共查询到20条相似文献,搜索用时 15 毫秒
1.
Marcel F. Alary-Bernard Marcel Briens Marcel M.G. Quillet Marie Goas 《Phytochemistry》1980,19(6):1111-1116
From purified cell walls and pectic, hemicellulosic and cellulosic fractions of Chara aspera and Nitella translucens, glycoproteins were isolated through affinity chromatography on concanvalin A (Con A)-Sepharose column. The chemical composition of protein fractions is qualitatively the same in both algae. The polysaccharidic moieties vary from one glycoprotein to another. None of the glycoproteins present contains cystine or hydroxyproline. 相似文献
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The monohydroxy analogue of phylloquinone found in Anacystis nidulans and Euglena gracilis has been characterized as 5′-monohydroxyphylloquinone by MS analysis. 相似文献
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Seyed Abdollah Mousavi Janina Österman Niklas Wahlberg Xavier Nesme Céline Lavire Ludovic Vial Lars Paulin Philippe de Lajudie Kristina Lindström 《Systematic and applied microbiology》2014
The genera Agrobacterium, Allorhizobium, and Rhizobium belong to the family Rhizobiaceae. However, the placement of a phytopathogenic group of bacteria, the genus Agrobacterium, among the nitrogen-fixing bacteria and the unclear position of Rhizobium galegae have caused controversy in previous taxonomic studies. To resolve uncertainties in the taxonomy and nomenclature within this family, the phylogenetic relationships of generic members of Rhizobiaceae were studied, but with particular emphasis on the taxa included in Agrobacterium and the “R. galegae complex” (R. galegae and related taxa), using multilocus sequence analysis (MLSA) of six protein-coding housekeeping genes among 114 rhizobial and agrobacterial taxa. The results showed that R. galegae, R. vignae, R. huautlense, and R. alkalisoli formed a separate clade that clearly represented a new genus, for which the name Neorhizobium is proposed. Agrobacterium was shown to represent a separate cluster of mainly pathogenic taxa of the family Rhizobiaceae. A. vitis grouped with Allorhizobium, distinct from Agrobacterium, and should be reclassified as Allorhizobium vitis, whereas Rhizobium rhizogenes was considered to be the proper name for former Agrobacterium rhizogenes. This phylogenetic study further indicated that the taxonomic status of several taxa could be resolved by the creation of more novel genera. 相似文献
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Juliana Alves Parente-Rocha Mariana Vieira Tomazett Laurine Lacerda Pigosso Alexandre Melo Bailão Aparecido Ferreira de Souza Juliano Domiraci Paccez Lilian Cristiane Baeza Maristela Pereira Mirelle Garcia Silva Bailão Clayton Luiz Borges Célia Maria de Almeida Soares 《Fungal biology》2018,122(6):505-513
Members of the Paracoccidioides complex are human pathogens that infect different anatomic sites in the host. The ability of Paracoccidioides spp. to infect host niches is putatively supported by a wide range of virulence factors, as well as fitness attributes that may comprise the transition from mycelia/conidia to yeast cells, response to deprivation of micronutrients in the host, expression of adhesins on the cell surface, response to oxidative and nitrosative stresses, as well as the secretion of hydrolytic enzymes in the host tissue. Our understanding of how those molecules can contribute to the infection establishment has been increasing significantly, through the utilization of several models, including in vitro, ex vivo and in vivo infection in animal models. In this review we present an update of our understanding on the strategies used by the pathogen to establish infection. Our results were obtained through a comparative proteomic analysis of Paracoccidioides spp. in models of infection. 相似文献
