RESUMO
The properties of new chimeric oligodeoxynucleotides made of short sequences (tetramers, pentamers, octamers, and decamers) bridged by hexamethylenediol and hexaethylene glycol linkers have been investigated. These chimeric oligonucleotides showed an improved resistance toward snake venom 3'-phosphodiesterase, with an increased stability when a terminal 3'-3'-internucleotide phosphodiester bond is present. It also has been demonstrated that the hybrid complexes formed by bridged oligonucleotides and a complementary 20-mer RNA are able to elicit the activity of ribonuclease H (RNase H) from Escherichia coli. The substrate properties of chimeric oligonucleotides depend on the length of the oligonucleotide fragments bridged by linkers. Introduction of a nonnucleotide spacer into the native oligonucleotide only slightly hampers the extent of the RNA hydrolysis in the hybrid complexes, whereas a modification of the site of reaction is observed as a possible consequence of the steric disturbance due to the aliphatic linkers. Hence, these new chimeric oligonucleotides, namely, short oligonucleotide fragments bridged by nonnucleotide linkers, demonstrate a favorable combination of exonuclease resistance and high substrate activity toward RNase H. As a consequence, these chimeric oligonucleotides could be proposed as new, promising analogs to be used in the antisense strategy.
Assuntos
Glicóis/metabolismo , Oligodesoxirribonucleotídeos/metabolismo , Ribonuclease H/metabolismo , Etilenoglicóis/química , Etilenoglicóis/metabolismo , Glicóis/química , Hidrólise , Oligodesoxirribonucleotídeos/química , Oligorribonucleotídeos/metabolismoRESUMO
A new amphiphilic, high-molecular weight poly (N-acryloylmorpholine) (PAcM) polymer has been used to be linked to oligonucleotide chains through a liquid-phase stepwise synthesis. This new conjugate has been investigated for its melting property, nuclease stability and capacity to elicit RNase H activity. Its antisense activity against an HIV-1 target has been also evaluated.
Assuntos
Morfolinas/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Ribonuclease H/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glucosídeos , Inosina/análogos & derivados , Estrutura Molecular , Peso Molecular , Morfolinas/síntese química , Morfolinas/química , Desnaturação de Ácido Nucleico , Oligonucleotídeos Antissenso/síntese química , Oligonucleotídeos Antissenso/química , Polietilenoglicóis/química , SolubilidadeRESUMO
Two conjugates of an anti-HIV oligonucleotide (ODN) with different high molecular weight monomethoxy polyethylene glycols (MPEGs) have been tested for their activity as substrate towards RNase H. The MPEG does not impede the formation of the regular hybrid duplex with the target RNA sequence as pointed out by the persistence of the RNase H activity; thus, these derivatives stimulate the hydrolysis of RNA by the enzyme at the same site and with the same extent of cleavage as the native sequence.
