

  2. Global developmental delay in guanidionacetate methyltransferase deficiency : differences in formal testing and clinical observation

    NARCIS (Netherlands)

    Verbruggen, Krijn T.; Knijff, Wilma A.; Soorani-Lunsing, Roelineke J.; Sijens, Paul E.; Verhoeven, Nanda M.; Salomons, Gajja S.; Goorhuis-Brouwer, Siena M.; van Spronsen, Francjan J.

    2007-01-01

    Guanidinoacetate N-methyltransferase (GAMT) deficiency is a defect in the biosynthesis of creatine (Cr). So far, reports have not focused on the description of developmental abilities in this disorder. Here, we present the result of formal testing of developmental abilities in a GAMT-deficient patie

  3. DNA repair methyltransferase (Mgmt) knockout mice are sensitive to the lethal effects of chemotherapeutic alkylating agents.

    NARCIS (Netherlands)

    B.J. Glassner (Brian); G. Weeda (Geert); J.M. Allan (James); J.L.M. Broekhof (Jose'); N.H.E. Carls (Nick); I. Donker (Ingrid); B.P. Engelward (Bevin); R.J. Hampson (Richard); R. Hersmus (Remko); M.J. Hickman (Mark); R.B. Roth (Richard); H.B. Warren (Henry); M.M. Wu (Mavis); J.H.J. Hoeijmakers (Jan); L.D. Samson (Leona)

    1999-01-01

    textabstractWe have generated mice deficient in O6-methylguanine DNA methyltransferase activity encoded by the murine Mgmt gene using homologous recombination to delete the region encoding the Mgmt active site cysteine. Tissues from Mgmt null mice displayed very low O6-methylguanine DNA methyltransf

  4. Local chromatin microenvironment determines DNMT activity : from DNA methyltransferase to DNA demethylase or DNA dehydroxymethylase

    NARCIS (Netherlands)

    van der Wijst, Monique G. P.; Venkiteswaran, Muralidhar; Chen, Hui; Xu, Guo-Liang; Plosch, Torsten; Rots, Marianne G.

    2015-01-01

    Insights on active DNA demethylation disproved the original assumption that DNA methylation is a stable epigenetic modification. Interestingly, mammalian DNA methyltransferases 3A and 3B (DNMT-3A and -3B) have also been reported to induce active DNA demethylation, in addition to their well-known fun

  5. DNA methyltransferase and alcohol dehydrogenase: gene-nutrient interactions in relation to risk of colorectal polyps.

    NARCIS (Netherlands)

    Jung, A.Y.; Poole, E.M.; Bigler, J.; Whitton, J.; Potter, J.D.; Ulrich, C.M.

    2008-01-01

    Disturbances in DNA methylation are a characteristic of colorectal carcinogenesis. Folate-mediated one-carbon metabolism is essential for providing one-carbon groups for DNA methylation via DNA methyltransferases (DNMTs). Alcohol, a folate antagonist, could adversely affect one-carbon metabolism. In

  6. Clinical Pharmacogenetics Implementation Consortium guidelines for thiopurine methyltransferase genotype and thiopurine dosing

    DEFF Research Database (Denmark)

    Relling, M V; Gardner, E E; Sandborn, W J;

    2011-01-01

    Thiopurine methyltransferase (TPMT) activity exhibits monogenic co-dominant inheritance, with ethnic differences in the frequency of occurrence of variant alleles. With conventional thiopurine doses, homozygous TPMT-deficient patients (~1 in 178 to 1 in 3,736 individuals with two nonfunctional TP...

  7. A fluorescence resonance energy transfer-based method for histone methyltransferases

    DEFF Research Database (Denmark)

    Devkota, Kanchan; Lohse, Brian; Nyby Jakobsen, Camilla;

    2015-01-01

    A simple dye–quencher fluorescence resonance energy transfer (FRET)-based assay for methyltransferases was developed and used to determine kinetic parameters and inhibitory activity at EHMT1 and EHMT2. Peptides mimicking the truncated histone H3 tail were functionalized in each end with a dye...

  8. Suz12 is essential for mouse development and for EZH2 histone methyltransferase activity

    DEFF Research Database (Denmark)

    Pasini, Diego; Bracken, Adrian P; Jensen, Michael R;

    2004-01-01

    SUZ12 is a recently identified Polycomb group (PcG) protein, which together with EZH2 and EED forms different Polycomb repressive complexes (PRC2/3). These complexes contain histone H3 lysine (K) 27/9 and histone H1 K26 methyltransferase activity specified by the EZH2 SET domain. Here we show...

  9. The histone methyltransferase SET8 is required for S-phase progression

    DEFF Research Database (Denmark)

    Jørgensen, Stine; Elvers, Ingegerd; Trelle, Morten Beck;

    2008-01-01

    Chromatin structure and function is influenced by histone posttranslational modifications. SET8 (also known as PR-Set7 and SETD8) is a histone methyltransferase that monomethylates histonfe H4-K20. However, a function for SET8 in mammalian cell proliferation has not been determined. We show...

  10. 辽西地区露地西兰花(绿花椰菜)栽培技术要点%Cultivation Technology of Broccoli in Western Area of Liaoning

    Institute of Scientific and Technical Information of China (English)

    颜津宁; 胡新颖; 杨迎东; 裴新辉; 商旭文; 颜范悦

    2012-01-01

    Planting technology of broccoli in autumn, including variety selection, seedling breeding, planting and managements, prevention and cure for plant diseases and insect pests, harvest were introduced. These techniques would provide references for the production of broccoli in autumn.%该文从品种选择、秧苗培育、整地定植、病虫害防治、收获及贮藏等方面介绍了辽西地区西兰花秋茬栽培技术,以期指导露地秋茬西兰花生产。

  11. 盐碱胁迫对西兰花种子萌发的影响%Effect of Salt and Alkaline Stress on Seed Germination of Broccoli

    Institute of Scientific and Technical Information of China (English)

    徐芬芬

    2012-01-01

    The germination and protection enzyme activities of Brassica oleracea L. var. botrytis L. embryo under the different concentration of NaCl and Na2CO3 stress were examined in this experiment. The results showed that the germination of broccoli was promoted under the low concentration of NaCl (≤20 mmol/L). Germination of broccoli was inhibited under the Na2CO3 stress when concentration of Na+ was the same. SOD and POD activities of embryo under the Na2CO3 stress were lower than the NaCl stress, and MDA content was higher than the NaCl stress. Comprehensive analysis showed that the threshold values of broccoli tolerance to NaCl and Na2CO3 were 445.5 mmol/L and 64.1 mmol/L.%本试验通过采用不同浓度的NaCl和Na2CO3胁迫萌发期的西兰花(Brassica oleracea L.var.botrytis L.)种子,调查了其发芽和胚保护酶活性等指标.研究结果表明,低浓度(≤20 mmol/L)的NaCl胁迫对西兰花各发芽指标有促进作用,在等Na+浓度胁迫下,各Na2CO3胁迫对各发芽指标均表现出抑制作用.Na2CO3胁迫处理胚的SOD和POD活性低于NaCl胁迫处理,MDA含量高于NaCl胁迫处理.综合分析表明,西兰花耐盐阈值和耐碱阈值分别为445.5 mmol/L和64.1 mmol/L.

  12. Floral Benzenoid Carboxyl Methyltransferases: From in Vitro to in Planta Function

    Energy Technology Data Exchange (ETDEWEB)

    Effmert,U.; Saschenbrecker, S.; Ross, J.; Negre, F.; Fraser, C.; Noel, J.; Dudareva, N.; Piechulla, B.

    2005-01-01

    Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from Clarkia breweri, Stephanotis floribunda, Antirrhinum majus, Hoya carnosa, and Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from A. majus, Arabidopsis thaliana, Arabidopsis lyrata, and Nicotiana suaveolens prefer benzoic acid. The elucidation of C. breweri SAMT's three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in plants depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses

  13. Physiology and Posttranscriptional Regulation of Methanol:Coenzyme M Methyltransferase Isozymes in Methanosarcina acetivorans C2A ▿ §

    OpenAIRE

    Opulencia, Rina B.; Bose, Arpita; Metcalf, William W.

    2009-01-01

    Methanosarcina species possess three operons (mtaCB1, mtaCB2, and mtaCB3) encoding methanol-specific methyltransferase 1 (MT1) isozymes and two genes (mtaA1 and mtaA2) with the potential to encode a methanol-specific methyltransferase 2 (MT2). Previous genetic studies showed that these genes are differentially regulated and encode enzymes with distinct levels of methyltransferase activity. Here, the effects of promoter strength on growth and on the rate of methane production were examined by ...

  14. Standardized cultivation technique for exported pollution-free broccoli%出口西兰花无公害标准化栽培技术

    Institute of Scientific and Technical Information of China (English)

    陈少珍

    2012-01-01

    根据10多年的引种试验、无公害栽培试验和示范推广的结果,总结一套符合出口质量要求、高产优质高效的西兰花无公害标准化栽培技术。%According to the results of introduction,pollution-free cultivation,demonstration and popularization in local area for more than ten years,a standardized pollution-free cultivation technique for broccoli which meet the quality requirements for exportation,with high yield and benefit was summarized in this paper.

  15. Establishment and Optimization of Broccoli Regeneration System%西兰花再生体系的建立与优化

    Institute of Scientific and Technical Information of China (English)

    刘煜; 王红波; 王传琦; 李晶

    2013-01-01

    Objective: Using axenic seedlings as explants, several factors influencing regeneration rate of broccoli were studied and a successful tissue regeneration system was established and optimized. Methods: Using tissue culture mesthod to induce the explant of broccoli yielding bud and root. Results: The study showed that the geno⁃type influenced regeneration rate greatly. The regeneration rate of Zhu-lv and Qing-xiu was above 91% while Ding⁃feng1 is 80.3%; differentiation ability of hypocotyls which had been cultured 6 days was the strongest. When the medium contained 3 mg/L 6-BA and 0.2 mg/L IAA, the differentiation rate of hypocotyls reached the highest lev⁃el and the degree of vitrification was the lowest. In the medium contains 0.2 mg/L IBA or 0.2 mg/L NAA, adventi⁃tious root could be successfully induced from the adventitious buds. Conclusion: Broccoli regeneration system has been successfully established, which laid the foundation for the establishment of broccoli genetic transformation sys⁃tem.%  目的:以西兰花无菌苗为材料,对影响西兰花再生的各种素进行研究,建立并优化西兰花的再生体系.方法:用组织培养法,对西兰花的外植体进行诱导生芽、生根.结果:不同品种的再生率差别较大,珠绿和青秀两个品种的再生率达91%以上,而鼎丰一号仅为80.3%;培养6 d 的下胚轴分化能力最强;当培养基中添加3 mg/L 6-BA 和0.2 mg/L IAA 时,下胚轴的分化率最高,玻璃化程度也降到最低;当培养基中添加0.2 mg/L IBA 或0.2 mg/L NAA时,可成功诱导不定芽生根.结论:建立并优化了西兰花再生体系,为西兰花遗传转化体系的建立奠定了基础.

  16. Research Progress of Broccoli in the Prevention and Treatment of Diseases%西兰花预防和治疗肿瘤研究的新进展

    Institute of Scientific and Technical Information of China (English)

    洪姣; 王佳蕊; 黄春琦; 徐殿琴; 张婷; 许健

    2014-01-01

    In recent years, the morbidity of cancer, cardiovascular disease, diabetes and other diseases were increasing constantly. Meanwhile, people gradually realized that diet played an important role in the prevention or treatment of chronic disease by providing useful elements. Many papers have confirmed that glucosinolates, anthocyanin, vitamins and other beneficial ingredients in broccoli had the function of preventing cancer, diabetes and eye disease, and protecting cardio-vascular and antioxidation. This suggested that increasing our daily diet intake of broccoli could promote the health, prevent diseases. In this paper, we reviewed the medicinal value of broccoli and the influence of cooking and temperature on its useful elements, and illustrated different roles of different effective components of broccoli in the treatment of diseases.%近年来,肿瘤、心血管疾病及糖尿病等疾病的发病率不断上升,人们意识到可以在日常饮食中通过提供有益成分而起到预防或治疗疾病的作用。大量文献证实西兰花中所含有的芥子油苷、花青素、维生素等有益成分具有抗癌、预防糖尿病及眼部疾病、保护心血管抗氧化等作用,提示在日常饮食中增加西兰花的摄入可以促进身体健康,起到防病、治病和改善体质的功效。本文主要综述了西兰花的药用价值以及烹饪、温度等对其有效成分的影响,并总结了西兰花中不同的有效成分治疗疾病的作用。

  17. 打孔包装对西兰花品质的影响%Influence of Perforated Packaging on Broccoli Quality

    Institute of Scientific and Technical Information of China (English)

    杨静; 张蕾

    2012-01-01

    分别在2种厚度的PP薄膜(40,50μm)上以一定间距打不同数量的孔(φ280μm),制得了PP微孔薄膜。将PP微孔薄膜(40μm)制成了自立袋采包装西兰花。通过改变自立袋上微孔的位置,观测袋内气体和西兰花叶绿素含量的变化。结果表明:开孔位置影响袋内O2和CO2气体含量;打孔数量为2个,孔间隔2cm,开孔在西兰花花蕾处时,袋内花蕾处呈低O2和高CO2状态,所包西兰花的叶绿素含量最高,西兰花最新鲜;在环境温度一定的条件下,PP微孔自立袋的厚度、开孔位置、孔径和孔数是影响袋内气体含量的重要因素。%The PP micro-perforated films of 40μm and 50 μm thickness with different number of holes (diameter of 280 μm) in certain distance were prepared. Self-supporting bag was made using the micro-perforated PP film (40μm) for packing broccoli. Change of gas content and chlorophyll content of broccoli was observed by altering micro-perforation's position. The experiment results showed that micro perforation's position affect the content of O2 and CO2 ; when 2 holes separating by 2crn are punched in the broccoli bud, high O2 concentration and CO2 low concentration is produced, content of broccoli's chlorophyll is highest and broccoli is the freshest. The thickness of micro-perforated self-supporting bag, micro-perforation's position, perforation diameter and perforation number are important factors influencing gas content in the package when the environmental temperature is certain.

  18. 青花菜流通过程中营养品质变化的研究%Study on changes of nutritional quality in circulation of broccoli

    Institute of Scientific and Technical Information of China (English)

    郭李维; 王清; 杨娜; 高丽朴

    2011-01-01

    研究了不同流通温度和包装方式对青花菜外观品质与营养成分的影响。实验结果表明:青花菜在流通过程中随着组织的衰老,其叶绿素、VC、可溶性糖及可溶性蛋白质含量均呈下降趋势。青花菜在5℃中流通比在20℃中能更好地保持其营养成分。利用0.03mm厚的聚乙烯薄膜包装既可避免青花菜失水萎蔫,又可抑制黄化率。20℃无包装处理的青花菜最佳流通时间为1d,20℃PE处理的为2d,5℃无包装处理的为6d,5℃PE处理的为12d。%The effect of different temperature and packaging on the quality and nutrients of broccoli was studied.The results showed that the contents of chlorophyll,ascorbic acid,soluble sugars were decreased with senescence of broccoli in the circulation process.In addition,The broccoli were circulated at 5℃ that could better maintain the quality and nutrients than circulation at 20℃.Packaged with 0.03mm PE could not only prevent the loss of water,but also inhibit the rate of yellowing.Therefore,the broccoli PE packaging could keep a better appearance for 2 days,1 day longer than those directly exposed to the air at 20℃,while cold chain could show great advantage during transportation,the brocoli packed by PE film could store 12d at 5℃,and the unpackaged might keep better quality for 6 days as well.

  19. Transcriptome and Metabolome Analyses of Glucosinolates in Two Broccoli Cultivars Following Jasmonate Treatment for the Induction of Glucosinolate Defense to Trichoplusia ni (Hübner).

    Science.gov (United States)

    Ku, Kang-Mo; Becker, Talon M; Juvik, John A

    2016-01-01

    Lepidopteran larvae growth is influenced by host plant glucosinolate (GS) concentrations, which are, in turn, influenced by the phytohormone jasmonate (JA). In order to elucidate insect resistance biomarkers to lepidopteran pests, transcriptome and metabolome analyses following JA treatments were conducted with two broccoli cultivars, Green Magic and VI-158, which have differentially induced indole GSs, neoglucobrassicin and glucobrassicin, respectively. To test these two inducible GSs on growth of cabbage looper (Trichoplusia ni), eight neonate cabbage looper larvae were placed onto each of three plants per JA treatments (0, 100, 200, 400 µM) three days after treatment. After five days of feeding, weight of larvae and their survival rate was found to decrease with increasing JA concentrations in both broccoli cultivars. JA-inducible GSs were measured by high performance liquid chromatography. Neoglucobrassicin in Green Magic and glucobrassicin in VI-158 leaves were increased in a dose-dependent manner. One or both of these glucosinolates and/or their hydrolysis products showed significant inverse correlations with larval weight and survival (five days after treatment) while being positively correlated with the number of days to pupation. This implies that these two JA-inducible glucosinolates can influence the growth and survival of cabbage looper larvae. Transcriptome profiling supported the observed changes in glucosinolate and their hydrolysis product concentrations following JA treatments. Several genes related to GS metabolism differentiate the two broccoli cultivars in their pattern of transcriptional response to JA treatments. Indicative of the corresponding change in indole GS concentrations, transcripts of the transcription factor MYB122, core structure biosynthesis genes (CYP79B2, UGT74B1, SUR1, SOT16, SOT17, and SOT18), an indole glucosinolate side chain modification gene (IGMT1), and several glucosinolate hydrolysis genes (TGG1, TGG2, and ESM1) were

  20. A conformational switch in the active site of BT_2972, a methyltransferase from an antibiotic resistant pathogen B. thetaiotaomicron.

    Directory of Open Access Journals (Sweden)

    Veerendra Kumar

    Full Text Available Methylation is one of the most common biochemical reactions involved in cellular and metabolic functions and is catalysed by the action of methyltransferases. Bacteroides thetaiotaomicron is an antibiotic-resistant bacterium that confers resistance through methylation, and as yet, there is no report on the structure of methyltransferases from this bacterium. Here, we report the crystal structure of an AdoMet-dependent methyltransferase, BT_2972 and its complex with AdoMet and AdoHcy for B. thetaiotaomicron VPI-5482 strain along with isothermal titration calorimetric assessment of the binding affinities. Comparison of the apo and complexed BT_2972 structures reveals a significant conformational change between open and closed forms of the active site that presumably regulates the association with cofactors and may aid interaction with substrate. Together, our analysis suggests that BT_2972 is a small molecule methyltransferase and might catalyze two O-methylation reaction steps involved in the ubiquinone biosynthesis pathway.

  1. A conformational switch in the active site of BT_2972, a methyltransferase from an antibiotic resistant pathogen B. thetaiotaomicron.

    Science.gov (United States)

    Kumar, Veerendra; Sivaraman, J

    2011-01-01

    Methylation is one of the most common biochemical reactions involved in cellular and metabolic functions and is catalysed by the action of methyltransferases. Bacteroides thetaiotaomicron is an antibiotic-resistant bacterium that confers resistance through methylation, and as yet, there is no report on the structure of methyltransferases from this bacterium. Here, we report the crystal structure of an AdoMet-dependent methyltransferase, BT_2972 and its complex with AdoMet and AdoHcy for B. thetaiotaomicron VPI-5482 strain along with isothermal titration calorimetric assessment of the binding affinities. Comparison of the apo and complexed BT_2972 structures reveals a significant conformational change between open and closed forms of the active site that presumably regulates the association with cofactors and may aid interaction with substrate. Together, our analysis suggests that BT_2972 is a small molecule methyltransferase and might catalyze two O-methylation reaction steps involved in the ubiquinone biosynthesis pathway. PMID:22140448

  2. Study of Cleome Gynandra Extract on Broccoli Preservation%白花菜提取物对花椰菜保鲜效果的研究

    Institute of Scientific and Technical Information of China (English)

    曾维丽; 张臻; 刘少阳; 王飞

    2015-01-01

    论文研究了白花菜提取物对花椰菜中微生物、褐变指数和VC含量的影响。结果表明,白花菜提取物能有效抑制微生物的生长,有效减缓花椰菜的褐变速度和VC的降解速度,较好地保持花椰菜的品质,其中1.0 g/L白花菜提取物的保鲜效果最好。%The effects of Cleome gynandra extract on total number of colony, as well as browning index and vitamin C content of Broccoli were studied. The results showed that Cleome gynandra extract could effectively eliminate the microorganism, delay the browning rate and slow down the degradation of vitamin C. 1.0g/L Cleome gynandra extract was shown to be the best to fresh-keeping and storage quality of broccoli.

  3. Laser synthesized super-hydrophobic conducting carbon with broccoli-type morphology as a counter-electrode for dye sensitized solar cells

    Science.gov (United States)

    Gokhale, Rohan; Agarkar, Shruti; Debgupta, Joyashish; Shinde, Deodatta; Lefez, Benoit; Banerjee, Abhik; Jog, Jyoti; More, Mahendra; Hannoyer, Beatrice; Ogale, Satishchandra

    2012-10-01

    A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode.A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode. Electronic supplementary information (ESI) available: Materials and equipment details, solar cell fabrication protocol, electrolyte spreading time measurement details, XPS spectra, electronic study, film adhesion test detailed analysis and field emission results. See DOI: 10.1039/c2nr32082g

  4. Study on Ultrasonic Extraction Technique of Broccoli Polysaccharide%超声波法提取西兰花多糖的工艺研究

    Institute of Scientific and Technical Information of China (English)

    郎艳婷; 刘波; 张振宇; 郝明月; 苏万平

    2012-01-01

    采用超声波辅助法提取西兰花多糖,通过单因素试验与正交试验对提取工艺进行优化,以期确定西兰花多糖的最佳提取工艺.结果表明,超声波辅助法提取西兰花多糖的最佳工艺参数为:超声时间50min,超声波功率80W,提取温度60℃,料液比1∶50(mL/g),多糖的得率为8.24%.该试验方法简单、易行,可为西兰花多糖的工业化生产提供参考.%To determine the best broccoli polysaccharide extraction process with the ultrasonic assisted-extraction technology. The technique was optimized by a single factor experiments and orthogonal test. The results showed that the optimum extraction parameters of polysaccharides was that ultrasonic time for50 min, 80 W ultrasonic power at 60℃, ratio of liquid feed 1:50 (ml/g), and polysaccharide yield was 8.24%. The test method is simple, easy, and can provide a reference for the industrial production of broccoli polysaccharide.

  5. MOLECULAR AND FUNCTIONAL CHARACTERIZATION OF A JUVENILE HORMONE ACID METHYLTRANSFERASE EXPRESSED IN THE CORPORA ALLATA OF MOSQUITOES

    OpenAIRE

    Mayoral, Jaime G.; Nouzova, Marcela; Yoshiyama, Michiyo; Shinoda, Tetsuro; Hernandez-Martinez, Salvador; Dolghih, Elena; Turjanski, Adrian G; Roitberg, Adrian E.; Priestap, Horacio; Perez, Mario; Mackenzie, Lucy; Li, Yiping; Noriega, Fernando G.

    2008-01-01

    A juvenile hormone acid methyltransferase (JHAMT) was isolated as an abundant EST in a library of the corpora allata of the adult female mosquito Aedes aegypti. Its full-length cDNA encodes a 278-aa protein that has 43 % amino acid identity with BmJHAMT, a juvenile hormone acid methyltransferase previously cloned from Bombyx mori. Heterologous expression produced a recombinant protein that metabolizes farnesoic acid (FA) into methyl farnesoate, as well as juvenile hormone acid into juvenile h...

  6. N-6-Adenine-Specific DNA Methyltransferase 1 (N6AMT1) Polymorphisms and Arsenic Methylation in Andean Women

    OpenAIRE

    Harari, Florencia; Engström, Karin; Concha, Gabriela; Colque, Graciela; Vahter, Marie; Broberg, Karin

    2013-01-01

    BACKGROUND: In humans, inorganic arsenic is metabolized to methylated metabolites mainly by arsenic (+3 oxidation state) methyltransferase (AS3MT). AS3MT polymorphisms are associated with arsenic metabolism efficiency. Recently, a putative N-6-adenine-specific DNA methyltransferase 1 (N6AMT1) was found to methylate arsenic in vitro. OBJECTIVE: We evaluated the role of N6AMT1 polymorphisms in arsenic methylation efficiency in humans. METHODS: We assessed arsenic methylation efficiency in 188 w...

  7. 花椰菜在不同贮藏温度下的品质变化及货架期预测%The Quality Changes of Broccoli Stored at Different Temperatures and Its Shelf Life Prediction

    Institute of Scientific and Technical Information of China (English)

    宋晨; 刘宝林; 王欣; 董庆利; 孙雅琼

    2009-01-01

    Broccoli is nutritious and tasty.In this study,Broccoli was stored at 0℃,6℃,24℃ respectively.The sensory quality,water loss and ascorbic acid content were measured at various time intervals to study the effects of temperature on the quality of broccoli.It was found that the degradation of ascorbic acid content followed the first order reaction kinetics.The activation energy of ascorbic acid was determined.Taking 50% ascorbic acid loss as the threshold,a mathematic model for predicting the shelf life of broccoli was established.%花椰菜是一种清香爽脆、营养丰富的蔬菜,试验在0、6℃及室温24℃下贮藏花椰菜,从感官品质、失水率及V_C含量3方面研究温度对其品质的影响.确定了花椰菜中V_C含量下降遵循一级动力学反应,并据此计算出反应的表观活化能Ea进一步推算出以V_C含量下降50%为货架期终点时,花椰菜的货架期计算公式.

  8. 不同贮藏性青花菜花球的抗氧化特性%Antioxidative Properties of Broccoli Florets of Cultivars with Different Storability

    Institute of Scientific and Technical Information of China (English)

    李进才; 赵习姮

    2011-01-01

    为研究青花菜(Brassica oleracea L.Var.italica)花球的抗氧化特性与贮藏性的关系,选取贮藏性不同的春季2个品种(“绿颜”和“城堡”)和秋季2个品种(“爱国者”和“高地”),将采后花球贮藏于20℃条件下,在贮藏开始时和4d后,测定了花球呼吸速率、衰老生理指标(叶绿素、蛋白质和丙二醛(MDA)含量)和抗氧化特性指标(活性氧超氧阴离子和过氧化氢含量,抗氧化酶超氧化物岐化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化氢酶(APX)活性,抗氧化物质抗坏血酸(AsA)和β-胡萝卜素(β-Car)含量).“绿颜”和“爱国者”贮藏开始时,呼吸速率低,活性氧含量少,抗氧化酶活性低;贮藏4d后,叶绿素和蛋白质含量高,MDA含量少,SOD、CAT和POD活性上升幅度大,APX活性和AsA、β-Car含量下降幅度小.结果表明:“绿颜”比“城堡”、“爱国者”比“高地”衰老慢,耐贮藏;耐贮藏青花菜品种的花球具有采收时抗氧化酶活性低,贮藏期间SOD、CAT和POD活性上升幅度大,APX活性和抗氧化物质含量下降幅度小的抗氧化特性.%In this work, relationship between the storability of broccoli {Brassica oleracea L. Var. Italica) florets and their antioxidative properties was investigated. Broccoli florets of four cultivars from the spring "Green face" and "Castle" and autumn "Patriot" and "Heights" with different storage properties were harvested and stored at 20 ℃ until use. Respiratory rate of broccoli florets and senescence physiological indicators (chlorophyll, protein and malondialdehyde (MDA) contents) and antioxidative properties indicators (reactive oxygen species contents of super-oxide and hydrogen peroxide, antioxidative enzymes activities of superoxide dismutase(SOD), catalase(CAT), peroxidase (POD), ascorbate peroxidase (APX), anti-oxidative substances contents of ascorbic acid (AsA) and β-carotene (β-Car)) of broccoli flower buds

  9. Studies on the Preparation and Antioxidant Activity of Lactobacillus-fermented Broccoli Beverage%西兰花乳酸菌饮料的制备及其抗氧化作用研究

    Institute of Scientific and Technical Information of China (English)

    董青青; 胡海杰; 肖文佳; 安兴娟; 姬阿美; 杜稳; 张同存; 罗学刚

    2015-01-01

    Using broccoli as main material,green-protecting condition,formulations,stability,fermentative strain and fermentation process of broccoli lactobacillus beverage were researched in this paper. The optimized technology was ultimately set up as after broccoli was stripped and sliced,Using 50% broccoli juice,10% orange juice,5% flavedo,6% sucrose,0.2% citric acid,0.25% salt and 0.2% CMC-Na as materials fermenting with lactobacillus plantarum for 4 hours at 30℃in anaerobic box. Broccoli lactobacillus beverage made by this technology has an unique flavor and nice trait. Additionally,broccoli has antioxidant activity,allows people to avoid free radical damage,reduce the incidence of cancer. the efficiency of antioxidant and antiradical of the Pre-fermentation and fermented broccoli was determined by the DPPH.%以西兰花为主要原料,通过对西兰花乳酸菌发酵饮料的原料护色方法、配方、稳定性、发酵菌种及发酵过程进行分析,最终优化建立了西兰花乳酸菌发酵制备工艺为:西兰花汁50%,橙汁10%,橙皮5%,蔗糖6%,柠檬酸0.2%,盐0.25%,CMC-Na为0.2%作为发酵原料,按照3%量接种植物乳杆菌后,在厌氧培养箱中30℃发酵4h。以此工艺生产的西兰花乳酸菌发酵饮料具有独特的风味和良好的性状。另外,西兰花具有抗氧化性,可以使人们避免受到自由基的伤害,降低发病几率。利用DPPH法对发酵前后西兰花的抗氧化、清除自由基能力进行了测定。西兰花汁发酵前对DPPH的清除率为67.09%,发酵后对DPPH的清除率为82.85%,结果表明发酵后比发酵前西兰花抗氧化能力明显增强。

  10. LED复合光处理对西兰花低温保鲜效果的影响%Effect of LED Composite Light on Preservation of Broccoli during Cold Storage

    Institute of Scientific and Technical Information of China (English)

    李宁; 阎瑞香; 张娜

    2015-01-01

    In order to study on effect of different treat of LED composite light on preservation of broccoli ,fresh broccoli was used as the main materials .By measuring the indicators at 4 ℃ low temperature conditions , such as sensory quality ,vitamin C content ,chlorophyll content and broccoli ethylene production rate ,effect of LED compos-ite light on preservation for broccoli was determined .The results showed that treatment with LED composite of red and blue was better for the quality of broccoli compared with non-light treatment.The former could extend storage time by 10-15 d.Meanwhile,it could got a higher score of sensory evaluation ,prevented the rapid decline in im-portant nutrient substance vitamin C content of broccoli ,delayed the time of the evolution of ethylene and the ap-pearance of respiration peak , decreased the respiration variable peak , and reduced membrane lipid peroxidation damage of broccoli during storage .%为研究不同LED复合光处理对西兰花保鲜效果的影响。以新鲜西兰花为材料,通过测定4℃低温条件下,西兰花的感官品质、维生素C含量、叶绿素含量、乙烯生成速率等各项指标,研究LED红蓝、LED红绿复合光处理对西兰花保鲜效果的影响。结果表明,与无光处理方式相比, LED红蓝复合光处理效果显著,不仅延长了西兰花保鲜期10~15 d左右,而且较好地保持了西兰花原有的外观品质,阻止了西兰花贮藏期间重要营养物质Vc含量的快速流失,延缓了贮藏期间乙烯释放量峰值和呼吸跃变出现的时间,显著降低了呼吸跃变的峰值,减少了膜脂过氧化对西兰花造成的损伤。

  11. Evaluation on the Apparent Metabolic Energy and Apparent Heal Amino Acid Digestibility of Broccoli LPC and Broccoli Residues for Broilers%西兰花叶蛋白和茎叶粉对肉仔鸡代谢能和回肠氨基酸表观消化率的影响

    Institute of Scientific and Technical Information of China (English)

    杨桂芹; 梁丽萍; 李建涛; 刘国华; 张姝; 郑爱娟

    2011-01-01

    通过2个试验测定了西兰花叶蛋白和茎叶粉在肉仔鸡中的氮校正表观代谢能和回肠氨基酸的表观消化率,为合理利用西兰花资源提供科学依据和数据参考.试验1选用体重相近的22日龄健康肉仔鸡144只,随机分成3个组,每组8个重复,公母各50%.其中1组饲喂基础日粮,另2组分别饲喂试验日粮(西兰花叶蛋白30%替代基础日粮,西兰花茎叶粉35%替代基础日粮).选用TiO2为外源指示剂进行代谢试验;试验2选用体重相近的26日龄健康肉仔鸡96只,随机分为2组,每组8个重复,公母各50%.选用TiO2为外源指示剂,采用回肠末端法进行代谢试验.结果表明:西兰花叶蛋白和茎叶粉在肉仔鸡中的表观代谢能分别为8.86MJ·kg-1和2.48 MJ·kg-1,氮校正表观代谢能分别为8.14 MJ·kg-1和1.86 MJ·kg-1;西兰花叶蛋白和茎叶粉在肉仔鸡中4种限制性氨基酸的回肠末端表观消化率分别为赖氨酸(48.11±4.28)%和(73.00±6.64)%,蛋氨酸(39.51±4.60)%和(79.18±3.91)%,苏氨酸(33.11±4.66)%和(59.38±6.25)%,胱氨酸(33.47±2.94)%和(65.82±4.46)%;存肉仔鸡中17种氨基酸的回肠末端表观消化率的平均值为(39.57±4.45)%和(71.75±4.85)%.可见,西兰花茎叶粉在肉仔鸡中的表观代谢能较低,西兰花叶蛋白在肉仔鸡中回肠末端氨基酸的消化率较低.%To assess the apparent metabolic energy and apparent ileal amino acid digestibility of broccoli leaf protein concentrate (LPC) and broccoli residues for broilers, two experiments were carried out. In experiment one,one hundred and forty-four 22-day-old broilers were allocated randomly into three treatments,each of them contained eight repetitions, male and female half and haft. Titanium dioxide was used as the exogenous indicator to carry out the metabolic test, One group was fed basic diet, other two groups were fed test diets in which the basic diet was replaced by 30% broccoli LPC and 35% broccoli residues respectively. In

  12. Aflatoxin B1 induced upregulation of protein arginine methyltransferase 5 in human cell lines.

    Science.gov (United States)

    Ghufran, Md Sajid; Ghosh, Krishna; Kanade, Santosh R

    2016-09-01

    The exposure of naturally occurring mycotoxins affects human health and play a vital role in cancer initiation and progression. Aflatoxin B1 is a difuranocoumarin mycotoxin, classified as a group I carcinogen. The present study was conducted to assess the effect of aflatoxin B1 on epigenetic regulatory proteins. The protein arginine methyltransferase 5 expression was induced upon aflatoxin B1 treatment in a dose and time dependent manner. Further global arginine methylation was also increased in the same manner. This is the first report showing the induction of epigenetic regulatory protein, protein arginine methyltransferase 5 upon aflatoxin B1 treatment. Further study is required to establish the detailed pathway of PRMT5 induction. PMID:27242039

  13. Targeting histone methyltransferases and demethylases in clinical trials for cancer therapy.

    Science.gov (United States)

    Morera, Ludovica; Lübbert, Michael; Jung, Manfred

    2016-01-01

    The term epigenetics is defined as heritable changes in gene expression that are not due to alterations of the DNA sequence. In the last years, it has become more and more evident that dysregulated epigenetic regulatory processes have a central role in cancer onset and progression. In contrast to DNA mutations, epigenetic modifications are reversible and, hence, suitable for pharmacological interventions. Reversible histone methylation is an important process within epigenetic regulation, and the investigation of its role in cancer has led to the identification of lysine methyltransferases and demethylases as promising targets for new anticancer drugs. In this review, we describe those enzymes and their inhibitors that have already reached the first stages of clinical trials in cancer therapy, namely the histone methyltransferases DOT1L and EZH2 as well as the demethylase LSD1. PMID:27222667

  14. Discovery of sphingosine 1-O-methyltransferase in rat kidney and liver homogenates

    Institute of Scientific and Technical Information of China (English)

    Santosh J SACKET; Dong-soon IM

    2008-01-01

    Aim:To characterize sphingosine methyltransferase in rat tissues.Methods:By using S-adenosyl-L-(methyl-3H) methionine,enzymatic activity was measured in the rat liver and kidney homogenates.Results:The optimum pH and reaction time for the enzyme assay were pH 7.8 and 1 h.ZnCl2 inhibited the activity,but not MgCl2,CaCl2,CoCl2,or NiCl2.In the kidney homogenate,enzymatic activity was detectable in the cytosol and all membrane fractions from the plasma membrane and other organelles; however,in the liver homogenate,enzymatic activity was detectable in all membrane fractions,but not in the cytosol.We also tested the enzymatic activity with structurally-modified sphingosine derivatives.Conclusion:We found sphingosine l-O-methyltransferase activity in the rat liver and kidney homogenates.

  15. Mutations in the DNA methyltransferase gene DNMT3A cause an overgrowth syndrome with intellectual disability

    DEFF Research Database (Denmark)

    Tatton-Brown, Katrina; Seal, Sheila; Ruark, Elise;

    2014-01-01

    Overgrowth disorders are a heterogeneous group of conditions characterized by increased growth parameters and other variable clinical features such as intellectual disability and facial dysmorphism. To identify new causes of human overgrowth, we performed exome sequencing in ten proband...... and histone binding. Similar mutations were not present in 1,000 UK population controls (13/152 cases versus 0/1,000 controls; P intellectual disability and greater height. DNMT3A encodes a DNA methyltransferase essential for establishing...

  16. Structural basis for S-adenosylmethionine binding and methyltransferase activity by mitochondrial transcription factor B1

    OpenAIRE

    Guja, Kip E.; Venkataraman, Krithika; Yakubovskaya, Elena; Hui SHI; Mejia, Edison; Hambardjieva, Elena; Karzai, A. Wali; Garcia-Diaz, Miguel

    2013-01-01

    Eukaryotic transcription factor B (TFB) proteins are homologous to KsgA/Dim1 ribosomal RNA (rRNA) methyltransferases. The mammalian TFB1, mitochondrial (TFB1M) factor is an essential protein necessary for mitochondrial gene expression. TFB1M mediates an rRNA modification in the small ribosomal subunit and thus plays a role analogous to KsgA/Dim1 proteins. This modification has been linked to mitochondrial dysfunctions leading to maternally inherited deafness, aminoglycoside sensitivity and di...

  17. Expression of O6-methylguanine DNA methyltransferase (MGMT) and its clinical significance in gastroenteropancreatic neuroendocrine neoplasm

    OpenAIRE

    Yang, Qiu-chen; Wang, Yu-Hong; Lin, Yuan; Xue, Ling; Chen, Yuan-Jia; Chen, Min-hu; Chen, Jie

    2014-01-01

    O6-methylguanine-DNA methyltransferase (MGMT) is a widespread DNA repair enzyme defending against mutation caused by guanine O6-alkylating agents. Until now, we know only little about the expression of MGMT in gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN). To study the expression of MGMT and its clinical significance in GEP-NEN, 174 specimens of GEP-NEN were examined, of which 152 specimens came from The First Affiliated Hospital, Sun Yat-sen University during October 1995 to Novem...

  18. Survival and tumorigenesis in O6-methylguanine DNA methyltransferase-deficient mice following cyclophosphamide exposure

    OpenAIRE

    Nagasubramanian, Ramamoorthy; Hansen, Ryan J.; Delaney, Shannon M.; Cherian, Mathew M.; Samson, Leona D.; Kogan, Scott C.; Dolan, M. Eileen

    2008-01-01

    O6-methylguanine DNA methyltransferase (MGMT) deficiency is associated with an increased susceptibility to alkylating agent toxicity. To understand the contribution of MGMT in protecting against cyclophosphamide (CP)-induced toxicity, mutagenesis and tumorigenesis, we compared the biological effects of this agent in transgenic Mgmt knockout and wild-type mice. In addition, neurofibromin (Nf1)+/− background was used to increase the likelihood of CP-induced tumorigenesis. Cohorts of Mgmt-profic...

  19. Somatic mutations in glioblastoma are associated with methylguanine-DNA methyltransferase methylation

    OpenAIRE

    McDonald, Kerrie L.; Tabone, Tania; Nowak, Anna K; Erber, Wendy N.

    2015-01-01

    The high level of methylguanine-DNA methyltransferase (MGMT) in glioblastoma is responsible for resistance to alkylating agents, such as temozolomide (TMZ). In glioblastomas with a methylated MGMT promoter, MGMT deficiency is presumed, resulting in an enhanced effect of TMZ. The aim of the present study was to investigate whether genomic alterations work synergistically with MGMT methylation status and contribute to the response to treatment and overall prognosis in glioblastoma. The current ...

