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Ibrahim Halil Bahcecioglu, Abdurrahman Sahin
Hepatitis delta virus (HDV) is a defective satellite virus and propagates in the presence of Hepatitis B virus (HBV) surface antigen (HBsAg). Approximately 5% of the people who infected with HBV are also infected with HDV. Chronic hepatitis caused by delta is the most severe form of chronic viral hepatitis including accelerated fibrosis, liver decompensation and development of hepatocellular carcinoma. Interferon-based therapies still remain the only treatment option of the hepatitis delta. The beneficiary effects of the interferon-based therapies, however, stop frequently with termination of the given therapy and relapse rate is very high...
January 16, 2017: Infectious Diseases
Io Antonopoulou, Laura Leonov, Peter Jütten, Gabriella Cerullo, Vincenza Faraco, Adamantia Papadopoulou, Dimitris Kletsas, Marianna Ralli, Ulrika Rova, Paul Christakopoulos
Five feruloyl esterases (FAEs; EC, FaeA1, FaeA2, FaeB1, and FaeB2 from Myceliophthora thermophila C1 and MtFae1a from M. thermophila ATCC 42464, were tested for their ability to catalyze the transesterification of vinyl ferulate (VFA) with prenol in detergentless microemulsions. Reaction conditions were optimized investigating parameters such as the medium composition, the substrate concentration, the enzyme load, the pH, the temperature, and agitation. FaeB2 offered the highest transesterification yield (71...
January 11, 2017: Applied Microbiology and Biotechnology
B Zhao, W Hu, S Kumar, P Gonyo, U Rana, Z Liu, B Wang, W Q Duong, Z Yang, C L Williams, Q R Miao
The localization of prenylated Ras at the plasma membrane promotes activation of Ras by receptor tyrosine kinases and stimulates oncogenic signaling by mutant Ras. The Nogo-B receptor (NgBR) is a transmembrane receptor that contains a conserved hydrophobic pocket. Here, we demonstrate that the NgBR promotes the membrane accumulation of Ras by directly binding prenylated Ras at the plasma membrane. We show that NgBR knockdown diminishes the membrane localization of Ras in multiple cell types. NgBR overexpression in NIH-3T3 fibroblasts increases membrane-associated Ras, induces the transformed phenotype in vitro, and promotes the formation of fibrosarcoma in nude mice...
January 9, 2017: Oncogene
Mai H El-Naggar, Amira Mira, Fatma M Abdel Bar, Kuniyoshi Shimizu, Mohamed M Amer, Farid A Badria
Leukotriene A4 hydrolase (LTA4H) is a proinflammatory enzyme that generates the inflammatory mediator leukotriene which may play an important role in chronic inflammation associated carcinogenesis. [6]-gingerol, the major bioactive compound of Zingiber officinale, is a potential inhibitor of LTA4H, a highly expressed enzyme in colorectal carcinoma. Eighteen compounds; seven of natural origin (including [4]-, [6]-, [8]-, and [10]-gingerol), five new and six known semi-synthesized [6]-gingerol derivatives were examined using docking, in vitro cytotoxicity against human colon cancer cells (HCT-116) and LTA4H aminopeptidase and epoxide hydrolase inhibitory studies...
December 29, 2016: Bioorganic & Medicinal Chemistry
Kajal Chakraborty, Vamshi Krishna Raola
Two oleanenes, olean-18(19)-en-3β-yl-(3,6-dimethyl-3E,6Z-dienoate) and (13α)-27-frido-olean-14(15)-en-(17α)-furanyl-3β-ol representing a class of rare natural pentacyclic triterpenoids were isolated from the chloroform extract of Asiatic mangrove, Rhizophora mucronata Lam. (Family: Rhizophoraceae). The furanyl oleanene exhibited significantly greater antioxidative activities (IC50 0.73-0.76 mg/mL), than prenylated oleanene (IC50 0.84-0.96 mg/mL) (P < 0.05). No significant differences in anti-5-lipoxygenase activities of these compounds with the synthetic drug ibuprofen was discernable (IC50 0...
January 3, 2017: Phytochemistry
Adam Oesterle, Ulrich Laufs, James K Liao
The statins have been used for 30 years to prevent coronary artery disease and stroke. Their primary mechanism of action is the lowering of serum cholesterol through inhibiting hepatic cholesterol biosynthesis thereby upregulating the hepatic low-density lipoprotein (LDL) receptors and increasing the clearance of LDL-cholesterol. Statins may exert cardiovascular protective effects that are independent of LDL-cholesterol lowering called pleiotropic effects. Because statins inhibit the production of isoprenoid intermediates in the cholesterol biosynthetic pathway, the post-translational prenylation of small GTP-binding proteins such as Rho and Rac, and their downstream effectors such as Rho kinase and nicotinamide adenine dinucleotide phosphate oxidases are also inhibited...
