共查询到20条相似文献,搜索用时 15 毫秒
1.
Background
Aminopeptidase N (APN) type proteins isolated from several species of lepidopteran insects have been implicated as Bacillus thuringiensis (Bt) toxin-binding proteins (receptors) for Cry toxins. We examined brush border membrane vesicle (BBMV) proteins from the mosquito Anopheles quadrimaculatus to determine if APNs from this organism would bind mosquitocidal Cry toxins that are active to it. 相似文献2.
Sara Tombelli Marco Mascini Barbara Scherm Gianni Battacone Quirico Migheli 《Monatshefte für Chemie / Chemical Monthly》2009,67(2):901-907
Abstract
In this work, we report on the development of a DNA-based piezoelectric biosensor specific for the detection of an amplicon of the aflD gene of Aspergillus flavus and A. parasiticus. Expression of this gene is consistently correlated with a strain’s ability to produce aflatoxins that are considered very potent liver carcinogens in various animal species and humans. The DNA biosensor has been characterized with synthetic oligonucleotides and amplicons. Moreover, it has been applied to the analysis of real samples consisting of amplicons of DNA extracted from flours and feed contaminated with A. flavus and A. parasiticus. 相似文献3.
Background
Iron-sulfur clusters are ubiquitous and evolutionarily ancient inorganic prosthetic groups, the biosynthesis of which depends on complex protein machineries. Three distinct assembly systems involved in the maturation of cellular Fe-S proteins have been determined, designated the NIF, ISC and SUF systems. Although well described in several organisms, these machineries are poorly understood in Gram-positive bacteria. Within the Firmicutes phylum, the Enterococcus spp. genus have recently assumed importance in clinical microbiology being considered as emerging pathogens for humans, wherein Enterococcus faecalis represents the major species associated with nosocomial infections. The aim of this study was to carry out a phylogenetic analysis in Enterococcus faecalis V583 and a structural and conformational characterisation of it SufU protein. 相似文献4.
Comparison of sterols and fatty acids in two species of <Emphasis Type="Italic">Ganoderma</Emphasis>
Background
Two species of Ganoderma, G. sinense and G. lucidum, are used as Lingzhi in China. Howerver, the content of triterpenoids and polysaccharides, main actives compounds, are significant different, though the extracts of both G. lucidum and G. sinense have antitumoral proliferation effect. It is suspected that other compounds contribute to their antitumoral activity. Sterols and fatty acids have obvious bioactivity. Therefore, determination and comparison of sterols and fatty acids is helpful to elucidate the active components of Lingzhi. 相似文献5.
Díaz Huerta V Fernández Sánchez ML Sanz-Medel A 《Analytical and bioanalytical chemistry》2006,384(4):902-907
Total determination and speciation analysis of Se in commercial and selenised Agaricus mushrooms have been performed to investigate the Se species naturally occurring in non-enriched mushrooms as well as those
present in specimens grown in a Se-enriched medium. Mushroom aqueous and enzymatic extracts have been analysed by three complementary
chromatographic separation mechanisms (size-exclusion, anion-exchange and reversed-phase) coupled to an inductively coupled
plasma mass spectrometer with an octopole reaction system. Post-column isotope dilution analysis has been used on-line with
the separations for quantification of the Se species eluted. The 78Se-to-77Se isotope ratio was monitored after adequate corrections for both total determinations and Se species quantitative speciation.
The results showed marked differences not only in total Se contents but also in Se species found in the two types of Agaricus mushrooms investigated. Selenomethionine was detected in both of them (free in commercial mushrooms and incorporated into
proteins in selenised ones) together with a number of unknown selenocompounds. 相似文献
6.
Emanuel Makrlík Petr Vaňura Jan Budka 《Monatshefte für Chemie / Chemical Monthly》2009,287(1):583-585
Abstract
The stability constant of the dibenzo-18-crown-6·H3O+ cationic complex species dissolved in nitrobenzene saturated with water has been determined from extraction experiments in the two-phase water–nitrobenzene system and from γ-activity measurements. Various structures of protonated dibenzo-18-crown-6 are discussed. 相似文献7.
