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Tomohisa Kuzuyama, Takeo Tomita, Masaya Kobayashi, Yuma Karita, Yoko Yasuno, Tetsuro Shinada, Makoto Nishiyama
Here, we report the three-dimensional structure of cyclolavandulyl diphosphate (CLPP) synthase (CLDS), which consecutively catalyses the condensation of two molecules of dimethylallyl diphosphate (DMAPP) followed by cyclisation to form a cyclic monoterpene, CLPP. The structures of apo-CLDS and CLDS in complex with Tris, pyrophosphate, and Mg2+ ion were refined at 2.00 Å resolution and 1.73 Å resolution, respectively. CLDS adopts a typical fold for cis-prenyl synthases and forms a homo-dimeric structure. An in vitro reaction using a regiospecifically 2H-substituted DMAPP substrate revealed the intramolecular proton transfer mechanism of the CLDS reaction...
September 18, 2017: Angewandte Chemie
Arnold De Loof
Cells are powerful miniature electrophoresis chambers, at least during part of their life cycle. They die at the moment the voltage gradient over their plasma membrane, and their ability to drive a self-generated electric current carried by inorganic ions through themselves irreversibly collapses. Senescence is likely due to the progressive, multifactorial damage to the cell's electrical system. This is the essence of the "Fading electricity theory of aging" (De Loof et al., Aging Res. Rev. 2013;12:58-66)...
2017: Communicative & Integrative Biology
Paola Maura Tricarico, Rossella Gratton, Luca Braga, Fulvio Celsi, Sergio Crovella
Mevalonate pathway deregulation has been observed in several diseases, including Mevalonate kinase deficiency (MKD). MKD is a hereditary auto-inflammatory disorder, due to mutations at mevalonate kinase gene (MVK), encoding mevalonate kinase (MK) enzyme. MVK mutations have been reported as associated with impairment of mevalonate pathway with consequent decrease of protein prenylation levels, defective autophagy and increase of IL-1β secretion, followed by cell death. Since 25-hydroxycholesterol (25-HC), a metabolite of cholesterol, can suppress IL-1β production, thus reducing inflammation, we evaluated the effect of 25-HC in an in vitro model of mevalonate pathway alteration, obtained using Lovastatin...
September 13, 2017: International Journal of Biochemistry & Cell Biology
Debarshi Kar Mahapatra, Sanjay Kumar Bharti, Vivek Asati
Chalcone or (E)-1,3-diphenyl-2-propene-1-one scaffold has gained considerable scientific interest in medicinal chemistry owing to its simple chemistry, ease in synthesizing a variety of derivatives and exhibiting a broad range of promising pharmacological activities by modulating several molecular targets. A number of natural and (semi-) synthetic chalcone derivatives have demonstrated admirable anti-inflammatory activity due to their inhibitory potential against various therapeutic targets like cyclooxygenase (COX), lipooxygenase (LOX), interleukins (IL), prostaglandins (PGs), nitric oxide synthase (NOS), leukotriene D4 (LTD4), nuclear factor-κB (NF-κB), intracellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1) and TLR4/MD-2, etc...
September 14, 2017: Current Topics in Medicinal Chemistry
Wei-Lun Hung, Joon Hyuk Suh, Yu Wang
Furanocoumarins are a specific group of secondary metabolites that commonly present in higher plants, such as citrus plants. The major furanocoumarins found in grapefruits (Citrus paradisi) include bergamottin, epoxybergamottin, and 6',7'-dihydroxybergamottin. During biosynthesis of these furanocoumarins, coumarins undergo biochemical modifications corresponding to a prenylation reaction catalyzed by the cytochrome P450 enzymes with the subsequent formation of furan rings. Because of undesirable interactions with several medications, many studies have developed methods for grapefruit furanocoumarin quantification that include high-performance liquid chromatography coupled with UV detector or mass spectrometry...
