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Methy donors

Fan Xiao, Ping Zhang, Ai-Hua Chen, Chun-Yan Wang, Wei Zou, Hong-Feng Gu, Xiao-Qing Tang
We have previously demonstrated the protective action of hydrogen sulfide (H2S) in 1-Methy-4-Phenylpyridinium Ion (MPP(+))-induced neurotoxicity. However, the exact mechanisms of this protection remain largely unknown. Aldehyde stress and endoplasmic reticulum (ER) stress play significant roles in the neurotoxicity of MPP(+). Brain derived neurotrophic factor (BDNF) is an important endogenous neuroprotectant. Therefore, we speculated that the protection of H2S against MPP(+) neurotoxicity results from inhibiting MPP(+)-induced aldehyde stress and ER stress via upregulation of BDNF...
October 15, 2016: Experimental Cell Research
Ahsan Ashraf, D M Nanditha M Dissanayake, David S Germack, Conan Weiland, Matthew D Eisaman
The effects of thin-film confinement on the material properties of ultrathin polymer (electron donor):fullerene (electron acceptor) bulk heterojunction films can be important for both fundamental understanding and device applications such as thin-film photovoltaics. We use variable angle spectroscopic ellipsometry and near edge X-ray absorption fine structure spectroscopy to measure the optical constants, donor-acceptor volume fraction profile, and the degree of interchain order as a function of the thickness of a poly(3-hexythiophene-2,5-diyl) and phenyl-C61-butyric acid methyl ester bulk heterojunction film...
January 28, 2014: ACS Nano
Jennifer Gerke, Ozgür Bayram, Gerhard H Braus
The filamentous fungus Aspergillus nidulans carries a single gene for the S-adenosylmethionine (SAM) synthetase SasA, whereas many other organisms possess multiple SAM synthetases. The conserved enzyme catalyzes the reaction of methionine and ATP to the ubiquitous methyl group donor SAM. SAM is the main methyl group donor for methyltransferases to modify DNA, RNA, protein, metabolites, or phospholipid target substrates. We show here that the single A. nidulans SAM synthetase encoding gene sasA is essential...
June 2012: Fungal Genetics and Biology: FG & B
Xiao-Qing Tang, Yuan-Yuan Zhuang, Li-Li Fan, Heng-Rong Fang, Cheng-Fang Zhou, Ping Zhang, Bi Hu
We previously reported that hydrogen sulfide (H(2)S) produces protection in PC12 cells during 1-methy-4-phenylpyridinium ion (MPP(+)) challenge. The present study aims to clarify the mechanisms underlying the neuroprotective effects of H(2)S. We showed that both glybenclamide, an ATP-sensitive potassium (K(ATP)) channel blocker, and LY294002, a specific PI(3)K-AKT pathway inhibitor, reversed the neuroprotective effect of NaHS (a H(2)S donor) against MPP(+)-induced cytotoxicity to PC12 cells and that NaHS up-regulated the activity of AKT in PC12 cells, which was abolished by blockade of K(ATP) channels with glybenclamide...
February 2012: Journal of Molecular Neuroscience: MN
Hiroyuki Akita
This review summarizes the chemoenzymatic synthesis of the biologically active natural products based on a combination of chemical diastereoselectivity and enzymatic enantioselectivity using biocatalyst. Asymmetric reduction of 2-methyl-3-keto ester with yeast gave the optically active syn-2-methyl-3-hydroxy ester, which was converted to natural product such as (-)-oudemansin B. Asymmetric hydrolysis of 3-acetoxy-2-methy esters possessing syn- or anti-structure afforded the optically active 3-hydroxy-2-methyl esters and 3-acetoxy-2-methy esters corresponding to the starting material...
February 2011: Yakugaku Zasshi: Journal of the Pharmaceutical Society of Japan
Shinjinee Sengupta, Paramita Chaudhuri, Sagar Lahiri, Trina Dutta, Shakri Banerjee, Ramdhan Majhi, Anil K Ghosh
The current study was undertaken to correlate post-translational protein modification by methylation with the functionality of enzymes involved in trehalose metabolism in Saccharomyces cerevisiae. Trehalose is an economically important disaccharide providing protection against various kinds of stresses. It also acts as a source of cellular energy by storing glucose. Methyl group donor S-adenosyl L-methionine (AdoMet) and methylation inhibitor-oxidized adenosine (AdOx) were used for the methylation study. AdoMet delayed initial growth of the cells but the overall growth rate remained same suggesting its interference in G1 phase of the cell cycle...
January 2011: Journal of Cellular Physiology
Xiao-Qing Tang, Li-Li Fan, Yu-Juan Li, Xin-Tian Shen, Yuan-Yuan Zhuan, Jian-Qin He, Jin-Hua Xu, Bi Hu, Yuan-Jian Li
Reactive oxygen species (ROS) overproduction contributes to the neurotoxicity of 1-methy-4-phenylpyridinium ion (MPP(+)). Increasing studies have shown that hydrogen sulfide (H(2)S) is an endogenous antioxidant gas. We have hypothesized that MPP(+)-caused neurotoxicity may involve the imbalance of proportion to this endogenous protective antioxidant gas. The aim of this study is to evaluate whether MPP(+) disturbs H(2)S synthesis in PC12 cells, a clonal rat pheochromocytoma cell line, and whether disturbance of H(2)S generation induced by MPP(+) is an underlying mechanism of MPP(+)-induced neurotoxicity...
