共查询到20条相似文献,搜索用时 15 毫秒
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Inhibition of micro-RNA-induced RNA silencing by 2′-O-methyl oligonucleotides in Drosophila S2 cells
Berger EM Dubrovsky EB Appleby L Dubrovskaya V 《In vitro cellular & developmental biology. Animal》2005,41(1-2):12-18
Summary More than 90 different micro-ribonucleic acid (miRNA) encoding genes have been identified in Drosophila, yet the function of only two of these, bantam and DmiR-14, has been elucidated. In an effort to develop a general strategy for the analysis of miRNA function in Drosophila, two procedures were developed, in a Schneider line 2 cell culture system, which may be adapted to that end. First, we show
that endogenous miRNAs can partially inhibit the expression of a transiently transfected reporter gene that has been modified
to contain sequences complementary to that miRNA in the 3′ UTR of a target messenger RNA (mRNA). Inhibition occurs by RNA
interference (RNAi), which involves mRNA degradation. Second, we demonstrate that this miRNA-induced RNAi can be partially
rescued with 2′-O-methyl oligonucleotides that contain sequences complementary to the cognate miRNA. We discuss how these techniques may be
used, in vivo, both for localizing the tissue distribution of endogenous miRNAs during Drosophila development and identifying phenotypes associated with a loss of miRNA function. 相似文献
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Wang Z Siwkowski A Lima WF Olsen P Ravikumar VT 《Bioorganic & medicinal chemistry》2006,14(14):5049-5060
Multiple 2'-O-methoxyethyl modified phosphorothioate oligonucleotides of 18-20-mer in length were synthesized at various scales using 4,5-dicyanoimidazole (DCI) as coupling activator. Extensive synthetic, analytical (using ion-pair LC-MS), and in vivo pharmacological, toxicological studies showed that oligonucleotides made with DCI and 1H-tetrazole are chemically and biologically equivalent. This extensive study will help the oligonucleotide therapeutic industry to move from using a potentially explosive activator (1H-tetrazole) to a safe activator (DCI). 相似文献
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Philip G. Bardin Mark A. Pickett Stephen B. Robinson Gwen Sanderson Stephen T. Holgate Sebastian L. Johnston 《Histochemistry and cell biology》1993,100(5):387-392
Oligonucleotide probes enzymatically labelled at the 3-end with biotin have been used successfully to detect target RNA and DNA in combination with in situ hybridisation. Addition of multiple biotin residues to the 3-end increases the hybridisation signals, but it is not known whether the same principle is applicable to the 5-end. We have labelled a 35-base oligonucleotide during synthesis with 1, 5 and 12 biotin molecules at the 5-end and compared it to conventional 3-labelling. In additional experiments the probes were labelled at both ends. Probes were applied to histological sections obtained from paraffin-embedded cell-clot-complexes that contain uninfected and Rhinoviral-infected cells, using a standard in situ hybridisation protocol with appropriate controls. Hybridisation signals were compared for intensity of cytoplasmic signal and sensitivity as number of positive cells. Both parameters increased in parallel with higher numbers of biotin residues attached to the 5-end and 12 biotin residues were almost as effective as 3-enzymatic tailing. The sensitivity could be increased above that of either 3- or 5-labelling by the addition of residues at both ends of the probe. The 5-attachment of biotin residues can extend the value of oligonucleotide probes employed for in situ hybridisation and yield increased sensitivity when combined with 3-enzymatic labelling. 相似文献
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S. V. Kochetkova A. M. Varizhuk N. A. Kolganova E. N. Timofeev V. L. Florent’ev 《Russian Journal of Bioorganic Chemistry》2009,35(1):68-74
An improved method for the synthesis of 3-deoxy-3-carboxymethyl nucleosides was suggested. Oxidation of 5-O-benzoyl-1,2-O-isopropylidene-α-D-xylofuranose resulted in the 3-keto derivative, which was treated with triethylphosphonoacetate in the presence of sodium hydride to obtain the 3-deoxy-3-ethoxycarbonylmethylene derivative. Hydrogenation of the unsaturated compound proceeded strictly stereospecifically and gave the product with the ribo-configuration. Acetolysis of the resulting compound with AcOH-Ac2O-CH3SO3H led to 1,2-di-O-acetyl-5-O-benzoyl-3-deoxy-3-ethoxycarbonylmethyl-D-ribofuranose, whose interaction with persilylated nucleic bases gave 3-deoxy-3-ethoxycarbonylmethylnucleosides in a total yield of 42–49% from the starting compound. 相似文献