January 6, 2017: Circulation Research
Stephen A Marshall, Karl Fisher, Aisling Ni Cheallaigh, Mark D White, Karl A P Payne, D A Parker, Stephen E J Rigby, David Leys
The activity of the reversible decarboxylase enzyme Fdc1 is dependent on prenylated FMN (prFMN), a recently discovered cofactor. The oxidized prFMN supports a 1,3-dipolar cycloaddition mechanism that underpins reversible decarboxylation. Fdc1 is a distinct member of the UbiD family of enzymes, with the canonical UbiD catalyzing the (de)carboxylation of para-hydroxybenzoic acid-type substrates. Here we show that the Escherichia coli UbiD enzyme, which is implicated in ubiquinone biosynthesis, cannot be isolated in an active holo-enzyme form, despite the fact active holo-Fdc1 is readily obtained...
January 5, 2017: Journal of Biological Chemistry
Matthias P Müller, Roger S Goody
Rab proteins are the major regulators of vesicular trafficking in eukaryotic cells. Their activity can be tightly controlled within cells: Regulated by guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), they switch between an active GTP-bound state and an inactive GDP-bound state, interacting with downstream effector proteins only in the active state. Additionally, they can bind to membranes via C-terminal prenylated cysteine residues and they can be solubilized and shuttled between membranes by chaperone-like molecules called GDP dissociation inhibitors (GDIs)...
January 5, 2017: Small GTPases
Inna Abramova, Benjamin Rudshteyn, Joel F Liebman, Alexander Greer
Hyperforin is a constituent of St. John's wort and coexists with the singlet oxygen sensitizer hypericin. Density functional theory, molecular mechanics and Connolly surface calculations show that accessibility in the singlet oxygen 'ene' reaction favors the hyperforin "southwest" and "southeast" prenyl (2-methyl-2-butenyl) groups over the northern prenyl groups. While the southern part of hyperforin is initially more susceptible to oxidation, up to 4 'ene' reactions of singlet oxygen can take place. Computational results assist in predicting the fate of adjacent hydroperoxides in hyperforin, where the loss of hydrogen atoms may lead to the formation of a hydrotrioxide and a carbonyl instead of a Russell reaction...
January 4, 2017: Photochemistry and Photobiology
Yong Zhou, Priyanka Prakash, Hong Liang, Kwang-Jin Cho, Alemayehu A Gorfe, John F Hancock
K-Ras is targeted to the plasma membrane by a C-terminal membrane anchor that comprises a farnesyl-cysteine-methyl-ester and a polybasic domain. We used quantitative spatial imaging and atomistic molecular dynamics simulations to examine molecular details of K-Ras plasma membrane binding. We found that the K-Ras anchor binds selected plasma membrane anionic lipids with defined head groups and lipid side chains. The precise amino acid sequence and prenyl group define a combinatorial code for lipid binding that extends beyond simple electrostatics; within this code lysine and arginine residues are non-equivalent and prenyl chain length modifies nascent polybasic domain lipid preferences...
January 12, 2017: Cell
Jolyn E Gisselberg, Lichao Zhang, Joshua E Elias, Ellen Yeh
Plasmodium parasites contain several unique membrane compartments in which prenylated proteins may play important roles in pathogenesis. Protein prenylation has also been proposed as an antimalarial drug target since farnesyltransferase inhibitors cause potent growth inhibition of blood-stage Plasmodium However, the specific prenylated proteins that mediate antimalarial activity have yet to be identified. Given the potential for new parasite biology and elucidating drug mechanism-of-action, we performed a large-scale identification of the prenylated proteome in blood-stage P...
December 31, 2016: Molecular & Cellular Proteomics: MCP
Kamol Yusook, Oratai Weeranantanapan, Yanling Hua, Pakarang Kumkrai, Nuannoi Chudapongse
In this study, lupinifolin, a prenylated flavonoid, was isolated from Derris reticulata stem, identified by NMR spectra and confirmed with mass spectrometry. Lupinifolin was freshly prepared by solubilizing in 0.1 N NaOH and immediately diluted in Müller-Hinton broth for antibacterial testing. The data showed that Gram-positive bacteria were more susceptible to lupinifolin than Gram-negative bacteria. Of four strains of Gram-positive bacteria tested, Staphylococcus aureus was the most susceptible. Using the two-fold microdilution method, it was found that lupinifolin possessed antimicrobial activity against S...
December 30, 2016: Journal of Natural Medicines
Ming Liu, Hua Yin, Xiaokun Qian, Jianjun Dong, Zhonghua Qian, Jinlai Miao
Xanthohumol is a unique prenylated flavonoid in hops (Humulus lupulus L.) and beer. Xanthohumol has been shown to possess a variety of pharmacological activities. There is little research on its effect on doxorubicin-resistant breast cancer cells (MCF-7/ADR) and the cancer stem-like cells exiting in this cell line. In the present study, we investigate the effect of xanthohumol on the viability and stemness of MCF-7/ADR cells. Xanthohumol inhibits viability, induces apoptosis, and arrests the cell cycle of MCF-7/ADR cells in a dose-dependent manner; in addition, xanthohumol sensitizes the inhibition effect of doxorubicin on MCF-7/ADR cells...