  20. Three-dimensional culture sensitizes epithelial ovarian cancer cells to EZH2 methyltransferase inhibition

    Science.gov (United States)

    Amatangelo, Michael D.; Garipov, Azat; Li, Hua; Conejo-Garcia, Jose R.; Speicher, David W.; Zhang, Rugang

    2013-01-01

    Inhibitors of EZH2 methyltransferase activity have been demonstrated to selectively suppress the growth of diffused large B cell lymphoma (DLBCL) cells with gain-of-function mutations in EZH2, while exhibiting very limited effects on the growth of DLBCL cells with wild-type EZH2. Given that EZH2 is often overexpressed but not mutated in solid tumors, it is important to investigate the determinants of sensitivity of solid tumor cells to EZH2 inhibitors. In the current study, we show that three-dimensional (3D) culture of epithelial ovarian cancer (EOC) cells that overexpress EZH2 sensitizes these cells to EZH2 methyltransferase inhibition. Treatment of EOC cells with GSK343, a specific inhibitor of EZH2 methyltransferase, decreases the level of H3K27Me3, the product of EZH2’s enzymatic activity. However, GSK343 exhibited limited effects on the growth of EOC cells in conventional two-dimensional (2D) culture. In contrast, GSK343 significantly suppressed the growth of EOC cells cultured in 3D matrigel extracellular matrix (ECM), which more closely mimics the tumor microenvironment in vivo. Notably, GSK343 induces apoptosis of EOC cells in 3D but not 2D culture. In addition, GSK343 significantly inhibited the invasion of EOC cells. In summary, we show that the 3D ECM sensitizes EOC cells to EZH2 methyltransferase inhibition, which suppresses cell growth, induces apoptosis and inhibits invasion. Our findings imply that in EZH2 wild-type solid tumors, the ECM tumor microenvironment plays an important role in determining sensitivity to EZH2 inhibition and suggest that targeting the ECM represents a novel strategy for enhancing EZH2 inhibitor efficacy. PMID:23759589

  1. Catecholamine-o-methyltransferase polymorphisms are associated with postoperative pain intensity.

    LENUS (Irish Health Repository)

    Lee, Peter J

    2011-02-01

    single nucleotide polymorphisms (SNPs) in the genes for catecholamine-O-methyltransferase (COMT), μ-opioid receptor and GTP cyclohydrolase (GCH1) have been linked to acute and chronic pain states. COMT polymorphisms are associated with experimental pain sensitivity and a chronic pain state. No such association has been identified perioperatively. We carried out a prospective observational clinical trial to examine associations between these parameters and the development of postoperative pain in patients undergoing third molar (M3) extraction.

  2. Towards more specific O6-Methylguanine-DNA methyltransferase (MGMT) inactivators

    OpenAIRE

    CORDEIRO MACHADO, ALESSANDRA; MC MURRY, THOMAS; Rozas, Isabel

    2011-01-01

    PUBLISHED Searching for a novel family of inactivators of the human DNA repair protein O6?methylguanine?DNA methyltransferase (MGMT) which is known to bind to the DNA minor groove, we have computationally modelled and synthesised two series of 2?amino?6?aryloxy?5?nitropyrimidines with morpholino or aminodiaryl substituents (potential minor groove binders) at the 4?position. Synthesis of these compounds was achieved by successive substitution of each of the two Cl atoms of 2?amino?4,6?dichl...

  3. miR-221/222 Target the DNA Methyltransferase MGMT in Glioma Cells

    OpenAIRE

    Cristina Quintavalle; Davide Mangani; Giuseppina Roscigno; Giulia Romano; Angel Diaz-Lagares; Margherita Iaboni; Elvira Donnarumma; Danilo Fiore; Pasqualino De Marinis; Ylermi Soini; Manel Esteller; Gerolama Condorelli

    2013-01-01

    Glioblastoma multiforme (GBM) is one of the most deadly types of cancer. To date, the best clinical approach for treatment is based on administration of temozolomide (TMZ) in combination with radiotherapy. Much evidence suggests that the intracellular level of the alkylating enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) impacts response to TMZ in GBM patients. MGMT expression is regulated by the methylation of its promoter. However, evidence indicates that this is not the only regula...

  4. O6-methylguanine-DNA methyltransferase (MGMT): can function explain a suicidal mechanism?

    OpenAIRE

    Gouws, Chrisna; Pretorius, Petrus Jacobus

    2011-01-01

    Why does O6-methylguanine-DNA methyltransferase (MGMT), an indispensable DNA repair enzyme, have a mechanism which seems to run counter to its importance? This enzyme is key to the removal of detrimental alkyl adducts from guanine bases. Although the mechanism is well known, an unusual feature surrounds its mode of action, which is its so-called suicidal endpoint. In addition, induction of MGMT is highly variable and its kinetics is atypical. These features raise some questions on the seeming...

  5. Kupplung der DNA-Methyltransferase M.SssI mit Triplehelix-bildenden Oligodesoxynucleotiden

    OpenAIRE

    Monami, Amélie Joséphine

    2007-01-01

    DNA modifying enzymes, like DNA methyltransferases (DNA MTases) and restriction endonucleases (REases), could in principle be used to map or manipulate genomes. However, these enzymes are inappropriate for that purpose because of their generally short recognition sequences. An increase of their sequence specificity would therefore be desirable. One strategy to produce megaspecific DNA modifying enzymes is to couple them with triple helix forming oligodeoxynucleotide (TFO). These additional DN...

  6. Thiopurine S-methyltransferase polymorphisms and thiopurine toxicity in treatment of inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To evaluate the relationship between thiopu- rine S-methyltransferase (TPMT) polymorphisms and thiopurine-induced adverse drug reactions (ADRs) in inflammatory bowel disease (IBD). METHODS: Eligible articles that compared the frequency of TPMT polymorphisms among thiopurine-tolerant and-intolerant adult IBD patients were included. Statistical analysis was performed with Review Manager 5.0. Sub-analysis/sensitivity analysis was also performed. RESULTS: Nine studies that investigated a total of 1309 part...

  7. Genetic, physiological and biochemical characterization of multiple methanol methyltransferase isozymes in Methanosarcina acetivorans C2A.

    Science.gov (United States)

    Pritchett, Matthew A; Metcalf, William W

    2005-06-01

    Biochemical evidence suggests that methanol catabolism in Methanosarcina species requires the concerted effort of methanol:5-hydroxybenzimidazolylcobamide methyltransferase (MtaB), a corrinoid-containing methyl-accepting protein (MtaC) and Co-methyl-5-hydroxybenzimidazolylcobamide:2-mercapto-ethanesulphonic acid methyltransferase (MtaA). Here we show that Methanosarcina acetivorans possesses three operons encoding putative methanol-specific MtaB and corrinoid proteins: mtaCB1, mtaCB2 and mtaCB3. Deletion mutants lacking the three operons, in all possible combinations, were constructed and characterized. Strains deleted for any two of the operons grew on methanol, whereas strains lacking all three did not. Therefore, each operon encodes a bona fide methanol-utilizing MtaB/corrinoid protein pair. Most of the mutants were similar to the wild-type strain, with the exception of the DeltamtaCB1 DeltamtaCB2 double mutant, which grew more slowly and had reduced cell yields on methanol medium. However, all mutants displayed significantly longer lag times when switching from growth on trimethylamine to growth on methanol. This indicates that all three operons are required for wild-type growth on methanol and suggests that each operon has a distinct role in the metabolism of this substrate. The combined methanol:CoM methyltransferase activity of strains carrying only mtaCB1 was twofold higher than strains carrying only mtaCB2 and fourfold higher than strains carrying only mtaCB3. Interestingly, the presence of the mtaCB2 and mtaCB3 operons, in addition to the mtaCB1 operon, did not increase the overall methyltransferase activity, suggesting that these strains may be limited by MtaA availability. All deletion mutants were unaffected with respect to growth on trimethylamine and acetate corroborating biochemical evidence indicating that each methanogenic substrate has specific methyltransfer enzymes. PMID:15882413

  8. The histone methyltransferase and putative oncoprotein MMSET is overexpressed in a large variety of human tumors

    DEFF Research Database (Denmark)

    Hudlebusch, Heidi Rye; Santoni-Rugiu, Eric; Simon, Ronald;

    2011-01-01

    Multiple myeloma SET (Suppressor of variegation, Enhancer of zeste, and Trithorax) domain (MMSET) is a histone lysine methyltransferase deregulated in a subgroup of multiple myelomas with the t(4;14)(p16;q32) translocation and poor prognosis. With the aim of understanding, if MMSET can be involve...... in other types of cancer we investigated the expression of MMSET protein in different types of human tumors....

  9. Identification and Characterization of a Highly Conserved Crenarchaeal Protein Lysine Methyltransferase with Broad Substrate Specificity

    OpenAIRE

    Chu, Yindi; Zhang, Zhenfeng; Wang, Qian; Luo, Yuanming; Huang, Li

    2012-01-01

    Protein lysine methylation occurs extensively in the Crenarchaeota, a major kingdom in the Archaea. However, the enzymes responsible for this type of posttranslational modification have not been found. Here we report the identification and characterization of the first crenarchaeal protein lysine methyltransferase, designated aKMT, from the hyperthermophilic crenarchaeon Sulfolobus islandicus. The enzyme was capable of transferring methyl groups to selected lysine residues in a substrate prot...

  10. 外源硝普钠处理对青花菜贮藏过程中品质的影响%The Effect of Exogenous Sodium Nitroprusside Treatment on Broccoli Quality during the Storage

    Institute of Scientific and Technical Information of China (English)

    史君彦; 王清; 高丽朴; 杨娜

    2012-01-01

    [Objective] The aim was to provide certain theoretical basis for the protection of broccoli. [ Method] Exogenous sodium nitroprusside was used to in the experiment. Under the condition of 20 ℃ and RH 95% , the optimal SNP concentration of broccoli was determined. [ Result ] The exogenous SNP could effectively maintain the quality of broccoli, inhabited the yellowing of broccoli and the increasing of cell membrane permeability, and maintain the soluble solids content, decreased the degradation rate of chlorophyll and delayed the loss of Vc. [ Conclusion] Exogenous sodium nitroprusside can effectively maintain the quality of broccoli to keep it fresh.%[目的]为常温下青花菜的科学保鲜提供理论依据.[方法]试验采用外源硝普钠(SNP)作为NO供体处理青花菜,并在常温(20℃)、RH95%条件下贮藏观察,确定最优SNP浓度下的青花菜相应品质指标.[结果]200μmol/L外源SNP处理可有效地延缓青花菜的黄化,抑制细胞膜透性的增加,维持了其可溶性固形物含量,降低了叶绿素的降解速率,延缓了Vc的流失,有效保持了青花菜的品质.[结论]适宜浓度的外源硝普钠处理能够有效保持青花菜的品质,有较好的保鲜效果.

  11. 冰温结合气调保鲜膜对西兰花保鲜效果的影响%The fresh-keeping effect of ice-temperature combined with plastic film on broccoli

    Institute of Scientific and Technical Information of China (English)

    张娜; 关文强; 张怡

    2012-01-01

    研究冰温条件下不同厚度保鲜膜包装的西兰花品质变化情况,为西兰花的长期保鲜提供依据。结果表明,冰温库的温度控制性能良好,在(-0.1±0.2)℃之间波动;保鲜膜结合冰温贮藏对西兰花具有保鲜效果,保鲜膜越厚,保鲜效果越明显,能够有效延长西兰花贮藏时间,可达110d,比普通冷库有效延长贮藏期30d,同时能够防止西兰花霉烂,保持Vc和可溶性固形物含量,抑制色素降解。%Under the condition of ice-temperature, the quality of broccoli packaged by different thickness of plastic film was test, which would provide the basis for long-term preservation of broccoli. The results showed that the ice-temperature storage had a stable temperature at -0.1 ℃ and the fluctuations is 0.2℃ . The ice-temperature storage combined with plastic-film package played a significant role in preservation of broccoli, the plastic film is thicker, the effect of preservation is more obvious, which can effectively extend the storage time of broccoli, up to 110 d, that is 30 d longer than the normal cold storage, meanwhile prevented broccoli to rot, maintained the Vc and soluble solids content, inhibited anthocyanin degraded.

  12. Effects of Different Pollination Periods on Seed Yield of Broccoli Self-incompatible Lines%不同授粉时期对青花菜自交不亲和系种子产量的影响

    Institute of Scientific and Technical Information of China (English)

    李易蓉; 木万福; 袁建民; 但忠; 苏银玲; 杨龙

    2013-01-01

    为了提高青花菜自交不亲和系种子产量,研究了授粉时期对不同熟性青花菜自交不亲和系结荚率、平均单荚籽粒数、种子千粒质量和种子产量的影响。研究结果表明,不同授粉时期对青花菜自交不亲和系种子生产有显著差异,早熟青花菜自交不亲和系在末花期授粉的结荚率、单荚籽粒数、种子千粒质量、种子产量最高,而中熟、晚熟青花菜自交不亲和系在盛花期授粉结荚率、单荚籽粒数、种子千粒质量、种子产量最高。%In order to increase the seed yield of self-incompatible lines of broccoli, we studied the effects of different pollination periods on podding rate, grain number of a single pod, thousand seed weight and seed yield of the self -incompatible lines of broccoli in this paper. The results showed that, different pollination periods affected the seed production of the self-incompatible lines of broccoli significantly. The late flowering period was the best pollination period for early-maturing broccoli cultivar, while the full-bloom period was best for mid-maturing and late-maturing cultivars, by doing so, we could obtain the highest podding rate, grain number of a single pod, thousand seed weight and seed yield of the three different kinds of broccoli cultivars.

  13. Cooperativity between DNA Methyltransferases in the Maintenance Methylation of Repetitive Elements

    Science.gov (United States)

    Liang, Gangning; Chan, Matilda F.; Tomigahara, Yoshitaka; Tsai, Yvonne C.; Gonzales, Felicidad A.; Li, En; Laird, Peter W.; Jones, Peter A.

    2002-01-01

    We used mouse embryonic stem (ES) cells with systematic gene knockouts for DNA methyltransferases to delineate the roles of DNA methyltransferase 1 (Dnmt1) and Dnmt3a and -3b in maintaining methylation patterns in the mouse genome. Dnmt1 alone was able to maintain methylation of most CpG-poor regions analyzed. In contrast, both Dnmt1 and Dnmt3a and/or Dnmt3b were required for methylation of a select class of sequences which included abundant murine LINE-1 promoters. We used a novel hemimethylation assay to show that even in wild-type cells these sequences contain high levels of hemimethylated DNA, suggestive of poor maintenance methylation. We showed that Dnmt3a and/or -3b could restore methylation of these sequences to pretreatment levels following transient exposure of cells to 5-aza-CdR, whereas Dnmt1 by itself could not. We conclude that ongoing de novo methylation by Dnmt3a and/or Dnmt3b compensates for inefficient maintenance methylation by Dnmt1 of these endogenous repetitive sequences. Our results reveal a previously unrecognized degree of cooperativity among mammalian DNA methyltransferases in ES cells. PMID:11756544

  14. Preliminary characterization of (nucleoside-2′-O-)-methyltransferase crystals from Meaban and Yokose flaviviruses

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, Eloise; Bollati, Michela; Milani, Mario [Department of Biomolecular Sciences and Biotechnology, CNR-INFM, University of Milano, Via Celoria 26, 20133 Milano (Italy); Lamballeire, Xavier de; Brisbare, Nadege [Unité des Virus Emergents, Faculté de Médecine, 27 Boulevard Jean Moulin, 13005 Marseille (France); Dalle, Karen; Lantez, Violaine; Egloff, Marie-Pierre; Coutard, Bruno; Canard, Bruno [Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 6098 CNRS ESIL, Case 932, 163 Avenue de Luminy, 13288 Marseille CEDEX 9 (France); Gould, Ernest; Forrester, Naomi [CEH Oxford, Mansfield Road, Oxford OX1 3SR (United Kingdom); Bolognesi, Martino, E-mail: martino.bolognesi@unimi.it [Department of Biomolecular Sciences and Biotechnology, CNR-INFM, University of Milano, Via Celoria 26, 20133 Milano (Italy)

    2006-08-01

    Two methyltransferases from flaviviruses (Meaban and Yokose viruses) have been overexpressed and crystallized. Diffraction data and characterization of the two crystal forms are presented, together with a preliminary molecular-replacement solution for both enzymes. Viral methyltranferases (MTase) are involved in the third step of the mRNA-capping process, transferring a methyl group from S-adenosyl-l-methionine (SAM) to the capped mRNA. MTases are classified into two groups: (guanine-N7)-methyltransferases (N7MTases), which add a methyl group onto the N7 atom of guanine, and (nucleoside-2′-O-)-methyltransferases (2′OMTases), which add a methyl group to a ribose hydroxyl. The MTases of two flaviviruses, Meaban and Yokose viruses, have been overexpressed, purified and crystallized in complex with SAM. Characterization of the crystals together with details of preliminary X-ray diffraction data collection (at 2.8 and 2.7 Å resolution, respectively) are reported here. The sequence homology relative to Dengue virus 2′OMTase and the structural conservation of specific residues in the putative active sites suggest that both enzymes belong to the 2′OMTase subgroup.

  15. miR-29 Represses the Activities of DNA Methyltransferases and DNA Demethylases

    Directory of Open Access Journals (Sweden)

    Izuho Hatada

    2013-07-01

    Full Text Available Members of the microRNA-29 (miR-29 family directly target the DNA methyltransferases, DNMT3A and DNMT3B. Disturbances in the expression levels of miR-29 have been linked to tumorigenesis and tumor aggressiveness. Members of the miR-29 family are currently thought to repress DNA methylation and suppress tumorigenesis by protecting against de novo methylation. Here, we report that members of the miR-29 family repress the activities of DNA methyltransferases and DNA demethylases, which have opposing roles in control of DNA methylation status. Members of the miR-29 family directly inhibited DNA methyltransferases and two major factors involved in DNA demethylation, namely tet methylcytosine dioxygenase 1 (TET1 and thymine DNA glycosylase (TDG. Overexpression of miR-29 upregulated the global DNA methylation level in some cancer cells and downregulated DNA methylation in other cancer cells, suggesting that miR-29 suppresses tumorigenesis by protecting against changes in the existing DNA methylation status rather than by preventing de novo methylation of DNA.

  16. Rapid restriction enzyme free detection of DNA methyltransferase activity based on DNA-templated silver nanoclusters.

    Science.gov (United States)

    Kermani, Hanie Ahmadzade; Hosseini, Morteza; Dadmehr, Mehdi; Ganjali, Mohammad Reza

    2016-06-01

    DNA methylation has significant roles in gene regulation. DNA methyltransferase (MTase) enzyme characterizes DNA methylation and also induces an aberrant methylation pattern that is related to many diseases, especially cancers. Thus, it is required to develop a method to detect the DNA MTase activity. In this study, we developed a new sensitive and reliable method for methyltransferase activity assay by employing DNA-templated silver nanoclusters (DNA/Ag NCs) without using restriction enzymes. The Ag NCs have been utilized for the determination of M.SssI MTase activity and its inhibition. We designed an oligonucleotide probe which contained an inserted six-cytosine loop as Ag NCs formation template. The changes in fluorescence intensity were monitored to quantify the M.SssI activity. The fluorescence spectra showed a linear decrease in the range of 0.4 to 20 U/ml with a detection limit of 0.1 U/ml, which was significant compared with previous reports. The proposed method was applied successfully for demonstrating the Gentamicin effect as MTase inhibitor. The proposed method showed convenient reproducibility and sensitivity indicating its potential for the determination of methyltransferase activity. PMID:27052776

  17. Methylated nucleosides in tRNA and tRNA methyltransferases

    Directory of Open Access Journals (Sweden)

    Hiroyuki eHori

    2014-05-01

    Full Text Available To date, more than 90 modified nucleosides have been found in tRNA and the biosynthetic pathways of the majority of tRNA modifications include a methylation step(s. Recent studies of the biosynthetic pathways have demonstrated that the availability of methyl group donors for the methylation in tRNA is important for correct and efficient protein synthesis. In this review, I focus on the methylated nucleosides and tRNA methyltransferases. The primary functions of tRNA methylations are linked to the different steps of protein synthesis, such as the stabilization of tRNA structure, reinforcement of the codon–anticodon interaction, regulation of wobble base pairing, and prevention of frameshift errors. However, beyond these basic functions, recent studies have demonstrated that tRNA methylations are also involved in the RNA quality control system and regulation of tRNA localization in the cell. In a thermophilic eubacterium, tRNA modifications and the modification enzymes form a network that responses to temperature changes. Furthermore, several modifications are involved in genetic diseases, infections, and the immune response. Moreover, structural, biochemical, and bioinformatics studies of tRNA methyltransferases have been clarifying the details of tRNA methyltransferases and have enabled these enzymes to be classified. In the final section, the evolution of modification enzymes is discussed.

  18. Purification of homologous protein carboxyl methyltransferase isozymes from human and bovine erythrocytes

    International Nuclear Information System (INIS)

    The authors have purified the two major isozymes of the L-isoaspartyl/D-aspartyl protein methyltransferase from both human and bovine erythrocytes. These four enzymes all have polypeptide molecular weights of approximately 26,500 and appear to be monomers in solution. Each of these enzymes cross-reacts with antibodies directed against protein carboxyl methyltransferase I from bovine brain. Their structures also appear to be similar when analyzed by dodecyl sulfate gel electrophoresis for the large fragments produced by digestion with Staphylococcus aureus protease V8 or when analyzed by high-performance liquid chromatography (HPLC) for tryptic peptides. The structural relatedness of these enzymes was confirmed by sequence analysis of a total of 433 residues in 32 tryptic fragments of the human erythrocyte isozymes I and II and of the bovine erythrocyte isozyme II. They found sequence identity or probable identity in 111 out of 112 residues when they compared the human isozymes I and II and identities in 127 out of 134 residues when the human and bovine isozymes II were compared. These results suggest that the erythrocyte isozymes from both organisms may have nearly identical structures and confirm the similarities in the function of these methyltransferases that have been previously demonstrated

  19. Transcriptome profiling of Set5 and Set1 methyltransferases: Tools for visualization of gene expression

    Directory of Open Access Journals (Sweden)

    Glòria Mas Martín

    2014-12-01

    Full Text Available Cells regulate transcription by coordinating the activities of multiple histone modifying complexes. We recently identified the yeast histone H4 methyltransferase Set5 and discovered functional overlap with the histone H3 methyltransferase Set1 in gene expression. Specifically, using next-generation RNA sequencing (RNA-Seq, we found that Set5 and Set1 function synergistically to regulate specific transcriptional programs at subtelomeres and transposable elements. Here we provide a comprehensive description of the methodology and analysis tools corresponding to the data deposited in NCBI's Gene Expression Omnibus (GEO under the accession number GSE52086. This data complements the experimental methods described in Mas Martín G et al. (2014 and provides the means to explore the cooperative functions of histone H3 and H4 methyltransferases in the regulation of transcription. Furthermore, a fully annotated R code is included to enable researchers to use the following computational tools: comparison of significant differential expression (SDE profiles; gene ontology enrichment of SDE; and enrichment of SDE relative to chromosomal features, such as centromeres, telomeres, and transposable elements. Overall, we present a bioinformatics platform that can be generally implemented for similar analyses with different datasets and in different organisms.

  20. Arsenic (+3 oxidation state) methyltransferase and the inorganic arsenic methylation phenotype

    International Nuclear Information System (INIS)

    Inorganic arsenic is enzymatically methylated; hence, its ingestion results in exposure to the parent compound and various methylated arsenicals. Both experimental and epidemiological evidences suggest that some of the adverse health effects associated with chronic exposure to inorganic arsenic may be mediated by these methylated metabolites. If i As methylation is an activation process, then the phenotype for inorganic arsenic methylation may determine risk associated with exposure to this metalloid. We examined inorganic arsenic methylation phenotypes and arsenic (+3 oxidation state) methyltransferase genotypes in four species: three that methylate inorganic arsenic (human (Homo sapiens), rat (Rattus norwegicus), and mouse (Mus musculus)) and one that does not methylate inorganic arsenic (chimpanzee, Pan troglodytes). The predicted protein products from arsenic (+3 oxidation state) methyltransferase are similar in size for rat (369 amino acid residues), mouse (376 residues), and human (375 residues). By comparison, a 275-nucleotide deletion beginning at nucleotide 612 in the chimpanzee gene sequence causes a frameshift that leads to a nonsense mutation for a premature stop codon after amino acid 205. The null phenotype for inorganic arsenic methylation in the chimpanzee is likely due to the deletion in the gene for arsenic (+3 oxidation state) methyltransferase that yields an inactive truncated protein. This lineage-specific loss of function caused by the deletion event must have occurred in the Pan lineage after Homo-Pan divergence about 5 million years ago

  1. Histone tails regulate DNA methylation by allosterically activating de novo methyltransferase

    Institute of Scientific and Technical Information of China (English)

    Bin-Zhong Li; Guo-Liang Xu; Zheng Huang; Qing-Yan Cui; Xue-Hui Song; Lin Du; Albert Jeltsch; Ping Chen; Guohong Li; En Li

    2011-01-01

    Cytosine methylation of genomic DNA controls gene expression and maintains genome stability. How a specific DNA sequence is targeted for methylation by a methyltransferase is largely unknown. Here, we show that histone H3 tails lacking lysine 4 (K4) methylation function as an allosteric activator for methyltransferase Dnmt3a by binding to its plant homeodomain (PHD). In vitro, histone H3 peptides stimulated the methylation activity of Dnmt3a up to 8-fold, in a manner reversely correlated with the level of K4 methylation. The biological significance of allosteric regulation was manifested by molecular modeling and identification of key residues in both the PHD and the catalytic domain of Dnmt3a whose mutations impaired the stimulation of methylation activity by H3 peptides but not the binding of H3 peptides. Significantly, these mutant Dnmt3a proteins were almost inactive in DNA methylation when expressed in mouse embryonic stem cells while their recruitment to genomic targets was unaltered. We therefore propose a two-step mechanism for de novo DNA methylation - first recruitment of the methyltransferase probably assisted by a chromatin- or DNA-binding factor, and then allosteric activation depending on the interaction between Dnmt3a and the histone tails - the latter might serve as a checkpoint for the methylation activity.

  2. Chromatin Targeting of de Novo DNA Methyltransferases by the PWWP Domain

    Institute of Scientific and Technical Information of China (English)

    Ying-ZiGe; Min-TiePu; HumairaGowher; Hai-PingWu; Jian-PingDing; AlbertJeltsch; Guo-LiangXu

    2005-01-01

    DNA methylation patterns of mammalian genomes are generated in gametogenesis and early embryonic development. Two de novo DNA methyltransferases, Dnmt3a and Dnmt3b, are responsible for the process. Both en-zymes contain a long N-terminal regulatory region linked to a conserved C-terminal domain responsible forthe catalytic activity. Although a PWWP domain in the N-terminal region has been shown to bind DNA in vitro, it is unclear how the DNA methyltransferases access their substrate in chromatin in vivo. We show here that the two proteins are associated with chromatin including mitotic chromosomes in mammalian cells, and the PWWP domain is essential for the chromatin targeting of the enzymes. The functional significance of PWWPmediated chromatin targeting is suggested by the fact that a missense mutation in this domain of human DNMT3B causes immunodeficiency, centromeric heterochromatin instability, facial anomalies (ICF) syndrome, which is characterized by loss of methylation insatellite DNA, pericentromeric instability, and immunodeficiency. We demonstrate that the mutant protein completely loses its chromatin targeting capacity. Our data establish the PWWP domain as a novel chromatin/chromosome-targeting module and suggest that the PWWP-mediated chromatin association is essential for the function of the de novo methyltransferases during development.

  3. Kinetic analysis of Yersinia pestis DNA adenine methyltransferase activity using a hemimethylated molecular break light oligonucleotide.

    Directory of Open Access Journals (Sweden)

    Robert J Wood

    Full Text Available BACKGROUND: DNA adenine methylation plays an important role in several critical bacterial processes including mismatch repair, the timing of DNA replication and the transcriptional control of gene expression. The dependence of bacterial virulence on DNA adenine methyltransferase (Dam has led to the proposal that selective Dam inhibitors might function as broad spectrum antibiotics. METHODOLOGY/PRINCIPAL FINDINGS: Herein we report the expression and purification of Yersinia pestis Dam and the development of a continuous fluorescence based assay for DNA adenine methyltransferase activity that is suitable for determining the kinetic parameters of the enzyme and for high throughput screening against potential Dam inhibitors. The assay utilised a hemimethylated break light oligonucleotide substrate containing a GATC methylation site. When this substrate was fully methylated by Dam, it became a substrate for the restriction enzyme DpnI, resulting in separation of fluorophore (fluorescein and quencher (dabcyl and therefore an increase in fluorescence. The assays were monitored in real time using a fluorescence microplate reader in 96 well format and were used for the kinetic characterisation of Yersinia pestis Dam, its substrates and the known Dam inhibitor, S-adenosylhomocysteine. The assay has been validated for high throughput screening, giving a Z-factor of 0.71+/-0.07 indicating that it is a sensitive assay for the identification of inhibitors. CONCLUSIONS/SIGNIFICANCE: The assay is therefore suitable for high throughput screening for inhibitors of DNA adenine methyltransferases and the kinetic characterisation of the inhibition.

  4. The Eukaryotic DNMT2 Genes Encode a New Class of Cytosine-5 DNA Methyltransferases

    Institute of Scientific and Technical Information of China (English)

    Lin-YaTang; M.NarsaReddy; VanyaRasheva; Tai-LinLee; Meng-JauLin; Ming-ShiuHung; C.-K.JamesShen

    2005-01-01

    DNMT2 is a subgroup of the eukaryotic cytosine-5 DNA methyltransferase gene family. Unlike the other family members, proteins encoded by DNMT2 genes were not known before to possess DNA methyltransferase activities. Most recently, we have showm that thegenome of Drosophila S2 cells stably expressing an exogenous Drosophila dDNMT2 cDNA became anoma-lously methylated at the 5'-positions of cytosines(Reddy, M. N., Tang, L. Y., Lee, T. L., and Shen, C.-K. J.(2003) Oncogene, in press). We present evidence here that the genomes of transgenic flies overexpressing the dDnmt2 protein also became hypermethylated at specific regions. Furthermore, transient transfection studies in combination with sodium bisulfite sequencing demonstrated that dDnmt2 as well as its mousc ortholog, mDnmt2, are capable of methylating a cotrans-fected plasmid DNA. These data provide solid evidence that the fly and mouse DNMT2 gene products are genuine cytosine-5 DNA methyltransferases.

  5. A novel methyltransferase from the intracellular pathogen Plasmodiophora brassicae methylates salicylic acid.

    Science.gov (United States)

    Ludwig-Müller, Jutta; Jülke, Sabine; Geiß, Kathleen; Richter, Franziska; Mithöfer, Axel; Šola, Ivana; Rusak, Gordana; Keenan, Sandi; Bulman, Simon

    2015-05-01

    The obligate biotrophic pathogen Plasmodiophora brassicae causes clubroot disease in Arabidopsis thaliana, which is characterized by large root galls. Salicylic acid (SA) production is a defence response in plants, and its methyl ester is involved in systemic signalling. Plasmodiophora brassicae seems to suppress plant defence reactions, but information on how this is achieved is scarce. Here, we profile the changes in SA metabolism during Arabidopsis clubroot disease. The accumulation of SA and the emission of methylated SA (methyl salicylate, MeSA) were observed in P. brassicae-infected Arabidopsis 28 days after inoculation. There is evidence that MeSA is transported from infected roots to the upper plant. Analysis of the mutant Atbsmt1, deficient in the methylation of SA, indicated that the Arabidopsis SA methyltransferase was not responsible for alterations in clubroot symptoms. We found that P. brassicae possesses a methyltransferase (PbBSMT) with homology to plant methyltransferases. The PbBSMT gene is maximally transcribed when SA production is highest. By heterologous expression and enzymatic analyses, we showed that PbBSMT can methylate SA, benzoic and anthranilic acids.

  6. Callus cell proliferation from broccoli leaf slice using IBA and BAP in vitro culture: Its biochemical and antioxidant properties.

    Science.gov (United States)

    Sharif Hossain, A B M; Haq, Imdadul; Ibrahim, Nasir A; Aleissa, Mohammed Saad

    2016-03-01

    Plant tissue or cell culture keeps a significant role in micro-propagation in the plant production industry. Combination of 6-Benzylaminopurine (BAP) and other plant growth regulators like 1-Naphthaleneacetic acid (NAA) or Indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA) was used in the most of the research in tissue culture. The study was carried out to investigate the optimization of the concentration of IBA and BAP combination (0, 0.25, 0.50, 1.0, 1.50, 2.0, 2.5, 3.0 and 3.5 mg/l) for the root, callus and leaf proliferation from the leaf cutting slice. The highest number (6.75) of root proliferation was observed in the concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination. The callus initiation was found in the concentration of IBA 1.0-3.5 mg/l+BAP 1.0-2.0 mg/l. However, the highest callus weight was observed at the concentration of IBA 1.5 mg/l+BAP 1.0 mg/l combination than other combination of concentrations. Positively leaf initiation and formation was better in the concentration of IBA 1-3.5 mg/l+BAP 1.0-2.0 mg/l combination. In addition, the 2,2-diphenyl-2-picrylhydarzyl (DPPH) free radical scavenging potential was higher (70.1%) in leaves extract than in callus extracts (46.3%) at the concentration of 10 mg/ml though both extracts had lower DPPH free radical scavenging activity compared to the positive control, vitamin C and BHT. Theresults conclude that the optimum concentration was IBA 1.5 mg/l+BAP 1.0 mg/l combination to produce callus cell proliferation and concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination was the optimum for root proliferation of broccoli in vitro.

  7. Callus cell proliferation from broccoli leaf slice using IBA and BAP in vitro culture: Its biochemical and antioxidant properties

    Directory of Open Access Journals (Sweden)

    A.B.M. Sharif Hossain

    2016-03-01

    Full Text Available Plant tissue or cell culture keeps a significant role in micro-propagation in the plant production industry. Combination of 6-Benzylaminopurine (BAP and other plant growth regulators like 1-Naphthaleneacetic acid (NAA or Indole-3-acetic acid (IAA or indole-3-butyric acid (IBA was used in the most of the research in tissue culture. The study was carried out to investigate the optimization of the concentration of IBA and BAP combination (0, 0.25, 0.50, 1.0, 1.50, 2.0, 2.5, 3.0 and 3.5 mg/l for the root, callus and leaf proliferation from the leaf cutting slice. The highest number (6.75 of root proliferation was observed in the concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination. The callus initiation was found in the concentration of IBA 1.0–3.5 mg/l+BAP 1.0–2.0 mg/l. However, the highest callus weight was observed at the concentration of IBA 1.5 mg/l+BAP 1.0 mg/l combination than other combination of concentrations. Positively leaf initiation and formation was better in the concentration of IBA 1–3.5 mg/l+BAP 1.0–2.0 mg/l combination. In addition, the 2,2-diphenyl-2-picrylhydarzyl (DPPH free radical scavenging potential was higher (70.1% in leaves extract than in callus extracts (46.3% at the concentration of 10 mg/ml though both extracts had lower DPPH free radical scavenging activity compared to the positive control, vitamin C and BHT. Theresults conclude that the optimum concentration was IBA 1.5 mg/l+BAP 1.0 mg/l combination to produce callus cell proliferation and concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination was the optimum for root proliferation of broccoli in vitro.

  8. The use of biodegradable mulch for tomato and broccoli production: Crop yield and quality, mulch deterioration, and growers' perceptions

    Science.gov (United States)

    Cowan, Jeremy Scott

    Biodegradable mulch may offer the benefits of polyethylene mulch for crop production with the added benefit of biodegradability. Four studies were carried out in Mount Vernon, WA to evaluate biodegradable mulch for tomato (Solanum lycopersicum L.) and broccoli (Brassica oleracea var. italica) production. The first study compared four biodegradable mulch treatments: BioAgri, BioTelo, WeedGuardPlus (cellulose product), and SB-PLA-10/11/12 (experimental, non-woven fabric), to polyethylene mulch and bare ground in high tunnels and in the open field for tomato yield and fruit quality over three growing seasons. Biodegradable plastic films produced yields and fruit quality comparable to polyethylene. Moreover, high tunnels increased total and marketable fruit weight five and eight times, respectively, compared to the open field. The second study quantified relationships among visual assessment parameters and mulch mechanical properties. Visual assessments and mechanical property tests of polyethylene, BioAgri, BioTelo, WeedGuardPlus, and SB-PLA-10/11/12, were made over three growing seasons. Regression analyses found the strongest relationship overall (r2 = 0.41) to be between the percent of initial breaking force in the machine direction and log 10 of percent visual deterioration. However, evaluating mulch products individually and increasing sample frequency are recommended for future research. The third study evaluated three biodegradable mulch products, BioAgri, Crown 1, and SB-PLA-11, after soil-incorporation. The average area of recovered mulch fragments decreased for all mulch products over time. The number of mulch fragments initially increased for all mulch products, with the greatest number of Crown 1 and BioAgri fragments recovered 132 and 299 days after incorporation, respectively. At 397 days after soil-incorporation, the total area of recovered fragments of Crown 1 and BioAgri was 0% and 34% of the theoretical maximum area, respectively. The fourth study

  9. The effect of soil mulching with organic mulches, on weed infestation in broccoli and tomato cultivated under polypropylene fibre, and without a cover

    Directory of Open Access Journals (Sweden)

    Kosterna Edyta

    2014-07-01

    Full Text Available An investigation was done on the effect of different types of organic mulches that were applied in form of straw to the soil mulching process, on the weed infestation, number, and fresh mass of weeds in broccoli cv. Milady F1 (Brassica oleracea L. var. italica Plenck and tomato cv. Polfast F1 (Lycopersicon esculentum Mill. grown under polypropylene fibre as a covering, or grown without a covering. The different types of organic straw mulches were: rye (Secale cereale L., corn (Zea mays L., rape (Brassica napus L. subsp. napus, and buckwheat (Fagopyrum esculentum Moench.. All the organic mulches were applied at a dose of 10 t/ha. The effect of the mulches was compared to a control plot which had no mulch. The type of organic mulch applied to the soil mulching process influenced species composition, number, and fresh mass of weeds. This effect could be the result of the properties of the mulch (colour, structure, etc. or the allelopathic effect on the germination and growth of individual weeds species. Irrespective of the investigated factors, 24 and 25 weeds species, respectively, were observed immediately after cover removal and before broccoli and tomato harvest. In the first date of estimation Chenopodium album L., Echinochloa crus-galli (L. P. Beauv., Fallopia convolvulus (L. Á. Löve, Stellaria media (L. Vill., and Viola tricolor L. dominated, however, before the vegetables were harvested Ch. album, V. tricolor, Veronica arvensis L., and E. crus-galli dominated. An application of polypropylene fibre contributed to an increase in the number and fresh mass of weeds in both vegetables in the first date of estimation (after cover removal. During this period, vegetables cannot compete with weeds. It is important to note, though, that before the vegetables were harvested, a decrease was found in the number and fresh mass of weeds in the covered plots. The most efficient weed limiter, both after cover removal and also before the broccoli and

  10. Effect of Zn on seed germination of broccoli%锌对青花菜种子萌发的影响

    Institute of Scientific and Technical Information of China (English)

    刘玲丽; 颉建明; 张帆; 郁继华

    2014-01-01

    以不同Zn2+浓度(0、0.05、0.5、5、10、50、100、200 mg/L)的ZnSO4溶液处理青花菜种子,研究锌对青花菜种子萌发的影响.结果表明:青花菜种子的发芽指标随着Zn2+浓度的增加均表现出先升高后降低的变化趋势;相对发芽率、相对发芽势、发芽指数均在 Zn2+浓度为100 mg/L 时达到最大;活力指数、胚根长、胚芽长和生物量在10 mg/L时达到最大;当Zn2+浓度大于100 mg/L时,对青花菜种子萌发和生长起到抑制作用.%The seeds of broccoli were treated by zinc sulfate solution of different Zn2+ concentrations(0, 0.05,0.5,5,10,50,100,200 mg/L),thus the effect of Zn on seed germination of broccoli was studied.The results showed that all the values of germination indexes firstly increased and then decreased with the in-creasing of Zn2+ concentration.The relative germination rate,relative germination potential and germina-tion index reached to their maximum values when the concentration of Zn2+ was 100 mg/L,while the seed vigor index,radicle root length,bud root length and biomass were all reached to their maximum values when the concentration of Zn2+ was 10 mg/L.When the concentration of Zn2+ was higher than 100 mg/L, it inhibited the germination and growth of broccoli seeds.

