RESUMO
The synthesis of a conjugated linear organic module containing terminal salicylaldehyde groups and a central activated ester, designed for conjugation to amino-modified oligonucleotides, is presented. The organic module has a phenylene-ethynylene backbone and is highly fluorescent. It is conjugated to oligonucleotide sequences and incorporated into specific locations in a well-defined DNA 4-helix bundle (4-HB). The DNA-nanostructure offers precise location control of the organic modules which allows for selective interhelical coupling reactions. In this study, metal-salen formation as well as dihydrazone formation are used to covalently interlink the organic modules. Both coupling reactions are highly dependent on the distances between the organic modules in the 4-HB. Neighboring modules dimerize easier, whereas more distanced modules are less prone to react, even when the linkers are extended. The dimeric products are characterized by denaturing polyacrylamide gel electrophoresis (PAGE), high performance liquid chromatography (HPLC), and matrix assisted laser desorption/absorption ionization time-of-flight (MALDI TOF) mass spectrometry.
Assuntos
Aldeídos/química , Alcinos/química , DNA/química , Ésteres/química , Éteres/química , Alcinos/síntese química , Éteres/síntese química , Modelos Moleculares , Estrutura Molecular , Conformação de Ácido Nucleico , EstereoisomerismoRESUMO
We are presenting the synthesis of a phenylene ethynylene-based rod containing an Fmoc protected amino group and an activated acid which can be applied to peptide couplings. This linear amino acid analogue is applied to the synthesis of di-, tri- and pentamers. The pentamer has a molecular mass of 6.5 kDa and is characterized by (1)H NMR spectroscopy and MALDI-TOF MS. The method has potential for the formation of long macromolecular oligomers.
Assuntos
Alcinos/química , Química/métodos , Éteres/química , Espectroscopia de Ressonância Magnética/métodos , Oligonucleotídeos/síntese química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Aminoácidos/química , Dimerização , Eletroquímica/métodos , Modelos Químicos , Conformação Molecular , Oligonucleotídeos/química , Peptídeos/química , SolubilidadeRESUMO
Assembly of gold nanoparticles (AuNP) into designer architectures with reliablity is important for nanophotonics and nanoelectronics applications. Toward this goal we present a new strategy to prepare AuNPs monofunctionalized with lipoic acid modified DNA oligos. This strategy offers increased bonding strength between DNA oligos and AuNP surface. These conjugates are further selectively mixed with other DNA strands and assembled into fixed sized DNA nanostructures carring a discrete number of AuNPs at desired positions. Atomic force microscopy imaging reveals a dramatically improved yield of the AuNPs on DNA tile structure compared to the ensembles using monothiolate AuNP-DNA conjugates.
Assuntos
DNA/química , Ouro/química , Nanopartículas/química , Nanotecnologia , Microscopia de Força Atômica , Propriedades de SuperfícieRESUMO
A series of homo- and heteroditopic thymine- and/or adenine-terminated molecules incorporating rigid aryl or oligo(phenylene ethynylene) linkers has been efficiently synthesized. The key steps involved in the synthesis are the construction of the N-arylated nucleobases using the Chan-Lam-Evans-modified Ullman coupling and their further elaboration using the Sonogashira coupling. Furthermore, the synthesis of a rigid tripodal thymine derivative is reported.
