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S-Adenosyl methionine

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https://www.readbyqxmd.com/read/29779660/in-vitro-analysis-of-cyanobacterial-nonheme-iron-dependent-aliphatic-halogenases-welo5-and-ambo5
#1
Xinyu Liu
Aliphatic carbon-halogen (C-X) bonds are prevalent in modern pharmaceuticals and bioactive natural products. Three distinct chemical strategies are known in Nature to generate these structural motifs. The first is via the nucleophilic substitution at a prefunctionalized electrophilic carbon center with a halide anion (X- ), known for the S-adenosyl-l-methionine-dependent halogenases. The second is via the electrophilic activation of an alkene or its equivalent by a halenium ion (X+ ) donor, known for the haloperoxidases and flavin-dependent halogenases...
2018: Methods in Enzymology
https://www.readbyqxmd.com/read/29779659/preparation-assay-and-application-of-chlorinase-sall-for-the-chemoenzymatic-synthesis-of-s-adenosyl-l-methionine-and-analogs
#2
Tony D Davis, Sylvia Kunakom, Michael D Burkart, Alessandra S Eustaquio
S-adenosyl-l-methionine (SAM) is universal in biology, serving as the second most common cofactor in a variety of enzymatic reactions. One of the main roles of SAM is the methylation of nucleic acids, proteins, and metabolites. Methylation often imparts regulatory control to DNA and proteins, and leads to an increase in the activity of specialized metabolites such as those developed as pharmaceuticals. There has been increased interest in using SAM analogs in methyltransferase-catalyzed modification of biomolecules...
2018: Methods in Enzymology
https://www.readbyqxmd.com/read/29777905/coupling-of-the-polyamine-and-iron-metabolism-pathways-in-the-regulation-of-proliferation-mechanistic-links-to-alterations-in-key-polyamine-biosynthetic-and-catabolic-enzymes
#3
Darius J R Lane, Dong-Hun Bae, Aritee R Siafakas, Yohan Suryo Rahmanto, Lina Al-Akra, Patric J Jansson, Robert A Casero, Des R Richardson
Many biological processes result from the coupling of metabolic pathways. Considering this, proliferation depends on adequate iron and polyamines, and although iron-depletion impairs proliferation, the metabolic link between iron and polyamine metabolism has never been thoroughly investigated. This is important to decipher, as many disease states demonstrate co-dysregulation of iron and polyamine metabolism. Herein, for the first time, we demonstrate that cellular iron levels robustly regulate 13 polyamine pathway proteins...
May 16, 2018: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29772716/kinetic-basis-of-the-bifunctionality-of-ssoii-dna-methyltransferase
#4
Nadezhda A Timofeyeva, Alexandra Yu Ryazanova, Maxim V Norkin, Tatiana S Oretskaya, Olga S Fedorova, Elena A Kubareva
Type II restriction⁻modification (RM) systems are the most widespread bacterial antiviral defence mechanisms. DNA methyltransferase SsoII (M.SsoII) from a Type II RM system SsoII regulates transcription in its own RM system in addition to the methylation function. DNA with a so-called regulatory site inhibits the M.SsoII methylation activity. Using circular permutation assay, we show that M.SsoII monomer induces DNA bending of 31° at the methylation site and 46° at the regulatory site. In the M.SsoII dimer bound to the regulatory site, both protein subunits make equal contributions to the DNA bending, and both angles are in the same plane...
May 16, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29768681/alkyl-radical-generation-by-an-intramolecular-homolytic-substitution-reaction-between-iron-ii-and-trialkylsulfonium-groups
#5
Stefan Jungen, Peter Chen
Intramolecular, homolytic substitution reactions between iron (II) species and various trialkylsulfonium groups were directly observed in the gas phase upon collision induced dissociation. In spite of the notoriously low reduction potential of trialkylsulfonium species and the mismatched oxidation potential of iron (II), the reactions proceed at moderate collision energies, forming an alkyl radical as well as a thioether coordinated to the iron. In contrast to classical homolytic substitutions, the attacking radical is a "metalloradical", namely iron (II) that is oxidized to iron (III) during the reaction...