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组蛋白作为核小体的基本组分,是染色质的结构和功能必需的。组蛋白的变体和修饰共同参与染色质修饰及基因的表达调控。真核生物细胞中的5种组蛋白在进化中高度保守,然而纤毛虫的组蛋白H4与其他真核生物相比有较大的差异。本实验应用PCR技术从八肋游仆虫(Euplotes octocarinatus)中获得了2种组蛋白H4基因,分别为H4A和H4B,GenBank登录号为:JN715068和JN715069。序列分析表明,H4A基因开放阅读框324 bp,预测编码107个氨基酸,分子量为11.6 ku,等电点为10.99。而H4B基因编码框384 bp,编码127个氨基酸,分子量为14.4 ku,等电点为9.93。Blast结果显示,H4A序列与其他生物中H4的一致性相对较高,达81%~94%,而H4B的一致性为36%~70%。H4A和H4B的一致性仅为44.7%。实时荧光定量PCR表明,H4A的转录本高于H4B。结果提示:在进化过程中八肋游仆虫可能进化出特殊的组蛋白H4基因,不同的组蛋白H4可能发挥不同的功能。 相似文献
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Jianbo Wu Chunkai Wang Derek Leas Mireille Vargas Karen L. White David M. Shackleford Gong Chen Austin G. Sanford Ryan M. Hemsley Paul H. Davis Yuxiang Dong Susan A. Charman Jennifer Keiser Jonathan L. Vennerstrom 《Bioorganic & medicinal chemistry letters》2018,28(3):244-248
N,N′-Diaryl ureas have recently emerged as a new antischistosomal chemotype. We now describe physicochemical profiling, in vitro ADME, plasma exposure, and ex vivo and in vivo activities against Schistosoma mansoni for twenty new N,N′-diaryl ureas designed primarily to increase aqueous solubility, but also to maximize structural diversity. Replacement of one of the 4-fluoro-3-trifluoromethylphenyl substructures of lead N,N′-diaryl urea 1 with azaheterocycles and benzoic acids, benzamides, or benzonitriles decreased lipophilicity, and in most cases, increased aqueous solubility. There was no clear relationship between lipophilicity and metabolic stability, although all compounds with 3-trifluoromethyl-4-pyridyl substructures were metabolically stable. N,N′-diaryl ureas containing 4-fluoro-3-trifluoromethylphenyl, 3-trifluoromethyl-4-pyridyl, 2,2-difluorobenzodioxole, or 4-benzonitrile substructures had high activity against ex vivo S. mansoni and relatively low cytotoxicity. N,N-diaryl ureas with 3-trifluoromethyl-4-pyridyl and 2,2-difluorobenzodioxole substructures had the highest exposures whereas those with 4-fluoro-3-trifluoromethylphenyl substructures had the best in vivo antischistosomal activities. There was no direct correlation between compound exposure and in vivo activity. 相似文献
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Barbara N. Timmermann Dori J. Luzbetak Joseph J. Hoffmann Shivanand D. Jolad Karl H. Schram Robert B. Bates Robert E. Klenck 《Phytochemistry》1983,22(2):523-525
The structures of nine grindelic acid related diterpenes isolated as methyl esters from Grindelia camporum and Chrysothamnus paniculatus, were elucidated based on their spectral properties. 相似文献
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Elisabeth Folkers 《Journal of insect physiology》1982,28(6):535-539
Dunce1, amnesiac, turnip and rutabaga, mutants of Drosophila melanogaster deficient in olfactory learning and/or memory, were tested for visual learning ability and memory. All these mutants are able to learn conditioned visual information, but not as well as the corresponding wildtype CS. Memory of all four mutants is reduced during the first 30 min after training, but indistinguishable from that of the wildtype two hours after conditioning. 相似文献
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Moreau Pierre-Arthur Bellanger Jean-Michel Lebeuf Renée Athanassiou Zacharias Athanasiades Antonis Lambert Herman Schwarz Christian Larsson Ellen Loizides Michael 《Fungal biology》2018,122(8):817-836
For many years, the binomial Hygrophorus hypothejus was widely applied to collections from various geographical regions in different continents, assuming a circum-boreal and circum-mediterranean distribution for this species. This hypothesis, however, had never been put to the test. To assess the diversity and species-limits within this complex of yellow-coloured waxcaps, a phylogenetic, morphological and taxonomical investigation into Hygrophorus sect. Aurei and similar species in sect. Olivaceoumbrini was carried out, including material of pan-European origin, as well as the east and west coasts of North America. Following sequencing of the ITS rDNA locus, nine lineages are confirmed in sect. Aurei, most of them highly continentalised. Of these, two are new to science, introduced here as Hygrophorus boyeri sp. nov., from Pinus banksiana and P. rigida forests in eastern North America and from P. muricata