  11. 西兰花种子中萝卜硫素酶解浸提工艺研究%Leaching Process Research of Sulforaphane with Broccoli Seeds

    Institute of Scientific and Technical Information of China (English)

    谢述琼; 何珺; 舒华

    2016-01-01

    西兰花中含有丰富的抗癌物质,对大多数癌症都有较强的作用。本文研究了从西兰花种子中酶解浸提萝卜硫素的工艺,确定其最佳的酶解浸提参数。通过单因素梯度实验研究,采用自身芥子苷酶酶解以及密封浸提方式提取西兰花种子中萝卜硫素,主要对酶解时间,酶解料液比,酶解pH,超声浸提乙醇浓度,超声浸提时间,超声浸提次数几种浸提参数进行研究。结果表明:西兰花种子中萝卜硫素酶解浸提最佳条件为:酶解时间为8 h以上,酶解料液比为12,酶解pH为7,超声浸提溶剂为80%乙醇,超声浸提时间为30 min,超声浸提的次数为2次。西兰花种子中萝卜硫素的酶解浸提工艺参数达到最佳时,其提取率可以大大的提高。%Broccoli contains abundant anti-cancer substances, for most cancer it has a stronger effect. This experiment studied Enzyme solution leaching process of sulforaphane in broccoli seeds, determining the optimum enzymic extraction parameters. Through the single factor gradient experiment research, using own mustard glucoside enzyme digestion and seal extraction method to extract sulforaphane in broccoli seeds, enzymatic hydrolysis time, solid-liquid ratio, acidity leaching, extraction of ethanol concentration, extraction time and ultrasonic extraction times were mainly studied. Results showed that the optimum leaching conditions were as follows: enzymolysis time of 8 h, solid-liquid ratio of 12, leaching pH of 7, extraction solvent of 80% ethanol, extraction time for 30 min, the number of ultrasonic extraction of 2 times. The extraction parameter of sulforaphane gets to the best, its extraction efficiency can be greatly improved.

  12. Broccoli production depending on the seed production system and organic and mineral fertilizer Produção de brócolos em função do sistema de produção da semente e do tipo de substrato

    OpenAIRE

    José Carlos Lopes; Janaína Mauri; Adésio Ferreira; Rodrigo S Alexandre; Allan R de Freitas

    2012-01-01

    The experiment was conducted in a greenhouse at the Universidade Federal do Espirito Santo, in Alegre, Espirito Santo state, Brazil, to evaluate the broccoli production depending on the seed production system and organic and mineral fertilization. Seeds of the broccoli cultivar Ramoso Piracicaba were originated from lots of seed obtained in an organic and conventional production system. The experimental design was of randomized blocks, with four replications in a factorial arrangement combina...

  13. Free radical scavenging, antiproliferative activities and profiling of variations in the level of phytochemicals in different parts of broccoli (Brassica oleracea italica).

    Science.gov (United States)

    Chaudhary, Ashun; Sharma, Upendra; Vig, Adarsh Pal; Singh, Bikram; Arora, Saroj

    2014-04-01

    In the present study, the seeds of Broccoli (cultivar Palam samridhi) at different stages of development were being analysed for their antioxidant and antiproliferative properties. Among the antioxidant assays performed, a remarkable inhibition of superoxide radicals i.e. 94.25% observed with extracts of five days old sprout (PS5) at 2 mg/ml concentration. Although, all the extracts showed high cytotoxicity but the floret extract (PSF) found to be most effective with IC₅₀ value of 25.94 μg/ml while leaves extract (PSL) was least effective. The cell cycle analysis showed increased G₀/G₁ phase population as compare to positive control camptothecin. Profiling of various phytochemicals executed by using gas chromatography-mass spectroscopy in order to correlate the bioactivities of the extracts. A wide variation observed in the profile of GLS hydrolytic products of different extracts obtained from the seeds, sprouts (three, five and seven days), leaves and florets.

  14. Green pests and diseases-controlling techniques and efficacy of broccoli%花椰菜病虫害绿色防控技术及其效果

    Institute of Scientific and Technical Information of China (English)

    张明真

    2012-01-01

    福建省云霄县佳州村“佳田农民专业合作社”蔬菜生产基地推广实施花椰菜病虫害绿色防控技术,取得显著成效。该文介绍了绿色防控技术的示范效果及主要措施。%Green pests and diseases-controlling techniques of broccoli were popularized and applied to vegetable production bases of Jia tian farmers' professional co-operatives in Jia zhou village, Yunxiao county, Fujian province. This demonstration obtained significant effect. This paper introduced the demonstration effect and main measures of green controlling techniques.

  15. 青花菜新品种瑞青8号的选育%Breeding of Broccoli New Variety Ruiqing No.8

    Institute of Scientific and Technical Information of China (English)

    秦文斌; 戴忠良; 吴国平; 王建华; 张振超; 潘跃平

    2013-01-01

    瑞青8号是以青花菜细胞质雄性不育材料CMS034为不育源,与优良稳定的青花菜自交系0512经过多代回交转育,育成的不育性稳定、经济性状良好的青花菜细胞质雄性不育系CMS0512,再以雄性不育系CMS0512为母本,优良的青花菜自交系038为父本配制的杂交一代品种.瑞青8号株高60 em左右,株幅65 cm左右,叶色绿,叶面光滑;花球半球形,横径17.5 cm左右,纵径14 cm左右;花球紧密,蕾粒细小,色浓绿,花茎细,不中空,单花球重0.55 kg左右,产量达1400 kg/667 m2左右.属中早熟,定植后72 d左右采收,腋芽2~4个,在主花球采收后,侧花球可连续采收1~2次,植株生长势强、整齐度高、抗逆性强,抗霜霉病、黑腐病.%Cauliflower male sterile line CMS034 used as sterile source was crossed and backcrossed by broccoli inbred line 0512 with excellent stability for several successive generations, and broccoli oytoplasmic male sterile line CMS0512 with stable sterility and good economic traits was bred. Then, CMS0512 (female parent) was hybridized by good broccoli inbred line 038 (male parent) , finally the broccoli hybrid Ruiqing No. 8 was bred. The plant height of Ruiqing No. 8 is about 60 cm, and its plant breadth is about 65 cm with green and glossy leaves. The ball - flower is semi - circular and close with the horizontal diameter of a-bout 17.5 cm and vertical diameter of about 14 cm, and it has small bud granulocyte, dark green color, and fine flower stems without hollow. Its single ball - flower is about 0. 55 kg in weight, and its yield is about 1400 kg/667 m2. Ruiqing No. 8 belongs to middle - early maturing variety, and it can be harvested about 72 d after transplanting. This variety has 2-4 axillary buds. After the harvest of main ball - flower, the lateral ball - flowers can be picked continuously for 1 ~ 2 times. Ruiqing No. 8 has strong growth potential, high uniformity, strong adversity resistance, and resistance to downy mildew and

  16. 青花菜主要农艺性状的相关分析%Correlation Analysis of Main Agronomic Characters of Broccoli (B. oleracea var. italica)

    Institute of Scientific and Technical Information of China (English)

    陆信娟; 杨峰; 樊继德

    2011-01-01

    The 21 agronomic characters of 29 cultivars of broccoli (B. oleracea L. var. italica Planch. ) were evaluated, and the correlations among these agronomic characters were analyzed. The correlation analysis indicated that there were significant correlations (P < 0. 05 ) between 23 pairs of characters and very significant correlations (P < 0. 01 ) between 14 pairs of characters.%对29个青花菜品种的21个农艺性状进行了评价和相关分析.相关分析结果表明: 23对性状之间相关性达到显著水平,14对性状之间相关性达到极显著水平.

  17. 中早熟花椰菜品种对比试验初报%Comparison Test of Early Maturing Broccoli Varieties

    Institute of Scientific and Technical Information of China (English)

    孙国坤; 叶明鑫; 黄永修; 李文北

    2015-01-01

    In this test, Fengtianquansong 65d, Changsheng 65d and other 8 new cauliflower varieties were introduced, with Qingnong 65d as comparison. The results showed that there was strong disease resistance, good quality, and high yield in Changsheng 65d. Therefore, Changsheng 65d could be considered as early maturing broccoli variety and extended at Xiamen area.%本实验引进了丰田全松65d、长胜65d等8个青梗花椰菜新品种,以庆农65d作为对照进行比较试验。结果发现,长胜65d品种抗病性强、品质好、产量高、市场畅销,可作为厦门秋季花椰菜中早熟品种进行推广种植。

  18. Variety of Sulforaphane Content Among 15 Broccoli Sprouts%15个西兰花芽苗菜中萝卜硫素含量差异研究

    Institute of Scientific and Technical Information of China (English)

    高灿红; 林俊城; 徐福乐; 郑金贵

    2012-01-01

    High nutrition, rich in sulforaphane, could prevent and inhibit cancer make broccoli sprouts becoming popular in foreign. Composite design of response surface analysis was taken to optimize the extraction of sulforaphane from broccoli sprouts. Then, the optimization extraction method was used to analyze variation of sulforaphane content among 15 broccoli sprouts. The result showed that optimization of extraction method was transonic processing time of 12 min, pH value of 5.0 and hydrolysis time of 4.3 h. There was a significant deference in content of sulforaphane among 15 germplasms of broccoli sprouts. The highest one was CDBY-10 (506.896 (μg/g) and the lowest one was CDBY-22 (50.416 μg/g). Most of their contents were between 0-200 μg/g, frequency fitting were not well. Anymore, sulforaphane content in most of the germplasms was in line with late-maturing>early-maturing>mid-maturing. CDBY-10, CDBY-20, CDBY-15 needed to be further studied and business developed as high sulforaphane content cultivars.%西兰花芽苗菜营养价值高且富含萝卜硫素,具有预防和抑制癌症的功效.为分析种质资源间萝卜、硫素含量的差异,采用响应面中心复合设计法对超声浸提时间、水解时间和提取液pH条件3个因素进行优化分析,获得最优萝卜硫素提取方法,并用该方法对种质资源中萝卜硫素含量差异分析.结果表明,超声处理时间为12 min、pH条件为5.0、水解时间为4.3 h是提取西兰花芽苗菜萝卜、硫素的最佳条件.利用该方法检测到15个种质资源的芽苗菜中萝卜硫素含量差异显著,其中CDBY-10中含量最高(506.896 μg/g)、CDBY-22中含量最低(50.416 μg/g).15个种质资源中萝卜硫素含量主要分布在0~200 μg/g,频次拟合不显著.多数种质资源萝卜硫素含量符合晚熟>早熟>中熟的规律.CDBY-10、CDBY-20、CDBY-15可作为高萝卜、硫素西兰花芽苗菜进行深入科学研究和商业开发.

  19. Vigor de sementes de brócolos submetidas a coberturas biodegradáveis e micronutrientes Vigor of broccoli seeds submitted to biodegradable coatings and micronutrients

    Directory of Open Access Journals (Sweden)

    Juliana A. Batista

    2005-07-01

    Full Text Available O desenvolvimento e a aplicação de filmes ou coberturas biodegradáveis na horticultura são técnicas praticadas há vários anos, que visam promover melhoria na qualidade do produto. no presente trabalho desenvolveu-se e caracterizou-se biofilmes de pectina, gelatina e ácidos graxos e verificou-se sua eficiência como cobertura para sementes de brócolos (Brassica oleracea L. var. italica. Os filmes foram caracterizados quanto à solubilidade em água. A contagem e a observação de plantas de brócolos, a partir da germinação de sementes cobertas e não cobertas foi realizada em média a cada três dias, aos 27 dias fêz-se a quantificação da matéria fresca e seca. Os filmes de pectina e ácido esteárico foram 100% solúveis em água, enquanto os elaborados com pectina e gelatina (1/1 foram apenas 18%. A aplicação das coberturas filmogênicas nas sementes de brócolos não afetou a emergência das plantas, demonstrando assim sua potencialidade para uso comercial. Os fertilizantes molibdato de sódio (0,2 mg L-1 e ácido bórico (1mg L-1, aplicados juntamente com os biofilmes, também não afetaram a emergência e o desenvolvimento das plantas.The development and application of biodegradable coatings and films have been used for many years in order to improve quality of the coated or packed product. The development and characterization of pectin and pectin/gelatin-based biofilms with fatty acids was evaluated and verified their efficiency as coatings to broccoli seeds (Brassica oleracea L. var. italica. The solubility in water of the films was determined. The counting and visual observations of the germinated broccoli seeds were done each three days and fresh and dried weight of the plants were determined at the end of the experiment. Pectin-based films with stearic acid were 100% soluble in water and composite films of pectin and gelatin were 18%. The application of the biodegradable coatings on broccoli seeds had no effect on the

  20. Effects of Trichoderma harzianum Rifai over Plasmodiophora brassicae Woronin in broccoli, in Escagüey, municipality of Rangel, Mérida State

    Directory of Open Access Journals (Sweden)

    Mirna Labrador Morales

    2016-03-01

    Full Text Available The effectiveness of Trichoderma harzianum in suppressing clubroot of brassicas, which is caused by Plasmodiophora brassicae, was tested on broccoli (Brassica oleracea var. italica Plenck, in field conditions, in Escagüey, municipality of Rangel, Merida State, Venezuela. The experiment showed that the applications of a biopesticide based on this antagonist had a significant effect on the percentage of health plants and the crop yields, in dependence of the dose used. In addition, the relation benefits/cost was also favorable. These results showed that, for these particular conditions, P. brassicae is an adequate biological alternative to control the clubroot of brassicas, no aggressive to environment and human beings, useful for the transition phase toward a sustainable agriculture, without chemical pesticides.

  1. The catechol-O-methyltransferase inhibitory potential of Z-vallesiachotamine by in silicoand in vitro approaches

    Directory of Open Access Journals (Sweden)

    Carolina dos Santos Passos

    2015-08-01

    Full Text Available AbstractZ-Vallesiachotamine is a monoterpene indole alkaloid that has a β-N-acrylate group in its structure. This class of compounds has already been described in different Psychotriaspecies. Our research group observed that E/Z-vallesiachotamine exhibits a multifunctional feature, being able to inhibit targets related to neurodegeneration, such as monoamine oxidase A, sirtuins 1 and 2, and butyrylcholinesterase enzymes. Aiming at better characterizing the multifunctional profile of this compound, its effect on cathecol-O-methyltransferase activity was investigated. The cathecol-O-methyltransferase activity was evaluated in vitro by a fluorescence-based method, using S-(5′-adenosyl-l-methionine as methyl donor and aesculetin as substrate. The assay optimization was performed varying the concentrations of methyl donor (S-(5′-adenosyl-l-methionine and enzyme. It was observed that the highest concentrations of both factors (2.25 U of the enzyme and 100 µM of S-(5′-adenosyl-l-methionine afforded the more reproducible results. The in vitro assay demonstrated that Z-vallesiachotamine was able to inhibit the cathecol-O-methyltransferase activity with an IC50 close to 200 µM. Molecular docking studies indicated that Z-vallesiachotamine can bind the catechol pocket of catechol-O-methyltransferase enzyme. The present work demonstrated for the first time the inhibitory properties of Z-vallesiachotamine on cathecol-O-methyltransferase enzyme, affording additional evidence regarding its multifunctional effects in targets related to neurodegenerative diseases.

  2. 青花菜新品种湘绿2号、湘绿3号光合特性比较%Comparison of Photosynthetic Characteristics between New Broccoli Cultivars Xianglv No.2 and Xianglv No.3

    Institute of Scientific and Technical Information of China (English)

    姚丹燕; 吴秋云; 龚意辉; 黄科

    2013-01-01

    The new broccoli cultivars,Xianglv No.2 and Xianglv No.3,were taken as materials and broccoli cultivar Shenglv was taken as control to compare the photosynthetic characteristics among the three broccoli cultivars.The results indicated that the leaf photosynthetic rate showed a positive correlation with yield of broccoli,namely the yield of broccoli was high when leaf photosynthetic rate was high without midday depression.The Xianglv No.3 had the highest activity of nitrate reductase,relatively high photosynthetic efficiency and yield,but its fertilizer tolerance was weak.The Xianglv No.2 had the lowest activity of nitrate reductase,the highest photosynthetic efficiency and yield,its fertilizer tolerance was also strong.The assimilation ability of broccoli to nitrate nitrogen was strong in Xianglv No.3 and weak in Xianglv No.2.The Xianglv No.2 could be extended because its yield is the highest,and it is a crop with high photosynthetic efficiency.%以青花菜新品种湘绿2号、湘绿3号为材料,以青花菜圣绿品种为对照,比较了3种青花菜品种的光合特性.结果表明:青花菜叶片的光合速率与产量呈正相关,叶片光合速率高,其产量也高,且没有午休现象.湘绿3号硝酸还原酶活性最高,光合效率也比较高,产量较高,耐肥性弱;湘绿2号硝酸还原酶活性最低,光合效率最高,产量也最高,耐肥性强.湘绿3号对硝态氮的吸收同化能力强,湘绿2号对硝态氮的吸收同化能力弱.湘绿2号产量最高,是高光效的作物,可以推广种植.

  3. 基于颜色参数变化的青花菜叶绿素含量预测模型%A Prediction Model for Chlorophyll Content in Post-harvest Broccoli Based on Color Parameter Changes

    Institute of Scientific and Technical Information of China (English)

    许凤; 杨震峰; 裴娇艳; 郑永华

    2011-01-01

    为研究青花菜贮藏期间叶绿素含量和颜色变化的关系,通过不同温度贮藏实验建立基于颜色参数-a/b值的叶绿素含量预测模型。将青花菜贮藏在273、278、283、293、303K条件下,测定花蕾-a/b值和叶绿素含量的变化。基于Arrhenius动力学方程分别建立青花菜-a/b值、叶绿素含量与贮藏时间和温度之间的动力学模型,再根据-a/b值与叶绿素含量变化的线性关系,进一步建立基于-a/b值的叶绿素含量预测模型。在275、280、285、295、305K贮藏温度条件下对基于-a/b值的叶绿素含量预测模型进行验证,%In order to explore the relationship between chlorophyll content and color change of post-harvest broccoli during storage,a prediction model for chlorophyll content was established based on color parameter changes.Freshly harvested broccoli was stored at different temperatures(273,278,283,293 K and 303 K),and the color parameter-a/b value and chlorophyll content of broccoli were determined.Kinetic models of-a/b value and chlorophyll content with respect to storage time and temperature were established on the basis of Arrhenius equation.In addition,a prediction model for chlorophyll content based on-a/b value was further developed according to the linear relationship between chlorophyll content and-a/b value.Moreover,the prediction model for chlorophyll content based on-a/b value was validated using broccoli stored at 275,280,285,295 K and 305 K with a relative prediction error of 4.31%.The chlorophyll content of broccoli can be accurately predicted at the storage temperature from 273 K to 305 K using this prediction model.Therefore,the prediction model is acceptable for applying the color parameter-a/b to evaluate broccoli quality.

  4. Comparison of New Broccoli Cultivars in Jiangsu Area%江苏地区青花菜新品种比较试验

    Institute of Scientific and Technical Information of China (English)

    宋立晓; 曾爱松; 高兵; 严继勇

    2014-01-01

    2011-2012年,在江苏南京以圣绿为对照,对江苏省近年来育成的6个青花菜品种进行比较试验。试验结果表明,苏绿3号、苏绿2号、瑞绿5号和瑞绿6号4个品种单花球质量大,产量高,商品花球合格率较高,抗病性强,营养品质较佳,综合性状较好,可作为保鲜出口或中球内销预选品种在江苏省推广种植,为江苏省选择高产、优质、商品性佳的青花菜新品种提供了基础依据。%We took Shenglv as control cultivar, and carried out the comparative test of six broccoli cultivars from 2011 to 2012. The results showed that the four cultivars Sulv No.3, Sulv No.2, Ruilv No.5 and Ruilv No.6 had outstanding comprehensive characters, and their single flower head weight, yield, commercial qualification rate, resistance to diseases and nutrition quality were better than those of control and the other cultivars, so they were suitable for extension of cultivation in Jiangsu area for fresh-keeping export and domestic sales. Furthermore, this comparative test provided basic references for screening of new broccoli cultivars with high yield, excellent quality and good commercial characters.

  5. Water balance and N-metabolism in broccoli (Brassica oleracea L. var. Italica) plants depending on nitrogen source under salt stress and elevated CO2.

    Science.gov (United States)

    Zaghdoud, Chokri; Carvajal, Micaela; Ferchichi, Ali; Del Carmen Martínez-Ballesta, María

    2016-11-15

    Elevated [CO2] and salinity in the soils are considered part of the effects of future environmental conditions in arid and semi-arid areas. While it is known that soil salinization decreases plant growth, an increased atmospheric [CO2] may ameliorate the negative effects of salt stress. However, there is a lack of information about the form in which inorganic nitrogen source may influence plant performance under both conditions. Single factor responses and the interactive effects of two [CO2] (380 and 800ppm), three different NO3(-)/NH4(+) ratios in the nutrient solution (100/0, 50/50 and 0/100, with a total N concentration of 3.5mM) and two NaCl concentrations (0 and 80mM) on growth, leaf gas exchange parameters in relation to root hydraulic conductance and N-assimilating enzymes of broccoli (Brassica oleracea L. var. Italica) plants were determined. The results showed that a reduced NO3(-) or co-provision of NO3(-) and NH4(+) could be an optimal source of inorganic N for broccoli plants. In addition, elevated [CO2] ameliorated the effect of salt exposure on the plant growth through an enhanced rate of photosynthesis, even at low N-concentration. However, NO3(-) or NO3(-)/NH4(+) co-provision display differential plant response to salt stress regarding water balance, which was associated to N metabolism. The results may contribute to our understanding of N-fertilization modes under increasing atmospheric [CO2] to cope with salt stress, where variations in N nutrition significantly influenced plant response.

  6. Dietary Intake of Sulforaphane-Rich Broccoli Sprout Extracts during Juvenile and Adolescence Can Prevent Phencyclidine-Induced Cognitive Deficits at Adulthood.

    Directory of Open Access Journals (Sweden)

    Yumi Shirai

    Full Text Available Oxidative stress and inflammation play a role in cognitive impairment, which is a core symptom of schizophrenia. Furthermore, a hallmark of the pathophysiology of this disease is the dysfunction of cortical inhibitory γ-aminobutyric acid (GABA neurons expressing parvalbumin (PV, which is also involved in cognitive impairment. Sulforaphane (SFN, an isothiocyanate derived from broccoli, is a potent activator of the transcription factor Nrf2, which plays a central role in the inducible expressions of many cytoprotective genes in response to oxidative stress. Keap1 is a cytoplasmic protein that is essential for the regulation of Nrf2 activity. Here, we found that pretreatment with SFN attenuated cognitive deficits, the increase in 8-oxo-dG-positive cells, and the decrease in PV-positive cells in the medial prefrontal cortex and hippocampus after repeated administration of phencyclidine (PCP. Furthermore, PCP-induced cognitive deficits were improved by the subsequent subchronic administration of SFN. Interestingly, the dietary intake of glucoraphanin (a glucosinolate precursor of SFN during the juvenile and adolescence prevented the onset of PCP-induced cognitive deficits as well as the increase in 8-oxo-dG-positive cells and the decrease in PV-positive cells in the brain at adulthood. Moreover, the NRF2 gene and the KEAP1 gene had an epistatic effect on cognitive impairment (e.g., working memory and processing speed in patients with schizophrenia. These findings suggest that SFN may have prophylactic and therapeutic effects on cognitive impairment in schizophrenia. Therefore, the dietary intake of SFN-rich broccoli sprouts during the juvenile and adolescence may prevent the onset of psychosis at adulthood.

  7. Water balance and N-metabolism in broccoli (Brassica oleracea L. var. Italica) plants depending on nitrogen source under salt stress and elevated CO2.

    Science.gov (United States)

    Zaghdoud, Chokri; Carvajal, Micaela; Ferchichi, Ali; Del Carmen Martínez-Ballesta, María

    2016-11-15

    Elevated [CO2] and salinity in the soils are considered part of the effects of future environmental conditions in arid and semi-arid areas. While it is known that soil salinization decreases plant growth, an increased atmospheric [CO2] may ameliorate the negative effects of salt stress. However, there is a lack of information about the form in which inorganic nitrogen source may influence plant performance under both conditions. Single factor responses and the interactive effects of two [CO2] (380 and 800ppm), three different NO3(-)/NH4(+) ratios in the nutrient solution (100/0, 50/50 and 0/100, with a total N concentration of 3.5mM) and two NaCl concentrations (0 and 80mM) on growth, leaf gas exchange parameters in relation to root hydraulic conductance and N-assimilating enzymes of broccoli (Brassica oleracea L. var. Italica) plants were determined. The results showed that a reduced NO3(-) or co-provision of NO3(-) and NH4(+) could be an optimal source of inorganic N for broccoli plants. In addition, elevated [CO2] ameliorated the effect of salt exposure on the plant growth through an enhanced rate of photosynthesis, even at low N-concentration. However, NO3(-) or NO3(-)/NH4(+) co-provision display differential plant response to salt stress regarding water balance, which was associated to N metabolism. The results may contribute to our understanding of N-fertilization modes under increasing atmospheric [CO2] to cope with salt stress, where variations in N nutrition significantly influenced plant response. PMID:27450252

  8. Genetic examination of SETD7 and SUV39H1/H2 methyltransferases and the risk of diabetes complications in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Syreeni, Anna; El-Osta, Assam; Forsblom, Carol;

    2011-01-01

    episodes of hyperglycemia. Epigenetic modifications mediated by histone methyltransferases are associated with gene-activating events that promote enhanced expression of key proinflammatory molecules implicated in vascular injury. In this study, we investigated genetic polymorphisms of the SETD7, SUV39H1......, and SUV39H2 methyltransferases as predictors of risk for micro- and macrovascular complications in type 1 diabetes....

  9. 2'-O methylation of internal adenosine by flavivirus NS5 methyltransferase.

    Directory of Open Access Journals (Sweden)

    Hongping Dong

    Full Text Available RNA modification plays an important role in modulating host-pathogen interaction. Flavivirus NS5 protein encodes N-7 and 2'-O methyltransferase activities that are required for the formation of 5' type I cap (m(7GpppAm of viral RNA genome. Here we reported, for the first time, that flavivirus NS5 has a novel internal RNA methylation activity. Recombinant NS5 proteins of West Nile virus and Dengue virus (serotype 4; DENV-4 specifically methylates polyA, but not polyG, polyC, or polyU, indicating that the methylation occurs at adenosine residue. RNAs with internal adenosines substituted with 2'-O-methyladenosines are not active substrates for internal methylation, whereas RNAs with adenosines substituted with N⁶-methyladenosines can be efficiently methylated, suggesting that the internal methylation occurs at the 2'-OH position of adenosine. Mass spectroscopic analysis further demonstrated that the internal methylation product is 2'-O-methyladenosine. Importantly, genomic RNA purified from DENV virion contains 2'-O-methyladenosine. The 2'-O methylation of internal adenosine does not require specific RNA sequence since recombinant methyltransferase of DENV-4 can efficiently methylate RNAs spanning different regions of viral genome, host ribosomal RNAs, and polyA. Structure-based mutagenesis results indicate that K61-D146-K181-E217 tetrad of DENV-4 methyltransferase forms the active site of internal methylation activity; in addition, distinct residues within the methyl donor (S-adenosyl-L-methionine pocket, GTP pocket, and RNA-binding site are critical for the internal methylation activity. Functional analysis using flavivirus replicon and genome-length RNAs showed that internal methylation attenuated viral RNA translation and replication. Polymerase assay revealed that internal 2'-O-methyladenosine reduces the efficiency of RNA elongation. Collectively, our results demonstrate that flavivirus NS5 performs 2'-O methylation of internal adenosine of

  10. Furanocoumarin biosynthesis in Ammi majus L. Cloning of bergaptol O-methyltransferase.

    Science.gov (United States)

    Hehmann, Marc; Lukacin, Richard; Ekiert, Halina; Matern, Ulrich

    2004-03-01

    Plants belonging to the Apiaceae or Rutaceae accumulate methoxylated psoralens, such as bergapten or xanthotoxin, as the final products of their furanocoumarin biosynthesis, and the rate of accumulation depends on environmental and other cues. Distinct O-methyltransferase activities had been reported to methylate bergaptol to bergapten and xanthotoxol to xanthotoxin, from induced cell cultures of Ruta graveolens, Petroselinum crispum and Ammi majus. Bergaptol 5-O-methyltransferase (BMT) cDNA was cloned from dark-grown Ammi majus L. cells treated with a crude fungal elicitor. The translated polypeptide of 38.7 kDa, composed of 354 amino acids, revealed considerable sequence similarity to heterologous caffeic acid 3-O-methyltransferases (COMTs). For homologous comparison, COMT was cloned from A. majus plants and shown to share 64% identity and about 79% similarity with the BMT sequence at the polypeptide level. Functional expression of both enzymes in Escherichia coli revealed that the BMT activity in the bacterial extracts was labile and rapidly lost on purification, whereas the COMT activity remained stable. Furthermore, the recombinant AmBMT, which was most active in potassium phosphate buffer of pH 8 at 42 degrees C, showed narrow substrate specificity for bergaptol (Km SAM 6.5 micro m; Km Bergaptol 2.8 micro m) when assayed with a variety of substrates, including xanthotoxol, while the AmCOMT accepted 5-hydroxyferulic acid, esculetin and other substrates. Dark-grown A. majus cells expressed significant BMT activity which nevertheless increased sevenfold within 8 h upon the addition of elicitor and reached a transient maximum at 8-11 h, whereas the COMT activity was rather low and did not respond to the elicitation. Complementary Northern blotting revealed that the BMT transcript abundance increased to a maximum at 7 h, while only a weak constitutive signal was observed for the COMT transcript. The AmBMT sequence thus represents a novel database accession

  11. Epigenetic changes of Arabidopsis genome associated with altered DNA methyltransferase and demethylase expressions after gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Eun; Cho, Eun Ju; Kim, Ji Hong; Chung, Byung Yeoup; Kim, Jin Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    DNA methylation at carbon 5 of cytosines is a hall mark of epigenetic inactivation and heterochromatin in both plants and mammals. In Arabidopsis, DNA methylation has two roles that protect the genome from selfish DNA elements and regulate gene expression. Plant genome has three types of DNA methyltransferase, METHYLTRANSFERASE 1 (MET1), DOMAINREARRANGED METHYLASE (DRM) and CHROMOMETHYLASE 3 (CMT3) that are capable of methylating CG, CHG (where H is A, T, or C) and CHH sites, respectively. MET1 is a maintenance DNA methyltransferase that controls CG methylation. Two members of the DRM family, DRM1 and DRM2, are responsible for de novo methylation of CG, CHG, and CHH sites but show a preference for CHH sites. Finally, CMT3 principally carries out CHG methylation and is involved in both de novo methylation and maintenance. Alternatively, active DNA demethylation may occur through the glycosylase activity by removing the methylcytosines from DNA. It may have essential roles in preventing transcriptional silencing of transgenes and endogenous genes and in activating the expression of imprinted genes. DNA demetylation in Arabidopsis is mediated by the DEMETER (DME) family of bifunctional DNA glycosylase. Three targets of DME are MEA (MEDEA), FWA (FLOWERING WAGENINGEN), and FIS2 (FERTILIZATION INDEPENDENT SEED 2). The DME family contains DEMETER-LIKE 2 (DML2), DML3, and REPRESSOR OF SILENING 1 (ROS1). DNA demetylation by ROS1, DML2, and DML3 protect the hypermethylation of specific genome loci. ROS1 is necessary to suppress the promoter methylation and the silencing of endogenous genes. In contrast, the function of DML2 and DML3 has not been reported. Several recent studies have suggested that epigenetic alterations such as change in DNA methylation and histone modification should be caused in plant genomes upon exposure to ionizing radiation. However, there is a lack of data exploring the underlying mechanisms. Therefore, the present study aims to characterize and

  12. Arabidopsis DNA methyltransferase AtDNMT2 associates with histone deacetylase AtHD2s activity

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yuan [Key Laboratory of Arid and Grassland Agroecology, Ministry of Education, School of Life Science, Lanzhou University, Lanzhou 730000 (China); Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada); Wu, Keqiang [Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan (China); Dhaubhadel, Sangeeta [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada); An, Lizhe, E-mail: lizhean@lzu.edu.cn [Key Laboratory of Arid and Grassland Agroecology, Ministry of Education, School of Life Science, Lanzhou University, Lanzhou 730000 (China); Tian, Lining, E-mail: tianl@agr.gc.ca [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada)

    2010-05-28

    DNA methyltransferase2 (DNMT2) is always deemed to be enigmatic, because it contains highly conserved DNA methyltransferase motifs but lacks the DNA methylation catalytic capability. Here we show that Arabidopsis DNA methyltransferase2 (AtDNMT2) is localized in nucleus and associates with histone deacetylation. Bimolecular fluorescence complementation and pull-down assays show AtDNMT2 interacts with type-2 histone deacetylases (AtHD2s), a unique type of histone deacetylase family in plants. Through analyzing the expression of AtDNMT2: ss-glucuronidase (GUS) fusion protein, we demonstrate that AtDNMT2 has the ability to repress gene expression at transcription level. Meanwhile, the expression of AtDNMT2 gene is altered in athd2c mutant plants. We propose that AtDNMT2 possibly involves in the activity of histone deacetylation and plant epigenetic regulatory network.

  13. Arabidopsis DNA methyltransferase AtDNMT2 associates with histone deacetylase AtHD2s activity

    International Nuclear Information System (INIS)

    DNA methyltransferase2 (DNMT2) is always deemed to be enigmatic, because it contains highly conserved DNA methyltransferase motifs but lacks the DNA methylation catalytic capability. Here we show that Arabidopsis DNA methyltransferase2 (AtDNMT2) is localized in nucleus and associates with histone deacetylation. Bimolecular fluorescence complementation and pull-down assays show AtDNMT2 interacts with type-2 histone deacetylases (AtHD2s), a unique type of histone deacetylase family in plants. Through analyzing the expression of AtDNMT2: ss-glucuronidase (GUS) fusion protein, we demonstrate that AtDNMT2 has the ability to repress gene expression at transcription level. Meanwhile, the expression of AtDNMT2 gene is altered in athd2c mutant plants. We propose that AtDNMT2 possibly involves in the activity of histone deacetylation and plant epigenetic regulatory network.

  14. Archease from Pyrococcus abyssi improves substrate specificity and solubility of a tRNA m5C methyltransferase

    DEFF Research Database (Denmark)

    Auxilien, Sylvie; El Khadali, Fatima; Rasmussen, Anette;

    2007-01-01

    Members of the archease superfamily of proteins are represented in all three domains of life. Archease genes are generally located adjacent to genes encoding proteins involved in DNA or RNA processing. Archease have therefore been predicted to play a modulator or chaperone role in selected steps...... of DNA or RNA metabolism, although the roles of archeases remain to be established experimentally. Here we report the function of one of these archeases from the hyperthermophile Pyrococcus abyssi. The corresponding gene (PAB1946) is located in a bicistronic operon immediately upstream from a second open...... reading frame (PAB1947), which is shown here to encode a tRNA m(5)C methyltransferase. In vitro, the purified recombinant methyltransferase catalyzes m(5)C formation at several cytosines within tRNAs with preference for C49. The specificity of the methyltransferase is increased by the archease...

  15. Structural Basis for Binding of RNA and Cofactor by a KsgA Methyltransferase

    OpenAIRE

    Tu, Chao; Tropea, Joseph E.; Austin, Brian P; Court, Donald L.; Waugh, David S.; Ji, Xinhua

    2009-01-01

    Among methyltransferases, KsgA and the reaction it catalyzes are conserved throughout evolution. However, the specifics of substrate recognition by the enzyme remain unknown. Here, we report structures of Aquifex aeolicus KsgA, in its ligand-free form, in complex with RNA and in complex with both RNA and S-adenosylhomocysteine (SAH, reaction product of cofactor S-adenosylmethionine), providing the first pieces of structural information on KsgA-RNA and KsgA-SAH interactions. Moreover, the stru...

  16. Juvenile hormone acid methyltransferase: A key regulatory enzyme for insect metamorphosis

    OpenAIRE

    Shinoda, Tetsuro; Itoyama, Kyo

    2003-01-01

    Juvenile hormone (JH) acid methyltransferase (JHAMT) is an enzyme that converts JH acids or inactive precursors of JHs to active JHs at the final step of JH biosynthesis pathway in insects. By fluorescent mRNA differential display, we have cloned a cDNA encoding JHAMT from the corpora allata (CA) of the silkworm, Bombyx mori (BmJHAMT). The BmJHAMT cDNA encodes an ORF of 278 aa with a calculated molecular mass of 32,544 Da. The predicted amino acid sequence contains a conserved S-adenosyl-l-me...

  17. EmtA, a rRNA methyltransferase conferring high-level evernimicin resistance

    DEFF Research Database (Denmark)

    Mann, P. A.; Xiong, L.; Mankin, A. S.;

    2001-01-01

    Enterococcus faecium strain 9631355 was isolated from animal sources on the basis of its resistance to the growth promotant avilamycin. The strain also exhibited high-level resistance to evernimicin, a drug undergoing evaluation as a therapeutic agent in humans. Ribosomes from strain 9631355...... exhibited a dramatic reduction in evernimicin binding, shown by both cell-free translation assays and direct-binding assays. The resistance determinant was cloned from strain 9631355; sequence alignments suggested it was a methyltransferase and therefore it was designated emtA for evernimicin...

  18. O6-Methylguanine-DNA methyltransferase deficiency in developing brain: Implications for brain tumorigenesis

    OpenAIRE

    Bobola, Michael S.; Blank, A.; Berger, Mitchel S.; Silber, John R

    2007-01-01

    The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is a cardinal defense against the mutagenic and carcinogenic effects of alkylating agents. We have reported evidence that absence of detectable MGMT activity (MGMT− phenotype) in human brain is a predisposing factor for primary brain tumors that affects ca. 12% of individuals [J.R. Silber, et. al. Proc. Natl. Acad. Sci. USA 93 (1996) 6941–6946]. We report here that MGMT− phenotype in the brain of children and adults, and the...

  19. Verminderte Expression von O6-Methylguanin-DNA-Methyltransferase bei Gliomen durch Promotormethylierung

    OpenAIRE

    Nickolay, Carla

    2009-01-01

    Pro Jahr erkranken 10 von 100 000 Menschen an einem malignen Hirntumor. Die Prognose ist schlecht. Die Therapie schließt Chirurgie, Bestrahlung und Chemotherapie ein. Das DNA-Reparaturenzym O6-Methylguanin-DNA-Methyltransferase, MGMT, erkennt DNA-Schäden, die durch alkylierende Substanzen wie Temozolomid entstanden sind. Übermäßige Methylierung der Promotorregion von MGMT führt zum Funktionsverlust des Enzyms. Dieser kann zu einer erhöhten Sensibilität für Alkylanzien führen. In der Therapie ...

  20. The DmtA methyltransferase contributes to Aspergillus flavus conidiation, sclerotial production, aflatoxin biosynthesis and virulence

    OpenAIRE

    Kunlong Yang; Linlin Liang; Fanlei Ran; Yinghang Liu; Zhenguo Li; Huahui Lan; Peili Gao; Zhenhong Zhuang; Feng Zhang; Xinyi Nie; Shimuye Kalayu Yirga; Shihua Wang

    2016-01-01

    DNA methylation is essential for epigenetic regulation of gene transcription and development in many animals, plants and fungi. We investigated whether DNA methylation plays a role in the development and secondary metabolism of Aspergillus flavus, identified the DmtA methyltransferase from A. flavus, and produced a dmtA knock-out mutant by replacing the dmtA coding sequence with the pyrG selectable marker. The A. flavus dmtA null mutant lines produced white fluffy mycelium in liquid medium, a...

  1. Inhibition of SUV39H1 Methyltransferase Activity by DBC1*

    OpenAIRE

    Li, Zhenyu; Chen, Lihong; Kabra, Neha; Wang, Chuangui; Fang, Jia; Chen, Jiandong

    2009-01-01

    SUV39H1 is a histone H3K9-specific methyltransferase important for heterochromatin formation, regulation of gene expression, and induction of senescence in premalignant cells. SUV39H1 forms a complex with SirT1, and its activity is stimulated by SirT1 binding. Here we present evidence that the product of the DBC1 (deleted in breast cancer 1) gene disrupts the SUV39H1-SirT1 complex. Furthermore, DBC1 binds to the SUV39H1 catalytic domain and inhibits its ability to ...

  2. Histone methyltransferase Suv39h1 represses MyoD-stimulated myogenic differentiation

    OpenAIRE

    Mal, Asoke K.

    2006-01-01

    Suv39h1 is a histone H3 lysine-9 (H3-K9) specific methyltransferase (HMT) that is associated with gene silencing through chromatin modification. The transition from proliferation into differentiation of muscle cell is accompanied by transcriptional activation of previously silent muscle genes. I report Suv39h1 interaction with myogenic regulator MyoD in proliferating muscle cells and its HMT activity, which is associated with MyoD, diminishes as differentiation proceeds. The Suv39h1–MyoD comp...

  3. Crystal structure of phosphoethanolamine methyltransferase from Plasmodium falciparum in complex with amodiaquine

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soon Goo; Alpert, Tara D.; Jez, Joseph M. (WU)

    2012-07-17

    Phosphoethanolamine N-methyltransferase (PMT) is essential for phospholipid biogenesis in the malarial parasite Plasmodium falciparum. PfPMT catalyzes the triple methylation of phosphoethanolamine to produce phosphocholine, which is then used for phosphatidylcholine synthesis. Here we describe the 2.0 {angstrom} resolution X-ray crystal structure of PfPMT in complex with amodiaquine. To better characterize inhibition of PfPMT by amodiaquine, we determined the IC{sub 50} values of a series of aminoquinolines using a direct radiochemical assay. Both structural and functional analyses provide a possible approach for the development of new small molecule inhibitors of PfPMT.