April 2011: Neurotoxicity Research
Steven T Pullan, Mark D Gidley, Richard A Jones, Jason Barrett, Tania M Stevanin, Robert C Read, Jeffrey Green, Robert K Poole
We previously elucidated the global transcriptional responses of Escherichia coli to the nitrosating agent S-nitrosoglutathione (GSNO) in both aerobic and anaerobic chemostats, demonstrated the expression of nitric oxide (NO)-protective mechanisms, and obtained evidence of critical thiol nitrosation. The present study was the first to examine the transcriptome of NO-exposed E. coli in a chemostat. Using identical conditions, we compared the GSNO stimulon with the stimulon of NO released from two NO donor compounds {3-[2-hydroxy-1-(1-methyl-ethyl)-2-nitrosohydrazino]-1-propanamine (NOC-5) and 3-(2-hydroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-propanamine (NOC-7)} simultaneously and demonstrated that there were marked differences in the transcriptional responses to these distinct nitrosative stresses...
March 2007: Journal of Bacteriology
U P Kelavkar, N S Harya, J Hutzley, D J Bacich, F A Monzon, U Chandran, R Dhir, D S O'Keefe
Fifteen (15)-lipoxygenase type 1 (15-LO-1, ALOX15), a highly regulated, tissue- and cell-type-specific lipid-peroxidating enzyme has several functions ranging from physiological membrane remodeling, pathogenesis of atherosclerosis, inflammation and carcinogenesis. Several of our findings support a possible role for 15-LO-1 in prostate cancer (PCa) tumorigenesis. In the present study, we identified a CpG island in the 15-LO-1 promoter and demonstrate that the methylation status of a specific CpG within this island region is associated with transcriptional activation or repression of the 15-LO-1 gene...
January 2007: Prostaglandins & Other Lipid Mediators
Osama A Badary, Azza S Awad, Sahar Abdel-Maksoud, Farid M A Hamada
1. Doxorubicin (DOX), a standard chemotherapeutic anthracycline agent, causes a positive inotropic effect in guinea-pig isolated atria in a concentration-dependent manner with an ED(50) of 3.6 micromol/L. This increase in contractility is strictly related to the generation of reactive oxygen species (ROS) as a consequence of quinone metabolism. The ED(50) of DOX is significantly increased (P < 0.05) in the presence of 150 U superoxide dismutase (SOD). In the heart, DOX may be subjected to one- or two-electron reductions catalysed by flavoenzymes in the presence of suitable electron donors...
December 2004: Clinical and Experimental Pharmacology & Physiology
H L Zhao, J Zang, Z Y Li, X Zhang, S Jiang, J Liu, X Wei, Y He
Peripheral blood lymphocytes (PBL) were obtained from healthy donors and treated with L-leucy-leucin methy (LeuLeu-OMe). The LeuLeu-OMe treated PBL were in vitro immunized with HFRS virus proteins (55kD, 67kD) for 6 days, and then fused with K6H6/B5 cells in medium containing 45% (PEG) and 7.5% DMSO. The fused cells were seeded in 96-well plates at cell density 0.5-1 x 10(5) cells/well in HAT supplemented RPMI-1640 medium. After 14-20 days, 3 positive wells were deteced by ELISA and two (1B7, 2D5) of the 3 hybridoma were stable after 4 time cloning...
March 1997: Chinese Journal of Experimental and Clinical Virology
C Bott, B Lembcke, J Stein
Nutritional factors are important contributors to colorectal cancer prevention. There is some evidence to suggest that a high dietary folate intake is associated with a reduced risk of colorectal cancer. Folate, which is found in green leafy vegetables, is involved in C1 group transfer and contributes to purin and thymi-dilate synthesis as well as to DNA methylation. Alterations in gene expression and DNA damage are discussed to result from low folate levels and might be associated with an elevated risk of colorectal malignancies...
March 2003: Zeitschrift Für Gastroenterologie
Robert M Bell, Helen L Maddock, Derek M Yellon
OBJECTIVE: Nitric oxide (NO) is reported to be both protective and detrimental in models of myocardial ischaemia/reperfusion injury, which may be concentration dependent. Our objective was to characterise this dichotomy using the nitric oxide donor, S-nitroso N-acetyl penicillamine (SNAP) in isolated perfused mouse heart and isolated mouse cardiac mitochondria. METHODS: To determine the effect of nitric oxide concentration on myocardial viability, isolated mouse hearts were subjected to 35 min global ischaemia and 30 min reperfusion in the presence of SNAP (0...