January 2017: Journal of Food and Drug Analysis
Simona Torriano, Nejla Erkilic, Valérie Faugère, Krishna Damodar, Christian P Hamel, Anne-Francoise Roux, Vasiliki Kalatzis
Choroideremia (CHM) is an inherited retinal dystrophy characterised by progressive degeneration of photoreceptors, retinal pigment epithelium (RPE) and underlying choroid. It is caused by loss-of-function mutations in CHM, which has an X-linked inheritance, and is thus an ideal candidate for gene replacement strategies. CHM encodes REP1, which plays a key role in the prenylation of Rab GTPases. We recently showed that an induced pluripotent stem cell (iPSc)-derived RPE model for CHM is fully functional and reproduces the underlying prenylation defect...
September 15, 2017: Human Molecular Genetics
Annalisa Marcuzzi, Claudia Loganes, Claudio Celeghini, Giulio Kleiner
Mevalonate Kinase Deficiency (MKD, OMIM #610377) is a rare autosomal recessive metabolic and inflammatory disease. In MKD, defective function of the enzyme mevalonate kinase (MK), due to a mutation in the MVK gene, leads to the shortage of mevalonate-derived intermediates, which results in unbalanced prenylation of proteins and altered metabolism of sterols. These defects lead to a complex multisystem inflammatory and metabolic syndrome. Although biologic therapies aimed at blocking the inflammatory cytokine interleukin-1 (IL-1) can significantly reduce inflammation, they cannot completely control the clinical symptoms that affects the nervous system...
September 11, 2017: Current Medicinal Chemistry
Liliana Mammino
Arzanol (C22H26O7) is a naturally occurring acylphloroglucinol largely responsible for the anti-inflammatory, anti-oxidant, antibiotic and antiviral activities of Helichrysum italicum. Like all acylphloroglucinols, the molecule contains a carboxylic substituent (-COR group); for arzanol, this is a -COCH3 group. The molecule is further characterized by the presence of an α-pyrone ring bonded in meta to -COR through a methylene bridge, and of a prenyl chain bonded to the other meta position. The molecule can form up to three intramolecular hydrogen bonds (IHB) simultaneously, and their presence and patterns are the major stabilizing factors...
September 12, 2017: Journal of Molecular Modeling
Nadav Sorek, Limor Poraty, Hasana Sternberg, Ella Buriakovsky, Einat Bar, Efraim Lewinsohn, Shaul Yalovsky
ROPs or RACs are plant Rho-related GTPases implicated in regulation of multitude of signaling pathways that function at the plasma membrane via posttranslational lipid modifications. The relations between ROP activation status and their membrane localization has not been established. Here, we show that endogenous ROPs, as well as a transgenic His6:GFP:AtROP6 fusion protein, were partitioned between Triton X-100 soluble and insoluble membranes. In contrast, the His6:GFP:Atrop6(CA) activated mutant accumulated exclusively in detergent resistant membranes...
September 11, 2017: Molecular and Cellular Biology
Yoseph Atilaw, Lois Muiva-Mutisya, Albert Ndakala, Hoseah M Akala, Redemptah Yeda, Yu J Wu, Paolo Coghi, Vincent K W Wong, Máté Erdélyi, Abiy Yenesew
Four new flavones with modified prenyl groups, namely (E)-5-hydroxytephrostachin (1), purleptone (2), (E)-5-hydroxyanhydrotephrostachin (3), and terpurlepflavone (4), along with seven known compounds (5-11), were isolated from the CH₂Cl₂/MeOH (1:1) extract of the stem of Tephrosia purpurea subsp. leptostachya, a widely used medicinal plant. Their structures were elucidated on the basis of NMR spectroscopic and mass spectrometric evidence. Some of the isolated compounds showed antiplasmodial activity against the chloroquine-sensitive D6 strains of Plasmodium falciparum, with (E)-5-hydroxytephrostachin (1) being the most active, IC50 1...
September 10, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Amila A Dissanayake, Baram A H Ameen, Muraleedharan G Nair
Purification of extracts from Prangos haussknechtii Bioss afforded prenylated coumarins 1 and 2, monoterpenoid 3, amino acid derivative 4, and seven known compounds. Spectroscopic methods permitted establishment of the structures and relative configuration of these compounds. The pure isolates were tested for antioxidant and anti-inflammatory activities using lipid peroxidation (LPO), 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and cyclooxygenase (COX-1 and -2) enzyme inhibitory assays...