Emanuel Makrlík Petr Toman Petr Vaňura Rajendra Rathore 《Monatshefte für Chemie / Chemical Monthly》2011,286(1):447-451
Abstract
From extraction experiments in the two-phase water/nitrobenzene system and γ-activity measurements, the stability constant of a hexaarylbenzene-based receptor. Tl+ complex species dissolved in nitrobenzene saturated with water was determined. By using the quantum-mechanical density functional level of theory calculations, the most probable structure of this complex was derived. 相似文献8.
Background
The S. cerevisiae origin recognition complex binds to the ARS consensus sequence in an ATP dependent fashion. Recently, the yeast Cdc6 has been reported to have DNA binding activity. Conservation of replication proteins among different species strongly supports their functional similarity. Here we report the results of an investigation into the DNA binding activity of human Cdc6 protein. Cdc6 was expressed and purified from baculovirus infected Sf9 (Spodoptera frugiperda) insect cells as GST fusion protein (GST-Cdc6) and its DNA binding activity was tested. 相似文献9.
Matthew D Krasowski Ni Ai Lee R Hagey Erin M Kollitz Seth W Kullman Erica J Reschly Sean Ekins 《BMC biochemistry》2011,12(1):5
Background
The farnesoid X receptor (FXR), pregnane X receptor (PXR), and vitamin D receptor (VDR) are three closely related nuclear hormone receptors in the NR1H and 1I subfamilies that share the property of being activated by bile salts. Bile salts vary significantly in structure across vertebrate species, suggesting that receptors binding these molecules may show adaptive evolutionary changes in response. We have previously shown that FXRs from the sea lamprey (Petromyzon marinus) and zebrafish (Danio rerio) are activated by planar bile alcohols found in these two species. In this report, we characterize FXR, PXR, and VDR from the green-spotted pufferfish (Tetraodon nigriviridis), an actinopterygian fish that unlike the zebrafish has a bile salt profile similar to humans. We utilize homology modelling, docking, and pharmacophore studies to understand the structural features of the Tetraodon receptors. 相似文献10.
Grzegorz Zi?ba Marcin Rojkiewicz Violetta Kozik Krystyna Jarzembek Anna Jarczyk Aleksander Sochanik Piotr Ku? 《Monatshefte für Chemie / Chemical Monthly》2012,58(4):153-159
Abstract
A series of mono-alkylcarboxylic acid derivatives of tetraphenylporphyrin have been prepared. All the porphyrins were completely characterized by use of mass, 1H NMR, UV–visible, and fluorescence spectroscopy. Experimental log P were determined by use of reversed-phase thin-layer chromatography with use of log P Rekker. These porphyrins are potential photosensitizers in photodynamic therapy. 相似文献11.
Jim N Burnell 《BMC biochemistry》2010,11(1):1
Background
Phosphoenolpyruvate synthetase (PEPS; EC 2.7.9.2) catalyzes the synthesis of phosphoenolpyruvate from pyruvate in Escherichia coli when cells are grown on a three carbon source. It also catalyses the anabolic conversion of pyruvate to phosphoenolpyruvate in gluconeogenesis. A bioinformatics search conducted following the successful cloning and expression of maize leaf pyruvate, orthophosphate dikinase regulatory protein (PDRP) revealed the presence of PDRP homologs in more than 300 bacterial species; the PDRP homolog was identified as DUF299. 相似文献12.
Grégory?Chevillard Marie-Claude?Clémencet Philippe?Etienne Pascal?Martin Thierry?Pineau Norbert?Latruffe Valérie?Nicolas-Francès
Background
In rats, two peroxisomal 3-ketoacyl-CoA thiolase genes (A and B) have been cloned, whereas only one thiolase gene is found in humans. The aim of this study was thus to clone the different mouse thiolase genes in order to study both their tissue expression and their associated enzymatic activity. 相似文献13.