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Maiko Higuchi Akio Kobori Asako Yamayoshi Akira Murakami 《Bioorganic & medicinal chemistry》2009,17(2):475-483
2′-O-Psoralen-conjugated antisense oligonucleotide was able to recognize a point mutation of mRNA. It had outstanding ability to photo-cross-link only to oligoribonucleotides (ORN) having a point mutation. This type of antisense molecule is the only one of its kind so far. To give high photo-cross-linking efficiency and sequence selectivity to antisense molecules, we synthesized novel photo-reactive oligonucleotides (2′-Ps-xom) containing psoralen at the 2′-O-position adenosine via an ethoxymethylene (2′-Ps-eom), propoxymethylene (2′-Ps-pom) and butoxymethylene (2′-Ps-bom) linker, respectively. We evaluated the photo-cross-linking efficiency and sequence selectivity in photo-cross-linking of 2′-Ps-xom to the complementary ORN and to an ORN having a mismatch base. Among them, 2′-Ps-eom exhibited superior photo-cross-linking efficiency with high sequence selectivity. 相似文献
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Abstract 2′-Azido-2′-deoxyuridine and 2′-azido-2′-deoxycytidine were evaluated for their inhibitory activity against ribonucleotide reductase and for subsequent cell growth inhibition. Their mono-and di-phosphates were synthesized and their inhibitory activities against the reductase were also determined in a permeabilized cell system, along with the two nucleosides. The results of the present study identify the first phosphorylation step involved in the conversion of the two azidonucleosides to the corresponding diphosphates to be rate-limiting in the overall activation. 相似文献
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Yoshiaki Masaki Keishi Yamamoto Takeshi Inde Keita Yoshida Atsuya Maruyama Tetsuya Nagata Jun Tanihata Shinichi Takeda Mitsuo Sekine Kohji Seio 《Bioorganic & medicinal chemistry letters》2019,29(2):160-163
The effect of 2′-O-(N-methylcarbamoyl)ethyl (MCE) modification on splice-switching oligonucleotides (SSO) was systematically evaluated. The incorporation of five MCE nucleotides at the 5′-termini of SSOs effectively improved the splice switching effect. In addition, the incorporation of 2′-O-(N-methylcarbamoylethyl)-5-methyl-2-thiouridine (s2TMCE), a duplex-stabilizing nucleotide with an MCE modification, into SSOs further improved splice switching. These SSOs may be useful for the treatment of genetic diseases associated with splicing errors. 相似文献
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Ivan Zlatev Jeremy G. Lackey Ligang Zhang Amy Dell Kathy McRae Sarfraz Shaikh Richard G. Duncan Kallanthottathil G. Rajeev Muthiah Manoharan 《Bioorganic & medicinal chemistry》2013,21(3):722-732
A fully automated chemical method for the parallel and high-throughput solid-phase synthesis of 5′-triphosphate and 5′-diphosphate oligonucleotides is described. The desired full-length oligonucleotides were first constructed using standard automated DNA/RNA solid-phase synthesis procedures. Then, on the same column and instrument, efficient implementation of an uninterrupted sequential cycle afforded the corresponding unmodified or chemically modified 5′-triphosphates and 5′-diphosphates. The method was readily translated into a scalable and high-throughput synthesis protocol compatible with the current DNA/RNA synthesizers yielding a large variety of unique 5′-polyphosphorylated oligonucleotides. Using this approach, we accomplished the synthesis of chemically modified 5′-triphosphate oligonucleotides that were annealed to form small-interfering RNAs (ppp-siRNAs), a potentially interesting class of novel RNAi therapeutic tools. The attachment of the 5′-triphosphate group to the passenger strand of a siRNA construct did not induce a significant improvement in the in vitro RNAi-mediated gene silencing activity nor a strong specific in vitro RIG-I activation. The reported method will enable the screening of many chemically modified ppp-siRNAs, resulting in a novel bi-functional RNAi therapeutic platform. 相似文献
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Abstract Two nucleoside analogs were synthesized to test the ribose conformational and electronic effects on phosphate hydrolysis at the 3′ position. It was found that under alkaline conditions, a 2′-fluoro-nucleoside (C3′-endo) resulted in a phosphate degradation that was ten times faster than the 2′-deoxynucleoside analog (C2′-endo). In addition to kinetic differences, product distributions will be presented. 相似文献
