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Cleo Pietschke, Christian Treitz, Sylvain Forêt, Annika Schultze, Sven Künzel, Andreas Tholey, Thomas C G Bosch, Sebastian Fraune
Bacterial communities colonize epithelial surfaces of most animals. Several factors, including the innate immune system, mucus composition, and diet, have been identified as determinants of host-associated bacterial communities. Here we show that the early branching metazoan Hydra is able to modify bacterial quorum-sensing signals. We identified a eukaryotic mechanism that enables Hydra to specifically modify long-chain 3-oxo-homoserine lactones into their 3-hydroxy-HSL counterparts. Expression data revealed that Hydra's main bacterial colonizer, Curvibacter sp...
September 18, 2017: Proceedings of the National Academy of Sciences of the United States of America
Marta Potrykus, Nicole Hugouvieux-Cotte-Pattat, Ewa Lojkowska
Bacteria from the genus Dickeya cause severe symptoms on numerous economically important plants. D. solani is the Dickeya species most frequently found on infected potato plants in Europe. D. solani strains from different countries show high genetic homogeneity but significant differences in their virulence level. Dickeya species possess two quorum sensing (QS) mechanisms: the Exp system based on classic N-acyl-homoserine lactone (AHL) signals and a specific system depending on the production and perception of a molecule of unknown structure, Virulence Factor Modulating (VFM)...
September 18, 2017: Molecular Plant Pathology
Duangtip Moonmangmee, Pawina Kanchanasin, Wongsakorn Phongsopitanun, Somboon Tanasupawat, Somporn Moonmangmee
A novel actinomycete, strain SR2-123T, belonging to the genus Streptomyces, was isolated from a soil sample collected from the Sakaerat Environmental Research Station, Thailand Institute of Scientific and Technological Research, Nakhon Ratchasima Province, Thailand. The taxonomic position of the strain was characterized using a polyphasic study. Strain SR2-123T contained ll-diaminopimelic acid, glucose, mannose and ribose in whole-cell hydrolysates. The N-acyl type of muramic acid was acetyl. Menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4)...
September 18, 2017: International Journal of Systematic and Evolutionary Microbiology
Tomonori Tamura, Zhining Song, Kazuma Amaike, Shin Lee, Sifei Yin, Shigeki Kiyonaka, Itaru Hamachi
Catalyst-mediated protein modification is a powerful approach for the imaging and engineering of natural proteins. We have previously developed affinity-guided 4-dimethylaminopyridine (DMAP) (AGD) chemistry as an efficient protein modification method using a catalytic acyl transfer reaction. However, because of the high electrophilicity of the thioester acyl donor molecule, AGD chemistry suffers from nonspecific reactions to proteins other than the target protein in crude biological environments, such as cell lysates, live cells, and tissue samples...
September 15, 2017: Journal of the American Chemical Society
Jessica Karlsson, Sandra Gouveia-Figueira, Mireille Alhouayek, Christopher J Fowler
Tumour necrosis factor α (TNFα) is involved in the pathogenesis of prostate cancer, a disease where disturbances in the endocannabinoid system are seen. In the present study we have investigated whether treatment of DU145 human prostate cancer cells affects anandamide (AEA) catabolic pathways. Additionally, we have investigated whether cyclooxygenase-2 (COX-2) can regulate the uptake of AEA into cells. Levels of AEA synthetic and catabolic enzymes were determined by qPCR. AEA uptake and hydrolysis in DU145 and RAW264...
2017: PloS One
Yangmin Ma, Chao Fan, Bin Jia, Pei Cheng, Jia Liu, Yuqiang Ma, Ke Qiao
Based on the spirotryprostatin A structure, a series of compounds belonging to spiro-indolyl diketopiperazine structural class were designed and synthesized, which embody an oxindole with an all-carbon quaternary stereocenter. The total synthesis can efficiently be accessed in a seven-step reaction sequence with 18-28% overall yield from commercially available materials, and a highly enantioselective 1,3-dipolar cycloaddition, N-acylation of the resulting stereochemically complex spiro[pyrrolidin-3,3'-oxindole]s core with Fmoc-L-pro-Cl and spontaneous ring closure upon N-deprotection were obtained...
September 14, 2017: Chirality
S Thirupathi Reddy, Musti J Swamy
N-Acylglycines (NAGs), the endogenous single-tailed lipids present in rat brain and other mammalian tissues, play significant roles in cell physiology and exhibit interesting pharmacological properties. In the present study, a homologous series of N-acylglycine alkyl esters (NAGEs) with matched chains were synthesized and characterized. Results of differential scanning calorimetric studies revealed that all NAGEs exhibit a single sharp phase transition and that the transition enthalpy and entropy show a linear dependence on the N-acyl and ester alkyl chain length...
