A carboxy derivative of the antimalarial cytotoxic drug cryptolepine was introduced into synthetic oligonucleotides by reaction of the carboxy derivative of cryptolepine with oligonucleotides carrying an amino group either at the 3'- or at the 5'-end. Oligonucleotides carrying the cryptolepine derivative bind their complementary sequences with greater affinity than unmodified ones. When cryptol...

BACKGROUND Pre-eclampsia (PE) poses a serious challenge to maternal and fetal health in Africa. It is associated with hemodynamic changes that may affect the internal carotid/ophthalmic artery circulation with consequent neuro-ophthalmic manifestations. Ophthalmic artery Doppler (OAD) ultrasound is an important tool that can be used to detect hemodynamic changes in PE and monitor its severity. ...

BACKGROUND Melting temperature of DNA structures can be determined on the LightCycler using quenching of FAM. This method is very suitable for pH independent melting point (Tm) determination performed at basic or neutral pH, as a high throughput alternative to UV absorbance measurements. At acidic pH quenching of FAM is not very suitable, since the fluorescence of FAM is strongly pH dependent a...

RNA editing from adenosine to inosine (A-to-I editing) is one of the mechanisms that regulate and diversify the transcriptome. Here, a triplex-forming peptide nucleic acid (PNA) modified with a 2-aminopyridine nucleobase was applied for the recognition of the A-to-I editing event in double-stranded RNAs. The triplex-forming PNA enabled sequence-specific detection of single nucleobase editing at...

This study is the first to investigate the interactions of hemin with a G-triplex DNA of T1 using different DNA binding assays. The low intrinsic peroxidatic activity of hemin could be significantly enhanced using T1. Furthermore, much decreased oxidation enhancement by T2 or T3 with one key guanine mutation was observed, and the observed peroxidatic activity of T1 should be directly due to the...

A DNA triplex is formed when pyrimidine or purine bases occupy the major groove of the DNA double Helix forming Hoogsteen pairs with purines of the Watson-Crick basepairs. Intermolecular triplexes are formed between triplex forming oligonucleotides (TFO) and target sequences on duplex DNA. Intramolecular triplexes are the major elements of H-DNAs, unusual DNA structures, which are formed in hom...

In order to enhance DNA triple helix stability synthetic oligonucleotides have been developed that bear amino groups on the sugar or base. One of the most effective of these is bis-amino-U (B), which possesses 5-propargylamino and 2'-aminoethoxy modifications. Inclusion of this modified nucleotide not only greatly enhances triplex stability, but also increases the affinity for related sequences...

Single-stranded guanine-rich sequences fold into compact G-quadruplexes. Although G-triplexes have been proposed and demonstrated as intermediates in the folding of G-quadruplexes, there is still a debate on their folding pathways. In this work, we employed magnetic tweezers to investigate the folding kinetics of single human telomeric G-quadruplexes in 100 mM Na(+) buffer. The results are cons...

Long noncoding RNAs (lncRNAs) regulate gene expression by association with chromatin, but how they target chromatin remains poorly understood. We have used chromatin RNA immunoprecipitation-coupled high-throughput sequencing to identify 276 lncRNAs enriched in repressive chromatin from breast cancer cells. Using one of the chromatin-interacting lncRNAs, MEG3, we explore the mechanisms by which ...