December 28, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Dong-Hang Tan, Yao-Fu Zeng, Yao Liu, Wen-Xin Lv, Qingjiang Li, Honggen Wang
The prenyl group is an important component in bioactive compounds. Herein, we report the assembly of prenylated heteroarenes through a cascade Minisci reaction and acid-promoted dehydration sequence. The use of potassium (3-hydroxy-3-methylbut-1-yl)trifluoroborate as a new coupling reagent allows the direct introduction of prenyl and 3-hydroxy-3-methylbutyl groups to a wide variety of electron-deficient heteroarenes. Synthetic application is also demonstrated.
December 2016: ChemistryOpen
Kang Zhou, Carsten Wunsch, Jungui Dai, Shu-Ming Li
Aspergillus terreus aromatic prenyltransferase (AtaPT) catalyzes predominantly C-monoprenylation of acylphloroglucinols in the presence of different prenyl diphosphates. With dimethylallyl diphosphate (DMAPP) as prenyl donor, gem-diprenylated products 1D3, 2D3, and 3D3 were also detected. High conversion of 1D1 to 1D3, 2D1 to 2D3, and 3D1 to 3D3 was demonstrated by incubation with AtaPT and DMAPP. The first example of gem-diprenylation by a member of the dimethylallyltryptophan synthase superfamily is provided...
December 28, 2016: Organic Letters
Rigui Ye, Yu-Hong Fan, Chao-Mei Ma
To exploit Glycyrrhiza uralensis resources, we examined the bioactive constituents of G. uralensis leaves. Seven chemical components were isolated by repeat column chromatography, and using spectroscopic methods, their structures were determined to be a novel prenylated dihydrostilbene, α,α'-dihydro-3,5,3',4'-tetrahydroxy-2,5'-diprenylstilbene (1); a methylated flavonoid, quercetin-3-Me ether (4); and 5 prenylated flavonoids-5'-prenylquercetin (3), 8-[(E)-3-hydroxymethyl-2-butenyl]-eriodictyol (7), 6-prenyleriodictyol (5), 5'-prenyleriodictyol (6), and 6-prenylquercetin-3-Me ether (2)...
December 26, 2016: Journal of Agricultural and Food Chemistry
Miaomiao Liu, Shanfa Lu
Plastoquinone (PQ) and ubiquinone (UQ) are two important prenylquinones, functioning as electron transporters in the electron transport chain of oxygenic photosynthesis and the aerobic respiratory chain, respectively, and play indispensable roles in plant growth and development through participating in the biosynthesis and metabolism of important chemical compounds, acting as antioxidants, being involved in plant response to stress, and regulating gene expression and cell signal transduction. UQ, particularly UQ10, has also been widely used in people's life...
2016: Frontiers in Plant Science
Hong Zhang, Dan Zheng, Zhi-Jie Ding, Yuan-Zhi Lao, Hong-Sheng Tan, Hong-Xi Xu
No abstract text is available yet for this article.
December 23, 2016: Scientific Reports
Jakub Gunera, Florian Kindinger, Shu-Ming Li, Peter Kolb
Prenyltransferases of the dimethylallyltryptophan synthase (DMATS 1 ) superfamily catalyze the attachment of prenyl or prenyl-like moieties to diverse acceptor compounds. These acceptor molecules are generally aromatic in nature and mostly indole or indole-like. Their catalytical transformation represent a major skeletal diversification step in the biosynthesis of secondary metabolites including the indole alkaloids. DMATS enzymes thus contribute significantly to the biological and pharmacological diversity of small molecule metabolites...
December 22, 2016: Journal of Biological Chemistry
Ridao Chen, Bingquan Gao, Xiao Liu, Feiying Ruan, Yong Zhang, Jizhong Lou, Keping Feng, Carsten Wunsch, Shu-Ming Li, Jungui Dai, Fei Sun
Aromatic prenyltransferases (aPTases) transfer prenyl moieties from isoprenoid donors to various aromatic acceptors, some of which have the rare property of extreme enzymatic promiscuity toward both a variety of prenyl donors and a large diversity of acceptors. In this study, we discovered a new aPTase, AtaPT, from Aspergillus terreus that exhibits unprecedented promiscuity toward diverse aromatic acceptors and prenyl donors and also yields products with a range of prenylation patterns. Systematic crystallographic studies revealed various discrete conformations for ligand binding with donor-dependent acceptor specificity and multiple binding sites within a spacious hydrophobic substrate-binding pocket...
December 19, 2016: Nature Chemical Biology
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