September 8, 2017: Journal of Natural Products
Ekaterina S Marakasova, Birgit Eisenhaber, Sebastian Maurer-Stroh, Frank Eisenhaber, Ancha Baranova
Intracellular bacteria were recently shown to employ eukaryotic prenylation system for modifying activity and ensuring proper intracellular localization of their own proteins. Following the same logic, the proteins of viruses may also serve as prenylation substrates. Using extensively validated high-confidence prenylation predictions by PrePS with a cut-off for experimentally confirmed farnesylation of hepatitis delta virus antigen, we compiled in silico evidence for several new prenylation candidates, including IRL9 (CMV) and few other proteins encoded by Herpesviridae, Nef (HIV-1), E1A (human adenovirus 1), NS5A (HCV), PB2 (influenza), HN (human parainfluenza virus 3), L83L (African swine fever), MC155R (molluscum contagiosum virus), other Poxviridae proteins, and some bacteriophages of human associated bacteria...
September 8, 2017: BioEssays: News and Reviews in Molecular, Cellular and Developmental Biology
Anjaneyulu Kowluru
Glucose-stimulated insulin secretion (GSIS) involves interplay between metabolic and cationic events. Seminal contributions from multiple laboratories affirm essential roles for small G-proteins (Rac1, Cdc42, Arf6, Rab27A) in GSIS. Activation of these signalling proteins promotes cytoskeletal remodeling, transport and docking of insulin granules on the plasma membrane for exocytotic secretion of insulin. Evidence in rodent and human islets suggests key roles for lipidation (farnesylation and geranylgeranylation) of these G-proteins for their targeting to appropriate cellular compartments for optimal regulation of effectors leading to GSIS...
September 2017: Diabetes, Obesity & Metabolism
Anna Caroline Aguiar, Lorena R F de Sousa, Celia R S Garcia, Glaucius Oliva, Rafael V C Guido
Malaria remains a major health problem, especially because of the emergence of resistant P. falciparum strains to artemisinin derivatives. In this context, safe and affordable antimalarial drugs are desperately needed. New proteins have been investigated as molecular targets for research and development of innovative compounds with well-defined mechanism of action. In this review, we highlight genetically and clinically validated plasmodial proteins as drug targets for the next generation of therapeutics. The enzymes described herein are involved in hemoglobin hydrolysis, the invasion process, elongation factors for protein synthesis, pyrimidine biosynthesis, post-translational modifications such as prenylation, phosphorylation and histone acetylation, generation of ATP in mitochondrial metabolism and aminoacylation of RNAs...
August 29, 2017: Current Medicinal Chemistry
Michael D Flythe, Isabelle A Kagan, Yuxi Wang, Nelmy Narvaez
Antibiotics can improve ruminant growth and efficiency by altering rumen fermentation via selective inhibition of microorganisms. However, antibiotic use is increasingly restricted due to concerns about the spread of antibiotic-resistance. Plant-based antimicrobials are alternatives to antibiotics in animal production. The hops plant (Humulus lupulus L.) produces a range of bioactive secondary metabolites, including antimicrobial prenylated phloroglucinols, which are commonly called alpha- and beta-acids. These latter compounds can be considered phyto-ionophores, phytochemicals with a similar antimicrobial mechanism of action to ionophore antibiotics (e...
2017: Frontiers in Veterinary Science
Qi Wang, Yi Kuang, Junbin He, Kai Li, Wei Song, Hongwei Jin, Xue Qiao, Min Ye
Prenylated phenolic compounds are an important class of bioactive natural products. One major in vivo metabolic pathway of these compounds is hydroxylation at terminal methyl of the isoprenyl group. This study aims to identify the P450 isozyme catalyzing this metabolic reaction. In human liver microsomes, 16 out of 24 screened compounds could be metabolized into their hydroxylated derivatives. Chemical inhibition assays using 11 isozyme specific inhibitors indicated the hydroxylation reactions of 12 compounds were primarily catalyzed by cytochrome P450 2A6 (CYP2A6)...