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Danny P. C. McGee Chandra Vargeese Yansheng Zhai Gary P. Kirschenheuter Alecia Settle Colleen R. Siedem 《Nucleosides, nucleotides & nucleic acids》2013,32(6):1329-1339
Abstract The synthesis of 2′-amino-2′-deoxypyrimidine 5′-triphosphates is described. The 2′-amino-2′-deoxyuridine 5′-triphosphate is obtained from uridine in four steps with 25% overall yield. The 2′-amino-2′-deoxycytidine 5′-triphosphate is obtained from uridine in seven steps with 13% overall yield. 相似文献
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A. M. Varizhuk S. V. Kochetkova N. A. Kolganova E. N. Timofeev V. L. Florent’ev 《Russian Journal of Bioorganic Chemistry》2009,35(5):585-591
A method for the synthesis of 5′-deoxy-5′-ethoxycarbonylmethyl nucleosides has been developed. 3-O-benzyloxymethyl-1,2-O-isopropylidene-α-D-allofuranose was oxidized by sodium periodate to form a 5′-aldo derivative, which was converted by the reaction with triethylphosphonoacetate
in the presence of sodium hydride into a 5-deoxy-5-ethoxycarbonylmethylene derivative. The hydration of the unsaturated compound
gave 5-deoxy-5-ethoxycarbonylmethyl-1,2-O-isopropylidene-α-D-ribofuranose. After the benzylation of 3-hydroxyl, the removal of the isopropylidene group by heating with acetic acid, and
the subsequent acetylation, 1,2-di-O-acetyl-3-O-benzyl-5-deoxy-5-ethoxycarbonylmethyl-D-ribofuranose was obtained, which reacted with persilylated nucleic acid bases to form 5′-deoxy-5′-ethoxycarbonylmethyl nucleosides. 相似文献
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The interaction of 4′-6-diamidino-2-phenylindole · 2 HCl with natural and synthetic polydeoxy- and polyribonucleotides of
different base content and sequences was studied with circular dichroism, ultracentrifugation, viscosity and calorimetry.
All the polymers show two types of binding. The strength of interaction and its resistence to ionic strength are related to
the content of AT clusters in the chain. On the other hand, sedimentation measurements rule out an intercalation mechanism.
A model of 4'-6-diamidino-2-phenylindole · 2 HCl interaction with DNA and double stranded RNA, similar to that displayed by
distamycin and netropsin, is proposed. 相似文献
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Takashi Utagawa Hirokazu Morisawa Shigeru Yamanaka Akihiro Yamazaki Yoshio Hirose 《Bioscience, biotechnology, and biochemistry》2013,77(9):2711-2717
The microbial synthesis of some purine 2′-amino-2′-deoxyribonucleosides from purine bases and 2′-amino-2′-deoxyuridine is described. Various bacteria, especially Erwinia herbicola, Salmonella schottmuelleri, Enterobacter aerogenes and Escherichia coli, were able to transfer the aminoribosyl moiety of 2′-amino-2′-deoxyuridine to purine bases (transaminoribosylation) in the presence of inorganic phosphate. The optimum conditions for the reaction were pH 7.0 and 63°C. No reaction was observed in the absence of inorganic phosphate and the optimum concentration of it was around 30 mm. Adenine, guanine, 2-chlorohypoxanthine and hypoxanthine were transformed to the corresponding 2′-amino-2′-deoxyribonucleosides by the catalytic activity of the wet cell paste of Enterobacter aerogenes AJ 11125. The enzymatically synthesized purine 2′-amino-2′-deoxyribonucleosides were isolated and identified by physicochemical means. 2′-Amino-2′-deoxyadenosine strongly inhibited the growth of Hela cells in tissue culture, and the ED50 was 2.5μ/ml. 相似文献
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Miroslav Bobek 《Carbohydrate research》1979,70(2):263-273
A general method for the preparation of 2′-azido-2′-deoxy- and 2′-amino-2′-deoxyarabinofuranosyl-adenine and -guanine nucleosides is described. Selective benzoylation of 3-azido-3-deoxy-1,2-O-isopropylidene-α-d-glucofuranose afforded 3-azido-6-O-benzoyl-3-deoxy-1,2-O-isopropylidene-α-d-glucofuranose (1). Acid hydrolysis of 1, followed by oxidation with sodium metaperiodate and hydrolysis by sodium hydrogencarbonate gave 2-azido-2-deoxy-5-O-benzoyl-d-arabinofuranose (3), which was acetylated to give 1,3-di-O-acetyl-2-azido-5-O-benzoyl-2-deoxy-d-arabinofuranose (4). Compound 4 was converted into the 1-chlorides 5 and 6, which were condensed with silylated derivatives of 6-chloropurine and 2-acetamido-hypoxanthine. The condensation reaction gave α and β anomers of both 7- and 9-substituted purine nucleosides. The structures of the nucleosides were determined by n.m.r. and u.v. spectroscopy, and by correlation of the c.d. spectra of the newly prepared nucleosides with those published for known purine nucleosides. 相似文献
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