Functionalization and Self-Assembly of DNA Bidimensional Arrays

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

α,γ-Peptide nanotube templating of one-dimensional parallel fullerene arrangements

(Figure Presented) The formation and full characterization of single self-assembling α,γ-peptide nanotubes (α,γ-SPNs) is described. The introduction of C60 into cyclic peptides allows the preparation of supramolecular 1D fullerene arrangements induced by peptide nanotube formation under appropriate conditions. © 2009 American Chemical Society.This work was supported by the Spanish Ministry of Education and Science and the ERDF [SAF2007-61015 and Consolider Ingenio 2010 (CSD2007-00006)] and the Xunta de Galicia (GRC2006/ 132, PGIDIT06PXIB209018PR, PGIDIT08CSA047209PR, and R2006/ 124). The work by J.M.V. and J.L.C. was supported by Grants BFU2007- 62382/BMC from the Spanish MEC (J.M.V.) and S-0505/MAT/0283 from the Madrid Regional Government (J.M.V. and J.L.C.). C.R. and R.J.B. thank the Spanish MEC for their FPU Fellowships. We also thank Dr. Carmen Serra (Nanotechnology and Surface Analysis Service at C.A.C.T.I., University of Vigo) for her help with STM. We also thank Dowpharma for their kind gift of ENZA enzymes used in the preparation of D-Boc-γ-Acp-OH.Peer reviewe

Solid-phase synthesis of oligodeoxynucleotides containing N4-[2-(t-butyldisulfanyl)ethyl]-5-methylcytosine moieties

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.This research was supported by the EECC (grants DYNAMO, NEST-ADV028669, FUNMOL, FP7-NMP-213382-2), by the Spanish Ministry of Education (BFU2007-63287) and the Generalitat de Catalunya (2009/SGR/208). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Peer reviewe

Assembly of two-dimensional DNA crystals carrying N 4-[2-(tert- butyldisulfanyl)ethyl]cytosine residues

DNA Lattices carrying two cytosine residues bearing the N 4-[(tert-butyldisulfanyl)ethyl] group at the apex of hairpin topological markers are prepared for first time. We show that these residues are important for the deposition of DNA lattices on gold surfaces.Peer reviewe

Synthesis of Oligonucleotide–Peptide Conjugates for Biomedical and Technological Applications

Oligonucleotide–peptide conjugates have attracted considerable interest especially for biomedical uses. In the first part of this chapter, we describe protocols for the stepwise synthesis of oligonucleotides carrying peptide sequences at the 3¢-end on a single support. The resulting oligonucleotide–peptide conjugates may be used as exogenous effectors for the specific control of gene expression. In the second part of this chapter, detailed postsynthetic conjugation protocols to introduce peptide sequences into oligonucleotide sequences are also presented.This work is supported by the Spanish Ministry of Education (BFU2007-63287/BMC), Generalitat de Catalunya (2009/ SGR/238), Instituto de Salud Carlos III (CIBER-BNN), and European Communities (DYNAMO contract 028669 (NEST), FUNMOL NMP4-SL-2009-213382).Peer reviewe

Synthesis and hybridization properties of modified oligodeoxynucleotides carrying non-natural bases

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 DNAmelting 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.Peer reviewe