RESUMO
Oligonucleotides carrying amino, thiol groups, as well as fluorescein, c-myc peptide sequence and nanogold at internal positions were prepared and used for the assembly of bidimensional DNA arrays.
Assuntos
DNA/química , DNA/síntese química , Conformação de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Aminoácidos/química , Sequência de Bases , Eletroforese em Gel de Ágar , Eletroforese em Gel de Poliacrilamida , Fluoresceína/química , Ouro/química , Nanopartículas Metálicas/química , Microscopia de Força Atômica , Oligonucleotídeos/química , Compostos de Sulfidrila/químicaRESUMO
An efficient route for the synthesis of the phosphoramidite derivative of 5-methylcytosine bearing a tert-butylsulfanyl group protected thiol is described. This building block is used for the preparation of oligonucleotides carrying a thiol group at the nucleobase at the internal position of a DNA sequence. The resulting thiolated oligonucleotides are useful intermediates to generate oligonucleotide conjugates carrying molecules of interest at internal positions of a DNA sequence.
Assuntos
5-Metilcitosina/análogos & derivados , 5-Metilcitosina/química , Química Orgânica/métodos , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/síntese química , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Corantes Fluorescentes/química , Iodo/química , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/genética , Soluções , terc-Butil Hidroperóxido/químicaRESUMO
The impact of the presence of nonnatural bases on the properties of oligodeoxynucleotides has been studied. First, oligodeoxynucleotides carrying 2'-deoxyzebularine were prepared, and the stability of duplexes carrying this analogue was determined by DNA melting experiments. Melting temperatures and thermodynamic data indicated the preference of 2'-deoxyzebularine for 2'-deoxyguanosine, which behaves as a 2'-deoxycytidine analogue, forming a less stable base pair due to the absence of the amino group at position 4. Moreover, the duplex-hairpin equilibrium of a self-complementary oligodeoxynucleotide carrying several natural and nonnatural bases including 2'-deoxyzebularine as a central mispair, was studied. Depending on the base present in the middle of the sequence, it is possible to affect the stability of the bimolecular duplex modulating the duplex-hairpin equilibrium. Magnesium ions were shown to stabilize preferentially the bimolecular duplex form. The results indicate the importance of the modifications and the role of cations in shifting the structural equilibrium.
Assuntos
Citidina/análogos & derivados , DNA/química , Oligodesoxirribonucleotídeos/química , Pareamento de Bases , Sequência de Bases , Citidina/síntese química , Citidina/química , DNA/genética , Conformação de Ácido Nucleico , Desnaturação de Ácido Nucleico , Hibridização de Ácido Nucleico , Oligodesoxirribonucleotídeos/genética , Temperatura , TermodinâmicaRESUMO
We have used DNA double crossover (DX) molecules to produce a translation system that generates unique molecular products. The particular species of DX molecule used contains an even number of half-turns between crossover points, so there is a continuous strand on both sides of the molecule. One of these strands acts as the input strand containing the message, and a second strand acts as the product of translation. The crossover strands carry the "code" that connects the two sides of the molecule. This system is more robust, more extendable, and simpler than previous DNA-based translation systems that have been reported. It is designed to be useful in a variety of applications that utilize the concept of translating from one code to another.
Assuntos
Computadores Moleculares , DNA/química , DNA/genética , Nanotecnologia/métodos , Biossíntese de Proteínas , Fenômenos BiomecânicosRESUMO
DNAzymes are catalytically active DNA molecules, which have previously been described in solution. Here, we organize these molecules into a series of two-dimensional (2D) arrays using a periodic arrangement of DNA structures based on the DNA double crossover motif. We demonstrate by means of atomic force microscopy that the DNAzymes are organized according to the design and that they retain their activity when attached in linear strings within the context of the 2D array.