  4. Queen pheromones modulate DNA methyltransferase activity in bee and ant workers.

    Science.gov (United States)

    Holman, Luke; Trontti, Kalevi; Helanterä, Heikki

    2016-01-01

    DNA methylation is emerging as an important regulator of polyphenism in the social insects. Research has concentrated on differences in methylation between queens and workers, though we hypothesized that methylation is involved in mediating other flexible phenotypes, including pheromone-dependent changes in worker behaviour and physiology. Here, we find that exposure to queen pheromone affects the expression of two DNA methyltransferase genes in Apis mellifera honeybees and in two species of Lasius ants, but not in Bombus terrestris bumblebees. These results suggest that queen pheromones influence the worker methylome, pointing to a novel proximate mechanism for these key social signals. PMID:26814223

  5. DNA Methyltransferase Gene dDnmt2 and Longevity of Drosophila

    Institute of Scientific and Technical Information of China (English)

    Meng-JauLin; Lin-YaTang; M.NarsaReddy; C.K.JamesShen

    2005-01-01

    The DNA methylation program of the fruit fly Drosophila melanogaster is carried out by the single DNA methyltransferase gene dDnmt2, the function of which is unknown before. We present evidence that intactness of the gene is required for maintenance of the normal life span of the fruit flies. In contrast, overexpression of dDnmt2 could extend Drosophila life span. The study links the Drosophila DNA methylation program with the small heatshock proteins and longevity/aging and has interesting implication on the eukaryotic DNA methyl-ation programs in general.

  6. Histone methyltransferase G9a contributes to H3K27 methylation in vivo

    Institute of Scientific and Technical Information of China (English)

    Hui Wu; Bing Zhu; Xiuzhen Chen; Jun Xiong; Yingfeng Li; Hong Li; Xiaojun Ding; Sheng Liu; She Chen; Shaorong Gao

    2011-01-01

    @@ Dear Editor, Histone modifications play a vital role in the conformation and function of their associated chromatin templates[1].Histone H3K27 methylation mediated by the PRC2 complex is critical for transcriptional regulation,Polycomb silencing,Drosophila segmentation,mammalian X inactivation and cancer[1].Interestingly,H3K27me1(H3 mono-methylated at residue K27)levels in vivo remain unaffected after PRC2 disruption[2,3],which is an indication for the existence of other contributing histone methyltransferase(s)to H3K27me1.

  7. DNA methyltransferase-dependent transcription of the phage Mu mom gene.

    OpenAIRE

    Hattman, S

    1982-01-01

    The phage Mu mom gene controls an unusual DNA modification. Expression of the mom function requires an active host (dam+) DNA adenine methylase [S-adenosyl-L-methionine:DNA (6-aminopurine)-methyltransferase]; in dam- hosts, Mu development is normal except that the viral DNA does not undergo the mom modification. The present communication compares transcription of the mom gene in dam+ versus dam- cells. 32P-labeled probes were prepared by nick-translation of a purified mom gene-containing rest...

  8. Discovery and development of DNA methyltransferase inhibitors using in silico approaches.

    Science.gov (United States)

    Medina-Franco, José L; Méndez-Lucio, Oscar; Dueñas-González, Alfonso; Yoo, Jakyung

    2015-05-01

    Multiple strategies have evolved during the past few years to advance epigenetic compounds targeting DNA methyltransferases (DNMTs). Significant progress has been made in HTS, lead optimization and determination of 3D structures of DNMTs. In light of the emerging concept of epi-informatics, computational approaches are employed to accelerate the development of DNMT inhibitors helping to screen chemical databases, mine the DNMT-relevant chemical space, uncover SAR and design focused libraries. Computational methods also synergize with natural-product-based drug discovery and drug repurposing. Herein, we survey the latest developments of in silico approaches to advance epigenetic drug and probe discovery targeting DNMTs.

  9. Yunnan-Guizhou Plateau in Summer and Autumn Broccoli Standardized Cultivation Techniques%云贵高原反季青花菜标准化栽培技术

    Institute of Scientific and Technical Information of China (English)

    刘兴平

    2012-01-01

    云贵高原夏秋季节气候温凉,适于种植反季青花菜,本文结合多年生产实践,从品种选择、培育壮苗、规格定植、肥水管理、病虫防治、适时采收等措施总结介绍了一套云贵高原冷凉山区反季青花菜标准化栽培技术。%Yunnan-Guizhou Plateau in summer and autumn climate was cool and suitable for growing-season broccoli, the paper summary description is a combination of years of production practices, species selection, nurturing seedlings, specifications planting, fertilizer and water management, pest control, timely harvest measuresYunnan-Guizhou Plateau in cold mountain-season broccoli standardization of cultivation techniques.

  10. Active packaging for fresh-cut broccoli using 1-methylcyclopropene in biodegradable sachet/ Embalagem ativa para brócolis minimamente processado utilizando 1-metilciclopropeno em sachê biodegradável

    Directory of Open Access Journals (Sweden)

    Marta de Toledo Benassi

    2006-07-01

    Full Text Available Fresh-cut broccoli florets were packed in polypropylene pots containing a sachet with 1- methylcyclopropene (1-MCP and sealed with biodegradable starch-based film. Broccoli was stored for 8 days at 12oC and after this time the color and the texture of the product were similar of the fresh broccoli, with no off-flavor development or decay. Active packaging with 1-MCP in a sachet was efficient to extent shelf life of broccoli florets retarding yellowing and vitamin C losses. It is an alternative of 1-MCP treatment for fresh-cut products and besides, the sachet can absorbs condensed water reducing spoilage and off-odor development.Brócolis minimamente processados foram embalados em bandejas de polipropileno com sachê contendo 1-metilciclopropeno (1-MCP e selado com filme biodegradável de amido. Os brócolis foram armazenados por 8 dias a 12oC e após este tempo a cor e a textura mantiveram-se similares às do produto fresco, sem desenvolvimento de odor não característico ou podridão. A embalagem ativa contendo 1-MCP na forma de sachê foi eficiente no aumento da vida de prateleira de brócolis, retardando o amarelecimento e a perda de vitamina C. Esta é uma alternativa para o tratamento com 1-MCP para produtos minimamente processados e além disso, o sachê pode absorver a água condensada, reduzindo a deterioração e o desenvolvimento de odor não característico.

  11. UV-C对西兰花抗氧化活性及相关品质的影响%Changes of Antioxidant Activity, Compounds and Quality of Broccoli Florets During Different Temperatures

    Institute of Scientific and Technical Information of China (English)

    张怡; 关文强; 张娜; 刘莉莉; 阎瑞香; 孙德岭

    2014-01-01

    在0℃条件下,采用不同剂量UV-C(1、4、7 kJ/m2)照射处理西兰花后冷藏并测定相关品质指标。结果表明4 kJ/m2 UV-C照射处理增加了西兰花抗氧化活性,可以更好地延缓西兰花的衰老。在21天以后,4 kJ/m2 UV-C处理增高西兰花的叶绿素、类胡萝卜素和花青素的含量,延缓其降解。UV-C照射能很好地保持西兰花的感官品质,减慢黄化过程,其中4 kJ/m2 UV-C照射的综合感官效果最好。%At 0℃condition, the processing broccoli by different doses of UV-C (1, 4, 7 kJ/m2)irradiation were chilled and determined related quality indicators.The result showed that:4 kJ/m2 UV-C irradiation increased antioxidant activity of broccoli and resisted senility better. After 21 days, 4 kJ/m2 UV-C treatment can heighten the content of chlorophyll, carotenoids and anthocyanins of broccoli and resisted degradation. UV-C irradiation remain well organoleptic quality of broccoli, delayed the yellowing process. 4 kJ/m 2 UV-C irradiation of synthesis organoleptic effect is the best.

  12. Effect of Different Drying Methods on the Sulforaphane Content of Broccoli%不同干燥方法对西兰花中萝卜硫素含量影响

    Institute of Scientific and Technical Information of China (English)

    谢述琼; 何珺; 杨佳年; 陈震

    2013-01-01

    Drying Broccoli's flower,stalk and leaf with three usual drying methods which were drying in the shade,50 ℃-90 ℃drying and drying in the sun,indentifying sulforaphane content with HPLC. Sulforaphane content in broccoli's different parts was seed>flower>stalk>leaf,with different drying methods,drying was the best and drying in the shade was the worst,with the five drying temperature it was 90 ℃ that there were the highest sulforaphane content of broccoli. with the different parts the sulforaphane content of broccoli's seed was the highest,it had 10.48 mg/g;the best drying methods was 90℃drying.%  采用阴干、50℃~90℃烘干及晒干三种常用干燥方式干燥西兰花的花、茎、叶,采用HPLC测定萝卜硫素含量。西兰花不同部位中萝卜硫素含量是种子>花>茎>叶;而不同干燥方法中烘干最好,阴干最差,5种烘干温度中以90℃烘干时萝卜硫素含量最高。西兰花不同部位中种子萝卜硫素含量最高,有10.48 mg/g;而干燥方式采用90℃烘干最佳。

  13. 高温多雨条件下不同品种青花菜生育期变化规律研究%Change Rules of Growth Period of Different Broccoli Cultivars under High Temperature and Rainy Conditions

    Institute of Scientific and Technical Information of China (English)

    苏英京

    2012-01-01

      2011年是气候条件十分特殊的一年,在主要播种期播种的临海青花菜生育期严重提前,基地青花菜上市期严重偏离正常季节。研究发现,青花菜生育期变化存在环境敏感性,不同品种生育期变化敏感性不同,高温和多雨是其生育期变化的2个主导因素。%  The weather of 2011 was abnormal, which made the growth period and the time to the markets of broccoli advanced seriously. The results showed that the growth period of broccoli was sensitive to environment factors, and high temperature and rainy conditions were the two key factors for the changes of growth period of broccoli.

  14. 光照处理提高鲜切西兰花贮藏品质%Quality Improvement of Fresh-Cut Broccoli (Brassica Oleracea L.) during Storage by Light Illumination

    Institute of Scientific and Technical Information of China (English)

    詹丽娟; 魏国强; 乔明武; 王慧荣

    2012-01-01

    In this study, the effect of continuous light illumination at 2000 lx on the quality of fresh-cut broccoli during 7 days of cold storage was investigated by spectrophotometry. The results indicated that light illumination significantly alleviated chlorophyll degradation and yellowing occurrence during storage, and meanwhile could maintain carotenoids, total soluble solid and vitamin C contents as well as antioxidant capacity of fresh-cut broccoli during storage. However, light illumination also induced more weight loss of fresh-cut broccoli during the whole storage compared with dark storage.%为减缓鲜切西兰花贮藏期间品质下降,延长贮藏期,运用分光光度法研究连续光照处理(2000ix)对鲜切西兰花低温贮藏期间品质变化的影响。结果表明,和黑暗对照相比,光照处理显著减缓鲜切西兰花贮藏期间叶绿素降解和黄化发生率,维持类胡萝卜素、可溶性固形物和抗坏血酸含量,从而使其保持较高的抗氧化力。然而,光照处理显著促进鲜切西兰花鲜质量损失。

  15. 危害分析和关键环节控制点在西兰花冷链物流中的应用研究%The Application of HACCP in Cold-chain Logistics of Broccoli

    Institute of Scientific and Technical Information of China (English)

    张艳艳; 刘斌

    2013-01-01

    Cold-chain logistics protects harvest quality and reduce loss of broccoli in circulation field.In this paper,the application of HACCP system in cold-chain logistics of broccoli was studied.Hazard analysis was analyzed and four critical control points including pre-cool,package,cold storage and transportation were determined.The corresponding HACCP program was made,so as to keep original quality and improve shelf life of broccoli in circulation field.%全程冷链是减少西兰花流通环节的损耗、保持采收时质量的重要条件.将危害分析和关键环节控制点(HACCP)管理体系的预防性思维应用于西兰花的冷链物流,通过危害分析,确定了预冷、包装、冷藏、运输4个关键控制点并制定了HACCP计划表,以最大限度地保持西兰花的原有品质、延长货架期.

  16. Research of Controling Freezing Point of Broccoli by Using Freezing Point Regulators%冰点调节剂对西兰花冰点的控制研究

    Institute of Scientific and Technical Information of China (English)

    林本芳; 鲁晓翔; 李江阔

    2012-01-01

    本文研究不同冰点调节剂对西兰花冰点的影响.实验选取葡萄糖、维生素C、氯化钙和山梨醇四种冰点调节剂,利用单因素比较实验法,系统研究了冰点调节剂种类及其使用条件对西兰花冰点的影响.结果表明,氯化钙是较好的冰点调节剂;3%氯化钙浸泡30min对西兰花的冰点调节效果较好,使西兰花冰点从-0.8℃降到-1℃.%In this research, the effects of different freezing point regulators on broccoli freezing point were investigated. Four kinds of freezing point regulators, including glucose, vitamin C, calcium chloride and sorbitol, were used for research on the influence of freezing point of broccoli by the single factor comparison experiment method. The results indicated that calcium chloride and glucose were the better freezing point regulators. When broccoli was soaked for 30 minutes with calcium chloride content being of 3%, its' freezing point was decreased from -0.8℃to-1 ℃.

  17. Crystallization and preliminary X-ray crystallographic studies of O-methyltransferase from Anabaena PCC 7120

    International Nuclear Information System (INIS)

    The O-methyltransferase (OMT) from the Anabaena PCC 7120 has been overexpressed in a soluble form in E. coli, purified and crystallized. The crystals belonged to space group C2221 and diffracted to 2.4 Å resolution. O-Methyltransferase (OMT) is a ubiquitous enzyme that exists in bacteria, plants and humans and catalyzes a methyl-transfer reaction using S-adenosyl-l-methionine as a methyl donor and a wide range of phenolics as acceptors. To investigate the structure and function of OMTs, omt from Anabaena PCC 7120 was cloned into expression vector pET21a and expressed in a soluble form in Escherichia coli strain BL21 (DE3). The recombinant OMT protein was purified to homogeneity using a two-step strategy. Crystals of OMT that diffracted to a resolution of 2.4 Å were obtained using the hanging-drop vapour-diffusion method. The crystals belonged to space group C2221, with unit-cell parameters a = 131.620, b = 227.994, c = 150.777 Å, α = β = γ = 90°. There are eight molecules per asymmetric unit

  18. PML-RARA requires DNA methyltransferase 3A to initiate acute promyelocytic leukemia.

    Science.gov (United States)

    Cole, Christopher B; Verdoni, Angela M; Ketkar, Shamika; Leight, Elizabeth R; Russler-Germain, David A; Lamprecht, Tamara L; Demeter, Ryan T; Magrini, Vincent; Ley, Timothy J

    2016-01-01

    The DNA methyltransferases DNMT3A and DNMT3B are primarily responsible for de novo methylation of specific cytosine residues in CpG dinucleotides during mammalian development. While loss-of-function mutations in DNMT3A are highly recurrent in acute myeloid leukemia (AML), DNMT3A mutations are almost never found in AML patients with translocations that create oncogenic fusion genes such as PML-RARA, RUNX1-RUNX1T1, and MLL-AF9. Here, we explored how DNMT3A is involved in the function of these fusion genes. We used retroviral vectors to express PML-RARA, RUNX1-RUNX1T1, or MLL-AF9 in bone marrow cells derived from WT or DNMT3A-deficient mice. Additionally, we examined the phenotypes of hematopoietic cells from Ctsg-PML-RARA mice, which express PML-RARA in early hematopoietic progenitors and myeloid precursors, with or without DNMT3A. We determined that the methyltransferase activity of DNMT3A, but not DNMT3B, is required for aberrant PML-RARA-driven self-renewal ex vivo and that DNMT3A is dispensable for RUNX1-RUNX1T1- and MLL-AF9-driven self-renewal. Furthermore, both the PML-RARA-driven competitive transplantation advantage and development of acute promyelocytic leukemia (APL) required DNMT3A. Together, these findings suggest that PML-RARA requires DNMT3A to initiate APL in mice. PMID:26595813

  19. X-ray crystal structure of N-6 adenine deoxyribose nucleic acid methyltransferase from Streptococcus pneumoniae

    Science.gov (United States)

    Tran, Phidung Hong

    X-ray diffraction by using resonant anomalous scattering has become a popular tool for solving crystal structures in the last ten years with the expanded availability of tunable synchrotron radiation for protein crystallography. Mercury atoms were used for phasing. The crystal structure of N-6 deoxyribose nucleic acid methyltransferase from Streptoccocus pneumoniae (DpnM) was solved by using the Multiple Anomalous Diffraction technique. The crystal structure reveals the formation of mercaptide between the mercury ion and the thiol group on the cysteine amino acid in a hydrophobic environment. The crystal structure contains the bound ligand, S- adenosyl-l-methionine on the surface of the concave opening. The direction of the β-strands on the beta sheets are identical to other solved methyltransferases. The highly conserved motifs, DPPY and the FxGxG, are found to be important in ligand binding and possibly in methyl group transfer. The structure has a concave cleft with an opening on the order of 30 Å that can accommodate a DNA duplex. By molecular modelling coupled to sequence alignment, two other highly conserved residues Arg21 and Gly19 are found to be important in catalysis.

  20. Regulation of DNA replication and chromosomal polyploidy by the MLL-WDR5-RBBP5 methyltransferases

    Science.gov (United States)

    Lu, Fei; Wu, Xiaojun; Yin, Feng; Chia-Fang Lee, Christina; Yu, Min; Mihaylov, Ivailo S.; Yu, Jiekai; Sun, Hong

    2016-01-01

    ABSTRACT DNA replication licensing occurs on chromatin, but how the chromatin template is regulated for replication remains mostly unclear. Here, we have analyzed the requirement of histone methyltransferases for a specific type of replication: the DNA re-replication induced by the downregulation of either Geminin, an inhibitor of replication licensing protein CDT1, or the CRL4CDT2 ubiquitin E3 ligase. We found that siRNA-mediated reduction of essential components of the MLL-WDR5-RBBP5 methyltransferase complexes including WDR5 or RBBP5, which transfer methyl groups to histone H3 at K4 (H3K4), suppressed DNA re-replication and chromosomal polyploidy. Reduction of WDR5/RBBP5 also prevented the activation of H2AX checkpoint caused by re-replication, but not by ultraviolet or X-ray irradiation; and the components of MLL complexes co-localized with the origin recognition complex (ORC) and MCM2-7 replicative helicase complexes at replication origins to control the levels of methylated H3K4. Downregulation of WDR5 or RBBP5 reduced the methylated H3K4 and suppressed the recruitment of MCM2-7 complexes onto replication origins. Our studies indicate that the MLL complexes and H3K4 methylation are required for DNA replication but not for DNA damage repair. PMID:27744293

  1. Identification and expression profiling of DNA methyltransferases during development and stress conditions in Solanaceae.

    Science.gov (United States)

    Kumar, Rahul; Chauhan, Pankaj Kumar; Khurana, Ashima

    2016-09-01

    DNA methyltransferase (DMTase) enzymes contribute to plant development and stress responses by de novo establishment and subsequent maintenance of DNA methylation during replication. However, the molecular mechanism underlying this activity remains obscure, especially in crop species. Using DMTase homolog complement in six Solanaceae species, we demonstrated here that their number remained conserved in Solanum lineage, whereas it was expanded in both pepper and Nicotiana benthamiana. Non-synonymous vs synonymous (Ka/Ks) substitution ratio revealed that most of the Solanaceous DMTase homologs undergo purifying selection. The genomic sequences of tomato DMT homologs in its wild relative, Solanum pennellii, remained highly conserved in their exons and methyltransferase domains. Structure analysis further revealed highly similar folding of DMTase homologs and conservation in the residues participating in protein-protein interaction in Solanum lineage, whereas a considerable diversification was observed of pepper homologs. Transcript profiling of DMTases highlighted both similar and distinct expression patterns of tomato homologs in other species during fruit development and stress responses. Overall, our analysis provides a strong basis for in-depth exploration of both conserved as well as distinct functions of tomato DMTase homologs in other economically important Solanaceae species. PMID:27380018

  2. Protein arginine methyltransferase 5 (PRMT5) is a novel coactivator of constitutive androstane receptor (CAR).

    Science.gov (United States)

    Kanno, Yuichiro; Inajima, Jun; Kato, Sayaka; Matsumoto, Maika; Tokumoto, Chikako; Kure, Yuki; Inouye, Yoshio

    2015-03-27

    The constitutive androstane receptor (CAR) plays a key role in the expression of xenobiotic/steroid and drug metabolizing enzymes and their transporters. In this study, we demonstrated that protein arginine methyltransferase 5 (PRMT5) is a novel CAR-interacting protein. Furthermore, the PRMT-dependent induction of a CAR reporter gene, which was independent of methyltransferase activity, was enhanced in the presence of steroid receptor coactivator 1 (SRC1), peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) or DEAD box DNA/RNA helicase DP97. Using tetracycline inducible-hCAR system in HepG2 cells, we showed that knockdown of PRMT5 with small interfering RNA suppressed tetracycline -induced mRNA expression of CYP2B6 but not of CYP2C9 or CYP3A4. PRMT5 enhanced phenobarbital-mediated transactivation of a phenobarbital-responsive enhancer module (PBREM)-driven reporter gene in co-operation with PGC-1α in rat primary hepatocytes. Based on these findings, we suggest PRMT5 to be a gene (or promoter)-selective coactivator of CAR by mediating the formation of complexes between hCAR and appropriate coactivators. PMID:25721668

  3. Improved radioenzymatic assay for plasma norepinephrine using purified phenylethanolamine n-methyltransferase

    International Nuclear Information System (INIS)

    Radioenzymatic assays have been developed for catecholamines using either catechol O-methyltransferase (COMT) or phenylethanolamine N-methyltransferase (PNMT). Assays using PNMT are specific for norepinephrine (NE) and require minimal manipulative effort but until now have been less sensitive than the more complex procedures using COMT. The authors report an improved purification scheme for bovine PNMT which has permitted development of an NE assay with dramatically improved sensitivity (0.5 pg), specificity and reproducibility (C.V. < 5%). PNMT was purified by sequential pH 5.0 treatment and dialysis and by column chromatographic procedures using DEAE-Sephacel, Sepharcryl S-200 and Phenyl-Boronate Agarose. Recovery of PNMT through the purification scheme was 50%, while blank recovery was <.001%. NE can be directly quantified in 25 ul of human plasma and an 80 tube assay can be completed within 4 h. The capillary to venous plasma NE gradient was examined in 8 normotensive male subjects. Capillary plasma (NE (211.2 +/- 61.3 pg/ml)) was lower than venous plasma NE (366.6 +/- 92.5 pg/ml) in all subjects (p < 0.005). This difference suggests that capillary (NE) may be a unique indicator of sympathetic nervous system activity in vivo. In conclusion, purification of PNMT has facilitated development of an improved radioenzymatic for NE with significantly improved sensitivity

  4. Thiopurine methyltransferase activity in the erythrocytes of adults and children: and HPLC-linked assay.

    Science.gov (United States)

    Micheli, V; Jacomelli, G; Fioravanti, A; Morozzi, G; Marcolongo, R; Pompucci, G

    1997-03-18

    A non-radioactive method that uses reverse-phase high performance liquid chromatography is described for the determination of thiopurine methyltransferase (E.C. 2.1.1.67) activity in human erythrocytes. The method is based on the direct quantitation of 6-methyl-mercaptopurine produced from 6-mercaptopurine by crude erythrocyte lysates. The method is accurate and reliable and suitable for diagnostic use. Activity values in control adults ranged from 5 to 32 pmol/h/mg haemoglobin. The activity in the erythrocytes of adult males was significantly higher compared to females (21 +/- 5 and 15 +/- 8 pmol/h/mg haemoglobin, respectively). The activity measured in the erythrocytes of children (22 +/- 5 pmol/h/mg haemoglobin) did not show any significant difference compared to adults. Thiopurine methyltransferase activity was measured in a female patient with systemic sclerosis who developed severe bone marrow depression after treatment with azathioprine and allopurinol. Activity (6.3 +/- 0.5 pmol/h/mg haemoglobin) was found in the lowest range of controls thus supporting the hypothesis that it could be responsible for increased azathioprine cytotoxicity. PMID:9086303

  5. Identification of the methyltransferase targeting C2499 in Deinococcus radiodurans 23S ribosomal RNA.

    Science.gov (United States)

    Mundus, Julie; Flyvbjerg, Karen Freund; Kirpekar, Finn

    2016-01-01

    The bacterium Deinococcus radiodurans-like all other organisms-introduces nucleotide modifications into its ribosomal RNA. We have previously found that the bacterium contains a Carbon-5 methylation on cytidine 2499 of its 23S ribosomal RNA, which is so far the only modified version of cytidine 2499 reported. Using homology search, we identified the open reading frame DR_0049 as the primary candidate gene for the methyltransferase that modifies cytidine 2499. Mass spectrometric analysis demonstrated that recombinantly expressed DR0049 protein methylates E. coli cytidine 2499 both in vitro and in vivo. We also inactivated the DR_0049 gene in D. radiodurans through insertion of a chloramphenicol resistance cassette. This resulted in complete absence of the cytidine 2499 methylation, which all together demonstrates that DR_0049 encodes the methyltransferase producing m(5)C2499 in D. radiodurans 23S rRNA. Growth experiments disclosed that inactivation of DR_0049 is associated with a severe growth defect, but available ribosome structures show that cytidine 2499 is positioned very similar in D. radiodurans harbouring the modification and E. coli without the modification. Hence there is no obvious structure-based explanation for the requirement for the C2499 posttranscriptional modification in D. radiodurans.

  6. Identification and characterization of new molecular partners for the protein arginine methyltransferase 6 (PRMT6.

    Directory of Open Access Journals (Sweden)

    Alessandra Lo Sardo

    Full Text Available PRMT6 is a protein arginine methyltransferase that has been implicated in transcriptional regulation, DNA repair, and human immunodeficiency virus pathogenesis. Only few substrates of this enzyme are known and therefore its cellular role is not well understood. To identify in an unbiased manner substrates and potential regulators of PRMT6 we have used a yeast two-hybrid approach. We identified 36 new putative partners for PRMT6 and we validated the interaction in vivo for 7 of them. In addition, using invitro methylation assay we identified 4 new substrates for PRMT6, extending the involvement of this enzyme to other cellular processes beyond its well-established role in gene expression regulation. Holistic approaches create molecular connections that allow to test functional hypotheses. The assembly of PRMT6 protein network allowed us to formulate functional hypotheses which led to the discovery of new molecular partners for the architectural transcription factor HMGA1a, a known substrate for PRMT6, and to provide evidences for a modulatory role of HMGA1a on the methyltransferase activity of PRMT6.

  7. Highly sensitive detection of M.SssI DNA methyltransferase activity using a personal glucose meter.

    Science.gov (United States)

    Deng, Huimin; Peng, Si Ying; Gao, Zhiqiang

    2016-08-01

    A simple method for highly sensitive and selective detection of M.SssI CpG methyltransferase (M.SssI MTase) activity is developed, leveraging on the portability and ease of use of a personal glucose meter (PGM). Briefly, DNA-invertase conjugates are hybridized with their complementary DNA strands pre-immobilized on magnetic beads. The 5'-CCGG-3' sequence present in the DNA duplexes serves as the recognition site for both Hpa II restriction enzyme and M.SssI MTase (5'-CG-3'). Hpa II restriction enzyme specifically cleaves at unmethylated 5'-CCGG-3' sequence, and the invertase that remains on the methylated DNA catalyzes the hydrolysis of sucrose to glucose and fructose. It is found that the amount of glucose is proportional to the M.SssI MTase methylation activity in the range of 0.5 to 80 U/mL with a detection limit of 0.37 U/mL. Due to the specific recognition sequence present in the DNA strands, this method also shows high selectivity for M.SssI MTase. In addition, inhibition studies with 5'-azacytidine demonstrate the capability of inhibition screening using this method. Graphical abstract Deteciton of M.SssI DNA methyltransferase activity by a personal glucose meter. PMID:27311957

  8. Conversion of nicotinic acid to trigonelline is catalyzed by N-methyltransferase belonged to motif B′ methyltransferase family in Coffea arabica

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, Kouichi, E-mail: koumno@akita-pu.ac.jp [Faculty of Bioresource Sciences, Akita Prefectural University, Akita City, Akita 010-0195 (Japan); Matsuzaki, Masahiro [Faculty of Bioresource Sciences, Akita Prefectural University, Akita City, Akita 010-0195 (Japan); Kanazawa, Shiho [Graduate School of Humanities and Sciences, Ochanomizu University, Otsuka, Bunkyo-ku, Tokyo 112-8610 (Japan); Tokiwano, Tetsuo; Yoshizawa, Yuko [Faculty of Bioresource Sciences, Akita Prefectural University, Akita City, Akita 010-0195 (Japan); Kato, Misako [Graduate School of Humanities and Sciences, Ochanomizu University, Otsuka, Bunkyo-ku, Tokyo 112-8610 (Japan)

    2014-10-03

    Graphical abstract: Trigonelline synthase catalyzes the conversion of nicotinic acid to trigonelline. We isolated and characterized trigonelline synthase gene(s) from Coffea arabica. - Highlights: • Trigonelline is a major compound in coffee been same as caffeine is. • We isolated and characterized trigonelline synthase gene. • Coffee trigonelline synthases are highly homologous with coffee caffeine synthases. • This study contributes the fully understanding of pyridine alkaloid metabolism. - Abstract: Trigonelline (N-methylnicotinate), a member of the pyridine alkaloids, accumulates in coffee beans along with caffeine. The biosynthetic pathway of trigonelline is not fully elucidated. While it is quite likely that the production of trigonelline from nicotinate is catalyzed by N-methyltransferase, as is caffeine synthase (CS), the enzyme(s) and gene(s) involved in N-methylation have not yet been characterized. It should be noted that, similar to caffeine, trigonelline accumulation is initiated during the development of coffee fruits. Interestingly, the expression profiles for two genes homologous to caffeine synthases were similar to the accumulation profile of trigonelline. We presumed that these two CS-homologous genes encoded trigonelline synthases. These genes were then expressed in Escherichiacoli, and the resulting recombinant enzymes that were obtained were characterized. Consequently, using the N-methyltransferase assay with S-adenosyl[methyl-{sup 14}C]methionine, it was confirmed that these recombinant enzymes catalyzed the conversion of nicotinate to trigonelline, coffee trigonelline synthases (termed CTgS1 and CTgS2) were highly identical (over 95% identity) to each other. The sequence homology between the CTgSs and coffee CCS1 was 82%. The pH-dependent activity curve of CTgS1 and CTgS2 revealed optimum activity at pH 7.5. Nicotinate was the specific methyl acceptor for CTgSs, and no activity was detected with any other nicotinate derivatives, or

  9. Conversion of nicotinic acid to trigonelline is catalyzed by N-methyltransferase belonged to motif B′ methyltransferase family in Coffea arabica

    International Nuclear Information System (INIS)

    Graphical abstract: Trigonelline synthase catalyzes the conversion of nicotinic acid to trigonelline. We isolated and characterized trigonelline synthase gene(s) from Coffea arabica. - Highlights: • Trigonelline is a major compound in coffee been same as caffeine is. • We isolated and characterized trigonelline synthase gene. • Coffee trigonelline synthases are highly homologous with coffee caffeine synthases. • This study contributes the fully understanding of pyridine alkaloid metabolism. - Abstract: Trigonelline (N-methylnicotinate), a member of the pyridine alkaloids, accumulates in coffee beans along with caffeine. The biosynthetic pathway of trigonelline is not fully elucidated. While it is quite likely that the production of trigonelline from nicotinate is catalyzed by N-methyltransferase, as is caffeine synthase (CS), the enzyme(s) and gene(s) involved in N-methylation have not yet been characterized. It should be noted that, similar to caffeine, trigonelline accumulation is initiated during the development of coffee fruits. Interestingly, the expression profiles for two genes homologous to caffeine synthases were similar to the accumulation profile of trigonelline. We presumed that these two CS-homologous genes encoded trigonelline synthases. These genes were then expressed in Escherichiacoli, and the resulting recombinant enzymes that were obtained were characterized. Consequently, using the N-methyltransferase assay with S-adenosyl[methyl-14C]methionine, it was confirmed that these recombinant enzymes catalyzed the conversion of nicotinate to trigonelline, coffee trigonelline synthases (termed CTgS1 and CTgS2) were highly identical (over 95% identity) to each other. The sequence homology between the CTgSs and coffee CCS1 was 82%. The pH-dependent activity curve of CTgS1 and CTgS2 revealed optimum activity at pH 7.5. Nicotinate was the specific methyl acceptor for CTgSs, and no activity was detected with any other nicotinate derivatives, or with

  10. Effect of Cold Acclimation Combined with Ice-Temperature Storage on the Quality of Broccolis%低温驯化结合冰温贮藏对西兰花品质的影响

    Institute of Scientific and Technical Information of China (English)

    林本芳; 鲁晓翔; 李江阔; 陈绍慧

    2012-01-01

    研究低温驯化结合冰温贮藏对西兰花保鲜品质的影响。贮藏期间每14d测定西兰花理化指标及营养成分。结果表明:与直接冰温贮藏或冷藏相比,低温驯化结合冰温贮藏处理对延缓西兰花VC含量和叶绿素含量的下降均有明显效果,且可降低呼吸强度和乙烯生成速率,提高西兰花过氧化物酶(POD)和过氧化氢酶(CAT)的活性,降低多酚氧化酶(PPO)活性,延缓相对电导率的升高。研究表明西兰花经低温驯化结合冰温贮藏的效果优于直接冰温贮藏的效果。%This study was conducted to investigate the effect of cold acclimation combined with ice-temperature storage(CACITS) on the quality of broccolis.Physicochemical indexes and nutritional components of broccolis were detected every 14 days during storage.The results show that the contents of VC and chlorophyll in broccoli were decreased more significantly by cold acclimation combined with ice-temperature storage than ice-temperature storage alone and ordinary cold storage;moreover,cold acclimation combined with ice-temperature storage could reduce respiratory intensity and ethylene generation rate in broccolis,increase peroxidase(POD) and catalase(CAT) activities,inhibit polyphenol oxidase(PPO) activity and delay the increase of relative electric conductivity.As a result,it can be concluded that cold acclimation combined with ice-temperature storage is better for the quality of of broccolis than ice-temperature storage alone.

  11. 不同出库方式对西兰花货架期品质的影响%Effect of different out-store tests on storage quality of broccolis during shelf-life period

    Institute of Scientific and Technical Information of China (English)

    林本芳; 鲁晓翔; 李江阔; 陈绍慧

    2012-01-01

    The effect of broccolis by different out-store tests after cold storage which temperature was -1 -1℃ was detected by analyzing physicochemical indexes and nutrition components. The research results showed that broccoli's Vc and chlorophyll content and firmness by low-temperature chain storage condition decreased less than that of progressively warming and control. Low-temperature chain storage increased superoxide dismutase (SOD) activity and slowed down polyphenol oxidase (PPO)activity, also decreased MDA content. Mildew spot index of broccolis was zero by low-temperature chain storage after 10d of out-store,whereas the values of progressively warming and control were 88.89% and 100% after 8d of out-store. Therefore,the effect of broccolis' shelf-life by different out-store tests was significant,the storage effect of broccolis by low- temperature chain storage was better than that of by progressively warming and control.%通过对西兰花在货架期间理化指标及营养成分变化规律的分析,探讨不同出库方式对冷藏(-1~1℃)后西兰花的保鲜效果。实验结果表明:与缓慢升温出库和直接出库(对照组)相比,低温冷链出库处理对延缓西兰花黄化以及Vc含量、叶绿素含量和硬度的下降均有明显效果,提高了西兰花超氧化物歧化酶(SOD)的活性,降低其多酚氧化酶(PPO)活性,延缓了丙二醛(MDA)含量的升高;该模式下货架期10d的西兰花仍没有生霉,而缓慢升温出库和直接出库的货架期8d时霉斑指数分别为88.89%和100%。这说明不同出库方式对西兰花的货架期有显著影响,低温冷链出库的西兰花保鲜效果更好。

  12. Application of Tissue Culture, Molecular Marker and QTL Analysis in Broccoli Breeding%组织培养、分子标记和QT L技术在青花菜育种中的应用

    Institute of Scientific and Technical Information of China (English)

    张志仙; 朱长志; 檀国印; 王峰; 何道根

    2015-01-01

    育种是优异种质资源基因的重组。除传统新种质产生的方法外,通过组织培养、分子标记等技术来扩大物种的遗传基础已成为新种质资源形成的重要手段。青花菜,芸薹属甘蓝中以绿色花球为食用器官的一个变种,近年来在中国的种植面积越来越大,利用现代生物技术手段进行青花菜育种研究工作也越来越受到关注和重视。本文综述了游离小孢子培养、原生质体融合和转基因技术在青花菜种质资源创制中的应用,分析了各种方法存在的问题,并对青花菜遗传图谱构建、花球相关农艺性状及抗病性QTL/基因定位研究进行了探讨,并对其未来研究方向做了展望。%Breeding is kind of the genomic combination of excellent germplasms. Apart from conventional breeding methods generating new germplasms, approaches based on tissue culture and the molecular marker assisted breeding have become very popular biotechnologies to create the new breeding materials. Broccoli (Brassica oleracea L. var. italica Plenck), is an important vegetable worldwilde. In recent decades, broccoli production and consumption has risen significantly and the usage of biotechnologies on broccoli breeding has made great progress in China. This paper reviewed the uses of microspore culture, protoplast culture and fusion, transgenic technologies in improvement breeding of broccoli, and the limitation in those researches was mentioned as well. Moreover, construction of linkage maps, QTLs/genes for agronomically important broccoli traits including head morphologies and diseases resistance were analyzed in this review.

  13. Burkholderia glumae ToxA Is a Dual-Specificity Methyltransferase That Catalyzes the Last Two Steps of Toxoflavin Biosynthesis.

    Science.gov (United States)

    Fenwick, Michael K; Philmus, Benjamin; Begley, Tadhg P; Ealick, Steven E

    2016-05-17

    Toxoflavin is a major virulence factor of the rice pathogen Burkholderia glumae. The tox operon of B. glumae contains five putative toxoflavin biosynthetic genes toxABCDE. ToxA is a predicted S-adenosylmethionine-dependent methyltransferase, and toxA knockouts of B. glumae are less virulent in plant infection models. In this study, we show that ToxA performs two consecutive methylations to convert the putative azapteridine intermediate, 1,6-didemethyltoxoflavin, to toxoflavin. In addition, we report a series of crystal structures of ToxA complexes that reveals the molecular basis of the dual methyltransferase activity. The results suggest sequential methylations with initial methylation at N6 of 1,6-didemethyltoxoflavin followed by methylation at N1. The two azapteridine orientations that position N6 or N1 for methylation are coplanar with a 140° rotation between them. The structure of ToxA contains a class I methyltransferase fold having an N-terminal extension that either closes over the active site or is largely disordered. The ordered conformation places Tyr7 at a position of a structurally conserved tyrosine site of unknown function in various methyltransferases. Crystal structures of ToxA-Y7F consistently show a closed active site, whereas structures of ToxA-Y7A consistently show an open active site, suggesting that the hydroxyl group of Tyr7 plays a role in opening and closing the active site during the multistep reaction. PMID:27070241

  14. Impaired Homocysteine Transmethylation and Protein-Methyltransferase Activity Reduce Expression of Selenoprotein P: Implications for Obesity and Metabolic Syndrome

    Science.gov (United States)

    Obesity causes Metabolic Syndrome and Type-II Diabetes, disrupting hepatic function, methionine (Met)/homocysteine (Hcy) transmethylation and methyltransferase (PRMT) activities. Selenoprotein P (SEPP1), exported from the liver, is the predominate form of plasma selenium (Se) and the physiological S...

  15. Thirteen new patients with guanidinoacetate methyltransferase deficiency and functional characterization of nineteen novel missense variants in the GAMT gene

    DEFF Research Database (Denmark)

    Mercimek-Mahmutoglu, Saadet; Ndika, Joseph; Kanhai, Warsha;

    2014-01-01

    Guanidinoacetate methyltransferase deficiency (GAMT-D) is an autosomal recessively inherited disorder of creatine biosynthesis. Creatine deficiency on cranial proton magnetic resonance spectroscopy, and elevated guanidinoacetate levels in body fluids are the biomarkers of GAMT-D. In 74 patients 5...