February 2003: Cardiovascular Research
Matiías A Avila, Elena R García-Trevijano, María L Martínez-Chantar, M Ujue Latasa, Isabel Pérez-Mato, L A Martínez-Cruz, Manuel M del Pino, Fernando J Corrales, José M Mato
Dietary methionine is mainly metabolized in the liver where it is converted into S-adenosylmethionine (AdoMet), the main biologic methyl donor. This reaction is catalyzed by methionine adenosyltransferase I/III (MAT I/III), the product of MAT1A gene, which is exclusively expressed in this organ. It was first observed that serum methionine levels were elevated in experimental models of liver damage and in liver cirrhosis in human beings. Results of further studies showed that this pathological alteration was due to reduced MAT1A gene expression and MAT I/III enzyme inactivation associated with liver injury...
July 2002: Alcohol
Kathryn R Lawson, Sarah Marek, Jennifer A Linehan, Patrick M Woster, Robert A Casero, Claire M Payne, Eugene W Gerner
PURPOSE: Analogues of the naturally occurring polyamines, alkylated on both terminal amines, are being developed as anticancer drugs. Because bisalkylated derivatives of putrescine (1,4-diaminobutane) are potent inhibitors of the flavin adenine dinucleotide-dependent polyamine oxidase (PAO), we asked whether PAO could detoxify synthetic bisalkylated polyamines with chain lengths longer than putrescine. EXPERIMENTAL DESIGN: We investigated the effects of one polyamine analogue in Chinese hamster ovary (CHO) and HCT116 human colon tumor-derived cells, which express dramatically different levels of PAO activity, and in these same cells treated with an inhibitor of PAO...
May 2002: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
E R García-Trevijano, M U Latasa, M V Carretero, C Berasain, J M Mato, M A Avila
Methionine metabolism starts with the formation of S-adenosylmethionine (AdoMet), the most important biological methyl donor. This reaction is catalyzed by methionine adenosyltransferase (MAT). MAT is the product of two different genes: MAT1A, which is expressed only in the adult liver, and MAT2A, which is widely distributed, expressed in the fetal liver, and replaces MAT1A in hepatocarcinoma. In the liver, preservation of high expression of MAT1A and low expression of MAT2A is critical for the maintenance of a functional and differentiated organ...
December 2000: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
A Nyyssola, J Kerovuo, P Kaukinen, N von Weymarn, T Reinikainen
Glycine betaine is a compatible solute, which is able to restore and maintain osmotic balance of living cells. It is synthesized and accumulated in response to abiotic stress. Betaine acts also as a methyl group donor and has a number of important applications including its use as a feed additive. The known biosynthetic pathways of betaine are universal and very well characterized. A number of enzymes catalyzing the two-step oxidation of choline to betaine have been isolated. In this work we have studied a novel betaine biosynthetic pathway in two phylogenically distant extreme halophiles, Actinopolyspora halophila and Ectothiorhodospira halochloris...
July 21, 2000: Journal of Biological Chemistry
H Tsukahara, E Noiri, M Z Jiang, M Hiraoka, M Mayumi
We examined the effect of nitric oxide (NO) on cell adhesion using cultured human pulmonary microvascular endothelial cells (PMVEC). Attachment of these cells to fibronectin was significantly inhibited by NO donors, spermine NONOate and S-nitroso-N-acetyl-penicillamine or L-arginine, but not 8-bromoguanosine-3',5'-cyclic-monophosphate. Similar results were obtained with the electrical cell-substrate impedance sensor (ECIS) technique. Addition of NO donors or L-arginine, but not 8-bromoguanosine-3',5'-cyclic-monophosphate or N2,2'-O-dibutyrylguanosine-3',5'-cyclic-monophosphate, to confluent PMVEC monolayers resulted in a transient decrease in cell adhesion, which was quantitated by the ECIS...
May 26, 2000: Life Sciences
Y Takehara, H Nakahara, S Okada, K Yamaoka, K Hamazaki, A Yamazato, M Inoue, K Utsumi
Nitric oxide (NO) functions as an endothelium-derived relaxation factor and regulates vascular resistance. Recent studies in this laboratory(Arch.Biochem.Biophys.323, 27-32, 1995) revealed that the lifetime of NO significantly increased at physiologically low levels of oxygen concentrations and, hence, this gaseous radical strongly inhibited mitochondrial electron transport for a fairly long duration at low oxygen concentrations. The present work describes the effect of oxygen concentration on NO-induced relaxation and guanylate cyclase (GC) activity of endothelium-denuded aorta of the rat...
April 1999: Free Radical Research
K Vaali, L Li, I Paakkari, H Vapaatalo
The relaxing effects of the nitric oxide (NO) donors 1,2,3,4-oxatriazolium,3-(3-chloro-2-methylphenyl-5-[[(4-methoxyphe nyl) sulfonyl]amino]-,hydroxide inner salt (GEA 3268) 1,2,3,4-oxatriazolium,3-(3-chloro-2-methyphenyl-5-[methys ulfonyl)amino]- hydroxide inner salt (GEA 5145), 3-morpholinosydnonimine (SIN-1) and S-nitroso-N-acetylpenicillamine (SNAP) were inhibited in vitro by iberiotoxin (IbTX) and charybdotoxin (ChTX), the two selective inhibitors of Ca(++)-activated K+ channels (KCa) in guinea pig trachea...
July 1998: Journal of Pharmacology and Experimental Therapeutics
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