May 16, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29758036/benzoxaborole-treatment-perturbs-s-adenosyl-l-methionine-metabolism-in-trypanosoma-brucei
#6
Pieter C Steketee, Isabel M Vincent, Fiona Achcar, Federica Giordani, Dong-Hyun Kim, Darren J Creek, Yvonne Freund, Robert Jacobs, Kevin Rattigan, David Horn, Mark C Field, Annette MacLeod, Michael P Barrett
The parasitic protozoan Trypanosoma brucei causes Human African Trypanosomiasis and Nagana in other mammals. These diseases present a major socio-economic burden to large areas of sub-Saharan Africa. Current therapies involve complex and toxic regimens, which can lead to fatal side-effects. In addition, there is emerging evidence for drug resistance. AN5568 (SCYX-7158) is a novel benzoxaborole class compound that has been selected as a lead compound for the treatment of HAT, and has demonstrated effective clearance of both early and late stage trypanosomiasis in vivo...
May 14, 2018: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/29751745/randomized-dna-libraries-construction-tool-a-new-3-bp-frequent-cutter-tthhb27i-sinefungin-endonuclease-with-chemically-induced-specificity
#7
Daria Krefft, Aliaksei Papkov, Maciej Prusinowski, Agnieszka Zylicz-Stachula, Piotr M Skowron
BACKGROUND: Acoustic or hydrodynamic shearing, sonication and enzymatic digestion are used to fragment DNA. However, these methods have several disadvantages, such as DNA damage, difficulties in fragmentation control, irreproducibility and under-representation of some DNA segments. The DNA fragmentation tool would be a gentle enzymatic method, offering cleavage frequency high enough to eliminate DNA fragments distribution bias and allow for easy control of partial digests. Only three such frequently cleaving natural restriction endonucleases (REases) were discovered: CviJI, SetI and FaiI...
May 11, 2018: BMC Genomics
https://www.readbyqxmd.com/read/29743535/identification-of-a-unique-radical-sam-methyltransferase-required-for-the-sp-3-c-methylation-of-an-arginine-residue-of-methyl-coenzyme-m-reductase
#8
Darja Deobald, Lorenz Adrian, Christian Schöne, Michael Rother, Gunhild Layer
The biological formation of methane (methanogenesis) is a globally important process, which is exploited in biogas technology, but also contributes to global warming through the release of a potent greenhouse gas into the atmosphere. The last and methane-releasing step of methanogenesis is catalysed by the enzyme methyl-coenzyme M reductase (MCR), which carries several exceptional posttranslational amino acid modifications. Among these, a 5-C-(S)-methylarginine is located close to the active site of the enzyme...
May 9, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29731364/covalent-inhibitors-of-nicotinamide-n-methyltransferase-nnmt-provide-evidence-for-target-engagement-challenges-in-situ
#9
Hsin-Yu Lee, Radu M Suciu, Benjamin D Horning, Ekaterina V Vinogradova, Olesya A Ulanovskaya, Benjamin F Cravatt
Nicotinamide N-methyltransferase (NNMT) catalyzes the N-methylation of nicotinamide using S-adenosyl-L-methionine (SAM) as a methyl donor and, through doing so, can modulate cellular methylation potential to impact diverse epigenetic processes. NNMT has been implicated in a range of diseases, including cancer and metabolic disorders. Potent, selective, and cell-active inhibitors would constitute valuable probes to study the biological functions and therapeutic potential of NNMT. We previously reported the discovery of electrophilic small molecules that inhibit NNMT by reacting with an active-site cysteine residue in the SAM-binding pocket...
April 10, 2018: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/29689291/dynamic-gene-amplification-and-function-diversification-of-grass-specific-o-methyltransferase-gene-family
#10
Zhen Liu, Miao Fan, Chao Li, Jian-Hong Xu
The plant O-methyltransferases are dependent on S-Adenosyl-l-methionine, which can catalyze a variety of secondary metabolites. Here we identified different number of OMT genes from the respective grass genomes. Phylogenetic analysis showed that this OMT gene family is a grass-specific gene family that is different from COMT. Most of genes were expanded by tandem and segment duplication after the species split from their progenitor. Furthermore, genes from Group I and two clusters from group II are only present in Panicoideae, which included Bx10 and Bx7 involved in the benzoxazinoids pathway, suggesting these genes could participate in insect resistance in Panicoideae...
April 21, 2018: Genomics
https://www.readbyqxmd.com/read/29687201/folate-promotes-s-adenosyl-methionine-reactions-and-the-microbial-methylation-cycle-and-boosts-ruminants-production-and-reproduction
#11
REVIEW
Imtiaz Hussain Raja Abbasi, Farzana Abbasi, Lamei Wang, Mohamed E Abd El Hack, Ayman A Swelum, Ren Hao, Junhu Yao, Yangchun Cao
Folate has gained significant attention due to its vital role in biological methylation and epigenetic machinery. Folate, or vitamin (B9 ), is only produced through a de novo mechanism by plants and micro-organisms in the rumen of mature animals. Although limited research has been conducted on folate in ruminants, it has been noted that ruminal synthesis could not maintain folate levels in high yielding dairy animals. Folate has an essential role in one-carbon metabolism and is a strong antiproliferative agent...
