Sequence-specific recognition of the major groove of DNA by oligodeoxynucleotides via triple helix formation. Footprinting studies.

Homopyrimidine oligodeoxynucleotides recognize the major groove of the DNA double helix at homopurine.homopyrimidine sequences by forming local triple helices. The oligonucleotide is bound parallel to the homopurine strand of the duplex. This binding can be revealed by a footprinting technique using copper-phenanthroline as a cleaving reagent. Oligonucleotide binding in the major groove prevents cleavage by copper-phenanthroline. The cleavage patterns on opposite strands of the duplex at the boundaries of the triple helix are asymmetric. They are shifted to the 3'-side, indicating that the copper-phenanthroline chelate binds in the minor groove of the duplex structure. Binding of the chelate at the junction between the triple and the double helix is not perturbed on the 5'-side of the bound homopyrimidine oligonucleotide. In contrast, a strong enhancement of cleavage is observed on the purine-containing strand at the triplex-duplex junction on the 3'-side of the homopyrimidine oligonucleotide

Therapeutical potentialities of 3'-end modified antisense oligonucleotides targeted to codon 12 mutated Ha-ras

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Oligonucleotides and oligonucleotide conjugates: A new approach for cancer treatment

In this account we summarise recent studies on oligonucleotides and oligonucleotide derivatives and their utilisation in antigene, antisense and decoy approaches, with particular attention to peptide nucleic acids, locked nucleic acids and oligonucleotide conjugates, the most promising compounds in this field

Oligonucleotides and Oligonucleotide Conjugates: A New Approach for Cancer Treatment

In this account we summarise recent studies on oligonucleotides and oligonucleotide derivatives and their utilisation in antigene, antisense and decoy approaches, with particular attention to peptide nucleic acids, locked nucleic acids and oligonucleotide conjugates, the most promising compounds in this field

Analysis of antisense oligonucleotides by on-capillary isotachophoresis and capillary polymer sieving electrophoresis

An attempt was made to evaluate the stability of an antisense oligonucleotide against nucleases present in HBL 100ras cells. To detect nanomolar concentrations of the oligonucleotide, a sensitive detection system was required. A combination of capillary electrophoresis/laser-induced fluorescence (CE-LIF) with fluorescence derivatization did not improve the sensitivity significantly and also resulted in loss of separation of the derivatized sample. On-column isotachophoresis for the preconcentration of oligonucleotide samples in DB-17 coated capillaries filled with hydroxyethyl cellulose solution could be an alternative. The isotachophoresis (ITP) step allows injection of up to 40% of the capillary volume without loss in peak resolution and peak efficiency. Using ITP-capillary polymer sieving electrophoresis (CPSE), the limit of quantitation at a signal-to-noise ratio of 10 was 73 ng/mL for a 12-mer oligonucleotide. Using these conditions, the gain in sensitivity was 125.status: publishe