September 1, 2017: European Journal of Pharmaceutical Sciences
Ivanildes C Dos Santos, Alex-Alan Furtado de Almeida, Carlos P Pirovani, Márcio Gilberto Cardoso Costa, Maria Fatima das Graças Fernandes da Silva, Barbara Sayuri Bellete, Luciano Freschi, Walter Soares Filho, Maurício Antônio Coelho Filho, Abelmon da Silva Gesteira
Water scarcity can elicit drastic changes in plant metabolic and hormonal regulation, which may be of fundamental importance to stress tolerance. The study of plant the metabolic alterations in response to water deficit, especially the effects of the rootstocks level, is important to elucidate the mechanisms associated to drought tolerance. To verify the influence of rootstock and grafting on the tolerance to drought in citrus plants, we analyzed the growth, phytohormone levels and flavonoid profiles in grafted and ungrafted citrus plants subjected to different soil water regimes on plant status (well-watered, moderate drought and severe drought and rehydrated) under field conditions...
August 25, 2017: Plant Physiology and Biochemistry: PPB
Mahboob Salim, Timothy J Knowles, Alfie T Baker, Martin S Davey, Mark Jeeves, Pooja Sridhar, John Wilkie, Carrie R Willcox, Hachemi Kadri, Taher E Taher, Pierre Vantourout, Adrian Hayday, Youcef Mehellou, Fiyaz Mohammed, Benjamin E Willcox
Human Vγ9/Vδ2 T-cells detect tumor cells and microbial infections by recognizing small phosphorylated prenyl metabolites termed phosphoantigens (P-Ag). The type-1 transmembrane protein Butyrophilin 3A1 (BTN3A1) is critical to the P-Ag-mediated activation of Vγ9/Vδ2 T-cells; however, the molecular mechanisms involved in BTN3A1-mediated metabolite sensing are unclear, including how P-Ag's are discriminated from nonantigenic small molecules. Here, we utilized NMR and X-ray crystallography to probe P-Ag sensing by BTN3A1...
September 14, 2017: ACS Chemical Biology
Fangyi Su, Zheng Zhao, Shuanggang Ma, Rubing Wang, Yong Li, Yunbao Liu, Yuhuan Li, Li Li, Jing Qu, Shishan Yu
Three pairs of racemic dimers, (±)-cnidimonins A-C (1-3), were isolated from the fruits of Cnidium monnieri. They represent novel hybrid-dimerization patterns of coumarin skeleton with structurally diverse units (flavonol, benzofuran, and chromone) via an unprecedented terminal chiral carbon of prenyl. The absolute configurations of the enantiomers were determined by electronic circular dichroism (ECD). To investigate their bioactivities in depth, (±)-cnidimonins A-C (1-3) were synthesized. The racemic mixture (±)-1 exhibited stronger antiviral activity against HSV-1 (IC50: 1...
August 31, 2017: Organic Letters
Stefan Payer, Stephen A Marshall, Natalie Bärland, Xiang Sheng, Tamara Reiter, Andela Dordic, Georg Steinkellner, Christiane Wuensch, Susann Kaltwasser, Karl Fisher, Stephen E J Rigby, Peter Macheroux, Janet Vonck, Karl Gruber, Kurt Faber, Fahmi Himo, David Leys, Tea Pavkov-Keller, Silvia M Glueck
The utilization of CO2 as carbon source for organic syntheses meets the urgent demand of more sustainability in chemical production. Here we report on the enzyme-catalyzed para-carboxylation of catechols, employing 3,4-dihydroxybenzoic acid decarboxylases (AroY) that belong to the UbiD enzyme family. Crystal structures and accompanying solution data confirm that AroY utilizes the recently discovered prenylated FMN (prFMN) cofactor, and requires oxidative maturation to form the catalytically competent prFMNiminium species...
August 30, 2017: Angewandte Chemie
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