September 7, 2017: Chemistry and Physics of Lipids
Guangyuan Lu, Yingzhi Xu, Kai Zhang, Yong Xiong, He Li, Lei Cui, Xianping Wang, Jizhong Lou, Yujia Zhai, Fei Sun, Xuejun C Zhang
In Gram-negative bacteria, lipid modification of proteins is catalysed in a three-step pathway. Apolipoprotein N-acyl transferase (Lnt) catalyses the third step in this pathway, whereby it transfers an acyl chain from a phospholipid to the amine group of the N-terminal cysteine residue of the apolipoprotein. Here, we report the 2.6-Å crystal structure of Escherichia coli Lnt. This enzyme contains an exo-membrane nitrilase domain fused to a transmembrane (TM) domain. The TM domain of Lnt contains eight TM helices which form a membrane-embedded cavity with a lateral opening and a periplasmic exit...
July 4, 2017: Nature Communications
Pawina Kanchanasin, Duangtip Moonmangmee, Wongsakorn Phongsopitanun, Somboon Tanasupawat, Somporn Moonmangmee
A novel actinomycete, strain SR3-134T, belonging to the genus Streptomyces, was isolated from soil collected from the Sakaerat Environmental Research Station, Thailand Institute of Scientific and Technological Research, Nakhon Ratchasima Province, Thailand. The taxonomic position of the strain was characterized by using a polyphasic approach. ll-Diaminopimelic acid, glucose, mannose and ribose were detected in its whole-cell hydrolysates. The N-acyl type of muramic acid was acetyl. The menaquinones were MK-9(H8), MK-9(H6), MK-9(H4) and MK-9(H2)...
September 8, 2017: International Journal of Systematic and Evolutionary Microbiology
Yanrong Li, Yamin Lou, Tong Mu, Aiying Ke, Zhaoshou Ran, Jilin Xu, Juanjuan Chen, Chengxu Zhou, Xiaojun Yan, Qingshan Xu, Yinghong Tan
Sphingolipid compositions are crucial for the structural and physiological properties of microalgae membranes. In the present study, we developed a quadrupole time-of-flight (Q-TOF) mass spectrometric method based on MS(E) data collection for the identification of sphingolipids with high efficiency, selectivity, sensitivity and mass accuracy and applied this method for precise structural identification and quantitative profiling of ceramides and glycosphingolipids in total lipid extracts from 17 strains of microalgae, including 11 strains of diatom, 3 strains of dinoflagellate and 3 strains of haptophyta...
September 15, 2017: Analytica Chimica Acta
Sirawit Wet-Osot, Wong Phakhodee, Mookda Pattarawarapan
5-Substituted-2-ethoxy-1,3,4-oxadiazoles were conveniently prepared through a one-pot sequential N-acylation/dehydrative cyclization between ethyl carbazate and N-acylbenzotriazoles in the presence of Ph3P-I2 as a dehydrating agent. Subsequent treatment with a stoichiometric amount of alkyl halides (X = Cl, Br, I) enables a rapid access to a variety of 3,5-disubstituted 1,3,4-oxadiazol-2(3H)-ones in good to excellent yields.
September 1, 2017: Journal of Organic Chemistry
Jan Leipert, Christian Treitz, Matthias Leippe, Andreas Tholey
N-acyl homoserine lactones (AHL) are small signal molecules involved in the quorum sensing of many gram-negative bacteria, and play an important role in biofilm formation and pathogenesis. Present analytical methods for identification and quantification of AHL require time-consuming sample preparation steps and are hampered by the lack of appropriate standards. By aiming at a fast and straightforward method for AHL analytics, we investigated the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)...
August 30, 2017: Journal of the American Society for Mass Spectrometry
Louis J Cohen, Daria Esterhazy, Seong-Hwan Kim, Christophe Lemetre, Rhiannon R Aguilar, Emma A Gordon, Amanda J Pickard, Justin R Cross, Ana B Emiliano, Sun M Han, John Chu, Xavier Vila-Farres, Jeremy Kaplitt, Aneta Rogoz, Paula Y Calle, Craig Hunter, J Kipchirchir Bitok, Sean F Brady
Commensal bacteria are believed to have important roles in human health. The mechanisms by which they affect mammalian physiology remain poorly understood, but bacterial metabolites are likely to be key components of host interactions. Here we use bioinformatics and synthetic biology to mine the human microbiota for N-acyl amides that interact with G-protein-coupled receptors (GPCRs). We found that N-acyl amide synthase genes are enriched in gastrointestinal bacteria and the lipids that they encode interact with GPCRs that regulate gastrointestinal tract physiology...