  16. The effect of Ecstasy on memory is moderated by a functional polymorphism in the cathechol-O-methyltransferase (COMT) gene

    NARCIS (Netherlands)

    T. Schilt; M.W.J. Koeter; M.M.L. de Win; J.R. Zinkstok; T.A. van Amelsvoort; B. Schmand; W. van den Brink

    2009-01-01

    There is ample evidence for decreased verbal memory in heavy Ecstasy users. However, findings on the presence of a dose-response relation are inconsistent, possibly due to individual differences in genetic vulnerability. Catechol-O-methyltransferase (COMT) is involved in the catabolism of Ecstasy. T

  17. No up-regulation of the phosphatidylethanolamine N-methyltransferase pathway and choline production by sex hormones in cats

    NARCIS (Netherlands)

    Valtolina, Chiara; Vaandrager, Arie B; Favier, Robert P; Robben, Joris H; Tuohetahuntila, Maidina; Kummeling, Anne; Jeusette, Isabelle; Rothuizen, Jan

    2015-01-01

    BACKGROUND: Feline hepatic lipidosis (FHL) is a common cholestatic disease affecting cats of any breed, age and sex. Both choline deficiency and low hepatic phosphatidylethanolamine N-methyltransferase (PEMT) activity are associated with hepatic lipidosis (HL) in humans, mice and rats. The PEMT expr

  18. Azathioprine-associated acute myeloid leukemia in a patient with Crohn's disease and thiopurine S-methyltransferase deficiency

    DEFF Research Database (Denmark)

    Yenson, P.R.; Forrest, D.; Schmiegelow, K.;

    2008-01-01

    Immunosuppressive thiopurines like azathioprine, 6-mercaptopurine, and thioguanine are commonly used in inflammatory and neoplastic disorders. A subset of these patients are genetically slow metabolizers due to point-mutations in enzyme thiopurine S-methyltransferase (TPMT), and are at a higher r...

  19. Current understanding of the interplay between catechol-O-methyltransferase genetic variants, sleep, brain development and cognitive performance in schizophrenia

    NARCIS (Netherlands)

    Tucci, Valter; Lassi, Glenda; Kas, Martien J

    2012-01-01

    Abnormal sleep is an endophenotype of schizophrenia. Here we provide an overview of the genetic mechanisms that link specific sleep physiological processes to schizophrenia-related cognitive defects. In particular, we will review the possible relationships between catechol-O-methyltransferase (COMT)

  20. Characterization of cytosine methylated regions and 5-cytosine DNA methyltransferase (Ehmeth) in the protozoan parasite Entamoeba histolytica.

    Science.gov (United States)

    Fisher, Ohad; Siman-Tov, Rama; Ankri, Serge

    2004-01-01

    The DNA methylation status of the protozoan parasite Entamoeba histolytica was heretofore unknown. In the present study, we developed a new technique, based on the affinity of methylated DNA to 5-methylcytosine antibodies, to identify methylated DNA in this parasite. Ribosomal DNA and ribosomal DNA circles were isolated by this method and we confirmed the validity of our approach by sodium bisulfite sequencing. We also report the identification and the characterization of a gene, Ehmeth, encoding a DNA methyltransferase strongly homologous to the human DNA methyltransferase 2 (Dnmt2). Immunofluorescence microscopy using an antibody raised against a recombinant Ehmeth showed that Ehmeth is concentrated in the nuclei of trophozoites. The recombinant Ehmeth has a weak but significant methyltransferase activity when E.histolytica genomic DNA is used as substrate. 5-Azacytidine (5-AzaC), an inhibitor of DNA methyltransferase, was used to study in vivo the role of DNA methylation in E.histolytica. Genomic DNA of trophozoites grown with 5-AzaC (23 microM) was undermethylated and the ability of 5-AzaC-treated trophozoites to kill mammalian cells or to cause liver abscess in hamsters was strongly impaired.

  1. Polymorphisms in O-methyltransferase genes are associated with stover cell wall digestibility in European maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Brenner, Everton A; Zein, Imad; Chen, Yongsheng;

    2010-01-01

    Background OMT (O-methyltransferase) genes are involved in lignin biosynthesis, which relates to stover cell wall digestibility. Reduced lignin content is an important determinant of both forage quality and ethanol conversion efficiency of maize stover. Results Variation in genomic sequences codi...

  2. Vagus nerve contributes to the development of steatohepatitis and obesity in phosphatidylethanolamine N-methyltransferase deficient mice

    NARCIS (Netherlands)

    Gao, Xia; van der Veen, Jelske N.; Zhu, Linfu; Chaba, Todd; Ordonez, Marta; Lingrell, Susanne; Koonen, Debby P. Y.; Dyck, Jason R. B.; Gomez-Munoz, Antonio; Vance, Dennis E.; Jacobs, Rene L.

    2015-01-01

    BACKGROUND & AIMS: Phosphatidylethanolamine N-methyltransferase (PEMT), a liver enriched enzyme, is responsible for approximately one third of hepatic phosphatidylcholine biosynthesis. When fed a high-fat diet (HFD), Pemt(-/-) mice are protected from HF-induced obesity; however, they develop steatoh

  3. Refolding of a fully functional flavivirus methyltransferase revealed that S-adenosyl methionine but not S-adenosyl homocysteine is copurified with flavivirus methyltransferase.

    Science.gov (United States)

    Brecher, Matthew B; Li, Zhong; Zhang, Jing; Chen, Hui; Lin, Qishan; Liu, Binbin; Li, Hongmin

    2015-01-01

    Methylation of flavivirus RNA is vital for its stability and translation in the infected host cell. This methylation is mediated by the flavivirus methyltransferase (MTase), which methylates the N7 and 2'-O positions of the viral RNA cap by using S-adenosyl-l-methionine (SAM) as a methyl donor. In this report, we demonstrate that SAM, in contrast to the reaction by-product S-adenosyl-l-homocysteine, which was assumed previously, is copurified with the Dengue (DNV) and West Nile virus MTases produced in Escherichia coli (E. coli). This endogenous SAM can be removed by denaturation and refolding of the MTase protein. The refolded MTase of DNV serotype 3 (DNV3) displays methylation activity comparable to native enzyme, and its crystal structure at 2.1 Å is almost identical to that of native MTase. We characterized the binding of Sinefungin (SIN), a previously described SAM-analog inhibitor of MTase function, to the native and refolded DNV3 MTase by isothermal titration calorimetry, and found that SIN binds to refolded MTase with more than 16 times the affinity of SIN binding to the MTase purified natively. Moreover, we show that SAM is also copurified with other flavivirus MTases, indicating that purification by refolding may be a generally applicable tool for studying flavivirus MTase inhibition.

  4. Methanol:coenzyme M methyltransferase from Methanosarcina barkeri. Zinc dependence and thermodynamics of the methanol:cob(I)alamin methyltransferase reaction.

    Science.gov (United States)

    Sauer, K; Thauer, R K

    1997-10-01

    In Methanosarcina barkeri, methanogenesis from methanol is initiated by the formation of methyl-coenzyme M from methanol and coenzyme M. This methyl transfer reaction is catalyzed by two enzymes, designated methyltransferases 1 (MT1) and 2 (MT2). Transferase MT1, which is composed of a 50-kDa subunit, MtaB, and a 27-kDa corrinoid-harbouring subunit, MtaC, has been shown recently to catalyze the methylation of free cob(I)alamin with methanol [Sauer, K., Harms, U. & Thauer, R. K. (1997) Eur. J. Biochem. 243, 670-677]. We report here that this reaction is catalyzed by subunit MtaB overproduced in Escherichia coli. MtaB also catalyzed the formation of methanol from methylcobalamin and H2O, the hydrolysis being associated with a free-energy change deltaG(o)' of approximately +7.0 kJ/mol. MtaB was found to contain 1 mol zinc, and its activity to be zinc dependent (pK(Zn2+) = 9.3). The zinc dependence of the MT2 (MtaA)-catalyzed reaction is also described (pK(Zn2+) = 9.6). PMID:9363780

  5. Identification of an S-adenosylmethionine (SAM) dependent arsenic methyltransferase in Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Hamdi, Mohamad [Department of Biological Sciences, Oakland University, Rochester, MI 48309 (United States); Yoshinaga, Masafumi; Packianathan, Charles; Qin, Jie [Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, FL33199 (United States); Hallauer, Janell; McDermott, Joseph R. [Department of Biological Sciences, Oakland University, Rochester, MI 48309 (United States); Yang, Hung-Chi [Department of Medical Biotechnology and Laboratory Sciences, Chang-Gung University, Tao-Yuan, Kwei-San 333, Taiwan (China); Tsai, Kan-Jen [School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan (China); Liu, Zijuan, E-mail: liu2345@oakland.edu [Department of Biological Sciences, Oakland University, Rochester, MI 48309 (United States)

    2012-07-15

    Arsenic methylation is an important cellular metabolic process that modulates arsenic toxicity and carcinogenicity. Biomethylation of arsenic produces a series of mono-, di- and tri-methylated arsenic metabolites that can be detected in tissues and excretions. Here we report that zebrafish exposed to arsenite (As{sup III}) produces organic arsenicals, including MMA{sup III}, MMA{sup V} and DMA{sup V} with characteristic tissue ratios, demonstrating that an arsenic methylation pathway exists in zebrafish. In mammals, cellular inorganic arsenic is methylated by a SAM-dependent arsenic methyltransferase, AS3MT. A zebrafish arsenic methyltransferase homolog, As3mt, was identified by sequence alignment. Western blotting analysis showed that As3mt was universally expressed in zebrafish tissues. Prominent expression in liver and intestine correlated with methylated arsenic metabolites detected in those tissues. As3mt was expressed in and purified from Escherichia coli for in vitro functional studies. Our results demonstrated that As3mt methylated As{sup III} to DMA{sup V} as an end product and produced MMA{sup III} and MMA{sup V} as intermediates. The activity of As3mt was inhibited by elevated concentrations of the substrate As{sup III} as well as the metalloid selenite, which is a well-known antagonistic micronutrient of arsenic toxicity. The activity As3mt was abolished by substitution of either Cys160 or Cys210, which corresponds to conserved cysteine residues in AS3MT homologs, suggesting that they are involved in catalysis. Expression in zebrafish of an enzyme that has a similar function to human and rodent orthologs in catalyzing intracellular arsenic biomethylation validates the applicability of zebrafish as a valuable vertebrate model for understanding arsenic-associated diseases in humans. -- Highlights: ► Zebrafish methylated As{sup III} to MMA{sup III}, MMA{sup V} and DMA{sup V}. ► A zebrafish arsenic methyltransferase (As3mt) was purified in E. coli.

  6. Structural Basis for Binding of RNA and Cofactor by a KsgA Methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Chao; Tropea, Joseph E.; Austin, Brian P.; Court, Donald L.; Waugh, David S.; Ji, Xinhua; (NCI)

    2009-03-27

    Among methyltransferases, KsgA and the reaction it catalyzes are conserved throughout evolution. However, the specifics of substrate recognition by the enzyme remain unknown. Here we report structures of Aquifex aeolicus KsgA, in its ligand-free form, in complex with RNA, and in complex with both RNA and S-adenosylhomocysteine (SAH, reaction product of cofactor S-adenosylmethionine), revealing critical structural information on KsgA-RNA and KsgA-SAH interactions. Moreover, the structures show how conformational changes that occur upon RNA binding create the cofactor-binding site. There are nine conserved functional motifs (motifs IVIII and X) in KsgA. Prior to RNA binding, motifs I and VIII are flexible, each exhibiting two distinct conformations. Upon RNA binding, the two motifs become stabilized in one of these conformations, which is compatible with the binding of SAH. Motif X, which is also stabilized upon RNA binding, is directly involved in the binding of SAH.

  7. Brain Histamine N-Methyltransferase As a Possible Target of Treatment for Methamphetamine Overdose

    Science.gov (United States)

    Kitanaka, Junichi; Kitanaka, Nobue; Hall, F. Scott; Uhl, George R.; Takemura, Motohiko

    2016-01-01

    Stereotypical behaviors induced by methamphetamine (METH) overdose are one of the overt symptoms of METH abuse, which can be easily assessed in animal models. Currently, there is no successful treatment for METH overdose. There is increasing evidence that elevated levels of brain histamine can attenuate METH-induced behavioral abnormalities, which might therefore constitute a novel therapeutic treatment for METH abuse and METH overdose. In mammals, histamine N-methyltransferase (HMT) is the sole enzyme responsible for degrading histamine in the brain. Metoprine, one of the most potent HMT inhibitors, can cross the blood–brain barrier and increase brain histamine levels by inhibiting HMT. Consequently, this compound can be a candidate for a prototype of drugs for the treatment of METH overdose. PMID:26966348

  8. Multi-site-specific 16S rRNA methyltransferase RsmF from Thermus thermophilus

    DEFF Research Database (Denmark)

    Demirci, Hasan; Larsen, Line H G; Hansen, Trine;

    2010-01-01

    Cells devote a significant effort toward the production of multiple modified nucleotides in rRNAs, which fine tune the ribosome function. Here, we report that two methyltransferases, RsmB and RsmF, are responsible for all four 5-methylcytidine (m(5)C) modifications in 16S rRNA of Thermus...... thermophilus. Like Escherichia coli RsmB, T. thermophilus RsmB produces m(5)C967. In contrast to E. coli RsmF, which introduces a single m(5)C1407 modification, T. thermophilus RsmF modifies three positions, generating m(5)C1400 and m(5)C1404 in addition to m(5)C1407. These three residues are clustered near...

  9. Strategy to target the substrate binding site of SET domain protein methyltransferases.

    Science.gov (United States)

    Nguyen, Kong T; Li, Fengling; Poda, Gennadiy; Smil, David; Vedadi, Masoud; Schapira, Matthieu

    2013-03-25

    Protein methyltransferases (PMTs) are a novel gene family of therapeutic relevance involved in chromatin-mediated signaling and other biological mechanisms. Most PMTs are organized around the structurally conserved SET domain that catalyzes the methylation of a substrate lysine. A few potent chemical inhibitors compete with the protein substrate, and all are anchored in the channel recruiting the methyl-accepting lysine. We propose a novel strategy to design focused chemical libraries targeting the substrate binding site, where a limited number of warheads each occupying the lysine-channel of multiple enzymes would be decorated by different substituents. A variety of sequence and structure-based approaches used to analyze the diversity of the lysine channel of SET domain PMTs support the relevance of this strategy. We show that chemical fragments derived from published inhibitors are valid warheads that can be used in the design of novel focused libraries targeting other PMTs.

  10. Molecular basis for oncohistone H3 recognition by SETD2 methyltransferase.

    Science.gov (United States)

    Yang, Shuang; Zheng, Xiangdong; Lu, Chao; Li, Guo-Min; Allis, C David; Li, Haitao

    2016-07-15

    High-frequency point mutations of genes encoding histones have been identified recently as novel drivers in a number of tumors. Specifically, the H3K36M/I mutations were shown to be oncogenic in chondroblastomas and undifferentiated sarcomas by inhibiting H3K36 methyltransferases, including SETD2. Here we report the crystal structures of the SETD2 catalytic domain bound to H3K36M or H3K36I peptides with SAH (S-adenosylhomocysteine). In the complex structure, the catalytic domain adopts an open conformation, with the K36M/I peptide snuggly positioned in a newly formed substrate channel. Our structural and biochemical data reveal the molecular basis underying oncohistone recognition by and inhibition of SETD2. PMID:27474439

  11. Cancer stem cell overexpression of nicotinamide N-methyltransferase enhances cellular radiation resistance

    DEFF Research Database (Denmark)

    D’Andrea, Filippo P.; Safwat, Akmal; Kassem, Moustapha;

    2011-01-01

    found the genes involved in cancer, proliferation, DNA repair and cell death. ConclusionsThe higher radiation resistance in clone CE8 is likely due to NNMT overexpression. The higher levels of NNMT could affect the cellular damage resistance through depletion of the accessible amounts of nicotinamide...... that could explain cancer stem cell radiation resistance. MethodsTumorigenic mesenchymal cancer stem cell clones BB3 and CE8 were irradiated at varying doses and assayed for clonogenic surviving fraction. Altered gene expression before and after 2Gy was assessed by Affymetric exon chip analysis and further...... validated with q-RT-PCR using TaqMan probes. ResultsThe CE8 clone was more radiation resistant than the BB3 clone. From a pool of 15 validated genes with altered expression in the CE8 clone, we found the enzyme nicotinamide N-methyltransferase (NNMT) more than 5-fold upregulated. In-depth pathway analysis...

  12. Minimal Substrate Features for Erm Methyltransferases Defined by Using a Combinatorial Oligonucleotide Library

    DEFF Research Database (Denmark)

    Hansen, Lykke H; Lobedanz, Sune; Douthwaite, Stephen;

    2011-01-01

    Erm methyltransferases are prevalent in pathogenic bacteria and confer resistance to macrolide, lincosamide, and streptogramin B antibiotics by specifically methylating the 23S ribosomal RNA at nucleotide A2058. We have identified motifs within the rRNA substrate that are required for methylation...... by Erm. Substrate molecules were constructed in a combinatorial manner from two separate sets (top and bottom strands) of short RNA sequences. Modifications, including LNA monomers with locked sugar residues, were incorporated into the substrates to stabilize their structures. In functional substrates......, the A2058 methylation target (on the 13- to 19-nucleotide top strand) was displayed in an unpaired sequence immediately following a conserved irregular helix, and these are the specific structural features recognized by Erm. Erm methylation was enhanced by stabilizing the top-strand conformation...

  13. Mechanistic and biological significance of DNA methyltransferase 1 upregulated by growth factors in human hepatocellular carcinoma.

    Science.gov (United States)

    Fang, Qin-Liang; Yin, Yi-Rui; Xie, Cheng-Rong; Zhang, Sheng; Zhao, Wen-Xiu; Pan, Chao; Wang, Xiao-Min; Yin, Zhen-Yu

    2015-02-01

    Dysregulation of growth factor signaling plays a pivotal role in controlling the malignancy phenotype and progression of hepatocellular carcinoma (HCC). However, the precise oncogenic mechanisms underlying transcription regulation of certain tumor suppressor genes (TSGs) by growth factors are poorly understood. In the present study, we report a novel insulin-like growth factor 1 (IGF1) pathway that mediates de novo DNA methylation and TSG (such as DLC1 and CHD5) silencing by upregulation of the DNA methyltransferase 1 (DNMT1) via an AKT/β-transducin repeat-containing protein (βTrCP)-mediated ubiquitin-proteasome pathway in HCC. Analysis of DNA methylation in CpG islands of target genes revealed high co-localization of DNMT1 and DNMT3B on the promoters of TSGs associated with enhanced CpG hypermethylation. Our results point to a novel epigenetic mechanism for growth factor-mediated repression of TSG transcription that involves DNA methylation. PMID:25420499

  14. Rationalization of Activity Cliffs of a Sulfonamide Inhibitor of DNA Methyltransferases with Induced-Fit Docking

    Directory of Open Access Journals (Sweden)

    José L. Medina-Franco

    2014-02-01

    Full Text Available Inhibitors of human DNA methyltransferases (DNMT are of increasing interest to develop novel epi-drugs for the treatment of cancer and other diseases. As the number of compounds with reported DNMT inhibition is increasing, molecular docking is shedding light to elucidate their mechanism of action and further interpret structure–activity relationships. Herein, we present a structure-based rationalization of the activity of SW155246, a distinct sulfonamide compound recently reported as an inhibitor of human DNMT1 obtained from high-throughput screening. We used flexible and induce-fit docking to develop a binding model of SW155246 with a crystallographic structure of human DNMT1. Results were in excellent agreement with experimental information providing a three-dimensional structural interpretation of ‘activity cliffs’, e.g., analogues of SW155246 with a high structural similarity to the sulfonamide compound, but with no activity in the enzymatic assay.

  15. Miniaturization of High-Throughput Epigenetic Methyltransferase Assays with Acoustic Liquid Handling.

    Science.gov (United States)

    Edwards, Bonnie; Lesnick, John; Wang, Jing; Tang, Nga; Peters, Carl

    2016-02-01

    Epigenetics continues to emerge as an important target class for drug discovery and cancer research. As programs scale to evaluate many new targets related to epigenetic expression, new tools and techniques are required to enable efficient and reproducible high-throughput epigenetic screening. Assay miniaturization increases screening throughput and reduces operating costs. Echo liquid handlers can transfer compounds, samples, reagents, and beads in submicroliter volumes to high-density assay formats using only acoustic energy-no contact or tips required. This eliminates tip costs and reduces the risk of reagent carryover. In this study, we demonstrate the miniaturization of a methyltransferase assay using Echo liquid handlers and two different assay technologies: AlphaLISA from PerkinElmer and EPIgeneous HTRF from Cisbio.

  16. Characterisation of the histone methyltransferase SET8 in cell cycle progression and the DNA damage response

    DEFF Research Database (Denmark)

    Jørgensen, Stine

    2008-01-01

    Histone modifications and their catalysing enzymes have within the last few years proven to be essential players in many biological processes. Due to their ability to modulate chromatin structure and affect signalling pathways they are found to affect diverse processes such as transcription, DNA...... recombination and repair. I therefore initiated a mass spectrometry based study to identify changes in histone modifications after DNA damage. By using SILAC labelling of cells to quantatively measure the changes in histone modifications, we observed a marked reduction in the level of monomethylated Histone H4...... lysine 20 (H4K20me1) after damage. H4K20me1 is catalysed by the histone methyltransferase SET8 (aka PR-SET7), and functional studies of this enzyme revealed that SET8 is important for S phase progression. We also showed that depletion of SET8 in several different cancer cell lines results in accumulation...

  17. Histone methyltransferases and demethylases:regulators in balancing osteogenic and adipogenic differentiation of mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Peng Deng; Qian-Ming Chen; Christine Hong; Cun-Yu Wang

    2015-01-01

    Mesenchymal stem cells (MSCs) are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su(var)3–9, enhancer-of-zeste, trithorax (SET) domain-containing family and the Jumonji C (JmjC) domain-containing family represent the major histone lysine methyltransferases (KMTs) and histone lysine demethylases (KDMs), respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containing KMTs and JmjC domain-containing KDMs balance the osteogenic and adipogenic differentiation of MSCs.

  18. Ash2 acts as an ecdysone receptor coactivator by stabilizing the histone methyltransferase Trr.

    Science.gov (United States)

    Carbonell, Albert; Mazo, Alexander; Serras, Florenci; Corominas, Montserrat

    2013-02-01

    The molting hormone ecdysone triggers chromatin changes via histone modifications that are important for gene regulation. On hormone activation, the ecdysone receptor (EcR) binds to the SET domain-containing histone H3 methyltransferase trithorax-related protein (Trr). Methylation of histone H3 at lysine 4 (H3K4me), which is associated with transcriptional activation, requires several cofactors, including Ash2. We find that ash2 mutants have severe defects in pupariation and metamorphosis due to a lack of activation of ecdysone-responsive genes. This transcriptional defect is caused by the absence of the H3K4me3 marks set by Trr in these genes. We present evidence that Ash2 interacts with Trr and is required for its stabilization. Thus we propose that Ash2 functions together with Trr as an ecdysone receptor coactivator.

  19. Glucoraphanin, the bioprecursor of the widely extolled chemopreventive agent sulforaphane found in broccoli, induces Phase-I xenobiotic metabolizing enzymes and increases free radical generation in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Perocco, Paolo [Department of Experimental Pathology, Cancerology Section, viale Filopanti 22, I-40126, University of Bologna, Bologna (Italy); Bronzetti, Giorgio [Institute of Biology and Agricultural Biotechnology - CNR Research Area, via Moruzzi, I-56124 Pisa (Italy); Canistro, Donatella; Sapone, Andrea; Affatato, Alessandra; Pozzetti, Laura; Broccoli, Massimiliano [Department of Pharmacology, Molecular Toxicology Unit, via Irnerio 48, I-40126, University of Bologna, Bologna (Italy); Valgimigli, Luca [Department of Organic Chemistry ' A. Mangini' , Viale Risorgimento 4, I-40127, Alma-Mater Studiorum, University of Bologna, Bologna (Italy); Pedulli, Gian Franco [Department of Organic Chemistry ' A. Mangini' , Viale Risorgimento 4, I-40127, Alma-Mater Studiorum, University of Bologna, Bologna (Italy); Iori, Renato [C.R.A - Research Institute for Industrial Crops, via di Corticella 133, I-40129 Bologna (Italy); Barillari, Jessica [Institute of Biology and Agricultural Biotechnology - CNR Research Area, via Moruzzi, I-56124 Pisa (Italy)]|[C.R.A - Research Institute for Industrial Crops, via di Corticella 133, I-40129 Bologna (Italy); Sblendorio, Valeriana [Department of Pharmacology, Molecular Toxicology Unit, via Irnerio 48, I-40126, University of Bologna, Bologna (Italy); Legator, Marvin S. [Department of Preventive Medicine and Community Health, Division of Environmental Toxicology, The University of Texas Medical Branch at Galveston, 700 Harborside Drive, Galveston, TX 77555-1110 (United States); Paolini, Moreno [Department of Pharmacology, Molecular Toxicology Unit, via Irnerio 48, I-40126, University of Bologna, Bologna (Italy); Abdel-Rahman, Sherif Z. [Department of Preventive Medicine and Community Health, Division of Environmental Toxicology, The University of Texas Medical Branch at Galveston, 700 Harborside Drive, Galveston, TX 77555-1110 (United States)]. E-mail: sabdelra@utmb.edu

    2006-03-20

    Epidemiological and animal studies linking high fruit and vegetable consumption to lower cancer risk have strengthened the belief that long-term administration of isolated naturally occurring dietary constituents could reduce the risk of cancer. In recent years, metabolites derived from phytoalexins, such as glucoraphanin found in broccoli and other cruciferous vegetables (Brassicaceae), have gained much attention as potential cancer chemopreventive agents. The protective effect of these micronutrients is assumed to be due to the inhibition of Phase-I carcinogen-bioactivating enzymes and/or induction of Phase-II detoxifying enzymes, an assumption that still remains uncertain. The protective effect of glucoraphanin is thought to be due to sulforaphane, an isothiocyanate metabolite produced from glucoraphanin by myrosinase. Here we show, in rat liver, that while glucoraphanin slightly induces Phase-II enzymes, it powerfully boosts Phase-I enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), nitrosamines and olefins. Induction of the cytochrome P450 (CYP) isoforms CYP1A1/2, CYP3A1/2 and CYP2E1 was confirmed by Western immunoblotting. CYP induction was paralleled by an increase in the corresponding mRNA levels. Concomitant with this Phase-I induction, we also found that glucoraphanin generated large amount of various reactive radical species, as determined by electron paramagnetic resonance (EPR) spectrometry coupled to a radical-probe technique. This suggests that long-term uncontrolled administration of glucoraphanin could actually pose a potential health hazard.

  20. Nutritional quality changes throughout shelf-life of fresh-cut kailan-hybrid and 'Parthenon' broccoli as affected by temperature and atmosphere composition.

    Science.gov (United States)

    Martínez-Hernández, Ginés Benito; Gómez, Perla A; Artés, Francisco; Artés-Hernández, Francisco

    2015-01-01

    The nutritional quality changes of the fresh-cut kailan-hybrid broccoli were compared with those of the 'Parthenon' cv. throughout 15 days at 2 ℃, 5 ℃ and 8 ℃ under air and modified atmosphere packaging. Florets showed higher dietary fiber content than stems. The total protein content of kailan-hybrid florets was 2.2-fold higher than that of 'Parthenon' cv. and higher amounts of S, Ca, Mg, Fe, Sr, Mn, Zn and Cu were found. However, 'Parthenon' florets registered higher initial total phenolics content than the kailan-hybrid edible part, followed by an increase throughout shelf-life favored at 5 ℃ and 8 ℃ under modified atmosphere packaging (5-7 kPa O2 + 14-15 kPa CO2). Modified atmosphere packaging stored samples at 8 ℃ showed higher individual phenolics content than modified atmosphere packaging stored samples at 2 ℃. The initial total antioxidant capacity of the kailan-hybrid edible part was higher than that of 'Parthenon' cv. florets. In conclusion, the kailan-hybrid florets generally showed healthier properties on the analyzed bioactive compounds, except total phenolic content, compared to the conventional 'Parthenon' cv.

  1. Induction of phase 2 antioxidant enzymes by broccoli sulforaphane: Perspectives in maintaining the antioxidant activity of vitamins A, C, and E

    Directory of Open Access Journals (Sweden)

    Sekhar s Boddupalli

    2012-01-01

    Full Text Available Consumption of fruits and vegetables is recognized as an important part of a healthy diet. Increased consumption of cruciferous vegetables in particular has been associated with a decreased risk of several degenerative and chronic diseases, including cardiovascular disease and certain cancers. Members of the cruciferous vegetable family, which includes broccoli, Brussels sprouts, cauliflower, and cabbage, accumulate significant concentrations of glucosinolates, which are metabolized in vivo to biologically active isothiocyanates (ITCs. The ITC sulforaphane, which is derived from glucoraphanin, has garnered particular interest due to its extraordinary ability to induce expression of several enzymes via the Keap1/Nrf2/ARE pathway. Nrf2/ARE gene products are typically characterized as Phase II detoxification enzymes and/or antioxidant (AO enzymes. Over the last decade, human clinical studies have begun to provide in vivo evidence of both Phase II and AO enzyme induction by SF. Many AO enzymes are redox cycling enzymes that maintain redox homeostasis and activity of free radical scavengers such as such as vitamins A, C and E. In this review, we present the existing evidence for induction of PII and AO enzymes by SF, the interactions of SF-induced AO enzymes and proposed maintenance of the essential vitamins A, C and E, and, finally, the current view of genotypic effects on ITC metabolism and AO enzyme induction and function.

  2. Glucoraphanin, the bioprecursor of the widely extolled chemopreventive agent sulforaphane found in broccoli, induces Phase-I xenobiotic metabolizing enzymes and increases free radical generation in rat liver

    International Nuclear Information System (INIS)

    Epidemiological and animal studies linking high fruit and vegetable consumption to lower cancer risk have strengthened the belief that long-term administration of isolated naturally occurring dietary constituents could reduce the risk of cancer. In recent years, metabolites derived from phytoalexins, such as glucoraphanin found in broccoli and other cruciferous vegetables (Brassicaceae), have gained much attention as potential cancer chemopreventive agents. The protective effect of these micronutrients is assumed to be due to the inhibition of Phase-I carcinogen-bioactivating enzymes and/or induction of Phase-II detoxifying enzymes, an assumption that still remains uncertain. The protective effect of glucoraphanin is thought to be due to sulforaphane, an isothiocyanate metabolite produced from glucoraphanin by myrosinase. Here we show, in rat liver, that while glucoraphanin slightly induces Phase-II enzymes, it powerfully boosts Phase-I enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), nitrosamines and olefins. Induction of the cytochrome P450 (CYP) isoforms CYP1A1/2, CYP3A1/2 and CYP2E1 was confirmed by Western immunoblotting. CYP induction was paralleled by an increase in the corresponding mRNA levels. Concomitant with this Phase-I induction, we also found that glucoraphanin generated large amount of various reactive radical species, as determined by electron paramagnetic resonance (EPR) spectrometry coupled to a radical-probe technique. This suggests that long-term uncontrolled administration of glucoraphanin could actually pose a potential health hazard

  3. The PRMT5 arginine methyltransferase: many roles in development, cancer and beyond.

    Science.gov (United States)

    Stopa, Nicole; Krebs, Jocelyn E; Shechter, David

    2015-06-01

    Post-translational arginine methylation is responsible for regulation of many biological processes. The protein arginine methyltransferase 5 (PRMT5, also known as Hsl7, Jbp1, Skb1, Capsuleen, or Dart5) is the major enzyme responsible for mono- and symmetric dimethylation of arginine. An expanding literature demonstrates its critical biological function in a wide range of cellular processes. Histone and other protein methylation by PRMT5 regulate genome organization, transcription, stem cells, primordial germ cells, differentiation, the cell cycle, and spliceosome assembly. Metazoan PRMT5 is found in complex with the WD-repeat protein MEP50 (also known as Wdr77, androgen receptor coactivator p44, or Valois). PRMT5 also directly associates with a range of other protein factors, including pICln, Menin, CoPR5 and RioK1 that may alter its subcellular localization and protein substrate selection. Protein substrate and PRMT5-MEP50 post-translation modifications induce crosstalk to regulate PRMT5 activity. Crystal structures of C. elegans PRMT5 and human and frog PRMT5-MEP50 complexes provide substantial insight into the mechanisms of substrate recognition and procession to dimethylation. Enzymological studies of PRMT5 have uncovered compelling insights essential for future development of specific PRMT5 inhibitors. In addition, newly accumulating evidence implicates PRMT5 and MEP50 expression levels and their methyltransferase activity in cancer tumorigenesis, and, significantly, as markers of poor clinical outcome, marking them as potential oncogenes. Here, we review the substantial new literature on PRMT5 and its partners to highlight the significance of understanding this essential enzyme in health and disease.

  4. Imatinib causes epigenetic alterations of PTEN gene via upregulation of DNA methyltransferases and polycomb group proteins

    International Nuclear Information System (INIS)

    We have recently reported the possible imatinib-resistant mechanism; long-term exposure of leukemia cells to imatinib downregulated levels of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) via hypermethylation of its promoter region (Leukemia 2010; 24: 1631). The present study explored the molecular mechanisms by which imatinib caused methylation on the promoter region of this tumor suppressor gene in leukemia cells. Real-time reverse transcription PCR found that long-term exposure of chronic eosinophilic leukemia EOL-1 cells expressing FIP1L1/platelet-derived growth factor receptor-α to imatinib induced expression of DNA methyltransferase 3A (DNMT3A) and histone-methyltransferase enhancer of zeste homolog 2 (EZH2), a family of polycomb group, thereby increasing methylation of the gene. Immunoprecipitation assay found the increased complex formation of DNMT3A and EZH2 proteins in these cells. Moreover, chromatin immunoprecipitation assay showed that amounts of both DNMT3A and EZH2 proteins bound around the promoter region of PTEN gene were increased in EOL-1 cells after exposure to imatinib. Furthermore, we found that levels of DNMT3A and EZH2 were strikingly increased in leukemia cells isolated from individuals with chronic myelogenous leukemia (n=1) and Philadelphia chromosome-positive acute lymphoblastic leukemia (n=2), who relapsed after treatment with imatinib compared with those isolated at their initial presentation. Taken together, imatinib could cause drug-resistance via recruitment of polycomb gene complex to the promoter region of the PTEN and downregulation of this gene's transcripts in leukemia patients

  5. Characterization of three O-methyltransferases involved in noscapine biosynthesis in opium poppy.

    Science.gov (United States)

    Dang, Thu-Thuy T; Facchini, Peter J

    2012-06-01

    Noscapine is a benzylisoquinoline alkaloid produced in opium poppy (Papaver somniferum) and other members of the Papaveraceae. It has been used as a cough suppressant and more recently was shown to possess anticancer activity. However, the biosynthesis of noscapine in opium poppy has not been established. A proposed pathway leading from (S)-reticuline to noscapine includes (S)-scoulerine, (S)-canadine, and (S)-N-methylcanadine as intermediates. Stem cDNA libraries and latex extracts of eight opium poppy cultivars displaying different alkaloid profiles were subjected to massively parallel pyrosequencing and liquid chromatography-tandem mass spectrometry, respectively. Comparative transcript and metabolite profiling revealed the occurrence of three cDNAs encoding O-methyltransferases designated as SOMT1, SOMT2, and SOMT3 that correlated with the accumulation of noscapine in the eight cultivars. SOMT transcripts were detected in all opium poppy organs but were most abundant in aerial organs, where noscapine primarily accumulates. SOMT2 and SOMT3 showed strict substrate specificity and regiospecificity as 9-O-methyltransferases targeting (S)-scoulerine. In contrast, SOMT1 was able to sequentially 9- and 2-O-methylate (S)-scoulerine, yielding (S)-tetrahydropalmatine. SOMT1 also sequentially 3'- and 7-O-methylated both (S)-norreticuline and (S)-reticuline with relatively high substrate affinity, yielding (S)-tetrahydropapaverine and (S)-laudanosine, respectively. The metabolic functions of SOMT1, SOMT2, and SOMT3 were investigated in planta using virus-induced gene silencing. Reduction of SOMT1 or SOMT2 transcript levels resulted in a significant decrease in noscapine accumulation. Reduced SOMT1 transcript levels also caused a decrease in papaverine accumulation, confirming the selective roles for these enzymes in the biosynthesis of both alkaloids in opium poppy. PMID:22535422

  6. Protein arginine methyltransferase 5 (PRMT5) is a novel coactivator of constitutive androstane receptor (CAR)

    International Nuclear Information System (INIS)

    The constitutive androstane receptor (CAR) plays a key role in the expression of xenobiotic/steroid and drug metabolizing enzymes and their transporters. In this study, we demonstrated that protein arginine methyltransferase 5 (PRMT5) is a novel CAR-interacting protein. Furthermore, the PRMT-dependent induction of a CAR reporter gene, which was independent of methyltransferase activity, was enhanced in the presence of steroid receptor coactivator 1 (SRC1), peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) or DEAD box DNA/RNA helicase DP97. Using tetracycline inducible-hCAR system in HepG2 cells, we showed that knockdown of PRMT5 with small interfering RNA suppressed tetracycline -induced mRNA expression of CYP2B6 but not of CYP2C9 or CYP3A4. PRMT5 enhanced phenobarbital-mediated transactivation of a phenobarbital-responsive enhancer module (PBREM)-driven reporter gene in co-operation with PGC-1α in rat primary hepatocytes. Based on these findings, we suggest PRMT5 to be a gene (or promoter)-selective coactivator of CAR by mediating the formation of complexes between hCAR and appropriate coactivators. - Highlights: • Nuclear receptor CAR interact with PRMT5. • PRMT5 enhances transcriptional activity of CAR. • PRMT5 synergistically enhances transactivity of CAR by the co-expression of SRC-1, DP97 or PGC1α. • PRMT5 is a gene-selective co-activator for hCAR

  7. Computational Investigation of the Interplay of Substrate Positioning and Reactivity in Catechol O-Methyltransferase.

    Science.gov (United States)

    Patra, Niladri; Ioannidis, Efthymios I; Kulik, Heather J

    2016-01-01

    Catechol O-methyltransferase (COMT) is a SAM- and Mg2+-dependent methyltransferase that regulates neurotransmitters through methylation. Simulations and experiments have identified divergent catecholamine substrate orientations in the COMT active site: molecular dynamics simulations have favored a monodentate coordination of catecholate substrates to the active site Mg2+, and crystal structures instead preserve bidentate coordination along with short (2.65 Å) methyl donor-acceptor distances. We carry out longer dynamics (up to 350 ns) to quantify interconversion between bidentate and monodentate binding poses. We provide a systematic determination of the relative free energy of the monodentate and bidentate structures in order to identify whether structural differences alter the nature of the methyl transfer mechanism and source of enzymatic rate enhancement. We demonstrate that the bidentate and monodentate binding modes are close in energy but separated by a 7 kcal/mol free energy barrier. Analysis of interactions in the two binding modes reveals that the driving force for monodentate catecholate orientations in classical molecular dynamics simulations is derived from stronger electrostatic stabilization afforded by alternate Mg2+ coordination with strongly charged active site carboxylates. Mixed semi-empirical-classical (SQM/MM) substrate C-O distances (2.7 Å) for the bidentate case are in excellent agreement with COMT X-ray crystal structures, as long as charge transfer between the substrates, Mg2+, and surrounding ligands is permitted. SQM/MM free energy barriers for methyl transfer from bidentate and monodentate catecholate configurations are comparable at around 21-22 kcal/mol, in good agreement with experiment (18-19 kcal/mol). Overall, the work suggests that both binding poses are viable for methyl transfer, and accurate descriptions of charge transfer and electrostatics are needed to provide balanced relative barriers when multiple binding poses are

  8. Functional characterisation of three o-methyltransferases involved in the biosynthesis of phenolglycolipids in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Roxane Simeone

    Full Text Available Phenolic glycolipids are produced by a very limited number of slow-growing mycobacterial species, most of which are pathogen for humans. In Mycobacterium tuberculosis, the etiologic agent of tuberculosis, these molecules play a role in the pathogenicity by modulating the host immune response during infection. The major variant of phenolic glycolipids produced by M. tuberculosis, named PGL-tb, consists of a large lipid core terminated by a glycosylated aromatic nucleus. The carbohydrate part is composed of three sugar residues, two rhamnosyl units and a terminal fucosyl residue, which is per-O-methylated, and seems to be important for pathogenicity. While most of the genes responsible for the synthesis of the lipid core domain and the saccharide appendage of PGL-tb have been characterized, the enzymes involved in the O-methylation of the fucosyl residue of PGL-tb remain unknown. In this study we report the identification and characterization of the methyltransferases required for the O-methylation of the terminal fucosyl residue of PGL-tb. These enzymes are encoded by genes Rv2954c, Rv2955c and Rv2956. Mutants of M. tuberculosis harboring deletion within these genes were constructed. Purification and analysis of the phenolglycolipids produced by these strains, using a combination of mass spectrometry and NMR spectroscopy, revealed that Rv2954c, Rv2955c and Rv2956 encode the methyltransferases that respectively catalysed the O-methylation of the hydroxyl groups located at positions 3, 4 and 2 of the terminal fucosyl residue of PGL-tb. Our data also suggest that methylation at these positions is a sequential process, starting with position 2, followed by positions 4 and 3.