Hiroyuki Kaiya Shiho Kodama Koutaro Ishiguro Kouhei Matsuda Minoru Uchiyama Mikiya Miyazato Kenji Kangawa 《BMC biochemistry》2009,10(1):30-15
Background
Ghrelin (GRLN) is now known to be an appetite-stimulating and growth hormone (GH)-releasing peptide that is predominantly synthesized and secreted from the stomachs of various vertebrate species from fish to mammals. Here, we report a GRLN-like peptide (GRLN-LP) in a cartilaginous fish, the red stingray, Dasyatis akajei. 相似文献14.
Background
Sphaeroides Heme Protein (SHP) was discovered in the purple photosynthetic bacterium, Rhodobacter sphaeroides, and is the only known c-type heme protein that binds oxygen. Although initially not believed to be widespread among the photosynthetic bacteria, the gene has now been found in more than 40 species of proteobacteria and generally appears to be regulated. Rb. sphaeroides is exceptional in not having regulatory genes associated with the operon. We have thus analyzed additional purple bacteria for the SHP gene and examined the genetic context to obtain new insights into the operon, its distribution, and possible function. 相似文献15.
Emanuel Makrlík Petr Toman Petr Vaňura 《Monatshefte für Chemie / Chemical Monthly》2012,289(3):199-202
Abstract
From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constant of the beauvericin–Cs+ complex species dissolved in nitrobenzene saturated with water was determined. By using quantum–mechanical density functional level of theory (DFT) calculations, the most probable structure of this complex was derived. 相似文献16.
Background
In Drosophila, cuticular sex pheromones are long-chain unsaturated hydrocarbons synthesized from fatty acid precursors in epidermal cells called oenocytes. The species D. melanogaster shows sex pheromone dimorphism, with high levels of monoenes in males, and of dienes in females. Some biosynthesis enzymes are expressed both in fat body and oenocytes, rendering it difficult to estimate the exact role of oenocytes and of the transport of fatty acids from fat body to oenocytes in pheromone elaboration. To address this question, we RNAi silenced two main genes of the biosynthesis pathway, desat1 and desatF, in the oenocytes of D. melanogaster, without modifying their fat body expression. 相似文献17.
Background
Arylamine N-acetyltransferases (NATs) are important drug- and carcinogen-metabolising enzymes that catalyse the transfer of an acetyl group from a donor, such as acetyl coenzyme A, to an aromatic or heterocyclic amine, hydrazine, hydrazide or N-hydroxylamine acceptor substrate. NATs are found in eukaryotes and prokaryotes, and they may also have an endogenous function in addition to drug metabolism. For example, NAT from Mycobacterium tuberculosis has been proposed to have a role in cell wall lipid biosynthesis, and is therefore of interest as a potential drug target. To date there have been no studies investigating the kinetic mechanism of a bacterial NAT enzyme. 相似文献18.
Madhukar N. Jachak Sandeep M. Bagul Bhausaheb K. Ghotekar Raghunath B. Toche 《Monatshefte für Chemie / Chemical Monthly》2009,20(5):655-662
Abstract
A series of (2E)-3-(1-chloro-6-methoxy-3,4-dihydronaphthalen-2-yl)-1-(4-aryl)prop-2-en-1-ones (chalcones) have been synthesized by a new synthetic route. The 3-pyridinecarbonitrile derivatives were synthesized by the Michael reaction of malononitrile (in base) and aroylacetonitriles (in acid) with chalcones in one pot. The fluorescent properties and quantum yields of these compounds were studied. 相似文献19.
Background
Escherichia coli MutY (EcMutY) reduces mutagenesis by removing adenines paired with guanines or 7,8-dihydro-8-oxo-guanines (8-oxoG). V45 and Q182 of EcMutY are considered to be the key determinants of adenine specificity. Both residues are spatially close to each other in the active site and are conserved in MutY family proteins but not in Methanobacterium thermoautotrophicum Mig.MthI T/G mismatch DNA glycosylase (A50 and L187 at the corresponding respective positions). 相似文献20.
Emanuel Makrlík Michal ?ajan Jan Budka Petr Vaňura 《Monatshefte für Chemie / Chemical Monthly》2011,287(3):5-9