256 results about "Nucleobase" patented technology

Based on the above and on the remarkable properties of the 2′-O,4′-C-methylene bridged LNA monomers it was decided to synthesise oligonucleotides comprising one or more 2′-O,4′-C-methylene-β-D-xylofuranosyl nucleotide monomer(s) as the first stereoisomer of LNA modified oligonucleotides. Modelling clearly indicated the xylo-LNA monomers to be locked in an N-type furanose conformation. Whereas the parent 2′-deoxy-β-D-xylofuranosyl nucleosides were shown to adopt mainly an N-type furanose conformation, the furanose ring of the 2′-deoxy-β-D-xylofuranosyl monomers present in xylo-DNA were shown by conformational analysis and computer modelling to prefer an S-type conformation thereby minimising steric repulsion between the nucleobase and the 3′-O-phopshate group (Seela, F.; Wömer, Rosemeyer, H. Helv. Chem. Acta 1994, 77, 883). As no report on the hybridisation properties and binding mode of xylo-configurated oligonucleotides in an RNA context was believed to exist, it was the aim to synthesise 2′-O,4′-C-methylene-β-D-xylofuranosyl nucleotide monomer and to study the thermal stability of oligonucleotides comprising this monomer. The results showed that fully modified or almost fully modified Xylo-LNA is useful for high-affinity targeting of complementary nucleic acids. When taking into consideration the inverted stereochemistry at C-3′ this is a surprising fact. It is likely that Xylo-LNA monomers, in a sequence context of Xylo-DNA monomers, should have an affinity-increasing effect.

Nucleic acid sequencing methods and related products are disclosed. Methods for sequencing a target nucleic acid comprise providing a daughter strand produced by a template-directed synthesis, the daughter strand comprising a plurality of subunits coupled in a sequence corresponding to a contiguous nucleotide sequence of all or a portion of the target nucleic acid, wherein the individual subunits comprise a tether, at least one probe or nucleobase residue, and at least one selectively cleavable bond. The selectively cleavable bond(s) is/are cleaved to yield an Xpandomer of a length longer than the plurality of the subunits of the daughter strand, the Xpandomer comprising the tethers and reporter elements for parsing genetic information in a sequence corresponding to the contiguous nucleotide sequence of all or a portion of the target nucleic acid. Reporter elements of the Xpandomer are then detected. Corresponding products, including Xpandomers and oligomeric and monomeric substrate constructs are also disclosed.

This application relates to monomers of the general formula (I) for the preparation of PNA (peptide nucleic acid) oligomers and provides method for the synthesis of both predefined sequence PNA oligomers and random sequence PNA oligomers:

wherein

• R1, R2, R3, R4, R5 is independently H, halogen, C₁–C₄ alkyl, nitro, nitrile, C₁–C₄ alkoxy, halogenated C₁–C₄ alkyl, or halogenated C₁–C₄ alkoxy, wherein at least one of R1, R3, and R5 is nitro;
• R6 is H or protected or unprotected side chain of natural or unnatural α-amino acid; and
• B is a natural or unnatural nucleobase, wherein when said nucleobase has an exocyclic amino function, said function is protected by protecting group which is labile to acids but stable to weak to medium bases.

The invention provides pharmaceutical compositions comprising short single stranded oligonucleotides, of length of between 8 and 17 nucleobases which are complementary to human microRNAs. The short oligonucleotides are particularly effective at alleviating miRNA repression in vivo. It is found that the incorporation of high affinity nucleotide analogues into the oligonucleotides results in highly effective anti-microRNA molecules which appear to function via the formation of almost irreversible duplexes with the miRNA target, rather than RNA cleavage based mechanisms, such as mechanisms associated with RNaseH or RISC.

One aspect of the present invention relates to a double-stranded oligonucleotide comprising at least one non-natural nucleobase. In certain embodiments, the non-natural nucleobase is difluorotolyl, nitroindolyl, nitropyrrolyl, or nitroimidazolyl. In a preferred embodiment, the non-natural nucleobase is difluorotolyl. In certain embodiments, only one of the two oligonucleotide strands comprising the double-stranded oligonucleotide contains a non-natural nucleobase. In certain embodiments, both of the oligonucleotide strands comprising the double-stranded oligonucleotide independently contain a non-natural nucleobase. In certain embodiments, the oligonucleotide strands comprise at least one modified sugar moiety. Another aspect of the present invention relates to a single-stranded oligonucleotide comprising at least one non-natural nucleobase. In a preferred embodiment, the non-natural nucleobase is difluorotolyl. In certain embodiments, the ribose sugar moiety that occurs naturally in nucleosides is replaced with a hexose sugar, polycyclic heteroalkyl ring, or cyclohexenyl group. In certain embodiments, at least one phosphate linkage in the oligonucleotide has been replaced with a phosphorothioate linkage.

The present invention relates to the use of oligonucleotides having modified nucleobases to inhibit gene expression and/or replication of viruses in a subject. The modified nucleobases may be mercapto-modified bases or hydroxy-modified nucleobases. It is contemplated that the oligonucleotides further comprise a nuclease complex which enhances anti-viral activity of the oligonucleotides.

The present invention relates to the production of a non-transgenic plant resistant or tolerant to a herbicide of the phosphonomethylglycine family, e.g., glyphosate. The present invention also relates to the use of a recombinagenic oligonucleobase to make a desired mutation in the chromosomal or episomal sequences of a plant in the gene encoding for 5-enol pyruvylshikimate-3-phosphate synthase (EPSPS). The mutated protein, which substantially maintains the catalytic activity of the wild-type protein, allows for increased resistance or tolerance of the plant to a herbicide of the phosphonomethylglycine family, and allows for the substantially normal growth or development of the plant, its organs, tissues or cells as compared to the wild-type plant irrespective of the presence or absence of the herbicide.

