Synthesis and Properties of 2′-Deoxycytidine Triphosphate Carrying C-Myc Tag Sequence

Abstract

The synthesis of 2′-deoxycytidine triphosphate carrying mercaptoethyl groups at position 4 of cytosine is described. This nucleoside triphosphate was reacted with a maleimido-peptide carrying the c-myc tag-sequence to yield a peptide-nucleoside triphosphate chimera. Primer extension studies showed that the nucleoside triphosphate modified with the peptide sequence is incorporated by DNA polymerases opposite guanine.     

Prokaryotic and viral community of the sulfate-rich crust from Peñahueca ephemeral lake,an astrobiology analogue

Peñahueca is an athalassohaline hypersaline inland ephemeral lake originated under semiarid conditions in the central Iberian Peninsula (Spain). Its chemical composition makes it extreme for microbial life as well as a terrestrial analogue of other planetary environments. To investigate the persistence of microbial life associated with sulfate-rich crusts, we applied cultivation-independent methods (optical and electron microscopy, 16S rRNA gene profiling and metagenomics) to describe the prokaryotic community and its associated viruses. The diversity for Bacteria was very low and was vastly dominated by endospore formers related to Pontibacillus marinus of the Firmicutes phylum. The archaeal assemblage was more diverse and included taxa related to those normally found in hypersaline environments. Several ‘metagenome assembled genomes’ were recovered, corresponding to new species of Pontibacillus, several species from the Halobacteria and one new member of the Nanohaloarchaeota. The viral assemblage, although composed of the morphotypes typical of high salt systems, showed little similarity to previously isolated/reconstructed halophages. Several putative prophages of Pontibacillus and haloarchaeal hosts were identified. Remarkably, the Peñahueca sulfate-rich metagenome contained CRISPR-associated proteins and repetitions which were over 10-fold higher than in most hypersaline systems analysed so far.     

Preparation of Oligonucleotides Containing Non-natural Base Analogues

Abstract

The preparation of a protected derivative of 2-aza- 2′-deoxyinosine carrying a photolabile protecting group is described. The new derivative is useful to prepare oligonucleotides containing 2-azahypoxanthine. The synthesis of oligonucleotides containing 2-fluorohypoxanthine and O⁴-alkylthymine is also described.     

Environmental Mold and Mycotoxin Exposures Elicit Specific Cytokine and Chemokine Responses

BackgroundMolds can cause respiratory symptoms and asthma. We sought to use isolated peripheral blood mononuclear cells (PBMCs) to understand changes in cytokine and chemokine levels in response to mold and mycotoxin exposures and to link these levels with respiratory symptoms in humans. We did this by utilizing an ex vivo assay approach to differentiate mold-exposed patients and unexposed controls. While circulating plasma chemokine and cytokine levels from these two groups might be similar, we hypothesized that by challenging their isolated white blood cells with mold or mold extracts, we would see a differential chemokine and cytokine release.ConclusionsThese findings demonstrate that chronic mold exposures induced changes in inflammatory and immune system responses to specific mold and mycotoxin challenges. These responses can differentiate mold-exposed patients from unexposed controls. This strategy may be a powerful approach to document immune system responsiveness to molds and other inflammation-inducing environmental agents.     

Triplex‐Stabilizing Properties of Parallel Clamps Carrying LNA Derivatives at the Hoogsteen Strand

DNA Parallel clamps with a polypurine strand linked to a polypyrimidine Hoogsteen strand containing locked nucleic acids bind their corresponding polypyrimidine targets with high affinity.     

Synthesis of Oligodeoxyribonucleotides Containing 2,6-Diaminopurine

Abstract

The preparation of a new protected derivative of 2,6-diaminopurine 2′-deoxyriboside carrying two phenoxyacetyl groups is described. The new derivative is useful to prepare oligonucleotides containing 2,6-diaminopurine and it is deprotected at the same time as the standard protecting groups of the natural bases.