August 30, 2017: Nature
Christopher Saeui, Lingshu Liu, Esteban Urias, Justin Morrissette-McAlmon, Rahul Bhattacharya, Kevin J Yarema
In this study, we catalog structure activity relationships (SAR) of several short chain fatty acid (SCFA)-modified hexosamine analogues used in metabolic glycoengineering (MGE) by comparing in silico and experimental measurements of physiochemical properties important in drug design. We then describe the impact of these compounds on selected biological parameters that influence the pharmacological properties and safety of drug candidates by monitoring P-glycoprotein (Pgp) efflux, inhibition of cytochrome P450 3A4 (CYP3A4), hERG channel inhibition, and cardiomyocyte cytotoxicity...
August 30, 2017: Molecular Pharmaceutics
Lianguo Chen, Pei-Yuan Qian
Better understanding of the mechanisms of antifouling compounds is recognized to be of high value in establishing sensitive biomarkers, allowing the targeted optimization of antifouling compounds and guaranteeing environmental safety. Despite vigorous efforts to find new antifouling compounds, information about the mechanisms of antifouling is still scarce. This review summarizes the progress into understanding the molecular mechanisms underlying antifouling activity since 2012. Non-toxic mechanisms aimed at specific targets, including inhibitors of transmembrane transport, quorum sensing inhibitors, neurotransmission blockers, adhesive production/release inhibitors and enzyme/protein inhibitors, are put forward for natural antifouling products or shelf-stable chemicals...
August 28, 2017: Marine Drugs
Jimena E Díaz, Silvia Ranieri, Nadia Gruber, Liliana R Orelli
A straightforward strategy for the synthesis of dihydroquinazolines is presented, which allows for the preparation of 3,4- and 1,4-dihydroquinazolines with different substitution patterns from 2-aminobenzylamine (2-ABA) as common precursor. The required functionalization of both amino groups present in 2-ABA was achieved by different routes involving selective N-acylation and cesium carbonate-mediated N-alkylation reactions, avoiding protection/deprotection steps. The heterocycles were efficiently synthesized in short reaction times by microwave-assisted ring closure of the corresponding aminoamides promoted by ethyl polyphosphate (PPE)...
2017: Beilstein Journal of Organic Chemistry
Zahir Hussain, Toru Uyama, Kazuhito Tsuboi, Natsuo Ueda
Bioactive N-acylethanolamines (NAEs) are ethanolamides of long-chain fatty acids, including palmitoylethanolamide, oleoylethanolamide and anandamide. In animal tissues, NAEs are biosynthesized from membrane phospholipids. The classical "transacylation-phosphodiesterase" pathway proceeds via N-acyl-phosphatidylethanolamine (NAPE), which involves the actions of two enzymes, NAPE-generating Ca(2+)-dependent N-acyltransferase (Ca-NAT) and NAPE-hydrolyzing phospholipase D (NAPE-PLD). Recent identification of Ca-NAT as Ɛ isoform of cytosolic phospholipase A2 enabled the further molecular biological approaches toward this enzyme...
August 23, 2017: Biochimica et Biophysica Acta
Andreas Gansäuer, Yong-Qiang Zhang, Elisabeth Vogelsang, Zheng-Wang Qu, Stefan Grimme
Aziridines activated by N-acylation are opened to the higher substituted radicals through electron transfer from titanocene(III) complexes in a novel catalytic reaction. It is applicable in conjugate additions, reductions, and cyclizations and suited for the constructions of quaternary carbon centers. The concerted mechanism of ring-opening was established by DFT-methods.
August 18, 2017: Angewandte Chemie
Caili Zhang, Suqin Zhu, Abdul-Nabi Jatt, Yurong Pan, Mingyong Zeng
Shewanella spp. are the common spoilage organisms found in aquatic food products stored at low temperature and their spoilage mechanism has been reported to be mediated by quorum sensing (QS). However, the specifically expressed proteins responding to N-acyl homoserine-lactone (AHLs) were seldom reported. The present study aims to evaluate the effects of different AHL signal molecules on Shewanella putrefaciens Z4 isolated from refrigerated turbot (Scophthalmus maximus) at the proteome level. The results revealed that exogenous AHLs were utilized as QS signal molecules by S...
August 21, 2017: Letters in Applied Microbiology
Joseph P Gerdt, Danielle M Wittenwyler, Joshua B Combs, Michelle E Boursier, Jacob W Brummond, He Xu, Helen E Blackwell
Cell-cell signaling between bacteria, including quorum-sensing (QS) communication systems, may play a role in the establishment and maintenance of polymicrobial communities. To better understand and model these interactions, we must uncover the degree to which neighboring species recognize each another's signals. In the current study, we tested the likelihood of whether the QS systems of two opportunistic pathogens (Acinetobacter baumannii and Pseudomonas aeruginosa) that frequently arise in polymicrobial infections would be affected by the QS signals of neighboring species...
September 15, 2017: ACS Chemical Biology
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