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We describe for the first time the co-existence of the parallel and antiparallel conformation of the heterodimeric E3/K3 and E3/R3 coiled-coil systems in solution. The introduction of a furanylated amino acid in the (EIAALEK)3 sequence allowed, upon photo-induced covalent crosslinking, freezing of the respective coiled-coil complexes present in solution. The occurrence of both parallel and antiparallel conformations in solution was supported by computational simulations and further confirmed by fluorescence experiments based on pyrene-pyrene stacking.

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Trastuzumab (Herceptin®) is an FDA-approved therapeutic antibody currently employed in the treatment of metastatic stages of breast cancer. Herein, we propose a simple, fast and cost-effective methodology to conjugate trastuzumab with 22-mer 5' thiol-modified oligonucleotides using a bifunctional crosslinker. The conjugates were successfully characterized by MALDI-ToF MS and SDS-PAGE, obviating the need for enzymatic digestion and difficult chromatographic separations. Furthermore, ELISA was performed to ensure that trastuzumab activity is not affected by oligonucleotide conjugation.

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We here report on the design and synthesis of tailor-made furan-modified peptide nucleic acid (PNA) probes for covalent targeting of single stranded DNA through a crosslinking strategy. After introducing furan-containing building blocks into a PNA sequence, hybridization and furan-oxidation based crosslinking to DNA is investigated. The structure of the crosslinked products is characterized and preliminary investigations concerning the application of these systems to double stranded DNA are shown.

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Furan mediated nucleic acid cross-linking, initially developed for DNA interstrand duplex cross-linking, has matured into a versatile tool for the study of protein and nucleic acid interactions, ready to face its applications. The methodology was initially developed for easy and clean chemical generation of DNA interstrand cross-linked duplexes, but has been further expanded for use with other probes, targets and triggers, now allowing mild biologically significant cross-linking with potential therapeutic benefit. It was shown that the methodology could be repurposed for RNA interstrand cross-linking, which is very relevant in today's antisense approaches or miRNA target identification endeavors. This further illustrates the furan oxidation method's generality and mildness, especially when using red light for oxidation. A complementary antigene approach has been explored through duplex targeting with furan modified triplex forming oligonucleotides (TFOs) and DNA binding proteins. Also targeting of peptides and proteins by furan-modified DNA and peptides has been explored. Thorough methodology examination exploring variable reaction conditions in combination with a series of different furan-modified building blocks and application of different activation signals resulted in a detailed understanding of the mechanisms involved and factors influencing the yield and selectivity of the reaction. In order to draw the bigger picture of the scope and limitations of furan-oxidation cross-linking, we here provide a unique side by side comparison and discussion of our published data, supplemented with unpublished results, providing a clear performance report of the currently established furan toolbox and its application potential in various biomacromolecular complexes.

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We here report on the furan oxidation methodology for interstrand cross-linking of RNA duplexes, which have a different structure and are more stiff, reactive and labile than their DNA counterparts. Through this mildly inducible approach, natural unmodified RNA can be selectively cross-linked in high yield. The method therefore has direct applications in the increasing number of RNA based technologies.

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A novel furan containing phosphoramidite was synthesized and incorporated into model oligonucleotides. This glycol nucleic acid based building block contains a furan unit substituting the natural base, and can be used for post synthetic oligonucleotide modifications by orthogonal chemistries such as Schiff base formation after in situ oxidation or Diels-Alder cycloadditions.

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A novel nucleoside analogue, 2'-naphthylmethyl-2'-deoxytubercidine, is synthesized and incorporated in oligonucleotides that stabilize bulges in partially complementary RNA.

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A convergent synthesis has been developed for the preparation of solid-phase bound construct 1, consisting of an orthogonally protected trifunctional core structure that is attached to TentaGel via a photocleavable linker. [structure: see text]

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Recursive deconvolution of a 729-membered peptide library has identified three active sequences, in which both Ser and His are present in one of the two tripeptidic chains generated on a steroidal scaffold (see structural formula), for the cleavage of an activated p-nitrophenyl ester. This combinatorial approach aims at searching for serine-protease-like activity.