  9. Protein arginine methyltransferase 5 (PRMT5) is a novel coactivator of constitutive androstane receptor (CAR)

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, Yuichiro, E-mail: ykanno@phar.toho-u.ac.jp; Inajima, Jun; Kato, Sayaka; Matsumoto, Maika; Tokumoto, Chikako; Kure, Yuki; Inouye, Yoshio

    2015-03-27

    The constitutive androstane receptor (CAR) plays a key role in the expression of xenobiotic/steroid and drug metabolizing enzymes and their transporters. In this study, we demonstrated that protein arginine methyltransferase 5 (PRMT5) is a novel CAR-interacting protein. Furthermore, the PRMT-dependent induction of a CAR reporter gene, which was independent of methyltransferase activity, was enhanced in the presence of steroid receptor coactivator 1 (SRC1), peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) or DEAD box DNA/RNA helicase DP97. Using tetracycline inducible-hCAR system in HepG2 cells, we showed that knockdown of PRMT5 with small interfering RNA suppressed tetracycline -induced mRNA expression of CYP2B6 but not of CYP2C9 or CYP3A4. PRMT5 enhanced phenobarbital-mediated transactivation of a phenobarbital-responsive enhancer module (PBREM)-driven reporter gene in co-operation with PGC-1α in rat primary hepatocytes. Based on these findings, we suggest PRMT5 to be a gene (or promoter)-selective coactivator of CAR by mediating the formation of complexes between hCAR and appropriate coactivators. - Highlights: • Nuclear receptor CAR interact with PRMT5. • PRMT5 enhances transcriptional activity of CAR. • PRMT5 synergistically enhances transactivity of CAR by the co-expression of SRC-1, DP97 or PGC1α. • PRMT5 is a gene-selective co-activator for hCAR.

  10. Molecular and biochemical characterization of the jasmonic acid methyltransferase gene from black cottonwood (Populus trichocarpa)

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Nan [ORNL; Yao, Jianzhuang [University of Tennessee, Knoxville (UTK); Chaiprasongsuk, Minta [University of Tennessee, Knoxville (UTK); Li, Guanglin [University of Tennessee, Knoxville (UTK); Guan, Ju [University of Tennessee, Knoxville (UTK); Tschaplinski, Timothy J [ORNL; Guo, Hong [University of Tennessee, Knoxville (UTK); Chen, Feng [University of Tennessee, Knoxville (UTK)

    2013-01-01

    Methyl jasmonate is a metabolite known to be produced by many plants and has roles in diverse biological processes. It is biosynthesized by the action of S-adenosyl-L-methionine:jasmonic acid carboxyl methyltransferase (JMT), which belongs to the SABATH family of methyltransferases. Herein is reported the isolation and biochemical characterization of a JMT gene from black cottonwood (Populus trichocarpa). The genome of P. trichocarpa contains 28 SABATH genes (PtSABATH1 to PtSABATH28). Recombinant PtSABATH3 expressed in Escherichia coli showed the highest level of activity with jasmonic acid (JA) among carboxylic acids tested. It was therefore renamed PtJMT1. PtJMT1 also displayed activity with benzoic acid (BA), with which the activity was about 22% of that with JA. PtSABATH2 and PtSABATH4 were most similar to PtJMT1 among all PtSABATHs. However, neither of them had activity with JA. The apparent Km values of PtJMT1 using JA and BA as substrate were 175 lM and 341 lM, respectively. Mutation of Ser-153 and Asn-361, two residues in the active site of PtJMT1, to Tyr and Ser respectively, led to higher specific activity with BA than with JA. Homology-based structural modeling indicated that substrate alignment, in which Asn-361 is involved, plays a role in determining the substrate specificity of PtJMT1. In the leaves of young seedlings of black cottonwood, the expression of PtJMT1 was induced by plant defense signal molecules methyl jasmonate and salicylic acid and a fungal elicitor alamethicin, suggesting that PtJMT1 may have a role in plant defense against biotic stresses. Phylogenetic analysis suggests that PtJMT1 shares a common ancestor with the Arabidopsis JMT, and functional divergence of these two apparent JMT orthologs has occurred since the split of poplar and Arabidopsis lineages.

  11. Overexpression of a soybean salicylic acid methyltransferase gene confers resistance to soybean cyst nematode.

    Science.gov (United States)

    Lin, Jingyu; Mazarei, Mitra; Zhao, Nan; Zhu, Junwei J; Zhuang, Xiaofeng; Liu, Wusheng; Pantalone, Vincent R; Arelli, Prakash R; Stewart, Charles N; Chen, Feng

    2013-12-01

    Salicylic acid plays a critical role in activating plant defence responses after pathogen attack. Salicylic acid methyltransferase (SAMT) modulates the level of salicylic acid by converting salicylic acid to methyl salicylate. Here, we report that a SAMT gene from soybean (GmSAMT1) plays a role in soybean defence against soybean cyst nematode (Heterodera glycines Ichinohe, SCN). GmSAMT1 was identified as a candidate SCN defence-related gene in our previous analysis of soybean defence against SCN using GeneChip microarray experiments. The current study started with the isolation of the full-length cDNAs of GmSAMT1 from a SCN-resistant soybean line and from a SCN-susceptible soybean line. The two cDNAs encode proteins of identical sequences. The GmSAMT1 cDNA was expressed in Escherichia coli. Using in vitro enzyme assays, E. coli-expressed GmSAMT1 was confirmed to function as salicylic acid methyltransferase. The apparent Km value of GmSAMT1 for salicylic acid was approximately 46 μM. To determine the role of GmSAMT1 in soybean defence against SCN, transgenic hairy roots overexpressing GmSAMT1 were produced and tested for SCN resistance. Overexpression of GmSAMT1 in SCN-susceptible backgrounds significantly reduced the development of SCN, indicating that overexpression of GmSAMT1 in the transgenic hairy root system could confer resistance to SCN. Overexpression of GmSAMT1 in transgenic hairy roots was also found to affect the expression of selected genes involved in salicylic acid biosynthesis and salicylic acid signal transduction.

  12. Discovery and characterization of new O-methyltransferase from the genome of the lignin-degrading fungus Phanerochaete chrysosporium for enhanced lignin degradation.

    Science.gov (United States)

    Thanh Mai Pham, Le; Kim, Yong Hwan

    2016-01-01

    Using bioinformatic homology search tools, this study utilized sequence phylogeny, gene organization and conserved motifs to identify members of the family of O-methyltransferases from lignin-degrading fungus Phanerochaete chrysosporium. The heterologous expression and characterization of O-methyltransferases from P. chrysosporium were studied. The expressed protein utilized S-(5'-adenosyl)-L-methionine p-toluenesulfonate salt (SAM) and methylated various free-hydroxyl phenolic compounds at both meta and para site. In the same motif, O-methyltransferases were also identified in other white-rot fungi including Bjerkandera adusta, Ceriporiopsis (Gelatoporia) subvermispora B, and Trametes versicolor. As free-hydroxyl phenolic compounds have been known as inhibitors for lignin peroxidase, the presence of O-methyltransferases in white-rot fungi suggested their biological functions in accelerating lignin degradation in white-rot basidiomycetes by converting those inhibitory groups into non-toxic methylated phenolic ones. PMID:26672450

  13. Large-Scale, Protection-Free Synthesis of Se-Adenosyl-l-selenomethionine Analogues and Their Application as Cofactor Surrogates of Methyltransferases

    OpenAIRE

    Bothwell, Ian R.; Luo, Minkui

    2014-01-01

    S-Adenosyl-l-methionine (SAM) analogues have previously demonstrated their utility as chemical reporters of methyltransferases. Here we describe the facile, large-scale synthesis of Se-alkyl Se-adenosyl-l-selenomethionine (SeAM) analogues and their precursor, Se-adenosyl-l-selenohomocysteine (SeAH). Comparison of SeAM analogues with their equivalent SAM analogues suggests that sulfonium-to-selenonium substitution can enhance their compatibility with certain protein methyltransferases, favorin...

  14. O6-Methylguanine-DNA Methyltransferase (MGMT) mRNA Expression Predicts Outcome in Malignant Glioma Independent of MGMT Promoter Methylation

    OpenAIRE

    Simone Kreth; Niklas Thon; Sabina Eigenbrod; Juergen Lutz; Carola Ledderose; Rupert Egensperger; Tonn, Joerg C.; Kretzschmar, Hans A.; Ludwig C Hinske; Kreth, Friedrich W.

    2011-01-01

    Background: We analyzed prospectively whether MGMT (O(6)-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylatio...

  15. Interplay among coactivator-associated arginine methyltransferase 1, CBP, and CIITA in IFN-γ-inducible MHC-II gene expression

    OpenAIRE

    Zika, Eleni; Fauquier, Lucas; Vandel, Laurence; Ting, Jenny P.-Y.

    2005-01-01

    Class II major histocompatibility (MHC-II) genes are prototype targets of IFN-γ. IFN-γ activates the expression of the non-DNA-binding master regulator of MHC-II, class II transactivator (CIITA), which is crucial for enhanceosome formation and gene activation. This report shows the importance of the histone methyltransferase, coactivator-associated arginine methyltransferase (CARM1/PRMT4), during IFN-γ-induced MHC-II gene activation. It also demonstrates the coordinated regulation of CIITA, C...

  16. 1-MCP处理结合冷藏对西兰花品质的影响%Effect of 1-MCP treatment on the quality of broccolis in cold storage

    Institute of Scientific and Technical Information of China (English)

    林本芳; 鲁晓翔; 李江阔; 陈绍慧

    2012-01-01

    This paper was conducted to investigated the effect of different concentrations (1.5, 2.5 μL/L) of 1-MCP on the quality of broccolis during 0℃ storage conditions. The physical and chemical indexes of broccolis were detected every 10 days. The results showed that: after treatment used 1-MCP, broccoli's soluble solids, Vc and chlorophyll content decreased less than ordinary storage. 1-MCP inhibited the increase of respiratory intensity, increased peroxidase(POD), superoxide dismutase(SOD) activities and slowed down polyphenol oxidase(PPO) activity. Additionally, treatment of 1-MCP also decreased the MDA content and cell membrane permeability, so delayed ripening of broccoli. 1-MCP treatment could delay ripening of broccoli, but 2.5 μL/L 1-MCP treatment is better than 1.5 μL/L treatment. Therefore, the storage effect of broccolis with 1-MCP treatment is superior to that of with only ordinary storage. 1-MCP still played normal function at low temperature.%研究了1—MCP处理对西兰花冷藏保鲜品质的影响。1-MCP处理浓度为1.5、2.5μL/L,冷藏期间每隔10d取样测定西兰花理化指标及营养成分。试验结果表明:与对照相比,1-MCP处理对于延缓西兰花可溶性固形物含量(TSS)、Vc含量及叶绿素含量的下降均有明显效果,并可抑制西兰花贮藏期间的呼吸强度。1-MCP处理提高西兰花过氧化物酶(POD)和超氧化物歧化酶(SOD)的活性,降低多酚氧化酶(PPO)活性,延缓了丙二醛(MDA)含量和细胞膜相对透性的升高,延缓了西兰花的衰老。1.5、2.5μL/L的1-MCP处理对西兰花的成熟衰老均有抑制作用,其中经2.5μL/L处理的西兰花的品质表现更好。这说明了冷藏结合1—MCP处理不仅较之普通冷藏更好地保持了西兰花的营养品质,同时也证明1—MCP在低温条件下仍可发挥正常作用。

  17. A SAM-dependent methyltransferase cotranscribed with arsenate reductase alters resistance to peptidyl transferase center-binding antibiotics in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Singh, Sudhir; Singh, Chhaya; Tripathi, Anil Kumar

    2014-05-01

    The genome of Azospirillum brasilense harbors a gene encoding S-adenosylmethionine-dependent methyltransferase, which is located downstream of an arsenate reductase gene. Both genes are cotranscribed and translationally coupled. When they were cloned and expressed individually in an arsenate-sensitive strain of Escherichia coli, arsenate reductase conferred tolerance to arsenate; however, methyltransferase failed to do so. Sequence analysis revealed that methyltransferase was more closely related to a PrmB-type N5-glutamine methyltransferase than to the arsenate detoxifying methyltransferase ArsM. Insertional inactivation of prmB gene in A. brasilense resulted in an increased sensitivity to chloramphenicol and resistance to tiamulin and clindamycin, which are known to bind at the peptidyl transferase center (PTC) in the ribosome. These observations suggested that the inability of prmB:km mutant to methylate L3 protein might alter hydrophobicity in the antibiotic-binding pocket of the PTC, which might affect the binding of chloramphenicol, clindamycin, and tiamulin differentially. This is the first report showing the role of PrmB-type N5-glutamine methyltransferases in conferring resistance to tiamulin and clindamycin in any bacterium.

  18. 30S Subunit-Dependent Activation of the Sorangium cellulosum So ce56 Aminoglycoside Resistance-Conferring 16S rRNA Methyltransferase Kmr

    Science.gov (United States)

    Savic, Miloje; Sunita, S.; Zelinskaya, Natalia; Desai, Pooja M.; Macmaster, Rachel; Vinal, Kellie

    2015-01-01

    Methylation of bacterial 16S rRNA within the ribosomal decoding center confers exceptionally high resistance to aminoglycoside antibiotics. This resistance mechanism is exploited by aminoglycoside producers for self-protection while functionally equivalent methyltransferases have been acquired by human and animal pathogenic bacteria. Here, we report structural and functional analyses of the Sorangium cellulosum So ce56 aminoglycoside resistance-conferring methyltransferase Kmr. Our results demonstrate that Kmr is a 16S rRNA methyltransferase acting at residue A1408 to confer a canonical aminoglycoside resistance spectrum in Escherichia coli. Kmr possesses a class I methyltransferase core fold but with dramatic differences in the regions which augment this structure to confer substrate specificity in functionally related enzymes. Most strikingly, the region linking core β-strands 6 and 7, which forms part of the S-adenosyl-l-methionine (SAM) binding pocket and contributes to base flipping by the m1A1408 methyltransferase NpmA, is disordered in Kmr, correlating with an exceptionally weak affinity for SAM. Kmr is unexpectedly insensitive to substitutions of residues critical for activity of other 16S rRNA (A1408) methyltransferases and also to the effects of by-product inhibition by S-adenosylhomocysteine (SAH). Collectively, our results indicate that adoption of a catalytically competent Kmr conformation and binding of the obligatory cosubstrate SAM must be induced by interaction with the 30S subunit substrate. PMID:25733511

  19. 不同质量浓度臭氧化水对鲜切西兰花贮藏品质的影响%Effect of Ozonated Water with Various Concentrations on Storage Quality of Fresh-cut Broccoli

    Institute of Scientific and Technical Information of China (English)

    王宏延; 曾凯芳; 贾凝; 陈存坤; 王文生

    2012-01-01

    采用不同质量浓度臭氧化水处理鲜切西兰花。结果表明:质量浓度2.0mg/L的臭氧化水处理组保鲜效果最优,在贮藏12d时与对照组相比,质量损失率降低24.37%,VC含量提高40.7%,多酚氧化酶酶活降低23.5%,过氧化物酶酶活降低25.6%;在4℃的条件下,质量浓度2.0mg/L的臭氧化水处理组鲜切西兰花贮藏期可达到15d。%Ozonated water can be used for disinfection,sterilization,deodorization and preservation with multiple advantages such as rapid sterilization rate,simple operation and without residues.It can be used directly for the sterilization of fresh-cut vegetables so that it is a potential technology of cold sterilization and green sterilization.The results showed that the best preservation effect on fresh-cut broccoli was observed at the condition of 2 mg/L ozonated water.Compared with the control,ozonated water-treated fresh-cut broccoli after storage for 12 days revealed a reduction by 24.37% for weight loss rate,an improvement by 40.7% for vitamin C,a decline by 23.5% for polyphenol oxidase activity and a decrease by 25.6% for peroxidase activity.The storage life of fresh-cut broccoli subjected to treatment with 2 mg/L ozonated water can be extended to 15 days at the storage temperature of 4 ℃.

  20. (Accumulation of methyl-deficient rat liver messenger ribonucleic acid on ethionine administration). Progress report. [Methyltransferase activity in Ehrlich ascites tumor cells and effects of phorbol ester on methyltransferase activity

    Energy Technology Data Exchange (ETDEWEB)

    Borek, E.

    1980-01-01

    Enzyme fractions were isolated from Ehrlich ascites cells which introduced methyl groups into methyl deficient rat liver mRNA and unmethylated vaccinia mRNA. The methyl groups were incorporated at the 5' end into cap 1 structures by the viral enzyme, whereas both cap 0 and cap 1 structures were formed by the Ehrlich ascites cell enzymes. Preliminary results indicate the presence of adenine N/sup 6/-methyltransferase activity in Ehrlich ascites cells. These results indicate that mRNA deficient in 5'-cap methylation and in internal methylation of adenine accumulated in rats on exposure to ethionine. The methyl-deficient mRNA isolated from the liver of ethionine-fed rats differed in its translational properties from mRNA isolated from control animals. Preliminary experiments indicate that single topical application of 17n moles of TPA to mouse skin altered tRNA methyltransferases. The extent of methylation was increased over 2-fold in mouse skin treated with TPA for 48 hours. These changes have been observed as early as 12 hours following TPA treatment. In contrast, the application of initiating dose of DMBA had no effect on these enzymes. It should be emphasized that the changes in tRNA methyltransferases produced by TPA are not merely an increase of the concentration of the enzyme, rather that they represent alterations of specificity of a battery of enzymes. In turn the change in enzyme specificity can produce alterations in the structure of tRNA. (ERB)

  1. A female adnexal tumor of probable Wolffian origin showing positive O-6-methylguanine-DNA methyltransferase methylation

    Science.gov (United States)

    Kwon, Min Jung; Yun, Min Jeong

    2016-01-01

    Female adnexal tumor of probable Wolffian origin (FATWO) is a rare disease entity that arises from the mesonephric duct system. FATWO is different than other gynecological cancers in terms of embryology. Here, we describe the case of a 52-year-old woman with malignant FATWO. The patient underwent explorative laparotomy and surgical staging after a frozen section revealed malignancy. Detailed examination of the pathologic findings were consistent with FATWO. Counseling and further testing were provided to the patient to assess the risk of germline mutation and epigenetic change. An O-6-methylguanine-DNA methyltransferase gene methylation test was positive, and all other tests were normal. This is the first study to report a case of O-6-methylguanine-DNA methyltransferase methylation with FATWO in Korea. PMID:27462603

  2. The Cfr rRNA methyltransferase confers resistance to Phenicols, Lincosamides, Oxazolidinones, Pleuromutilins, and Streptogramin A antibiotics

    DEFF Research Database (Denmark)

    Long, K. S.; Poehlsgaard, Jacob; Kehrenberg, C.;

    2006-01-01

    A novel multidrug resistance phenotype mediated by the Cfr rRNA methyltransferase is observed in Staphylococcus aureus and Escherichia coli. The cfr gene has previously been identified as a phenicol and lincosamide resistance gene on plasmids isolated from Staphylococcus spp. of animal origin...... and recently shown to encode a methyltransferase that modifies 23S rRNA at A2503. Antimicrobial susceptibility testing shows that S. aureus and E. coli strains expressing the cfr gene exhibit elevated MICs to a number of chemically unrelated drugs. The phenotype is named PhLOPSA for resistance to the following...... drug classes: Phenicols, Lincosamides, Oxazolidinones, Pleuromutilins, and Streptogramin A antibiotics. Each of these five drug classes contains important antimicrobial agents that are currently used in human and/or veterinary medicine. We find that binding of the PhLOPSA drugs, which bind...

  3. Crystallization and preliminary crystallographic analysis of tRNA (m7G46) methyltransferase from Escherichia coli

    Science.gov (United States)

    Liu, Qi; Gao, Yang; Yang, Weili; Zhou, Huihao; Gao, Yongxiang; Zhang, Xiao; Teng, Maikun; Niu, Liwen

    2008-01-01

    Transfer RNA (tRNA) (m7G46) methyltransferase (TrmB) belongs to the Rossmann-fold methyltransferase (RFM) family and uses S-adenosyl-l-methionine (SAM) as the methyl-group donor to catalyze the formation of N 7-­methylguanosine (m7G) at position 46 in the variable loop of tRNAs. After attempts to crystallize full-length Escherichia coli TrmB (EcTrmB) failed, a truncated protein lacking the first 32 residues of the N-terminus but with an additional His6 tag at the C-terminus was crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 3350 (PEG 3350) as precipitant at 283 K. An X-ray diffraction data set was collected using a single flash-cooled crystal that belonged to space group P21. PMID:18678947

  4. Crystallization and preliminary crystallographic analysis of tRNA (m(7)G46) methyltransferase from Escherichia coli.

    Science.gov (United States)

    Liu, Qi; Gao, Yang; Yang, Weili; Zhou, Huihao; Gao, Yongxiang; Zhang, Xiao; Teng, Maikun; Niu, Liwen

    2008-08-01

    Transfer RNA (tRNA) (m(7)G46) methyltransferase (TrmB) belongs to the Rossmann-fold methyltransferase (RFM) family and uses S-adenosyl-L-methionine (SAM) as the methyl-group donor to catalyze the formation of N(7)-methylguanosine (m(7)G) at position 46 in the variable loop of tRNAs. After attempts to crystallize full-length Escherichia coli TrmB (EcTrmB) failed, a truncated protein lacking the first 32 residues of the N-terminus but with an additional His(6) tag at the C-terminus was crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 3350 (PEG 3350) as precipitant at 283 K. An X-ray diffraction data set was collected using a single flash-cooled crystal that belonged to space group P2(1).

  5. 西兰花多肽对大鼠C6胶质瘤细胞生长的影响%The effect of broccoli polypeptide on C6 glioma cells of rat

    Institute of Scientific and Technical Information of China (English)

    徐俊杰; 于洪泉; 国巍; 赵伟; 金宏; 温娜; 齐玲

    2012-01-01

    目的 研究西兰花多肽对大鼠C6胶质瘤细胞生长的影响.方法 培养C6胶质瘤细胞,用西兰花多肽(0、0.01、0.1、1、10μ/ml)作用细胞72h,MTT法检测胶质瘤细胞的生长情况.结果 西兰花多肽作用C6胶质瘤细胞72h时,各药物浓度组都表现为对细胞的抑制作用,1μl/ml组(0.58 ±0.08 vs 0.75 ±0.02)和10μl/ml组(0.07 ±0.01 vs 0.75 ±0.02)表现出显著的抑制生长作用(P<0.01).结论 西兰花多肽可抑制C6胶质瘤细胞的生长,并且随着药物浓度升高药物作用增强,说明西兰花多肽具有抑制肿瘤细胞生长的作用.%Objective To study the effects of broccoli polypeptide on the proliferation of C6 glioma cells. Method Cultured C6 glioma cells were treated with different dose of broccoli polypeptide(0,0. 01 ,0. 1 ,1 , 10μl/ml)for 72h. The level of cell growth was detected by MTT assay. Results After 72h,all dosed of polypeptide inhibited the growth of cells, especially in 1(0,1/μml group(0. 58 ±0.08 vs 0.75 ±0.02) and 10(1,1/μml group(0.07 ±0.01 vs 0.75 ±0.02) when compared with respective control group(P <0. 01). Conclusion Broccoli polypeptide may inhibit the proliferation of C6 glioma cells, and the effect is increased with dose, which suggests that broccoli polypeptide can inhibit the growth of tumor cells.

  6. 细胞分裂素类生长调节剂对青花菜采后衰老的影响%Effects of Cytokinin Growth Regulators on Senescence of Harvested Broccoli (Brassica oleracea L. var. italica) Florets

    Institute of Scientific and Technical Information of China (English)

    王云莉; 王成荣; 王然; 杨绍兰; 刘宪路

    2009-01-01

    Application of cytokinin growth regulators, KT (Kinetin), 6-BA (Benzyladenine), and CPPU [N-(2-chloro-4-pyridyl)-N'-pheuylurea] on delaying senescence of harvested broccoli florets was studied. The results showed that use of KT, 6-BA or CPPU on harvested broccoli delayed floret yellowing and chlorophyll degradation, decreased respiration and ethylene production rate, postponed climacteric time, and retarded membrane permeability loss. The content of endogenous ABA was lower and the levels of IAA and GA were higher in the broccoli treated with 6-BA and CPPU than those in the control during 12-84 h. The treated effects enhanced with increasing concentration in the study. The CPPU treatment (40 mg·L~(-1)) was most effective in delaying the broccoli yellowing, followed by 6-BA and KT.%以青花菜'绿皇后'品种为试材,研究了25℃条件下细胞分裂素类生长调节剂KT、6-BA和CPPU对延缓青花菜采后衰老的效果.结果表明:3种细胞分裂素类生长调节剂处理均在不同程度上延缓了青花菜花蕾黄化和叶绿素分解,推迟了呼吸和乙烯跃变峰出现的时间,降低了峰值,并维持了细胞膜稳定性.内源激素测定结果表明,6-BA和CPPU处理使青花菜花蕾在试验的前期阶段(12~84 h)一直保持相对较高的内源IAA和GA水平,相对较低的内源ABA水平.3种细胞分裂素类生长调节剂以CPPU延缓青花菜衰老效果最为明显,其次是6-BA,KT效果最弱.延缓青花菜采后衰老效果随着处理的浓度增加而增加,以40 mg·L~(-1)CPPU延缓青花菜衰老效果最佳.

  7. 不同西兰花品种中硫代葡萄糖苷的组分与含量分析%Glucosinolate Component and Content Analysis of Different Broccoli Varieties

    Institute of Scientific and Technical Information of China (English)

    丁云花; 何洪巨; 宋曙辉; 简元才; 赵学志; 王文琪

    2015-01-01

    Glucosinolates component and content of 29 broccoli varieties were analyzed by HPLC method. As a result, a total of eight kinds of glucosinolates in broccoli bud-head were detected. Four kinds of them were aliphatic glucosino-lates, such as glucoiberin(IBE), progoitrin(PRO), glucoraphanin(RAA) and gluconapin(NAP), and the others were indolic glucosinolates, such as 4-Hydroxyglucobrassicin(4OH), glucobrassicin(GBC), 4-Methoxyglucobrassicin(4ME) and Neoglu-cobrassicin (NEO). The content of total glucosinolates was 11.27μmol·g-1 DW. RAA, GBC and NEO were the predomi-nant component of glucosinolates in broccoli bud-head, with a proportion of 34.78%, 25.02% and 23.25% respectively. The content of total glucosinolates in different variety of broccoli varied from 5.60 μmol·g-1 DW to 17.04 μmol·g-1 DW.%采用 HPLC 法测定分析了29个西兰花品种的硫代葡萄糖苷组分与含量,结果检测到8种硫代葡萄糖苷,包括4种脂肪族硫苷:3-甲基硫氧烯丙基硫苷、2-羟基-3-丁烯基硫苷、4-甲基硫氧丁基硫苷和3-丁烯基硫苷;4种吲哚族硫苷:4-羟基吲哚基-3-甲基硫苷、3-甲基吲哚基硫苷、4-甲氧基吲哚基-3-甲基硫苷和1-甲氧基吲哚基-3-甲基硫苷。总硫苷含量平均为11.27μmol/g,RAA、GBC 和 NEO 是西兰花三种主要的硫苷成分,分别占总硫苷含量的34.78%、25.02%和23.25%。不同西兰花品种的总硫苷含量变异范围5.60~17.04μmol/g,存在较大差异。

  8. Control Efficacy of Insecticides Mixture on Broccolis%几种药剂混配防治西兰花根部病害综合效果试验

    Institute of Scientific and Technical Information of China (English)

    方辉; 王会福; 余山红; 毛肇蓬

    2013-01-01

      为了有效防治西兰花根肿病、根腐病、根结线虫病等根部病害,提升西兰花的产量和品质,采用灌根法进行几种药剂混配防治西兰花根部病害田间药效试验,结果表明:68%精甲霜•锰锌WG 500倍+3.2%阿维菌素EC 1000倍+微补精力600倍+微补根力钙600倍对西兰花根部病害具有较好的综合防治效果,其中连续2次灌根后50 d的校正防效达82.1%,分别比68%精甲霜•锰锌WG 500倍+3.2%阿维菌素EC 1000倍、5%石灰氮GR 1200 kg/hm2高出5.6%、21.3%,持效期较长,安全性好,因此可以在生产上加以推广应用。%  The purpose of the trial was to control clubroot disease, ceitocybe bescens, root knot nematode disease of broccoli, in order to promote the broccoli production and quality. Mixture of several insecticides was used on broccoli by root­irrigation method in this trail. The result showed that the mixture of 68%Mefenoxam­Mancozeb WG 1:500 plus 3.2%Avermectins EC 1:1 000 plus 425 g/L MNPK­38 g/L Calcium 1:600 and 160 g/L Calcium 1:600 had better control effect on Broccoli root diseases, and the 50 days’ correction control effect after two consecutive root­pouring reached 82.1%, which was higher than that of the mixture of 68%Mefenoxam­Mancozeb WG 1:500 plus 3.2%Avermectins EC 1:1 000 and that of 5%Calcium Cyanamide GR 1 200kg/hm2 by 5.6% and 21.3%, respectively. With longer effective lasting period and better security, this mixture can be demonstrated to apply to the practical production.

  9. Facile synthesis of N-6 adenosine modified analogue toward S-adenosyl methionine derived probe for protein arginine methyltransferases

    Institute of Scientific and Technical Information of China (English)

    Wei Hong; James Dowden

    2011-01-01

    Chemically modified cellular co-factors that provide function, such as immobilization or incorporation of fluorescent dyes, are valuable probes of biological activity. A convenient route to obtain S-adenosyl methionine (AdoMet) analogues modified at N-6 adenosine to feature a linker terminating in azide functionality is described herein. Subsequent decoration of such AdoMet analogues with guanidinium terminated linkers leads to novel potential bisubstrate inhibitors for protein arginine methyltransferases, PRMTs.

  10. O6-methylguanine DNA methyltransferase as a promising target for the treatment of temozolomide-resistant gliomas

    OpenAIRE

    Fan, C-H; Liu, W-L; Cao, H.; Wen, C; Chen, L.; G. Jiang

    2013-01-01

    Temozolomide (TMZ) is an alkylating agent currently used as first-line therapy for gliomas treatment due to its DNA-damaging effect. However, drug resistance occurs, preventing multi-cycle use of this chemotherapeutic agent. One of the major mechanisms of cancer drug resistance is enhanced activity of a DNA repair enzyme, O6-methylguanine-DNA-methyltransferase (MGMT), which counteracts chemotherapy-induced DNA alkylation and is a key component of chemoresistance. MGMT repairs TMZ-induced DNA ...

  11. Cytoplasmic sequestration of an O6-methylguanine-DNA methyltransferase enhancer binding protein in DNA repair-deficient human cells

    OpenAIRE

    Frank Y. Chen; Harris, Linda C.; Joanna S Remack; Brent, Thomas P.

    1997-01-01

    O6-Methylguanine-DNA methyltransferase (MGMT), an enzyme that repairs adducts at O6 of guanine in DNA, is a major determinant of susceptibility to simple methylating carcinogens or of tumor response to anticancer chloroethylating drugs. To investigate the mechanisms underlying cellular expression of this DNA repair enzyme, we focused on the role of a 59-bp enhancer of the human MGMT gene in the regulation of its expression. By using chloramphenicol acetyltransferase reporter assays, we found ...

  12. Effects of Active‐Site Modification and Quaternary Structure on the Regioselectivity of Catechol‐O‐Methyltransferase

    OpenAIRE

    Law, Brian J. C.; Bennett, Matthew R.; Thompson, Mark L; Levy, Colin; Shepherd, Sarah A; Leys, David; Micklefield, Jason

    2016-01-01

    Abstract Catechol‐O‐methyltransferase (COMT), an important therapeutic target in the treatment of Parkinson's disease, is also being developed for biocatalytic processes, including vanillin production, although lack of regioselectivity has precluded its more widespread application. By using structural and mechanistic information, regiocomplementary COMT variants were engineered that deliver either meta‐ or para‐methylated catechols. X‐ray crystallography further revealed how the active‐site r...

  13. Cloning and characterization of a cDNA from Aspergillus parasiticus encoding an O-methyltransferase involved in aflatoxin biosynthesis.

    OpenAIRE

    Yu, J.; Cary, J W; D. Bhatnagar; Cleveland, T E; Keller, N. P.; Chu, F S

    1993-01-01

    Aflatoxins are polyketide-derived secondary metabolites produced by the fungi Aspergillus flavus and Aspergillus parasiticus. Among the catalytic steps in the aflatoxin biosynthetic pathway, the conversion of sterigmatocystin to O-methylsterigmatocystin and the conversion of dihydrosterigmatocystin to dihydro-O-methylsterigmatocystin are catalyzed by an S-adenosylmethionine-dependent O-methyltransferase. A cDNA library was constructed by using RNA isolated from a 24-h-old culture of wild-type...

  14. The histone methyltransferase SDG8 mediates the epigenetic modification of light and carbon responsive genes in plants

    OpenAIRE

    Ying LI; Mukherjee, Indrani; Thum, Karen E; Tanurdzic, Milos; Katari, Manpreet S.; Obertello, Mariana; Edwards, Molly B; McCombie, W Richard; Martienssen, Robert A.; Coruzzi, Gloria M.

    2015-01-01

    Background Histone methylation modifies the epigenetic state of target genes to regulate gene expression in the context of developmental and environmental changes. Previously, we used a positive genetic screen to identify an Arabidopsis mutant, cli186, which was impaired in carbon and light signaling. Here, we report a deletion of the Arabidopsis histone methyltransferase SDG8 in this mutant (renamed sdg8-5), which provides a unique opportunity to study the global function of a specific histo...

  15. GAMT2 Encodes a Methyltransferase of Gibberellic Acid That is Involved in Seed Maturation and Germination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Shufan Xing; Genji Qin; Yan Shi; Zhiqiang Ma; Zhangliang Chen; Hongya Gu; Li-Jia Qu

    2007-01-01

    Salicylic acid methyltransferase (SAMT), benzoic acid methyltransferase (BAMT) and theobromine methyltransferase (TH) (henceforth, SABATH) family proteins belong to a unique class of methyltransferase that can methylate small molecular compounds including indole-3-acidic acid (IAA), salicylic acid (SA) and jasmonic acid (JA), in plants. Here we report that the GAMT2 protein, which has 34.2% similarity with IAMT1 in the amino acid sequence, can methylate gibberellic acid (GA). Bioinformatics analysis suggests that GAMT2 may be able to methylate one molecule larger than SA. GAMT2 is predominantly expressed in the developing seed embryo and endosperm in Arabidopsis.During seed germination, the expression of GAMT2 decreases until the cotyledons expand out of the seed coat.Overexpression of GAMT2 in Arabidopsis resulted in multiple phenotypes, including dwarfism, retarded growth,late flowering, and reduced fertility, which are similar to the phenotypes of GA-deficient mutants. Seed germination assay showed that GAMT2 overexpression in plants was hypersensitive to GA biosynthesis inhibitor (ancymidol)and abscisic acid (ABA) treatments, whereas the GAMT2 null mutant (SALK_075450) was slightly insensitive to such treatments, suggesting that GAMT2 may methylate GA or ABA. Enzyme activity analysis indicated that GAMT2 was able to methylate GA3 into Methyl-GA3 in vitro, but could not methylate ABA. Microarray analysis on GAMT2overexpression plants suggested that Methyl-GA may be an inactive form of GA in Arabidopsis. These data suggest that GAMT2 is involved in seed maturation and germination by modulating GA activity.

  16. O6-Methylguanine-DNA methyltransferase status in neuroendocrine tumours: prognostic relevance and association with response to alkylating agents

    OpenAIRE

    Walter, T.; van Brakel, B; Vercherat, C; Hervieu, V; Forestier, J.; Chayvialle, J-A; Molin, Y.; Lombard-Bohas, C; Joly, M-O; Scoazec, J-Y

    2015-01-01

    Background: O6-Methylguanine-DNA methyltransferase (MGMT) loss of expression has been suggested to be predictive of response to temozolomide in neuroendocrine tumours (NETs), but so far, only limited data are available. We evaluated the prognostic and predictive value of MGMT status, assessed by two molecular methods and immunohistochemistry, in a large series of NETs of different origins. Methods: A total of 107 patients, including 53 treated by alkylants (temozolomide, dacarbazine or strept...

  17. Methylation pattern of the O6-methylguanine-DNA methyltransferase gene in colon during progressive colorectal tumorigenesis

    OpenAIRE

    NAGASAKA, Takeshi; Goel, Ajay; Notohara, Kenji; Takahata, Takaomi; Sasamoto, Hiromi; Uchida, Takuyuki; Nishida, Naoshi; Tanaka, Noriaki; Boland, Clement Richard; Matsubara, Nagahide

    2008-01-01

    O6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair gene which is frequently methylated in colorectal cancer (CRC). However, it remains controversial whether methylation of specific CpG sequences within MGMT promoter leads to loss of its protein expression, and if MGMT methylation correlates with G to A transition mutations in KRAS. Two methylation sensitive regions (Mp and Eh region) of MGMT promoter were investigated in 593 specimens of colorectal tissue: 233 CRCs, 104 adenomatous...

  18. Epistasis between catechol-O-methyltransferase and type II metabotropic glutamate receptor 3 genes on working memory brain function

    OpenAIRE

    Tan, Hao-Yang; Chen, Qiang; Sust, Steven; Joshua W Buckholtz; Meyers, John D.; Egan, Michael F.; Mattay, Venkata S.; Meyer-Lindenberg, Andreas; Weinberger, Daniel R.; Callicott, Joseph H.

    2007-01-01

    Dopaminergic and glutamatergic systems are critical components responsible for prefrontal signal-to-noise tuning in working memory. Recent functional MRI (fMRI) studies of genetic variation in these systems in catechol-O-methyltransferase (COMT) and in metabotropic glutamate receptor mgluR3 (GRM3), respectively, suggest that these genes influence prefrontal physiological signal-to-noise in humans. Here, using fMRI, we extend these individual gene findings to examine the combined effects of CO...

  19. Genome-wide identification and comparative analysis of cytosine-5 DNA methyltransferases and demethylase families in wild and cultivated peanut

    Directory of Open Access Journals (Sweden)

    Pengfei eWang

    2016-02-01

    Full Text Available AbstractDNA methylation plays important roles in genome protection, regulation of gene expression and was associated with plants development. Plant DNA methylation pattern was mediated by cytosine-5 DNA methyltransferases and demethylase. Although the genomes of AA and BB wild peanuts have been fully sequence, these two gene families have not been studied. In this study we report the identification and analysis of putative cytosine-5 DNA methyltransferases (C5-MTases and demethylase in AA and BB wild peanuts. Cytosine-5 DNA methyltransferases in AA and BB wild peanuts could be classified in known MET, CMT and DRM2 groups based on their domain organization. This result was supported by the gene and protein structural characteristics and phylogenetic analysis. We found that some wild peanut DRM2 numbers didn’t contain UBA domain which was different from other plants such as Arabidopsis, maize, soybean. Five DNA demethylase were found in AA genome and five in BB genome. The selective pressure analysis showed that wild peanut C5-MTases gene mainly underwent purifying selection but many positive selection sites can be detected. Conversely, DNA demethylase genes mainly underwent positive selection during evolution. Additionally, the expression dynamic of cytosine-5 DNA methyltransferases and demethylase genes in different cultivated peanut tissues were analyzed. Expression result showed that cold, heat or drought stress could influence the expression level of C5-MTases and DNA demethylase genes in cultivated peanut. These results are useful for better understanding the complexity of these two gene families, and will facilitate epigenetic studies in peanut.

  20. Therapy and progression – induced O6-methylguanine-DNA methyltransferase and mismatch repair alterations in recurrent glioblastoma multiforme

    OpenAIRE

    Agarwal, S.; Suri, V.; M C Sharma; C. Sarkar

    2015-01-01

    Despite multimodality treatment protocol including surgical resection, radiotherapy, and chemotherapy in patients with glioblastoma multiforme (GBM), most suffer from treatment failure and tumor recurrence within a few months of initial surgery. The effectiveness of temozolomide (TMZ), the most commonly used chemotherapeutic agent, is largely dependent on the methylation status of the promoter of the gene O6-methylguanine-DNA methyltransferase (MGMT) and the integrity of the mismatch repair (...

  1. Noncompetitive Inhibition of Indolethylamine-N-methyltransferase by N,N-Dimethyltryptamine and N,N-Dimethylaminopropyltryptamine

    OpenAIRE

    Chu, Uyen B.; Vorperian, Sevahn K.; Satyshur, Kenneth; Eickstaedt, Kelsey; Cozzi, Nicholas V; Mavlyutov, Timur; Hajipour, Abdol R.; Ruoho, Arnold E.

    2014-01-01

    Indolethylamine-N-methyltransferase (INMT) is a Class 1 transmethylation enzyme known for its production of N,N-dimethyltryptamine (DMT), a hallucinogen with affinity for various serotonergic, adrenergic, histaminergic, dopaminergic, and sigma-1 receptors. DMT is produced via the action of INMT on the endogenous substrates tryptamine and S-adenosyl-l-methionine (SAM). The biological, biochemical, and selective small molecule regulation of INMT enzyme activity remain largely unknown. Kinetic m...

