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931.
Olga Adelfinskaya Weidong Wu V. Jo Davisson Donald E. Bergstrom 《Nucleosides, nucleotides & nucleic acids》2013,32(10-12):1919-1945
Two novel C-linked oxadiazole carboxamide nucleosides 5-(2′-deoxy-3′,5′-β-D-erythro-pentofuranosyl)-1,2,4-oxadiazole-5-carboxamide (1) and 5-(2′-deoxy-3′,5′-β-D-erythro-pentofuranosyl)-1,2,4-oxadiazole-3-carboxamide (2) were successfully synthesized and characterized by X-ray crystallography. The crystallographic analysis shows that both unnatural nucleoside analogs 1 and 2 adapt the C2′-endo (“south”) conformation. The orientation of the oxadiazole carboxamide nucleobase moiety was determined as anti (conformer A) and high anti (conformer B) in the case of the nucleoside analog 1 whereas the syn conformation is adapted by the unnatural nucleoside 2. Furthermore, nucleoside analogs 1 and 2 were converted with high efficiency to corresponding nucleoside triphosphates through the combination chemo-enzymatic approach. Oxadiazole carboxamide deoxyribonucleoside analogs represent valuable tools to study DNA polymerase recognition, fidelity of nucleotide incorporation, and extension. 相似文献
932.
933.
Karine Lambou Andrea Pennati Isabel Valsecchi Rui Tada Stephen Sherman Hajime Sato Remi Beau Giovanni Gadda Jean-Paul Latgé 《Eukaryotic cell》2013,12(6):853-863
The choline oxidase (CHOA) and betaine aldehyde dehydrogenase (BADH) genes identified in Aspergillus fumigatus are present as a cluster specific for fungal genomes. Biochemical and molecular analyses of this cluster showed that it has very specific biochemical and functional features that make it unique and different from its plant and bacterial homologs. A. fumigatus ChoAp catalyzed the oxidation of choline to glycine betaine with betaine aldehyde as an intermediate and reduced molecular oxygen to hydrogen peroxide using FAD as a cofactor. A. fumigatus Badhp oxidized betaine aldehyde to glycine betaine with reduction of NAD+ to NADH. Analysis of the AfchoAΔ::HPH and AfbadAΔ::HPH single mutants and the AfchoAΔAfbadAΔ::HPH double mutant showed that AfChoAp is essential for the use of choline as the sole nitrogen, carbon, or carbon and nitrogen source during the germination process. AfChoAp and AfBadAp were localized in the cytosol of germinating conidia and mycelia but were absent from resting conidia. Characterization of the mutant phenotypes showed that glycine betaine in A. fumigatus functions exclusively as a metabolic intermediate in the catabolism of choline and not as a stress protectant. This study in A. fumigatus is the first molecular, cellular, and biochemical characterization of the glycine betaine biosynthetic pathway in the fungal kingdom. 相似文献
934.
Leandro Freire dos Santos Ana Lucia Zanatta Vanete Thomaz Soccol Maria Fernanda Torres Sandro José Ribeiro Bonatto Rosália Rubel Carlos Ricardo Soccol 《Biotechnology and Bioprocess Engineering》2013,18(1):201-208
The ability of Pleurotus ostreatus biomass, cultived by submerged fermentation, to produce beneficial effect on lipid profile and macrophages activity during a high-fat diet (HFD) for a long-term intake was investigated. Blood samples were collected through cardiac puncture to measure the plasma cholesterol, triglycerides, low-density protein (LDL), high-density protein (HDL), aspartate aminotransferase (AST) activity, urea-blood urea nitrogen (BUN)/creatinine ratio of rats fed on an HFD for 4 months. Dosage of lipid hydroperoxides was carried out on methanolic extract of liver tissue. Peritoneal macrophages activity was evaluated in relation to the superoxide anion, hydrogen peroxide and nitric oxide production, phagocytosis and lysosomal volume. The administration of P. ostreatus significantly altered the lipid profile and oxidative stress as related to the LDL and triglycerides decrease and inhibitory effects on superoxide anion and hydrogen peroxide production. All findings of this study lead us to suggest that the P. ostreatus maybe a beneficial agent in the hyperlipidemia and atherosclerosis treatments. 相似文献
935.