The invention provides pharmaceutical compositions comprising short single stranded oligonucleotides, of length of between 8 and 26 nucleobases which are complementary to human microRNAs selected from the group consisting of miR19b, miR21, miR122a, miR155 and miR375. The short oligonucleotides are particularly effective at alleviating miRNA repression in vivo. It is found that the incorporation of high affinity nucleotide analogues into the oligonucleotides results in highly effective anti-microRNA molecules which appear to function via the formation of almost irreversible duplexes with the miRNA target, rather than RNA cleavage based mechanisms, such as mechanisms associated with RNaseH or RISC.

The present invention relates to novel methods and novel solid support materials for the tandem synthesis of two or more different oligonucleotides on the same solid support in one synthetic run. The methods involve novel support preparations comprised of two or more types of orthogonally protected anchor groups. Subsequent to the selective removal of the first of the respective protective groups, the first oligonucleotide is assembled on the deblocked anchor groups according to standard methods, preferably via phosphoramidite chemistry. Following the capping of said first oligonucleotide, the anchor groups blocked by the second type of protective group are selectively liberated and serve is the starting point for the assembly of a second oligonucleotide, and so forth. After completion of all of the syntheses on the solid support, the oligonucleotides are released from the solid support and deprotected at the nucleobases, using standard methods. Preparations obtained using the method of this invention, generally contain two or more different oligonucleotides. Such preparations are particularly useful in applications that require pairs of oligonucleotide primers, several probes at a time, duplexed nucleic acid fragments, or other combinations of oligonucleotides that are useful in applications such as PCR, sequencing, multiplexed genotyping, cloning and RNA interference. The invention includes procedures for the preparation of the novel solid supports of the invention.

The present invention relates to intercalator pseudonucleotides. Intercalator pseudonucleotides according to the invention are capable of being incorporated into the backbone of a nucleic acid or nucleic acid analogue and they comprise an intercalator comprising a flat conjugated system capable of co-stacking with nucleobases of DNA. The invention also relates to oligonucleotides or oligonucleotide analogues comprising at least one intercalator pseudo nucleotide. The invention furthermore relates to methods of synthesising intercalator pseudo nucleotides and methods of synthesising oligonucleotides or oligonucleotide analogues comprising at least one intercalator pseudonucleotide. In addtition, the invention describes methods of separating sequence specific DNA(s) from a mixture comprising nucleic acids, methods of detecting a sequence specific DNA (target DNA) in a mixture comprising nucleic acids and/or nucleic acid analogues and methods of detecting a sequence specific RNA in a mixture comprising nucleic acids and/or nucleic acid analogues. In particular said methods may involve the use of oligonucleotides comprising intercalator pseudo nucleotides. The invention furthermore relates to pairs of oligonucleotides or oligonucleotide analogues capable of hybridising to one another, wherein said pairs comprise at least one intercalator pseudonucleotide. Methods for inhibiting a DNAse and/or a RNAse and methods of modulating transcription of one or more specific genes are also described.

Oligonucleotide conjugates, where an oligonucleotide is covalently attached to an aromatic system, are provided. In particular embodiments the oligonucleotide is complementary to the RNA component of human telomerase and is covalently attached to a nucleobase via an optional linker. The conjugates inhibit telomerase enzyme activity.

A novel nucleoside analog is disclosed which comprises a piperazine ring in the place of the ring ribose or deoxyribose sugar. Monomers utilizing a broad variety of nucleobases are disclosed, as well as oligomers comprising the monomers disclosed herein linked by a variety of linkages, including amide, phosphonamide, and sulfonamide linkages. A method of synthesizing the nucleoside analogs is also disclosed.

Some aspects of this disclosure provide strategies, systems, reagents, methods, and kits that are useful for the targeted editing of nucleic acids, including editing a single site within the genome ofa cell or subject, e.g., within the human genome. In some embodiments, fusion proteins of Cas9 and nucleic acid editing proteins or protein domains, e.g., deaminase domains, are provided. In some embodiments, methods for targeted nucleic acid editing are provided. In some embodiments, reagents and kits for the generation of targeted nucleic acid editing proteins, e.g., fusion proteins of Cas9 andnucleic acid editing proteins or domains, are provided.

An artificial promoter library (or a set of promoter sequences) for a selected organism or group of organisms is constructed as a mixture of double stranded DNA fragments, the sense strands of which comprise at least two consensus sequences of efficient promoters from said organism or group of organisms, or parts thereof comprising at least half of each, and surrounding intermediate nucleotide sequences (spacers) of variable length in which at least 7 nucleotides are selected randomly among the nucleobases A, T, C and G. The sense strands of the double stranded DNA fragments may also include a regulatory DNA sequence imparting a specific regulatory feature, such as activation by a change in the growth conditions, to the promoters of the library. Further, they may have a sequence comprising one or more recognition sites for restriction endonucleases added to one or both of their ends. The selected organism or group of organisms may be selected from prokaryotes and from eukaryotes; and in prokaryotes the consensus sequences to be retained most often will comprise the −35 signal (−35 to −30): TTGACA and the −10 signal (−12 to −7): TATAAT or parts of both comprising at least 3 conserved nucleotides of each, while in eukaryotes said consensus sequences should comprise a TATA box and at least one upstream activation sequence (UAS). Such artificial promoter libraries can be used, e.g., for optimizing the expression of specific genes in various selected organisms.