  2. The Histone Methyltransferase Inhibitor A-366 Uncovers a Role for G9a/GLP in the Epigenetics of Leukemia.

    Directory of Open Access Journals (Sweden)

    William N Pappano

    Full Text Available Histone methyltransferases are epigenetic regulators that modify key lysine and arginine residues on histones and are believed to play an important role in cancer development and maintenance. These epigenetic modifications are potentially reversible and as a result this class of enzymes has drawn great interest as potential therapeutic targets of small molecule inhibitors. Previous studies have suggested that the histone lysine methyltransferase G9a (EHMT2 is required to perpetuate malignant phenotypes through multiple mechanisms in a variety of cancer types. To further elucidate the enzymatic role of G9a in cancer, we describe herein the biological activities of a novel peptide-competitive histone methyltransferase inhibitor, A-366, that selectively inhibits G9a and the closely related GLP (EHMT1, but not other histone methyltransferases. A-366 has significantly less cytotoxic effects on the growth of tumor cell lines compared to other known G9a/GLP small molecule inhibitors despite equivalent cellular activity on methylation of H3K9me2. Additionally, the selectivity profile of A-366 has aided in the discovery of a potentially important role for G9a/GLP in maintenance of leukemia. Treatment of various leukemia cell lines in vitro resulted in marked differentiation and morphological changes of these tumor cell lines. Furthermore, treatment of a flank xenograft leukemia model with A-366 resulted in growth inhibition in vivo consistent with the profile of H3K9me2 reduction observed. In summary, A-366 is a novel and highly selective inhibitor of G9a/GLP that has enabled the discovery of a role for G9a/GLP enzymatic activity in the growth and differentiation status of leukemia cells.

  3. Catechol O-Methyltransferase Haplotype Predicts Immediate Musculoskeletal Neck Pain and Psychological Symptoms after Motor Vehicle Collision

    OpenAIRE

    McLean, Samuel A.; Diatchenko, Luda; Lee, Young M.; Swor, Robert A.; Domeier, Robert M; Jones, Jeffrey S.; Jones, Christopher W.; Reed, Caroline; Harris, Richard E; Maixner, William; Clauw, Daniel J.; Liberzon, Israel

    2010-01-01

    Genetic variations in the catechol-o-methyltransferase (COMT) gene have been associated with experimental pain and risk of chronic pain development, but no studies have examined genetic predictors of neck pain intensity and other patient characteristics after motor vehicle collision (MVC). We evaluated the association between COMT genotype and acute neck pain intensity and other patient characteristics in 89 Caucasian individuals presenting to the emergency department (ED) after MVC. In the E...

  4. Investigating the Potential Role of Genetic and Epigenetic Variation of DNA Methyltransferase Genes in Hyperplastic Polyposis Syndrome

    OpenAIRE

    Drini, Musa; Nicholas C. Wong; Hamish S Scott; Craig, Jeffrey M; Dobrovic, Alexander; Chelsee A Hewitt; Dow, Christofer; Young, Joanne P; Jenkins, Mark A; Saffery, Richard; Macrae, Finlay A.

    2011-01-01

    Background Hyperplastic Polyposis Syndrome (HPS) is a condition associated with multiple serrated polyps, and an increased risk of colorectal cancer (CRC). At least half of CRCs arising in HPS show a CpG island methylator phenotype (CIMP), potentially linked to aberrant DNA methyltransferase (DNMT) activity. CIMP is associated with methylation of tumor suppressor genes including regulators of DNA mismatch repair (such as MLH1, MGMT), and negative regulators of Wnt signaling (such as WIF1). In...

  5. A novel route to product specificity in the Suv4-20 family of histone H4K20 methyltransferases

    OpenAIRE

    Southall, Stacey M.; Cronin, Nora B.; Wilson, Jon R.

    2013-01-01

    The delivery of site-specific post-translational modifications to histones generates an epigenetic regulatory network that directs fundamental DNA-mediated processes and governs key stages in development. Methylation of histone H4 lysine-20 has been implicated in DNA repair, transcriptional silencing, genomic stability and regulation of replication. We present the structure of the histone H4K20 methyltransferase Suv4-20h2 in complex with its histone H4 peptide substrate and S-adenosyl methion...

  6. Protein Isoaspartate Methyltransferase Prevents Apoptosis Induced by Oxidative Stress in Endothelial Cells: Role of Bcl-Xl Deamidation and Methylation

    OpenAIRE

    Amelia Cimmino; Rosanna Capasso; Fabbri Muller; Irene Sambri; Lucia Masella; Marianna Raimo; Maria Luigia De Bonis; Stefania D'Angelo; Vincenzo Zappia; Patrizia Galletti; Diego Ingrosso

    2008-01-01

    BACKGROUND: Natural proteins undergo in vivo spontaneous post-biosynthetic deamidation of specific asparagine residues with isoaspartyl formation. Deamidated-isomerized molecules are both structurally and functionally altered. The enzyme isoaspartyl protein carboxyl-O-methyltransferase (PCMT; EC 2.1.1.77) has peculiar substrate specificity towards these deamidated proteins. It catalyzes methyl esterification of the free alpha-carboxyl group at the isoaspartyl site, thus initiating the repair ...

  7. Molecular phylogenetics and comparative modeling of HEN1, a methyltransferase involved in plant microRNA biogenesis

    Directory of Open Access Journals (Sweden)

    Obarska Agnieszka

    2006-01-01

    Full Text Available Abstract Background Recently, HEN1 protein from Arabidopsis thaliana was discovered as an essential enzyme in plant microRNA (miRNA biogenesis. HEN1 transfers a methyl group from S-adenosylmethionine to the 2'-OH or 3'-OH group of the last nucleotide of miRNA/miRNA* duplexes produced by the nuclease Dicer. Previously it was found that HEN1 possesses a Rossmann-fold methyltransferase (RFM domain and a long N-terminal extension including a putative double-stranded RNA-binding motif (DSRM. However, little is known about the details of the structure and the mechanism of action of this enzyme, and about its phylogenetic origin. Results Extensive database searches were carried out to identify orthologs and close paralogs of HEN1. Based on the multiple sequence alignment a phylogenetic tree of the HEN1 family was constructed. The fold-recognition approach was used to identify related methyltransferases with experimentally solved structures and to guide the homology modeling of the HEN1 catalytic domain. Additionally, we identified a La-like predicted RNA binding domain located C-terminally to the DSRM domain and a domain with a peptide prolyl cis/trans isomerase (PPIase fold, but without the conserved PPIase active site, located N-terminally to the catalytic domain. Conclusion The bioinformatics analysis revealed that the catalytic domain of HEN1 is not closely related to any known RNA:2'-OH methyltransferases (e.g. to the RrmJ/fibrillarin superfamily, but rather to small-molecule methyltransferases. The structural model was used as a platform to identify the putative active site and substrate-binding residues of HEN and to propose its mechanism of action.

  8. O6-Methylguanine DNA methyltransferase protein expression in tumor cells predicts outcome of temozolomide therapy in glioblastoma patients

    OpenAIRE

    Spiegl-Kreinecker, Sabine; Pirker, Christine; Filipits, Martin; Lötsch, Daniela; Buchroithner, Johanna; Pichler, Josef; Silye, Rene; Weis,Serge; Micksche, Michael; Fischer, Johannes; Berger, Walter

    2009-01-01

    O6-Methylguanine DNA methyltransferase (MGMT) is implicated as a major predictive factor for treatment response to alkylating agents including temozolomide (TMZ) of glioblastoma multiforme (GBM) patients. However, whether the MGMT status in GBM patients should be detected at the level of promoter methylation or protein expression is still a matter of debate. Here, we compared promoter methylation (by methylation-specific polymerase chain reaction) and protein expression (by Western blot) in t...

  9. Direct methylation of FXR by Set7/9, a lysine methyltransferase, regulates the expression of FXR target genes

    OpenAIRE

    Balasubramaniyan, Natarajan; Ananthanarayanan, Meena; Suchy, Frederick J.

    2012-01-01

    The farnesoid X receptor (FXR) is a ligand (bile acid)-dependent nuclear receptor that regulates target genes involved in every aspect of bile acid homeostasis. Upon binding of ligand, FXR recruits an array of coactivators and associated proteins, some of which have intrinsic enzymatic activity that modify histones or even components of the transcriptional complex. In this study, we show chromatin occupancy by the Set7/9 methyltransferase at the FXR response element (FXRE) and direct methylat...

  10. The Role of the Methyltransferase Domain of Bifunctional Restriction Enzyme RM.BpuSI in Cleavage Activity

    OpenAIRE

    Arthur Sarrade-Loucheur; Shuang-yong Xu; Siu-Hong Chan

    2013-01-01

    Restriction enzyme (REase) RM.BpuSI can be described as a Type IIS/C/G REase for its cleavage site outside of the recognition sequence (Type IIS), bifunctional polypeptide possessing both methyltransferase (MTase) and endonuclease activities (Type IIC) and endonuclease activity stimulated by S-adenosyl-L-methionine (SAM) (Type IIG). The stimulatory effect of SAM on cleavage activity presents a major paradox: a co-factor of the MTase activity that renders the substrate unsusceptible to cleavag...

  11. Characterization of a DNA Adenine Methyltransferase Gene of Borrelia hermsii and Its Dispensability for Murine Infection and Persistence

    Science.gov (United States)

    James, Allison E.; Rogovskyy, Artem S.; Crowley, Michael A.; Bankhead, Troy

    2016-01-01

    DNA methyltransferases have been implicated in the regulation of virulence genes in a number of pathogens. Relapsing fever Borrelia species harbor a conserved, putative DNA methyltransferase gene on their chromosome, while no such ortholog can be found in the annotated genome of the Lyme disease agent, Borrelia burgdorferi. In the relapsing fever species Borrelia hermsii, the locus bh0463A encodes this putative DNA adenine methyltransferase (dam). To verify the function of the BH0463A protein product as a Dam, the gene was cloned into a Dam-deficient strain of Escherichia coli. Restriction fragment analysis subsequently demonstrated that complementation of this E. coli mutant with bh0463A restored adenine methylation, verifying bh0463A as a Dam. The requirement of bh0463A for B. hermsii viability, infectivity, and persistence was then investigated by genetically disrupting the gene. The dam- mutant was capable of infecting immunocompetent mice, and the mean level of spirochetemia in immunocompetent mice was not significantly different from wild type B. hermsii. Collectively, the data indicate that dam is dispensable for B. hermsii viability, infectivity, and persistence. PMID:27195796

  12. Crystallization and preliminary crystallographic analysis of tRNA (m{sup 7}G46) methyltransferase from Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi; Gao, Yang; Yang, Weili; Zhou, Huihao; Gao, Yongxiang; Zhang, Xiao; Teng, Maikun, E-mail: mkteng@ustc.edu.cn; Niu, Liwen, E-mail: mkteng@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230027 (China); Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230027 (China)

    2008-08-01

    tRNA (m{sup 7}G46) methyltransferase from E. coli was overexpressed, purified and crystallized. Diffraction data were collected to 2.04 Å resolution. Transfer RNA (tRNA) (m{sup 7}G46) methyltransferase (TrmB) belongs to the Rossmann-fold methyltransferase (RFM) family and uses S-adenosyl-l-methionine (SAM) as the methyl-group donor to catalyze the formation of N{sup 7}-methylguanosine (m{sup 7}G) at position 46 in the variable loop of tRNAs. After attempts to crystallize full-length Escherichia coli TrmB (EcTrmB) failed, a truncated protein lacking the first 32 residues of the N-terminus but with an additional His{sub 6} tag at the C-terminus was crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 3350 (PEG 3350) as precipitant at 283 K. An X-ray diffraction data set was collected using a single flash-cooled crystal that belonged to space group P2{sub 1}.

  13. Composto orgânico na produção e qualidade de sementes de brócolis Organic compost in broccoli seed yield and quality

    Directory of Open Access Journals (Sweden)

    Felipe Oliveira Magro

    2010-06-01

    from high physiological potential seeds. Although there are studies about nutrition and recommendation of fertilization to broccoli (Brassica oleracea L. var. italica Plenk, rarely it finds out works that approach the nutrients effects in seed yield and quality. The objective of this work was to evaluate the organic compost influence in broccoli seed quality and yield. The experiment was lead at São Manuel Experimental Farm and the evaluations at Horticulture Sector in Agronomic Science School (FCA/UNESP in Botucatu. The treatments were four organic compost levels (30, 60, 90 and 120 t ha-1, and control without organic compost. The experimental design was randomized blocks with four replications. The characteristics evaluated were seed yield and number of seed per plant further the characteristics related with seed quality: one thousand seed mass, germination test, first germination counting, index of germination speed and electrical conductivity. The regression showed a linear response in function of organic compost levels, where larger levels resulted higher yield despite the seed quality is not affected.

  14. Imidazoline derivative templated synthesis of broccoli-like Bi2S3 and its electrocatalysis towards the direct electrochemistry of hemoglobin.

    Science.gov (United States)

    Chen, Xiaoqian; Wang, Qingxiang; Wang, Liheng; Gao, Feng; Wang, Wei; Hu, Zhengshui

    2015-04-15

    A broccoli-like bismuth sulfide (bBi2S3) was synthesized via a solvothermal method using a self-made imidazoline derivative of 2-undecyl-1-dithioureido-ethyl-imidazoline as the soft template. The morphology and chemical constitution of the product were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Electrochemical characterization experiments show that the bBi2S3 has the higher specific surface area and standard heterogeneous electron transfer rate constant than the rod-like Bi2S3 (rBi2S3). Hemoglobin (Hb) was then chosen as a protein model to investigate the electrocatalytic property of the synthesized bBi2S3. The results show that Hb entrapped in the composite film of chitosan and bBi2S3 displays an excellent direct electrochemistry, and retains its biocatalytic activity toward the electro-reduction of hydrogen peroxide. The current response in the amperometry shows a linear response to H2O2 concentrations in the range from 0.4 to 4.8µM with high sensitivity (444µAmM(-1)) and low detection limit (0.096µM). The Michaelis-Menten constant (KM(app)) of the fabricated bioelectrode for H2O2 was determined as low as 1µM. These results demonstrate that the synthesized bBi2S3 offers a new path for the immobilization of redox-active protein and the construction of the third-generation biosensors. PMID:25437355

  15. Effect of Broccoli Sprouts and Live Attenuated Influenza Virus on Peripheral Blood Natural Killer Cells: A Randomized, Double-Blind Study.

    Directory of Open Access Journals (Sweden)

    Loretta Müller

    Full Text Available Enhancing antiviral host defense responses through nutritional supplementation would be an attractive strategy in the fight against influenza. Using inoculation with live attenuated influenza virus (LAIV as an infection model, we have recently shown that ingestion of sulforaphane-containing broccoli sprout homogenates (BSH reduces markers of viral load in the nose. To investigate the systemic effects of short-term BSH supplementation in the context of LAIV-inoculation, we examined peripheral blood immune cell populations in non-smoking subjects from this study, with a particular focus on NK cells. We carried out a randomized, double-blinded, placebo-controlled study measuring the effects of BSH (N = 13 or placebo (alfalfa sprout homogenate, ASH; N = 16 on peripheral blood mononuclear cell responses to a standard nasal vaccine dose of LAIV in healthy volunteers. Blood was drawn prior to (day-1 and post (day2, day21 LAIV inoculation and analyzed for neutrophils, monocytes, macrophages, T cells, NKT cells, and NK cells. In addition, NK cells were enriched, stimulated, and assessed for surface markers, intracellular markers, and cytotoxic potential by flow cytometry. Overall, LAIV significantly reduced NKT (day2 and day21 and T cell (day2 populations. LAIV decreased NK cell CD56 and CD158b expression, while significantly increasing CD16 expression and cytotoxic potential (on day2. BSH supplementation further increased LAIV-induced granzyme B production (day2 in NK cells compared to ASH and in the BSH group granzyme B levels appeared to be negatively associated with influenza RNA levels in nasal lavage fluid cells. We conclude that nasal influenza infection may induce complex changes in peripheral blood NK cell activation, and that BSH increases virus-induced peripheral blood NK cell granzyme B production, an effect that may be important for enhanced antiviral defense responses.ClinicalTrials.gov NCT01269723.

  16. Histopathological changes in rat liver in hyper-and hypothyroidism are associated with DNA methyltransferase activity

    Institute of Scientific and Technical Information of China (English)

    Zaporozhan VM; Mescheryakova NV

    2013-01-01

    [Objective] There is evidence that thyroid hormones (TH) could affect on collagen development.Also there is some data that methylation play a significant role in fibrogenesis.That's why the aim of the article was to find out if such pathomorphological changes in liver as fibrosis that were caused by TH could be associated with the changes of DNA methyltransferase activity.[Methods] Experimental study was presented on 89 mature white rats.3 experimental groups were performed:1-experimental hyperthyroidism,2-experimental hypothyroidism,3-control group.The thyroid profile for T3,T4,TTH and profile activity for DNA methyltransferase (DNMT) were determined.The weight of liver was examined.Microscopy and morphometry were performed.[Results] In experimental hyperthyroidism and hypothyroidism the respective changes in TH concentrations occur with a normal level of TTH.It was revealed gender differences in TH levels under impaired thyroid status.In hypothyroidism a decrease of TH concentration occurs in females and males,but it is more expressed in males.In hyperthyroidism the increased concentrations of TH is observed in all rodents,but it is more significant in males.The weight of liver gain in hyperthyroid rodents and decreased of liver weight in hypothyroid rats.In experimentally hyperthyroidism the pathomorphological changed in liver were characterized as an acute vascular insufficiency,hypertension,inflammation,toxic effects of hormones,an initial stage of hepatitis with a high activity,traces of old hemorrhage and a marked fibrosis in the liver.Hypothyroidism also effects on the liver with the signs of acute vascular insufficiency,hypoxia,toxic effects of hormones,necrosis and mild fibrotic changes in the liver tissue.The enzymatic activity of DNMT was increased both in hyperthyroidism and in hypothyroidism.[Conclusions] From results that were've obtained we could conclude that persistent shifts of TH cause pathomorphological changes in the liver.They were more

  17. Structure of the corrinoid:coenzyme M methyltransferase MtaA from Methanosarcina mazei.

    Science.gov (United States)

    Hoeppner, Astrid; Thomas, Frank; Rueppel, Alma; Hensel, Reinhard; Blankenfeldt, Wulf; Bayer, Peter; Faust, Annette

    2012-11-01

    The zinc-containing corrinoid:coenzyme M methyltransferase MtaA is part of the methanol-coenzyme M-methyltransferase complex of Methanosarcina mazei. The whole complex consists of three subunits: MtaA, MtaB and MtaC. The MtaB-MtaC complex catalyses the cleavage of methanol (bound to MtaB) and the transfer of the methyl group onto the cobalt of cob(I)alamin (bound to MtaC). The MtaA-MtaC complex catalyses methyl transfer from methyl-cob(III)alamin (bound to MtaC) to coenzyme M (bound to MtaA). The crystal structure of the MtaB-MtaC complex from M. barkeri has previously been determined. Here, the crystal structures of MtaA from M. mazei in a substrate-free but Zn(2+)-bound state and in complex with Zn(2+) and coenzyme M (HS-CoM) are reported at resolutions of 1.8 and 2.1 Å, respectively. A search for homologous proteins revealed that MtaA exhibits 23% sequence identity to human uroporphyrinogen III decarboxylase, which has also the highest structural similarity (r.m.s.d. of 2.03 Å for 306 aligned amino acids). The main structural feature of MtaA is a TIM-barrel-like fold, which is also found in all other zinc enzymes that catalyse thiol-group alkylation. The active site of MtaA is situated at the narrow bottom of a funnel such that the thiolate group of HS-CoM points towards the Zn(2+) ion. The Zn(2+) ion in the active site of MtaA is coordinated tetrahedrally via His240, Cys242 and Cys319. In the substrate-free form the fourth ligand is Glu263. Binding of HS-CoM leads to exchange of the O-ligand of Glu263 for the S-ligand of HS-CoM with inversion of the zinc geometry. The interface between MtaA and MtaC for transfer of the methyl group from MtaC-bound methylcobalamin is most likely to be formed by the core complex of MtaB-MtaC and the N-terminal segment (a long loop containing three α-helices and a β-hairpin) of MtaA, which is not part of the TIM-barrel core structure of MtaA. PMID:23090404

  18. Cloning and expression of two sterol C-24 methyltransferase genes from upland cotton (Gossypium hirsuturm L.)

    Institute of Scientific and Technical Information of China (English)

    Ming Luo; Kunling Tan; Zhongyi Xiao; Mingyu Hu; Peng Liao; Kuijun Chen

    2008-01-01

    Brassinosteroids (BRs) are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. Two kinds of intermediates, sitosterol and campesterol, play a crucial role in cell elongation, cellulose biosynthesis, and accumulation. To illuminate the effects of sitosterol and campesterol on the development of cotton (Gossypium hirsuturm L.) fibers through screening cotton fiber EST database and contigging the candidate ESTs, two key genes GhSMT2-1 and GhSMT2-2 controlling the sitosterol biosynthesis were cloned from developing fibers of upland cotton cv. Xuzhou 142. The full length of GhSMT2-1 was 1, 151bp, including an 8bp 5'-untranslated region (UTR), a 1, 086bp open reading frame (ORF), and a 57bp 3'-UTR. GhSMT2-1 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40kDa. The full length of GhSMT2-2 was 1, 166bp, including an 18bp 5'-UTR, a 1, 086bp ORF, and a 62bp 3'-UTR. GhSMT2-2 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40kDa. The two deduced amino acid sequences had high homology with the SMT2 from Arabidopsis thaliana and Nicotiana tabacum. Furthermore, the typical conserved structures characterized by the sterol C-24 methyltransferase, such as region I (LDVGCGVGGPIVIRAI), region Ⅱ (IEATCHAP), and region Ⅲ (YEWGWGQSFHF), were present in both deduced proteins. Southern blotting analysis indicated that GhSMT2-1 or GhSMT2-2 was a single copy in upland cotton genome. Quantitative real-time RT-PCR analysis revealed that the highest expression levels of both genes were detected in 10 DPA (day post anthesis) fibers, while the lowest levels were observed in cotyledon and leaves. The expression level of GhSMT2-1 was 10 times higher than that of GhSMT2-2 in all the organs and tissues detected. These results indicate that the homologue of sterol C-24 methyltransferase gene was cloned from upland cotton and both GhSMT2 genes play a crucial

  19. Functional characterization of a rice de novo DNA methyltransferase, OsDRM2, expressed in Escherichia coli and yeast

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Jinsong, E-mail: pangjs542@nenu.edu.cn [Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun, Jilin 130024 (China); Dong, Mingyue; Li, Ning; Zhao, Yanli [Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun, Jilin 130024 (China); Liu, Bao, E-mail: baoliu@nenu.edu.cn [Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun, Jilin 130024 (China)

    2013-03-01

    Highlights: ► A rice de novo DNA methyltransferase OsDRM2 was cloned. ► In vitro methylation activity of OsDRM2 was characterized with Escherichia coli. ► Assays of OsDRM2 in vivo methylation were done with Saccharomyces cerevisiae. ► OsDRM2 methylation activity is not preferential to any type of cytosine context. ► The activity of OsDRM2 is independent of RdDM pathway. - Abstract: DNA methylation of cytosine nucleotides is an important epigenetic modification that occurs in most eukaryotic organisms and is established and maintained by various DNA methyltransferases together with their co-factors. There are two major categories of DNA methyltransferases: de novo and maintenance. Here, we report the isolation and functional characterization of a de novo methyltransferase, named OsDRM2, from rice (Oryza sativa L.). The full-length coding region of OsDRM2 was cloned and transformed into Escherichia coli and Saccharomyces cerevisiae. Both of these organisms expressed the OsDRM2 protein, which exhibited stochastic de novo methylation activity in vitro at CG, CHG, and CHH di- and tri-nucleotide patterns. Two lines of evidence demonstrated the de novo activity of OsDRM2: (1) a 5′-CCGG-3′ containing DNA fragment that had been pre-treated with OsDRM2 protein expressed in E. coli was protected from digestion by the CG-methylation-sensitive isoschizomer HpaII; (2) methylation-sensitive amplified polymorphism (MSAP) analysis of S. cerevisiae genomic DNA from transformants that had been introduced with OsDRM2 revealed CG and CHG methylation levels of 3.92–9.12%, and 2.88–6.93%, respectively, whereas the mock control S. cerevisiae DNA did not exhibit cytosine methylation. These results were further supported by bisulfite sequencing of the 18S rRNA and EAF5 genes of the transformed S. cerevisiae, which exhibited different DNA methylation patterns, which were observed in the genomic DNA. Our findings establish that OsDRM2 is an active de novo DNA

  20. Characterization of NF-kB-mediated inhibition of catechol-O-methyltransferase

    Directory of Open Access Journals (Sweden)

    Conrad Matthew

    2009-03-01

    Full Text Available Abstract Background Catechol-O-methyltransferase (COMT, an enzyme that metabolizes catecholamines, has recently been implicated in the modulation of pain. Specifically, low COMT activity is associated with heightened pain perception and development of musculoskeletal pain in humans as well as increased experimental pain sensitivity in rodents. Results We report that the proinflammatory cytokine tumor necrosis factor α (TNFα downregulates COMT mRNA and protein in astrocytes. Examination of the distal COMT promoter (P2-COMT reveals a putative binding site for nuclear factor κB (NF-κB, the pivotal regulator of inflammation and the target of TNFα. Cell culture assays and functional deletion analyses of the cloned P2-COMT promoter demonstrate that TNFα inhibits P2-COMT activity in astrocytes by inducing NF-κB complex recruitment to the specific κB binding site. Conclusion Collectively, our findings provide the first evidence for NF-κB-mediated inhibition of COMT expression in the central nervous system, suggesting that COMT contributes to the pathogenesis of inflammatory pain states.

  1. Quantitation of DNA methyltransferase activity via chronocoulometry in combination with rolling chain amplification.

    Science.gov (United States)

    Ji, Jingjing; Liu, Yuanjian; Wei, Wei; Zhang, Yuanjian; Liu, Songqin

    2016-11-15

    In this paper, a rolling chain amplification (RCA) strategy was proposed for chronocoulometric detection of DNA methyltransferase (MTase) activity. Briefly, after the double DNA helix structure was assembled on the surface of gold electrode, it was first methylated by M. SssI MTase and then RCA was realized in the presence of E. coli and phi29 DNA polymerase. Successively, numerous hexaammineruthenium (III) chloride ([Ru(NH3)6)(3+), RuHex) were adsorbed on replicons by electrostatic interaction and generated a large electrochemical readout, the signal was "on". On the contrary, in the absence of M. SssI MTase, the methylated CpG site in the unmethylated double DNA helix structure could be specifically recognized and cleaved by HpaII, resulting in a disconnection of RCA from the electrode. This led seldom RuHex to be absorbed onto the surface of electrode, the signal was "off". Based on the proposed strategy, the activity of M. SssI MTase was assayed in the range of 0.5-60U/mL with a detection limit of 0.09U/mL (S/N=3). In addition, the inhibition of procaine and epicatechin on M. SssI MTase activity was evaluated. When the proposed method was applied in complex matrix such as human serum samples, acceptable accuracy, precision and high sensitivity were achieved. Therefore, the proposed method was a potential useful mean for clinical diagnosis and drug development. PMID:27155113

  2. Modulation of Epstein–Barr Virus Nuclear Antigen 2-dependent transcription by protein arginine methyltransferase 5

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cheng-Der; Cheng, Chi-Ping; Fang, Jia-Shih; Chen, Ling-Chih [Department of Life Sciences, Tzu-Chi University, 701 Chung-Yang Rd. Sec 3, Hualien 97004, Taiwan (China); Zhao, Bo; Kieff, Elliott [Department of Medicine and Microbiology and Molecular Genetics, Channing Laboratory, Brigham and Women’s Hospital and Harvard Medical School, 181 Longwood Ave., Boston 02115, MA (United States); Peng, Chih-Wen, E-mail: pengcw@mail.tcu.edu.tw [Department of Life Sciences, Tzu-Chi University, 701 Chung-Yang Rd. Sec 3, Hualien 97004, Taiwan (China)

    2013-01-18

    Highlights: ► Catalytic active PRMT5 substantially binds to the EBNA2 RG domain. ► PRMT5 augments the EBNA2-dependent transcription. ► PRMT5 triggers the symmetric dimethylation of the EBNA2 RG domain. ► PRMT5 enhances the promoter occupancy of EBNA2 on its target promoters. -- Abstract: Epstein–Barr Virus Nuclear Antigen (EBNA) 2 features an Arginine–Glycine repeat (RG) domain at amino acid positions 335–360, which is a known target for protein arginine methyltransferaser 5 (PRMT5). In this study, we performed protein affinity pull-down assays to demonstrate that endogenous PRMT5 derived from lymphoblastoid cells specifically associated with the protein bait GST-E2 RG. Transfection of a plasmid expressing PRMT5 induced a 2.5- to 3-fold increase in EBNA2-dependent transcription of both the LMP1 promoter in AKATA cells, which contain the EBV genome endogenously, and a Cp-Luc reporter plasmid in BJAB cells, which are EBV negative. Furthermore, we showed that there was a 2-fold enrichment of EBNA2 occupancy in target promoters in the presence of exogenous PRMT5. Taken together, we show that PRMT5 triggers the symmetric dimethylation of EBNA2 RG domain to coordinate with EBNA2-mediated transcription. This modulation suggests that PRMT5 may play a role in latent EBV infection.

  3. Biochemical and Computational Analysis of the Substrate Specificities of Cfr and RlmN Methyltransferases

    DEFF Research Database (Denmark)

    Ntokou, Eleni; Hansen, Lykke Haastrup; Kongsted, Jacob;

    2015-01-01

    Cfr and RlmN methyltransferases both modify adenine 2503 in 23S rRNA (Escherichia coli numbering). RlmN methylates position C2 of adenine while Cfr methylates position C8, and to a lesser extent C2, conferring antibiotic resistance to peptidyl transferase inhibitors. Cfr and RlmN show high sequence......-ray structure of RlmN. We used a trinucleotide as target sequence and assessed its positioning at the active site for methylation. The calculations are in accordance with different poses of the trinucleotide in the two enzymes indicating major evolutionary changes to shift the C2/C8 specificities. To explore...... to be responsible for the C2/C8 specificity and most of the combinations involve interchanging segments at this site. Almost all replacements showed no function in the primer extension assay, apart from a few that had a weak effect. Thus Cfr and RlmN appear to be much less similar than expected from their sequence...

  4. Methylation of ribosomal protein S10 by protein-arginine methyltransferase 5 regulates ribosome biogenesis.

    Science.gov (United States)

    Ren, Jinqi; Wang, Yaqing; Liang, Yuheng; Zhang, Yongqing; Bao, Shilai; Xu, Zhiheng

    2010-04-23

    Modulation of ribosomal assembly is a fine tuning mechanism for cell number and organ size control. Many ribosomal proteins undergo post-translational modification, but their exact roles remain elusive. Here, we report that ribosomal protein s10 (RPS10) is a novel substrate of an oncoprotein, protein-arginine methyltransferase 5 (PRMT5). We show that PRMT5 interacts with RPS10 and catalyzes its methylation at the Arg(158) and Arg(160) residues. The methylation of RPS10 at Arg(158) and Arg(160) plays a role in the proper assembly of ribosomes, protein synthesis, and optimal cell proliferation. The RPS10-R158K/R160K mutant is not efficiently assembled into ribosomes and is unstable and prone to degradation by the proteasomal pathway. In nucleoli, RPS10 interacts with nucleophosmin/B23 and is predominantly concentrated in the granular component region, which is required for ribosome assembly. The RPS10 methylation mutant interacts weakly with nucleophosmin/B23 and fails to concentrate in the granular component region. Our results suggest that PRMT5 is likely to regulate cell proliferation through the methylation of ribosome proteins, and thus reveal a novel mechanism for PRMT5 in tumorigenesis.

  5. Jasmonic acid carboxyl methyltransferase regulates development and herbivory-induced defense response in rice.

    Science.gov (United States)

    Qi, Jinfeng; Li, Jiancai; Han, Xiu; Li, Ran; Wu, Jianqiang; Yu, Haixin; Hu, Lingfei; Xiao, Yutao; Lu, Jing; Lou, Yonggen

    2016-06-01

    Jasmonic acid (JA) and related metabolites play a key role in plant defense and growth. JA carboxyl methyltransferase (JMT) may be involved in plant defense and development by methylating JA to methyl jasmonate (MeJA) and thus influencing the concentrations of JA and related metabolites. However, no JMT gene has been well characterized in monocotyledon defense and development at the molecular level. After we cloned a rice JMT gene, OsJMT1, whose encoding protein was localized in the cytosol, we found that the recombinant OsJMT1 protein catalyzed JA to MeJA. OsJMT1 is up-regulated in response to infestation with the brown planthopper (BPH; Nilaparvata lugens). Plants in which OsJMT1 had been overexpressed (oe-JMT plants) showed reduced height and yield. These oe-JMT plants also exhibited increased MeJA levels but reduced levels of herbivore-induced JA and jasmonoyl-isoleucine (JA-Ile). The oe-JMT plants were more attractive to BPH female adults but showed increased resistance to BPH nymphs, probably owing to the different responses of BPH female adults and nymphs to the changes in levels of H2 O2 and MeJA in oe-JMT plants. These results indicate that OsJMT1, by altering levels of JA and related metabolites, plays a role in regulating plant development and herbivore-induced defense responses in rice. PMID:26466818

  6. Structural insight into maintenance methylation by mouse DNA methyltransferase 1 (Dnmt1).

    Science.gov (United States)

    Takeshita, Kohei; Suetake, Isao; Yamashita, Eiki; Suga, Michihiro; Narita, Hirotaka; Nakagawa, Atsushi; Tajima, Shoji

    2011-05-31

    Methylation of cytosine in DNA plays a crucial role in development through inheritable gene silencing. The DNA methyltransferase Dnmt1 is responsible for the propagation of methylation patterns to the next generation via its preferential methylation of hemimethylated CpG sites in the genome; however, how Dnmt1 maintains methylation patterns is not fully understood. Here we report the crystal structure of the large fragment (291-1620) of mouse Dnmt1 and its complexes with cofactor S-adenosyl-L-methionine and its product S-adenosyl-L-homocystein. Notably, in the absence of DNA, the N-terminal domain responsible for targeting Dnmt1 to replication foci is inserted into the DNA-binding pocket, indicating that this domain must be removed for methylation to occur. Upon binding of S-adenosyl-L-methionine, the catalytic cysteine residue undergoes a conformation transition to a catalytically competent position. For the recognition of hemimethylated DNA, Dnmt1 is expected to utilize a target recognition domain that overhangs the putative DNA-binding pocket. Taking into considerations the recent report of a shorter fragment structure of Dnmt1 that the CXXC motif positions itself in the catalytic pocket and prevents aberrant de novo methylation, we propose that maintenance methylation is a multistep process accompanied by structural changes. PMID:21518897

  7. Inhibitor designing, virtual screening, and docking studies for methyltransferase: A potential target against dengue virus

    Science.gov (United States)

    Singh, Jagbir; Kumar, Mahesh; Mansuri, Rani; Sahoo, Ganesh Chandra; Deep, Aakash

    2016-01-01

    Aim: Aim of this work was to design and identify some S-adenosyl-L-homocysteine (SAH) analogs as inhibitors of S-adenosyl-L-methionine-dependent methyltransferase (MTase) protein using computational approaches. Introduction: According to the current scenario the dengue has been a global burden. The people are being killed by dengue virus in an abundant number. Despite of lot of research being going on dengue worldwide, there is no single drug which can kill its virus. This creates an urge for new drug target identification and designing. MTase has been reported as an effective target against dengue virus as it catalyzes an essential step in methylation and capping of viral RNA for viral replication. Materials and Methods: The crystal structure of MTase in complex with SAH was used for designing new analogs of SAH. SAH analogs designed were analyzed on the basis of docking, ADMET, and toxicity analysis done using Discovery Studio 3.5. Results: Seventeen analogs found noncarcinogenic, nonmutagenic, as well as good ADMET properties and good drug-like profile. Conclusion: These SAH analogs, inhibitors of MTase may act as drugs against dengue virus. Further synthesis and biological testing against dengue virus is under observation. PMID:27413346

  8. Molecular Cloning and Characterization of O-Methyltransferase from Mango Fruit (Mangifera indica cv. Alphonso).

    Science.gov (United States)

    Chidley, Hemangi G; Oak, Pranjali S; Deshpande, Ashish B; Pujari, Keshav H; Giri, Ashok P; Gupta, Vidya S

    2016-05-01

    Flavour of ripe Alphonso mango is invariably dominated by the de novo appearance of lactones and furanones during ripening. Of these, furanones comprising furaneol (4-hydroxy-2,5-dimethyl-3(2H)-furanone) and mesifuran (2,5-dimethyl-4-methoxy-3(2H)-furanone) are of particular importance due to their sweet, fruity caramel-like flavour characters and low odour detection thresholds. We isolated a 1056 bp complete open reading frame of a cDNA encoding S-adenosyl-L-methionine-dependent O-methyltransferase from Alphonso mango. The recombinantly expressed enzyme, MiOMTS showed substrate specificity towards furaneol and protocatechuic aldehyde synthesizing mesifuran and vanillin, respectively, in an in vitro assay reaction. A semi-quantitative PCR analysis showed fruit-specific expression of MiOMTS transcripts. Quantitative real-time PCR displayed ripening-related expression pattern of MiOMTS in both pulp and skin of Alphonso mango. Also, early and significantly enhanced accumulation of its transcripts was detected in pulp and skin of ethylene-treated fruits. Ripening-related and fruit-specific expression profile of MiOMTS and substrate specificity towards furaneol is a suggestive of its involvement in the synthesis of mesifuran in Alphonso mango. Moreover, a significant trigger in the expression of MiOMTS transcripts in ethylene-treated fruits point towards the transcriptional regulation of mesifuran biosynthesis by ethylene. PMID:27039187

  9. Analyses of methyltransferases across the pathogenicity spectrum of different mycobacterial species point to an extremophile connection.

    Science.gov (United States)

    Grover, Sonam; Gupta, Paras; Kahlon, Parvinderdeep S; Goyal, Sukriti; Grover, Abhinav; Dalal, Kuldeep; Sabeeha; Ehtesham, Nasreen Z; Hasnain, Seyed E

    2016-05-26

    Tuberculosis is a devastating disease, taking one human life every 20 seconds globally. We hypothesize that professional pathogens such as M.tb have acquired specific features that might assist in causing infection, persistence and transmissible pathology in their host. We have identified 121 methyltransferases (MTases) in the M.tb proteome, which use a variety of substrates - DNA, RNA, protein, intermediates of mycolic acid biosynthesis and other fatty acids - that are involved in cellular maintenance within the host. A comparative analysis of the proteome of the virulent strain H37Rv and the avirulent strain H37Ra identified 3 MTases, which displayed significant variations in terms of N-terminal extension/deletion and point mutations, possibly impacting various physicochemical properties. The cross-proteomic comparison of MTases of M.tb H37Rv with 15 different Mycobacterium species revealed the acquisition of novel MTases in a MTB complex as a function of evolution. Phylogenetic analysis revealed that these newly acquired MTases showed common roots with certain extremophiles such as halophilic and acidophilic organisms. Our results establish an evolutionary relationship of M.tb with halotolerant organisms and also the role of MTases of M.tb in withstanding the host osmotic stress, thereby pointing to their likely role in pathogenesis, virulence and niche adaptation. PMID:26983646

  10. Role of microRNAs and DNA methyltransferases in transmitting induced genomic instability between cell generations

    Directory of Open Access Journals (Sweden)

    Katriina eHuumonen

    2014-09-01

    Full Text Available There is limited understanding of how radiation or chemicals induce genomic instability, and how the instability is epigenetically transmitted to the progeny of exposed cells or organisms. Here we measured the expression of microRNAs (miRNAs and DNA methyltransferases (DNMTs in murine embryonal fibroblasts exposed to ionizing radiation or 2,3,7,8 -tetrachlorodibenzo-p-dioxin (TCDD, which were previously shown to induce genomic instability in this cell line. Cadmium was used as a reference agent that does not induce genomic instability in our experimental model. Measurements at 8 and 15 days after exposure did not identify any such persistent changes that could be considered as signals transmitting genomic instability to the progeny of exposed cells. However, measurements at 2 days after exposure revealed findings that may reflect initial stages of genomic instability. Changes that were common to TCDD and two doses of radiation (but not to cadmium included 5 candidate signature miRNAs and general up-regulation of miRNA expression. Expression of DNMT3a, DNMT3b and DNMT2 were suppressed by cadmium but not by TCDD or radiation, consistently with the hypothesis that sufficient expression of DNMTs is necessary in the initial phase of induced genomic instability.

  11. Protein arginine methyltransferase 5 is associated with malignant phenotype and peritoneal metastasis in gastric cancer.