and P. contorta forests in western North America, and Hygrophorus meridionalis sp. nov., from Pinus brutia and Pinus halepensis forests in the island of Cyprus and mainland Greece. H. hypothejus is lectotypified and epitypified, and here resolved as a strictly European species, with the old forgotten taxon Hygrophorus siccipes revived as its North American vicariant. The placement of Hygrophorus fuligineus in sect. Aurei is phylogenetically confirmed and detailed comparisons between morphologically similar and phylogenetically affiliated taxa in sect. Aurei and sect. Olivaceoumbrini are provided. The chronic confusion associated with Hygrophorus fuscoalbus, a highly controversial taxon described from Germany nearly two centuries ago and variously interpreted since, is discussed, concluding that this name is too ambiguous to be applied to any currently recognized species. 相似文献
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Flowering plants often have specific floral cues, which allow bees and other pollinators to differentiate between them. Many bee species exhibit specialised associations with flowers (oligolecty) and it is important for them to find and recognise their specific host plants. In this study we compared the visual and olfactory floral cues of different Echium and Pontechium (Boraginaceae) species with the closely related Anchusa officinalis (Boraginaceae). We tested whether plant-specific cues occur in Echium and Pontechium which may allow oligolectic Hoplitis adunca (Megachilidae) to recognise its host plants and to distinguish them from Anchusa non-hosts. Our investigations showed that Echium/Pontechium provides a specific scent bouquet. Furthermore, we identified compounds which were not described as floral scent before ((Z)-3-nonenal and 1,4-benzoquinone). These unique volatiles and the specific bouquet could act as a recognition cue for H. adunca. The corolla colours differed between all species, but were grouped together in the bee colour categories blue and UV-blue and can indicate potential host flowers for H. adunca. 相似文献
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Given the considerable promise whole-genome sequencing offers for phylogeny and classification, it is surprising that microbial systematics and genomics have not yet been reconciled. This might be due to the intrinsic difficulties in inferring reasonable phylogenies from genomic sequences, particularly in the light of the significant amount of lateral gene transfer in prokaryotic genomes. However, recent studies indicate that the species tree and the hierarchical classification based on it are still meaningful concepts, and that state-of-the-art phylogenetic inference methods are able to provide reliable estimates of the species tree to the benefit of taxonomy. Conversely, we suspect that the current lack of completely sequenced genomes for many of the major lineages of prokaryotes and for most type strains is a major obstacle in progress towards a genome-based classification of microorganisms. We conclude that phylogeny-driven microbial genome sequencing projects such as the Genomic Encyclopaedia of Archaea and Bacteria (GEBA) project are likely to rectify this situation. 相似文献
15.
Klaus Apel 《BBA》1977,462(2):390-402
In the green alga Acetabularia mediterranea a light-harvesting chlorophyll a/b · protein complex of 67 000 daltons has been found which contains two polypeptide chains of 21 500 and 23 000 daltons. These two polypeptides were isolated on a preparative scale and were further characterized by several different methods. Both polypeptides proved to be very similar. While their amino acid and sugar compositions as well as their immunochemical properties were almost identical the tryptic peptides and the cyanogen bromide fragments of the two polypeptides revealed minor but significant differences. The 67 000-dalton chlorophyll a/b · protein complex and its two polypeptide components were compared to the light-harvesting chlorophyll a/b · protein of higher plants. 相似文献
16.