April 23, 2018: AMB Express
https://www.readbyqxmd.com/read/29685976/hijacking-dna-methyltransferase-transition-state-analogues-to-produce-chemical-scaffolds-for-prmt-inhibitors
#12
Ludovic Halby, Nils Marechal, Dany Pechalrieu, Vincent Cura, Don-Marc Franchini, Céline Faux, Fréderic Alby, Nathalie Troffer-Charlier, Srikanth Kudithipudi, Albert Jeltsch, Wahiba Aouadi, Etienne Decroly, Jean-Claude Guillemot, Patrick Page, Clotilde Ferroud, Luc Bonnefond, Dominique Guianvarc'h, Jean Cavarelli, Paola B Arimondo
DNA, RNA and histone methylation is implicated in various human diseases such as cancer or viral infections, playing a major role in cell process regulation, especially in modulation of gene expression. Here we developed a convergent synthetic pathway starting from a protected bromomethylcytosine derivative to synthesize transition state analogues of the DNA methyltransferases. This approach led to seven 5-methylcytosine-adenosine compounds that were, surprisingly, inactive against hDNMT1, hDNMT3Acat, TRDMT1 and other RNA human and viral methyltransferases...
June 5, 2018: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/29683981/chronic-liver-diseases-and-the-potential-use-of-s-adenosyl-l-methionine-as-a-hepatoprotector
#13
Silvia I Mora, Jonathan García-Román, Iván Gómez-Ñañez, Rebeca García-Román
Chronic liver diseases result in overall deterioration of health status and changes in metabolism. The search for strategies to control and combat these hepatic diseases has witnessed a great boom in the last decades. Nutritional therapy for controlling and managing liver diseases may be a positive influence as it improves the function of the liver. In this review, we focus mainly on describing liver conditions such as nonalcoholic fatty liver disease, and intrahepatic cholestasis as well as using S-adenosyl-L-methionine as a dietary supplement and its potential alternative therapeutic effect to correct the hepatic dysfunction associated with these conditions...
April 20, 2018: European Journal of Gastroenterology & Hepatology
https://www.readbyqxmd.com/read/29662207/tracing-the-ninth-sulfur-of-the-nitrogenase-cofactor-via-a-semi-synthetic-approach
#14
Kazuki Tanifuji, Chi Chung Lee, Nathaniel S Sickerman, Kazuyuki Tatsumi, Yasuhiro Ohki, Yilin Hu, Markus W Ribbe
The M-cluster is the [(homocitrate)MoFe7 S9 C] active site of nitrogenase that is derived from an 8Fe core assembled viacoupling and rearrangement of two [Fe4 S4 ] clusters concomitant with the insertion of an interstitial carbon and a 'ninth sulfur'. Combining synthetic [Fe4 S4 ] clusters with an assembly protein template, here we show that sulfite can give rise to the ninth sulfur that is incorporated in the catalytically important belt region of the cofactor after the radical S-adenosyl-L-methionine-dependent carbide insertion and the concurrent 8Fe-core rearrangement have already taken place...
April 16, 2018: Nature Chemistry
https://www.readbyqxmd.com/read/29619168/a-benzylic-linker-promotes-methyltransferase-catalyzed-norbornene-transfer-for-rapid-bioorthogonal-tetrazine-ligation
#15
F Muttach, N Muthmann, D Reichert, L Anhäuser, A Rentmeister
Site-specific alkylation of complex biomolecules is critical for late-stage product diversification as well as post-synthetic labeling and manipulation of proteins and nucleic acids. Promiscuous methyltransferases in combination with analogs of S -adenosyl-l-methionine (AdoMet) can functionalize all major classes of biomolecules. We show that benzylic moieties are transferred by Ecm1 with higher catalytic efficiency than the natural AdoMet. A relative specificity of up to 80% is achieved when a norbornene moiety is placed in para -position, enabling for the first time enzymatic norbornene transfer to specific positions in DNA and RNA- even in cell lysate...