    Science.gov (United States)

    Kanda, Mitsuro; Shimizu, Dai; Fujii, Tsutomu; Tanaka, Haruyoshi; Shibata, Masahiro; Iwata, Naoki; Hayashi, Masamichi; Kobayashi, Daisuke; Tanaka, Chie; Yamada, Suguru; Nakayama, Goro; Sugimoto, Hiroyuki; Koike, Masahiko; Fujiwara, Michitaka; Kodera, Yasuhiro

    2016-09-01

    Identification of novel gastric cancer (GC)-related molecules is necessary to improve management of patients with GC in both diagnostic and therapeutic aspects. The aim of the present study was to determine whether protein arginine methyltransferase 5 (PRMT5) acts as an oncogene in the progression of GC and whether it serves as a novel diagnostic marker and therapeutic target. We conducted global expression profiling of GC cell lines and RNA interference experiments to evaluate the effect of PRMT5 expression on the phenotype of GC cells. We analysed tissues of 179 patients with GC to assess the association of PRMT5 mRNA levels with clinicopathological factors. Differential expression of PRMT5 mRNA by GC cell lines correlated positively with the levels of GEMIN2, STAT3 and TGFB3. PRMT5 knockdown reduced the proliferation, invasion and migration of a GC cell line. PRMT5 mRNA levels were significantly higher in GC tissues than the corresponding adjacent normal tissues and were independent of tumour depth, differentiation and lymph node metastasis. High PRMT5 expression was an independent risk factor of positive peritoneal lavage cytology (odds ratio 3.90, P=0.003) and decreased survival. PRMT5 enhances the malignant phenotype of GC cell lines and its expression in gastric tissues may serve as a biomarker for patient stratification and a potential target of therapy. PMID:27315569

  12. Role of type II protein arginine methyltransferase 5 in the regulation of Circadian Per1 gene.

    Directory of Open Access Journals (Sweden)

    Jungtae Na

    Full Text Available Circadian clocks are the endogenous oscillators that regulate rhythmic physiological and behavioral changes to correspond to daily light-dark cycles. Molecular dissections have revealed that transcriptional feedback loops of the circadian clock genes drive the molecular oscillation, in which PER/CRY complexes inhibit the transcriptional activity of the CLOCK/BMAL1 heterodimer to constitute a negative feedback loop. In this study, we identified the type II protein arginine methyltransferase 5 (PRMT5 as an interacting molecule of CRY1. Although the Prmt5 gene was constitutively expressed, increased interaction of PRMT5 with CRY1 was observed when the Per1 gene was repressed both in synchronized mouse liver and NIH3T3 cells. Moreover, rhythmic recruitment of PRMT5 and CRY1 to the Per1 gene promoter was found to be associated with an increased level of histone H4R3 dimethylation and Per1 gene repression. Consistently, decreased histone H4R3 dimethylation and altered rhythmic Per1 gene expression were observed in Prmt5-depleted cells. Taken together, these findings provide an insight into the link between histone arginine methylation by PRMT5 and transcriptional regulation of the circadian Per1 gene.

  13. Targeting EZH2 methyltransferase activity in ARID1A mutated cancer cells is synthetic lethal

    Science.gov (United States)

    Biter, Benjamin G.; Aird, Katherine M.; Garipov, Azat; Li, Hua; Amatangelo, Michael; Kossenkov, Andrew V.; Schultz, David C.; Liu, Qin; Shih, Ie-Ming; Conejo-Garcia, Jose R.; Speicher, David W.; Zhang, Rugang

    2015-01-01

    ARID1A, a chromatin remodeler, shows one of the highest mutation rates across many cancer types. Notably, ARID1A is mutated in over 50% of ovarian clear cell carcinomas, which currently has no effective therapy. To date, clinically applicable targeted cancer therapy based on ARID1A mutational status has not been described. Here we show that inhibition of the EZH2 methyltransferase acts in a synthetic lethal manner in ARID1A mutated ovarian cancer cells. ARID1A mutational status correlates with response to the EZH2 inhibitor. We identified PIK3IP1 as a direct ARID1A/EZH2 target, which is upregulated by EZH2 inhibition and contributes to the observed synthetic lethality by inhibiting PI3K/AKT signaling. Significantly, EZH2 inhibition causes regression of ARID1A mutated ovarian tumors in vivo. Together, these data demonstrate for the first time a synthetic lethality between ARID1A mutation and EZH2 inhibition. They indicate that pharmacological inhibition of EZH2 represents a novel treatment strategy for ARID1A mutated cancers. PMID:25686104

  14. Jasmonic acid carboxyl methyltransferase regulates development and herbivory-induced defense response in rice

    Institute of Scientific and Technical Information of China (English)

    Jinfeng Qi; Yonggen Lou; Jiancai Li; Xiu Han; Ran Li; Jianqiang Wu; Haixin Yu; Lingfei Hu; Yutao Xiao; Jing Lu

    2016-01-01

    Jasmonic acid (JA) and related metabolites play a key role in plant defense and growth. JA carboxyl methyltransferase (JMT) may be involved in plant defense and development by methylating JA to methyl jasmonate (MeJA) and thus influencing the concentrations of JA and related metabolites. However, no JMT gene has been well characterized in monocotyledon defense and development at the molecular level. After we cloned a rice JMT gene, OsJMT1, whose encoding protein was localized in the cytosol, we found that the recombinant OsJMT1 protein catalyzed JA to MeJA. OsJMT1 is up-regulated in response to infestation with the brown planthopper (BPH; Nilaparvata lugens). Plants in which OsJMT1 had been overexpressed (oe-JMT plants) showed reduced height and yield. These oe-JMT plants also exhibited increased MeJA levels but reduced levels of herbivore-induced JA and jasmonoyl-isoleucine (JA-Ile). The oe-JMT plants were more attractive to BPH female adults but showed increased resistance to BPH nymphs, probably owing to the different responses of BPH female adults and nymphs to the changes in levels of H2O2 and MeJA in oe-JMT plants. These results indicate that OsJMT1, by altering levels of JA and related metabolites, plays a role in regulating plant development and herbivore-induced defense responses in rice.

  15. Purification and properties of S-adenosylmethionine:dimethylselenide methyltransferase from the mouse

    International Nuclear Information System (INIS)

    Selenite is detoxified by reduction to H2Se and methylation from S-adenosylmethionine (AdoMet) to yield methylselenol, dimethylselenide (DMSe; exhaled), and trimethylselenonium ion (TMSe; excreted in urine). DMSe methyltransferase (DMSeMT) was assayed by its ability to generate [3H]TMSe from DMSe and [methyl-3H]AdoMet, with TMSe separated by cation-exchange HPLC. DMSeMT is found primarily in the cytosol. In terms of specific activity (umol/min/mg protein), the enzyme is most active in the lung (298) and liver (105), with much lower activity in kidney (8), heart (7), muscle (8), RBC (4), and is negligible in brain and spleen. Initial purification from liver cytosol was by DEAE and gel filtration column chromatography. Gel filtration and SDS polyacrylamide gel electrophoroesis indicate that the enzyme is monomeric with a molecular weight of 30,000 daltons. Activity assays on liver cytosol indicate a pH optimum of 6. DMSeMT is inhibited 50% by 25 uM Sinefungin, an AdoMet analog, and by its product, S-adenosylhomocysteine, at 40 uM. Purification to homogeneity will allow analysis of the ability of this enzyme to also catalyze the methylation of H2Se and/or to methylselenol

  16. miR-221/222 Target the DNA Methyltransferase MGMT in Glioma Cells

    Science.gov (United States)

    Roscigno, Giuseppina; Romano, Giulia; Diaz-Lagares, Angel; Iaboni, Margherita; Donnarumma, Elvira; Fiore, Danilo; De Marinis, Pasqualino; Soini, Ylermi; Esteller, Manel; Condorelli, Gerolama

    2013-01-01

    Glioblastoma multiforme (GBM) is one of the most deadly types of cancer. To date, the best clinical approach for treatment is based on administration of temozolomide (TMZ) in combination with radiotherapy. Much evidence suggests that the intracellular level of the alkylating enzyme O6-methylguanine–DNA methyltransferase (MGMT) impacts response to TMZ in GBM patients. MGMT expression is regulated by the methylation of its promoter. However, evidence indicates that this is not the only regulatory mechanism present. Here, we describe a hitherto unknown microRNA-mediated mechanism of MGMT expression regulation. We show that miR-221 and miR-222 are upregulated in GMB patients and that these paralogues target MGMT mRNA, inducing greater TMZ-mediated cell death. However, miR-221/miR-222 also increase DNA damage and, thus, chromosomal rearrangements. Indeed, miR-221 overexpression in glioma cells led to an increase in markers of DNA damage, an effect rescued by re-expression of MGMT. Thus, chronic miR-221/222-mediated MGMT downregulation may render cells unable to repair genetic damage. This, associated also to miR-221/222 oncogenic potential, may poor GBM prognosis. PMID:24147153

  17. MiR-221/222 target the DNA methyltransferase MGMT in glioma cells.

    Directory of Open Access Journals (Sweden)

    Cristina Quintavalle

    Full Text Available Glioblastoma multiforme (GBM is one of the most deadly types of cancer. To date, the best clinical approach for treatment is based on administration of temozolomide (TMZ in combination with radiotherapy. Much evidence suggests that the intracellular level of the alkylating enzyme O(6-methylguanine-DNA methyltransferase (MGMT impacts response to TMZ in GBM patients. MGMT expression is regulated by the methylation of its promoter. However, evidence indicates that this is not the only regulatory mechanism present. Here, we describe a hitherto unknown microRNA-mediated mechanism of MGMT expression regulation. We show that miR-221 and miR-222 are upregulated in GMB patients and that these paralogues target MGMT mRNA, inducing greater TMZ-mediated cell death. However, miR-221/miR-222 also increase DNA damage and, thus, chromosomal rearrangements. Indeed, miR-221 overexpression in glioma cells led to an increase in markers of DNA damage, an effect rescued by re-expression of MGMT. Thus, chronic miR-221/222-mediated MGMT downregulation may render cells unable to repair genetic damage. This, associated also to miR-221/222 oncogenic potential, may poor GBM prognosis.

  18. Expression of O6-methylguanine DNA methyltransferase (MGMT) and its clinical significance in gastroenteropancreatic neuroendocrine neoplasm

    Science.gov (United States)

    Yang, Qiu-Chen; Wang, Yu-Hong; Lin, Yuan; Xue, Ling; Chen, Yuan-Jia; Chen, Min-Hu; Chen, Jie

    2014-01-01

    O6-methylguanine-DNA methyltransferase (MGMT) is a widespread DNA repair enzyme defending against mutation caused by guanine O6-alkylating agents. Until now, we know only little about the expression of MGMT in gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN). To study the expression of MGMT and its clinical significance in GEP-NEN, 174 specimens of GEP-NEN were examined, of which 152 specimens came from The First Affiliated Hospital, Sun Yat-sen University during October 1995 to November 2013, 22 specimens came from Peking Union Medical College Hospital during September 2004 to April 2010. MGMT protein was detected with EnVision immunohistochemical staining method. Clinicopathological factors were also collected and analyzed. We observed that the overall expression rate of MGMT was 83.9%. Over expression of MGMT protein was not associated with sex, age, functional status, primary tumor location, grading, classification, TNM stage and metastasis (P > 0.05). Kaplan-Meier analysis revealed that there was no significant difference in survival between MGMT-positive and MGMT-negative tumors of GEP-NEN patients (χ2 = 0.887, P = 0.346). In multivariate analyses carried out by Cox proportional hazards regression model, MGMT expression was also not an independent predictors of survival. These results demonstrated that MGMT protein was highly expressed in GEP-NEN. MGMT deficiency rate was similar in pancreatic NEN and in gastrointestinal NEN. MGMT expression was not correlated with prognosis of GEP-NEN. PMID:25120800

  19. O6-methylguanine DNA methyltransferase in human fetal tissues: fetal and maternal factors

    International Nuclear Information System (INIS)

    O6-Methylguanine methyltransferase (O6-MT) was measured and compared in extracts of 7 human fetal tissues obtained from 21 different fetal specimens as a function of fetal age and race, and maternal smoking and drug usage. Activity was determined from the proteinase-K solubilized radioactivity transferred from the DNA to the O6-MT. S9 homogenates were incubated with a heat depurinated [3H]-methylnitrosourea alkylated DNA. Liver exhibited the highest activity followed by kidney, lung, small intestine, large intestine, skin and brain. Each of the tissues exhibited a 3- to 5-fold level of interindividual variation of O6-MT. There did not appear to be any significant difference of O6-MT in the tissues obtained from mothers who smoked cigarettes during pregnancy. Also, fetal race and age did not appear to account for the level of variation of O6-MT. The fetal tissues obtained from an individual using phenobarbital and smoking exhibited 4-fold increases in O6-MT activity. The tissues obtained from another individual on kidney dialysis were 2- to 3-fold higher than the normal population. These data suggest that the variation in human O6-MT can not be explained by racial or smoking factors, but may be modulated by certain drugs

  20. Molecular characterization of methanogenic N(5)-methyl-tetrahydromethanopterin: Coenzyme M methyltransferase.

    Science.gov (United States)

    Upadhyay, Vikrant; Ceh, Katharina; Tumulka, Franz; Abele, Rupert; Hoffmann, Jan; Langer, Julian; Shima, Seigo; Ermler, Ulrich

    2016-09-01

    Methanogenic archaea share one ion gradient forming reaction in their energy metabolism catalyzed by the membrane-spanning multisubunit complex N(5)-methyl-tetrahydromethanopterin: coenzyme M methyltransferase (MtrABCDEFGH or simply Mtr). In this reaction the methyl group transfer from methyl-tetrahydromethanopterin to coenzyme M mediated by cobalamin is coupled with the vectorial translocation of Na(+) across the cytoplasmic membrane. No detailed structural and mechanistic data are reported about this process. In the present work we describe a procedure to provide a highly pure and homogenous Mtr complex on the basis of a selective removal of the only soluble subunit MtrH with the membrane perturbing agent dimethyl maleic anhydride and a subsequent two-step chromatographic purification. A molecular mass determination of the Mtr complex by laser induced liquid bead ion desorption mass spectrometry (LILBID-MS) and size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) resulted in a (MtrABCDEFG)3 heterotrimeric complex of ca. 430kDa with both techniques. Taking into account that the membrane protein complex contains various firmly bound small molecules, predominantly detergent molecules, the stoichiometry of the subunits is most likely 1:1. A schematic model for the subunit arrangement within the MtrABCDEFG protomer was deduced from the mass of Mtr subcomplexes obtained by harsh IR-laser LILBID-MS. PMID:27342374

  1. Catechol-O-methyltransferase val158met Polymorphism Interacts with Sex to Affect Face Recognition Ability

    Science.gov (United States)

    Lamb, Yvette N.; McKay, Nicole S.; Singh, Shrimal S.; Waldie, Karen E.; Kirk, Ian J.

    2016-01-01

    The catechol-O-methyltransferase (COMT) val158met polymorphism affects the breakdown of synaptic dopamine. Consequently, this polymorphism has been associated with a variety of neurophysiological and behavioral outcomes. Some of the effects have been found to be sex-specific and it appears estrogen may act to down-regulate the activity of the COMT enzyme. The dopaminergic system has been implicated in face recognition, a form of cognition for which a female advantage has typically been reported. This study aimed to investigate potential joint effects of sex and COMT genotype on face recognition. A sample of 142 university students was genotyped and assessed using the Faces I subtest of the Wechsler Memory Scale – Third Edition (WMS-III). A significant two-way interaction between sex and COMT genotype on face recognition performance was found. Of the male participants, COMT val homozygotes and heterozygotes had significantly lower scores than met homozygotes. Scores did not differ between genotypes for female participants. While male val homozygotes had significantly lower scores than female val homozygotes, no sex differences were observed in the heterozygotes and met homozygotes. This study contributes to the accumulating literature documenting sex-specific effects of the COMT polymorphism by demonstrating a COMT-sex interaction for face recognition, and is consistent with a role for dopamine in face recognition. PMID:27445927

  2. Using oriented peptide array libraries to evaluate methylarginine-specific antibodies and arginine methyltransferase substrate motifs

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    Gayatri, Sitaram; Cowles, Martis W.; Vemulapalli, Vidyasiri; Cheng, Donghang; Sun, Zu-Wen; Bedford, Mark T.

    2016-01-01

    Signal transduction in response to stimuli relies on the generation of cascades of posttranslational modifications that promote protein-protein interactions and facilitate the assembly of distinct signaling complexes. Arginine methylation is one such modification, which is catalyzed by a family of nine protein arginine methyltransferases, or PRMTs. Elucidating the substrate specificity of each PRMT will promote a better understanding of which signaling networks these enzymes contribute to. Although many PRMT substrates have been identified, and their methylation sites mapped, the optimal target motif for each of the nine PRMTs has not been systematically addressed. Here we describe the use of Oriented Peptide Array Libraries (OPALs) to methodically dissect the preferred methylation motifs for three of these enzymes – PRMT1, CARM1 and PRMT9. In parallel, we show that an OPAL platform with a fixed methylarginine residue can be used to validate the methyl-specific and sequence-specific properties of antibodies that have been generated against different PRMT substrates, and can also be used to confirm the pan nature of some methylarginine-specific antibodies. PMID:27338245

  3. Polymorphism of the catechol-O-methyltransferase gene in Han Chinese patients with psoriasis vulgaris

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    Lin Gao

    2009-01-01

    Full Text Available Psoriasis vulgaris is defined by a series of linked cellular changes in the skin: hyperplasia of epidermal keratinocytes, vascular hyperplasia and ectasia, and infiltration of T lymphocytes, neutrophils and other types of leukocytes in the affected skin. Catechol-O-methyltransferase ( COMT 158 polymorphism can reduce the activity of the COMT enzyme that may trigger defective differentiation of keratinocytes in psoriasis. Immunocytes can degrade and inactivate catecholamines via monamine oxidase (MAO and COMT in the cells. We hypothesized that the COMT-158 G > A polymorphism was associated with the risk of psoriasis vulgaris in Han Chinese people. In a hospital-based case-control study, 524 patients with psoriasis vulgaris and 549 psoriasis-free controls were studied. COMT-158 G > A polymorphism was genotyped using the PCR sequence-specific primer (PCR-SSP technique. We found no statistically significant association between the COMT-158 allele A and the risk of psoriasis vulgaris (p = 0.739 adjusted OR = 1.03; 95% CI = 0.81-1.31. This suggests that the COMT-158 G > A polymorphism may not contribute to the etiology of psoriasis vulgaris in the Han Chinese population.

  4. Homocysteine homeostasis and betaine-homocysteine S-methyltransferase expression in the brain of hibernating bats.

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    Yijian Zhang

    Full Text Available Elevated homocysteine is an important risk factor that increases cerebrovascular and neurodegenerative disease morbidity. In mammals, B vitamin supplementation can reduce homocysteine levels. Whether, and how, hibernating mammals, that essentially stop ingesting B vitamins, maintain homocysteine metabolism and avoid cerebrovascular impacts and neurodegeneration remain unclear. Here, we compare homocysteine levels in the brains of torpid bats, active bats and rats to identify the molecules involved in homocysteine homeostasis. We found that homocysteine does not elevate in torpid brains, despite declining vitamin B levels. At low levels of vitamin B6 and B12, we found no change in total expression level of the two main enzymes involved in homocysteine metabolism (methionine synthase and cystathionine β-synthase, but a 1.85-fold increase in the expression of the coenzyme-independent betaine-homocysteine S-methyltransferase (BHMT. BHMT expression was observed in the amygdala of basal ganglia and the cerebral cortex where BHMT levels were clearly elevated during torpor. This is the first report of BHMT protein expression in the brain and suggests that BHMT modulates homocysteine in the brains of hibernating bats. BHMT may have a neuroprotective role in the brains of hibernating mammals and further research on this system could expand our biomedical understanding of certain cerebrovascular and neurodegenerative disease processes.

  5. Single-Turnover Kinetics of Methyl Transfer to tRNA by Methyltransferases

    Science.gov (United States)

    Hou, Ya-Ming

    2016-01-01

    Summary Methyl transfer from S-adenosyl methionine (abbreviated as AdoMet) to biologically active molecules such as mRNAs and tRNAs is one of the most fundamental and widespread reactions in nature, occurring in all three domains of life. The measurement of kinetic constants of AdoMet-dependent methyl transfer is therefore important for understanding the reaction mechanism in the context of biology. When kinetic constants of methyl transfer are measured in steady state over multiple rounds of turnover, the meaning of these constants is difficult to define and is often limited by non-chemical steps of the reaction, such as product release after each turnover. Here the measurement of kinetic constants of methyl transfer by tRNA methyltransferases in rapid equilibrium binding condition for one methyl transfer is described. The advantage of such a measurement is that the meaning of kinetic constants can be directly assigned to the steps associated with the chemistry of methyl transfer, including the substrate binding affinity to the methyl transferase, the pre-chemistry re-arrangement of the active site, and the chemical step of methyl transfer. An additional advantage is that kinetic constants measured for one methyl transfer can be correlated with structural information of the methyl transferase to gain direct insight into its reaction mechanism. PMID:26965259

  6. Structural and functional profiling of the human histone methyltransferase SMYD3.

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    Kenneth W Foreman

    Full Text Available The SET and MYND Domain (SMYD proteins comprise a unique family of multi-domain SET histone methyltransferases that are implicated in human cancer progression. Here we report an analysis of the crystal structure of the full length human SMYD3 in a complex with an analog of the S-adenosyl methionine (SAM methyl donor cofactor. The structure revealed an overall compact architecture in which the "split-SET" domain adopts a canonical SET domain fold and closely assembles with a Zn-binding MYND domain and a C-terminal superhelical 9 α-helical bundle similar to that observed for the mouse SMYD1 structure. Together, these structurally interlocked domains impose a highly confined binding pocket for histone substrates, suggesting a regulated mechanism for its enzymatic activity. Our mutational and biochemical analyses confirm regulatory roles of the unique structural elements both inside and outside the core SET domain and establish a previously undetected preference for trimethylation of H4K20.

  7. Structural and Functional Profiling of the Human Histone Methyltransferase SMYD3

    Energy Technology Data Exchange (ETDEWEB)

    Foreman, Kenneth W.; Brown, Mark; Park, Frances; Emtage, Spencer; Harriss, June; Das, Chhaya; Zhu, Li; Crew, Andy; Arnold, Lee; Shaaban, Salam; Tucker, Philip (AltheaDx); (DiscoverEluc.); (Abbott Bioresearch); (OSI Pharm.); (Lilly); (Texas)

    2012-10-23

    The SET and MYND Domain (SMYD) proteins comprise a unique family of multi-domain SET histone methyltransferases that are implicated in human cancer progression. Here we report an analysis of the crystal structure of the full length human SMYD3 in a complex with an analog of the S-adenosyl methionine (SAM) methyl donor cofactor. The structure revealed an overall compact architecture in which the 'split-SET' domain adopts a canonical SET domain fold and closely assembles with a Zn-binding MYND domain and a C-terminal superhelical 9 ?-helical bundle similar to that observed for the mouse SMYD1 structure. Together, these structurally interlocked domains impose a highly confined binding pocket for histone substrates, suggesting a regulated mechanism for its enzymatic activity. Our mutational and biochemical analyses confirm regulatory roles of the unique structural elements both inside and outside the core SET domain and establish a previously undetected preference for trimethylation of H4K20.

  8. EWS is a substrate of type I protein arginine methyltransferase, PRMT8.

    Science.gov (United States)

    Kim, Jun-Dal; Kako, Koichiro; Kakiuchi, Misako; Park, Gwi Gun; Fukamizu, Akiyoshi

    2008-09-01

    EWS, a pro-oncoprotein which is encoded by the Ewing sarcoma (EWS) gene, contains arginine-glycine-glycine repeats (RGG box) in its COOH-terminus. We previously found that the RGG box of EWS is a target for dimethylation catalyzed by protein arginine methyltransferases (PRMTs). Although it has been observed that arginine residues in EWS are dimethylated in vivo, the endogenous enzyme(s) responsible for this reaction have not been identified to date. In the present study, we determined that EWS was physically associated with PRMT8, the novel eighth member of the PRMT family, through the COOH-terminal region of EWS including RGG3 with the NH2-terminal region of PRMT8 encompassing the S-adenosyl-L-methionine binding domain, and that arginine residues in EWS were asymmetrically dimethylated by PRMT8 using amino acid analysis with thin-layer chromatography. These results suggested that EWS is a substrate for PRMT8, as efficient as for PRMT1.

  9. Mechanistic insights on the inhibition of c5 DNA methyltransferases by zebularine.

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    Christine Champion

    Full Text Available In mammals DNA methylation occurs at position 5 of cytosine in a CpG context and regulates gene expression. It plays an important role in diseases and inhibitors of DNA methyltransferases (DNMTs--the enzymes responsible for DNA methylation--are used in clinics for cancer therapy. The most potent inhibitors are 5-azacytidine and 5-azadeoxycytidine. Zebularine (1-(beta-D-ribofuranosyl-2(1H- pyrimidinone is another cytidine analog described as a potent inhibitor that acts by forming a covalent complex with DNMT when incorporated into DNA. Here we bring additional experiments to explain its mechanism of action. First, we observe an increase in the DNA binding when zebularine is incorporated into the DNA, compared to deoxycytidine and 5-fluorodeoxycytidine, together with a strong decrease in the dissociation rate. Second, we show by denaturing gel analysis that the intermediate covalent complex between the enzyme and the DNA is reversible, differing thus from 5-fluorodeoxycytidine. Third, no methylation reaction occurs when zebularine is present in the DNA. We confirm that zebularine exerts its demethylation activity by stabilizing the binding of DNMTs to DNA, hindering the methylation and decreasing the dissociation, thereby trapping the enzyme and preventing turnover even at other sites.

  10. Catechol O-methyltransferase Val158Met polymorphism is associated with cognitive performance in nondemented adults.

    Science.gov (United States)

    de Frias, Cindy M; Annerbrink, Kristina; Westberg, Lars; Eriksson, Elias; Adolfsson, Rolf; Nilsson, Lars-Göran

    2005-07-01

    The catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine in the prefrontal cortex. In the present study, we examined the effect of a Val158Met polymorphism in the COMT gene on individual differences and changes in cognition (executive functions and visuospatial ability) in adulthood and old age. The participants were 292 nondemented men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula study) tested at two occasions with a 5-year interval. Confirmatory factor analyses were used to test the underlying structure of three indicators of executive functions (verbal fluency, working memory, and Tower of Hanoi). Associations between COMT, age, executive functioning, and visuospatial (block design) tasks were examined using repeated-measures analyses of variance. Carriers of the Val allele (with higher enzyme activity) compared with carriers of the Met/Met genotype (with low enzyme activity) performed worse on executive functioning and visuospatial tasks. Individuals with the Val/Val genotype declined in executive functioning over the 5-year period, whereas carriers of the Met allele remained stable in performance. An Age x COMT interaction for visuospatial ability located the effect for middle-aged men only. This COMT polymorphism is a plausible candidate gene for executive functioning and fluid intelligence in nondemented middle-aged and older adults. PMID:16102234

  11. Characterization and structure of DhpI, a phosphonate O-methyltransferase involved in dehydrophos biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin-Hee; Bae, Brian; Kuemin, Michael; Circello, Benjamin T.; Metcalf, William W.; Nair, Satish K.; van der Donk, Wilfred A. (UIUC)

    2012-03-15

    Phosphonate natural products possess a range of biological activities as a consequence of their ability to mimic phosphate esters or tetrahedral intermediates formed in enzymatic reactions involved in carboxyl group metabolism. The dianionic form of these compounds at pH 7 poses a drawback with respect to their ability to mimic carboxylates and tetrahedral intermediates. Microorganisms producing phosphonates have evolved two solutions to overcome this hurdle: biosynthesis of monoanionic phosphinates containing two P-C bonds or esterification of the phosphonate group. The latter solution was first discovered for the antibiotic dehydrophos that contains a methyl ester of a phosphonodehydroalanine group. We report here the expression, purification, substrate scope, and structure of the O-methyltransferase from the dehydrophos biosynthetic gene cluster. The enzyme utilizes S-adenosylmethionine to methylate a variety of phosphonates including 1-hydroxyethylphosphonate, 1,2-dihydroxyethylphosphonate, and acetyl-1-aminoethylphosphonate. Kinetic analysis showed that the best substrates are tripeptides containing as C-terminal residue a phosphonate analog of alanine suggesting the enzyme acts late in the biosynthesis of dehydrophos. These conclusions are corroborated by the X-ray structure that reveals an active site that can accommodate a tripeptide substrate. Furthermore, the structural studies demonstrate a conformational change brought about by substrate or product binding. Interestingly, the enzyme has low substrate specificity and was used to methylate the clinical antibiotic fosfomycin and the antimalaria clinical candidate fosmidomycin, showing its promise for applications in bioengineering.

  12. DNA methyltransferase inhibition increases efficacy of adoptive cellular immunotherapy of murine breast cancer.

    Science.gov (United States)

    Terracina, Krista P; Graham, Laura J; Payne, Kyle K; Manjili, Masoud H; Baek, Annabel; Damle, Sheela R; Bear, Harry D

    2016-09-01

    Adoptive T cell immunotherapy is a promising approach to cancer treatment that currently has limited clinical applications. DNA methyltransferase inhibitors (DNAMTi) have known potential to affect the immune system through multiple mechanisms that could enhance the cytotoxic T cell responses, including: upregulation of tumor antigen expression, increased MHC class I expression, and blunting of myeloid derived suppressor cells (MDSCs) expansion. In this study, we have investigated the effect of combining the DNAMTi, decitabine, with adoptive T cell immunotherapy in the murine 4T1 mammary carcinoma model. We found that expression of neu, MHC class I molecules, and several murine cancer testis antigens (CTA) was increased by decitabine treatment of 4T1 cells in vitro. Decitabine also increased expression of multiple CTA in two human breast cancer cell lines. Decitabine-treated 4T1 cells stimulated greater IFN-gamma release from tumor-sensitized lymphocytes, implying increased immunogenicity. Expansion of CD11b + Gr1 + MDSC in 4T1 tumor-bearing mice was significantly diminished by decitabine treatment. Decitabine treatment improved the efficacy of adoptive T cell immunotherapy in mice with established 4T1 tumors, with greater inhibition of tumor growth and an increased cure rate. Decitabine may have a role in combination with existing and emerging immunotherapies for breast cancer. PMID:27416831

  13. The methyltransferase Setdb1 is essential for meiosis and mitosis in mouse oocytes and early embryos.

    Science.gov (United States)

    Eymery, Angeline; Liu, Zichuan; Ozonov, Evgeniy A; Stadler, Michael B; Peters, Antoine H F M

    2016-08-01

    Oocytes develop the competence for meiosis and early embryogenesis during their growth. Setdb1 is a histone H3 lysine 9 (H3K9) methyltransferase required for post-implantation development and has been implicated in the transcriptional silencing of genes and endogenous retroviral elements (ERVs). To address its role in oogenesis and pre-implantation development, we conditionally deleted Setdb1 in growing oocytes. Loss of Setdb1 expression greatly impaired meiosis. It delayed meiotic resumption, altered the dynamics of chromatin condensation, and impaired kinetochore-spindle interactions, bipolar spindle organization and chromosome segregation in more mature oocytes. The observed phenotypes related to changes in abundance of specific transcripts in mutant oocytes. Setdb1 maternally deficient embryos arrested during pre-implantation development and showed comparable defects during cell cycle progression and in chromosome segregation. Finally, transcriptional profiling data indicate that Setdb1 downregulates rather than silences expression of ERVK and ERVL-MaLR retrotransposons and associated chimearic transcripts during oogenesis. Our results identify Setdb1 as a newly discovered meiotic and embryonic competence factor safeguarding genome integrity at the onset of life. PMID:27317807

  14. Catechol-O-methyltransferase val158met polymorphism predicts placebo effect in irritable bowel syndrome.

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    Kathryn T Hall

    Full Text Available Identifying patients who are potential placebo responders has major implications for clinical practice and trial design. Catechol-O-methyltransferase (COMT, an important enzyme in dopamine catabolism plays a key role in processes associated with the placebo effect such as reward, pain, memory and learning. We hypothesized that the COMT functional val158met polymorphism, was a predictor of placebo effects and tested our hypothesis in a subset of 104 patients from a previously reported randomized controlled trial in irritable bowel syndrome (IBS. The three treatment arms from this study were: no-treatment ("waitlist", placebo treatment alone ("limited" and, placebo treatment "augmented" with a supportive patient-health care provider interaction. The primary outcome measure was change from baseline in IBS-Symptom Severity Scale (IBS-SSS after three weeks of treatment. In a regression model, the number of methionine alleles in COMT val158met was linearly related to placebo response as measured by changes in IBS-SSS (p = .035. The strongest placebo response occurred in met/met homozygotes treated in the augmented placebo arm. A smaller met/met associated effect was observed with limited placebo treatment and there was no effect in the waitlist control. These data support our hypothesis that the COMT val158met polymorphism is a potential biomarker of placebo response.

  15. Analysis of oxidative stress status, catalase and catechol-O-methyltransferase polymorphisms in Egyptian vitiligo patients.

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    Dina A Mehaney

    Full Text Available Vitiligo is the most common depigmentation disorder of the skin. Oxidative stress is implicated as one of the probable events involved in vitiligo pathogenesis possibly contributing to melanocyte destruction. Evidence indicates that certain genes including those involved in oxidative stress and melanin synthesis are crucial for development of vitiligo. This study evaluates the oxidative stress status, the role of catalase (CAT and catechol-O-Methyltransferase (COMT gene polymorphisms in the etiology of generalized vitiligo in Egyptians. Total antioxidant capacity (TAC and malondialdehyde (MDA levels as well as CAT exon 9 T/C and COMT 158 G/A polymorphisms were determined in 89 patients and 90 age and sex-matched controls. Our results showed significantly lower TAC along with higher MDA levels in vitiligo patients compared with controls. Meanwhile, genotype and allele distributions of CAT and COMT polymorphisms in cases were not significantly different from those of controls. Moreover, we found no association between both polymorphisms and vitiligo susceptibility. In conclusion, the enhanced oxidative stress with the lack of association between CAT and COMT polymorphisms and susceptibility to vitiligo in our patients suggest that mutations in other genes related to the oxidative pathway might contribute to the etiology of generalized vitiligo in Egyptian population.

  16. Sequential Inactivation of Gliotoxin by the S-Methyltransferase TmtA.

    Science.gov (United States)

    Duell, Elke R; Glaser, Manuel; Le Chapelain, Camille; Antes, Iris; Groll, Michael; Huber, Eva M

    2016-04-15

    The epipolythiodioxopiperazine (ETP) gliotoxin mediates toxicity via its reactive thiol groups and thereby contributes to virulence of the human pathogenic fungus Aspergillus fumigatus. Self-intoxication of the mold is prevented either by reversible oxidation of reduced gliotoxin or by irreversible conversion to bis(methylthio)gliotoxin. The latter is produced by the S-methyltransferase TmtA and attenuates ETP biosynthesis. Here, we report the crystal structure of TmtA in complex with S-(5'-adenosyl)-l-homocysteine. TmtA features one substrate and one cofactor binding pocket per protein, and thus, bis-thiomethylation of gliotoxin occurs sequentially. Molecular docking of substrates and products into the active site of TmtA reveals that gliotoxin forms specific interactions with the protein surroundings, and free energy calculations indicate that methylation of the C10a-SH group precedes alkylation of the C3-SH site. Altogether, TmtA is well suited to selectively convert gliotoxin and to control its biosynthesis, suggesting that homologous enzymes serve to regulate the production of their toxic natural sulfur compounds in a similar manner.

  17. 5-Methyltetrahydrofolate-homocysteine methyltransferase gene polymorphism (MTR and risk of head and neck cancer

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    A.L.S. Galbiatti

    2010-05-01

    Full Text Available The functional effect of the A>G transition at position 2756 on the MTR gene (5-methyltetrahydrofolate-homocysteine methyltransferase, involved in folate metabolism, may be a risk factor for head and neck squamous cell carcinoma (HNSCC. The frequency of MTR A2756G (rs1805087 polymorphism was compared between HNSCC patients and individuals without history of neoplasias. The association of this polymorphism with clinical histopathological parameters was evaluated. A total of 705 individuals were included in the study. The polymerase chain reaction-restriction fragment length polymorphism technique was used to genotype the polymorphism. For statistical analysis, the chi-square test (univariate analysis was used for comparisons between groups and multiple logistic regression (multivariate analysis was used for interactions between the polymorphism and risk factors and clinical histopathological parameters. Using univariate analysis, the results did not show significant differences in allelic or genotypic distributions. Multivariable analysis showed that tobacco and alcohol consumption (P < 0.05, AG genotype (P = 0.019 and G allele (P = 0.028 may be predictors of the disease and a higher frequency of the G polymorphic allele was detected in men with HNSCC compared to male controls (P = 0.008. The analysis of polymorphism regarding clinical histopathological parameters did not show any association with the primary site, aggressiveness, lymph node involvement or extension of the tumor. In conclusion, our data provide evidence that supports an association between the polymorphism and the risk of HNSCC.

  18. Arsenic (+3 oxidation state methyltransferase is a specific but replaceable factor against arsenic toxicity

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    Maki Tokumoto

    2014-01-01

    Full Text Available Inorganic metalloids, such as arsenic (As, antimony (Sb, selenium (Se, and tellurium (Te, are methylated in biota. In particular, As, Se, and Te are methylated and excreted in urine. The biomethylation is thought to be a means to detoxify the metalloids. The methylation of As is catalyzed by arsenic (+3 oxidation state methyltransferase (AS3MT. However, it is still unclear whether AS3MT catalyzes the methylation of the other metalloids. It is also unclear whether other factors catalyze the As methylation instead of AS3MT. Recombinant human AS3MT (rhAS3MT was prepared and used in the in vitro methylation of As, Se, and Te. As, but not Se and Te, was specifically methylated in the presence of rhAS3MT. Then, siRNA targeting AS3MT was introduced into human hepatocarcinoma (HepG2 cells. Although AS3MT protein expression was completely silenced by the gene knockdown, no increase in As toxicity was found in the HepG2 cells transfected with AS3MT-targeting siRNA. We conclude that AS3MT catalyzes the methylation of As and not other biomethylatable metalloids, such as Se and Te. We speculate that other methylation enzyme(s also catalyze the methylation of As in HepG2 cells.

  19. Crystal structures of the bifunctional tRNA methyltransferase Trm5a.

    Science.gov (United States)

    Wang, Caiyan; Jia, Qian; Chen, Ran; Wei, Yuming; Li, Juntao; Ma, Jie; Xie, Wei

    2016-01-01

    tRNA methyltransferase Trm5 catalyses the transfer of a methyl group from S-adenosyl-L-methionine to G37 in eukaryotes and archaea. The N1-methylated guanosine is the product of the initial step of the wyosine hypermodification, which is essential for the maintenance of the reading frame during translation. As a unique member of this enzyme family, Trm5a from Pyrococcus abyssi (PaTrm5a) catalyses not only the methylation of N1, but also the further methylation of C7 on 4-demethylwyosine at position 37 to produce isowyosine, but the mechanism for the double methylation is poorly understood. Here we report four crystal structures of PaTrm5a ranging from 1.7- to 2.3-Å, in the apo form or in complex with various SAM analogues. These structures reveal that Asp243 specifically recognises the base moiety of SAM at the active site. Interestingly, the protein in our structures all displays an extended conformation, quite different from the well-folded conformation of Trm5b from Methanocaldococcus jannaschii reported previously, despite their similar overall architectures. To rule out the possibilities of crystallisation artefacts, we conducted the fluorescence resonance energy transfer (FRET) experiments. The FRET data suggested that PaTrm5a adopts a naturally extended conformation in solution, and therefore the open conformation is a genuine state of PaTrm5a. PMID:27629654

  20. Identification and characterization of DNAzymes targeting DNA methyltransferase I for suppressing bladder cancer proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiangbo; Zhang, Lu; Ding, Nianhua; Yang, Xinghui; Zhang, Jin; He, Jiang; Li, Zhi; Sun, Lun-Quan, E-mail: lunquansun@csu.edu.cn

    2015-05-29

    Epigenetic inactivation of genes plays a critical role in many important human diseases, especially in cancer. A core mechanism for epigenetic inactivation of the genes is methylation of CpG islands in genome DNA, which is catalyzed by DNA methyltransferases (DNMTs). The inhibition of DNMTs may lead to demethylation and expression of the silenced tumor suppressor genes. Although DNMT inhibitors are currently being developed as potential anticancer agents, only limited success is achieved due to substantial toxicity. Here, we utilized a multiplex selection system to generate efficient RNA-cleaving DNAzymes targeting DNMT1. The lead molecule from the selection was shown to possess efficient kinetic profiles and high efficiency in inhibiting the enzyme activity. Transfection of the DNAzyme caused significant down-regulation of DNMT1 expression and reactivation of p16 gene, resulting in reduced cell proliferation of bladder cancers. This study provides an alternative for targeting DNMTs for potential cancer therapy. - Highlights: • Identified DNMT1-targeted DNAzymes by multiplex selection system. • Biochemically characterized a lead DNAzyme with high kinetic efficiency. • Validated DNMT1-targeted DNAzyme in its enzymatic and cellular activities.