Laurence A.N. Egue Florent K. Nguessan Solange Aka-Gbezo Jean-Paul K.M. Bouatenin Marina Koussemon-Camara 《Fungal biology》2018,122(5):283-292
The increase of infections due to non-Candida albicans species made it very necessary to conduct adequate characterization to be able to identify the species of Candida isolated from traditional fermented foods. In this study, based on their hue on Candida Chromogenic Agar medium, a total of 136 yeast strains were isolated from tchapalo and bangui. Molecular identification based on PCR-RFLP of internal transcribed spacers of rDNA (ITS) and sequencing of the ITS and the D1/D2 regions allowed us to assign these isolates to seven species: Candida tropicalis, Candida inconspicua, Candida rugosa, Saccharomyces cerevisiae, Kluyveromyces marxianus, Hanseniaspora guilliermondii, Trichosporon asahii. With the respect to each beverage, six species were found among with four species are regarded as opportunistic pathogens. From these, C. tropicalis, C. inconspicua and K. marxianus were the most commonly encountered. The enzyme activities of the potential pathogens assessed using API ZYM system showed that almost strains had esterase, esterase lipase, valine and cystine arylamidase, alpha chymotrypsin, alkaline phosphatase and naphthol phosphohydrolase activities. The activity of α-glucosidase was found only in C. tropicalis and C. inconspicua strains isolated from tchapalo while β-glucosidase activity was found in all strains from tchapalo and only in C. inconspicua isolated from bangui. 相似文献
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R-(-)-β-O-methylsynephrine (OMe-Syn) is an active compound isolated from a plant of the Rutaceae family. We conducted cell proliferation assays on various cell lines and found that OMe-Syn more strongly inhibited the growth of human umbilical vein endothelial cells (HUVECs) than that of other normal and cancer cell lines tested. In angiogenesis assays, it inhibited vascular endothelial growth factor (VEGF)-induced invasion and tube formation of HUVECs with no toxicity. The anti-angiogenic activity of OMe-Syn was also validated in vivo using the chorioallantonic membrane (CAM) assay in growing chick embryos. Expression of the growth factors VEGF, hepatocyte growth factor, and basic fibroblast growth factor was suppressed by OMe-Syn in a dose-dependent manner. Taken together, our results indicate that this compound could be a novel basis for a small molecule targeting angiogenesis. 相似文献
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Toru Iwatani Mai Sakakura Yoshimitsu Takakura Makoto Ito Takeshi Yamamoto Yoshimitsu Kakuta 《FEBS letters》2009,583(12):2083-2087
α/β-Galactoside α2,3-sialyltransferase produced by Photobacterium phosphoreum JT-ISH-467 is a unique enzyme that catalyzes the transfer of N-acetylneuraminic acid residue from cytidine monophosphate N-acetylneuraminic acid to acceptor carbohydrate groups. The enzyme recognizes both mono- and di-saccharides as acceptor substrates, and can transfer Neu5Ac to both α-galactoside and β-galactoside, efficiently. To elucidate the structural basis for the broad acceptor substrate specificity, we determined the crystal structure of the α2,3-sialyltransferase in complex with CMP. The overall structure belongs to the glycosyltransferase-B structural group. We could model a reasonable active conformation structure based on the crystal structure. The predicted structure suggested that the broad substrate specificity could be attributed to the wider entrance of the acceptor substrate binding site. 相似文献
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Anastasios Malandrakis Efrosini Rafaella Daskalaki Vasiliki Skiada Kalliope K. Papadopoulou Nektarios Kavroulakis 《Fungal biology》2018,122(12):1215-1221
The potential of FsK, a non-pathogenic endophytic Fusarium solani strain, to be utilized as a biocontrol agent in combination with nine selected fungicides registered in tomato crops in Greece was evaluated. In vitro fungitoxicity tests revealed that FsK was insensitive to doses exceeding 100 μg/mL of thiophanate-methyl, fenhexamid, cyprodinil, boscalid and mancozeb. On the contrary, prochloraz, fludioxonil, pyraclostrobin and difenoconazole were most toxic to FsK. None of the later fungicides affected conidial production in an adverse way. Drenching of tomato plants with the above fungicides at recommended doses did not significantly affect colonization of tomato roots by FsK as revealed by in vitro isolation and Real Time PCR quantification. The disease suppressive ability of FsK against Fusarium oxysporum f.sp.radicis lycopersici (FORL) was not adversely affected by the post-inoculation application of commercial formulations of fludioxonil (Switch) and pyraclostrobin (Comet) at the recommended doses. Even more, the Comet–FsK combination resulted in enhanced disease suppression compared to either of the two treatments applied individually. In conclusion, not only biocontrol agent FsK is suitable for use in tomato integrated disease management programs that include all tested fungicides but also, some FsK –fungicide combinations can have additive effect against FORL disease incidence. 相似文献