December 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/29604896/the-multi-state-energy-landscape-of-the-sam-i-riboswitch-a-single-molecule-f%C3%A3-rster-resonance-energy-transfer-spectroscopy-study
#16
Christoph Manz, Andrei Yu Kobitski, Ayan Samanta, Andres Jäschke, G Ulrich Nienhaus
RNA (ribonucleic acid) molecules are highly flexible biopolymers fluctuating at physiological temperatures among many different conformations that are represented by minima in a hierarchical conformational free energy landscape. Here we have employed single-molecule FRET (smFRET) to explore the energy landscape of the B. subtilis yitJ SAM-I riboswitch (RS). In this small RNA molecule, specific binding of an S-adenosyl-L-methionine (SAM) ligand in the aptamer domain regulates gene expression by inducing structural changes in another domain, the expression platform, causing transcription termination by the RNA polymerase...
March 28, 2018: Journal of Chemical Physics
https://www.readbyqxmd.com/read/29572390/methionine-adenosyltransferase-4-mediates-dna-and-histone-methylation
#17
Jingjing Meng, Lishuan Wang, Jingyi Wang, Xiaowen Zhao, Jinkui Cheng, Wenxiang Yu, Dan Jin, Qing Li, Zhizhong Gong
DNA and histone methylation co-regulate heterochromatin formation and gene silencing in animals and plants. To identify factors involved in maintaining gene silencing, we conducted a forward genetic screen for mutants that release the silenced transgene Pro35S::NEOMYCIN PHOSPHOTRANSFERASE II in the transgenic Arabidopsis thaliana line L119. We identified MAT4/SAMS3/MTO3/AT3G17390, which encodes methionine adenosyltransferase 4 (MAT4)/S-adenosyl-methionine synthetase 3 that catalyzes the synthesis of S-adenosyl-methionine (SAM) in the one-carbon metabolism cycle...
March 23, 2018: Plant Physiology
https://www.readbyqxmd.com/read/29566247/increased-polyamines-as-protective-disease-modifiers-in-congenital-muscular-dystrophy
#18
D U Kemaladewi, J S Benjamin, E Hyatt, E A Ivakine, R D Cohn
Most Mendelian disorders, including neuromuscular disorders, display extensive clinical heterogeneity that cannot be solely explained by primary genetic mutations. This phenotypic variability is largely attributed to the presence of disease modifiers, which can exacerbate or lessen the severity and progression of the disease.LAMA2-deficient Congenital Muscular Dystrophy (LAMA2-CMD) is a fatal degenerative muscle disease resulting from mutations in the LAMA2 gene encoding Laminin-α2. Progressive muscle weakness is predominantly observed in the lower limbs in LAMA2-CMD patients, whereas upper limbs muscles are significantly less affected...
March 15, 2018: Human Molecular Genetics
https://www.readbyqxmd.com/read/29531009/-communication-melatonin-hyperhomocysteinemia-thioretinaco-ozonide-adenosylmethionine-and-mitochondrial-dysfunction-in-aging-and-dementia
#19
Kilmer S McCully
The indoleamine hormone melatonin is synthesized by the pineal gland, controls circadian rhythm, and is dependent upon adenosyl methionine for enzymatic synthesis of melatonin from N-acetyl serotonin. Pineal melatonin secretion declines dramatically with aging and dementia. Elevated plasma homocysteine is a risk factor for atherosclerosis and Alzheimer's disease, and the marked decline in adenosyl methionine with aging leads to dysregulation of methionine metabolism and hyperhomocysteinemia. Thioretinaco ozonide is a disulfonium complex formed from thioretinamide, cobalamin, and ozone, which binds the alpha and gamma-phosphate groups of adenosine triphosphate (ATP) and oxygen in the process of oxidative phosphorylation within mitochondria...
January 2018: Annals of Clinical and Laboratory Science
https://www.readbyqxmd.com/read/29523717/polyamines-regulate-strawberry-fruit-ripening-by-abscisic-acid-auxin-and-ethylene
#20
Jiaxuan Guo, Shufang Wang, Xiaoyang Yu, Rui Dong, Yuzhong Li, Xurong Mei, Yuanyue Shen
Polyamines (PAs) participate in many plant growth and developmental processes, including fruit ripening. However, it is not clear whether PAs play a role in the ripening of strawberry ( Fragaria ananassa ), a model nonclimacteric plant. Here, we found that the content of the PA spermine (Spm) increased more sharply after the onset of fruit coloration than did that of the PAs putrescine (Put) or spermidine (Spd). Spm dominance in ripe fruit resulted from abundant transcripts of a strawberry S -adenosyl-l-Met decarboxylase gene ( FaSAMDC ), which encodes an enzyme that generates a residue needed for PA biosynthesis...
May 2018: Plant Physiology
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