Laçine Aksoy Erdi Kolay Yasin Ağılönü Zeyneb Aslan Mustafa Kargıoğlu 《Saudi Journal of Biological Sciences》2013,20(3):235-239
Thermopsis turcica, endemic to Turkey, is in danger of extinction. Studies on this species are very few due to the fact that it was only discovered in 1983 and grows in a small circumscribed area in Turkey. In this study, free radical scavenging activity, total phenolic content, total oxidant status (TOS), and total antioxidant status (TAS) of methanol (TTM) and acetone (TTA) extracts of T. turcica were measured spectroscopically. Free radical scavenging activity was determined according to the elimination of DPPH radicals and total phenol content was determined by the Folin–Ciocalteu reaction. Total oxidant status (TOS) and total antioxidant status (TAS) were measured with commercially available kits. Methanol and acetone extracts of T. turcica were found to have a specific radical scavenging effect. This effect was found to be related to the total phenolic content of the extracts. Since the TTA had a higher phenolic content than the methanol extract, it had a stronger radical scavenging effect. In addition, the total antioxidant capacity of the methanol extract was observed to be higher than that of its acetone counterpart. As a result, due to its antioxidative properties, T. turcica is thought to be a natural source of antioxidants. 相似文献
936.
Mathias Ahii Chia Ana Teresa Lombardi Maria da Graça Gama Melão 《Phycological Research》2013,61(4):286-291
Quantification of the calorific content of microalgae is critical in studies of energy flow, trophic partitioning, plant/herbivore interactions in aquaculture and biomass production for biofuels. We investigated the calorific value and biochemical composition of Chlorella vulgaris at different phosphorus (P) concentrations (6.0 × 10?7, 2.3 × 10?6 and 2.3 × 10?4 mol L?1 P). As expected, the control (2.3 × 10?4 mol L?1 P) supported better growth than P limited treatments. Biomolecules like total carbohydrates and lipids accumulated under P limitation, which significantly correlated with high calorific values. Lipid class composition showed that triacylglycerols were the most accumulated under P limited conditions. The calorific value reported under control conditions (13.78 kJ g?1) was less than those obtained under P limitation (30.47–33.07 kJ g?1). The highest calorific value with less growth retardation was obtained at 2.3 × 10?6 mol L?1 P. 相似文献
937.
The physiological ecology of Prasiola stipitata was examined in situ from two supralittoral sites in the Bay of Fundy (Nova Scotian, Canada) during November 2011, when the population was undergoing major expansion. Photosynthetic parameters (effective quantum yield, ΦPSII, maximum quantum yield, Fv/Fm, and relative electron transport rate, rETR) were evaluated using chlorophyll fluorescence of PSII. A largely shaded and continuously moist population showed no change in ΦPSII from one hour after sunrise to sunset in which natural irradiance varied between 3 and 300 μmol photons m?2 s?1. High irradiance (up to 1800 μmol photons m?2 s?1) had no apparent negative impacts on either quantum yield or rETR, but high desiccation in the field reduced quantum yield to almost zero. When thalli were brought into the laboratory, no change in Fv/Fm was observed up to 60% dehydration; however, there was a steep decline in Fv/Fm between 60% and 85% dehydration. Thalli showed complete recovery of Fv/Fm within one hour of reimmersion in seawater after 2 days of desiccation. After 15 days of desiccation full recovery required 24 h and after 30 days of desiccation thalli showed only partial recovery. These observations confirm the adaptation to photosynthesis in high irradiances and the rapid recovery following extreme desiccation observed in other Prasiola species. 相似文献
938.
Sachiko N. Isobe Hideki Hirakawa Shusei Sato Fumi Maeda Masami Ishikawa Toshiki Mori Yuko Yamamoto Kenta Shirasawa Mitsuhiro Kimura Masanobu Fukami Fujio Hashizume Tomoko Tsuji Shigemi Sasamoto Midori Kato Keiko Nanri Hisano Tsuruoka Chiharu Minami Chika Takahashi Tsuyuko Wada Akiko Ono Kumiko Kawashima Naomi Nakazaki Yoshie Kishida Mitsuyo Kohara Shinobu Nakayama Manabu Yamada Tsunakazu Fujishiro Akiko Watanabe Satoshi Tabata 《DNA research》2013,20(1):79-92
939.
940.
João de Pina‐Cabral 《The journal of the Royal Anthropological Institute》2013,19(1):75-101
This article is a study of personal naming using drawings made by secondary school students from two small towns in coastal Bahia (Brazil) of the persons who gave them their names. The article explores the relation between namer and named as one of continued identity created by imaginative processes of surrogation akin to pretend‐play. In early ontogeny, the person is constituted through a series of mutualities of being that come to constitute a core of affects. The article aims to contribute towards a better understanding of the processes of constitution of personhood in the context of human relatedness. 相似文献