Exploring i-Motif DNA binding with benzothiazolino Coumarins: Synthesis, Screening, and spectroscopic insights.

I-motif (iM) DNA structures are dynamic cytosine-rich secondary structures that are increasingly recognized for their roles in transcriptional regulation, genomic stability, and for their potential as therapeutic targets in cancer. Despite their significance, the development of selective small-molecule probes for iM DNA remains a challenge. In this study, a series of iminocoumarin-benzothaizole derivatives were designed, synthesized, and subjected to extensive screening to explore their interactions with various iM DNA constructs, including H-Telo, HRAS1, HRAS2, VEGF, and BCL2, as well as duplex DNA.

Expression of bluetongue virus full-length VP7 protein in insect cells and its diagnostic utility for detection of antibodies to the virus infection.

Bluetongue (BT) is a vector-borne viral disease of multiple domestic and wild ruminants across the globe. The VP7 protein of bluetongue virus (BTV) is the major immune-dominant structural protein that is conserved across the BTV serotypes and therefore, targeted for the development of immuno-diagnostics for BT. In this study, full-length recombinant VP7 protein (rVP7) of BTV-1 was expressed in Trochoplusia ni derived insect cells (Tn5) using codon-optimized synthetic gene construct through baculovirus expression system.

ERα, HER-2, pan-RAS, p53, and aromatase expression in spontaneous malignant canine mammary tumors: Prognostic relevance and association with clinicohistological parameters.

Aim: The interlacing interaction between proto-oncoproteins and tumor-suppressing proteins in malignant canine mammary tumors (mCMT) microenvironment remains largely unexplored. The present study intended to decipher the i) association between the intratumoral expression of ERα, HER-2, pan-RAS, p53 and aromatase, ii) their relationship with the clinicohistological parameters and serum sex hormones, and iii) their prognostic relevance in mCMT.

Materials And Methods: Tumor samples from animals with mCMT (n = 27) were subjected to histopathology and immunohistochemistry for ERα, HER-2, pan-RAS, p53, and aromatase.

G4-Ligand-Conjugated Oligonucleotides Mediate Selective Binding and Stabilization of Individual G4 DNA Structures.

G-quadruplex (G4) DNA structures are prevalent secondary DNA structures implicated in fundamental cellular functions, such as replication and transcription. Furthermore, G4 structures are directly correlated to human diseases such as cancer and have been highlighted as promising therapeutic targets for their ability to regulate disease-causing genes, e.g.

Parallel G-Quadruplex DNA Structures from Nuclear and Mitochondrial Genomes Trigger Emission Enhancement in a Nonfluorescent Nano-aggregated Fluorine-Boron-Based Dye.

Molecular self-assembly is a powerful tool for the development of functional nanostructures with adaptive optical properties. However, in aqueous solution, the hydrophobic effects in the monomeric units often afford supramolecular architectures with typical side-by-side π-stacking arrangement with compromised emissive properties. Here, we report on the role of parallel DNA guanine quadruplexes (G4s) as supramolecular disaggregating-capture systems capable of coordinating a zwitterionic fluorine-boron-based dye and promoting activation of its fluorescence signal.

The effect of side chain variations on quinazoline-pyrimidine G-quadruplex DNA ligands.

G-quadruplex (G4) DNA structures are involved in central biological processes such as DNA replication and transcription. These DNA structures are enriched in promotor regions of oncogenes and are thus promising as novel gene silencing therapeutic targets that can be used to regulate expression of oncoproteins and in particular those that has proven hard to drug with conventional strategies. G4 DNA structures in general have a well-defined and hydrophobic binding area that also is very flat and featureless and there are ample examples of G4 ligands but their further progression towards drug development is limited.

Development of ELISA for the detection of antibodies against VP2 protein of bluetongue virus serotype-1.

Serotype-specific diagnosis of bluetongue virus (BTV) is necessary for sero-surveillance and taking effective control measures. The VP2 is the major serotype determining protein and BTV-1 is the most predominant serotype in India. In the present study, an indirect ELISA (i-ELISA) was optimized for the detection of serotype-specific antibody against BTV-1 serotype.

Gd and Ga complexes with a new tris-3,4-HOPO ligand as new imaging probes: complex stability, magnetic properties and biodistribution.

The development of metal-based multimodal imaging probes is a highly challenging field in coordination chemistry. In this context, we have developed a bifunctional hexadentate tripodal ligand (HL2) with three 3,4-HOPO moieties attached to a flexible tetrahedral carbon bearing a functionalizable nitro group. Complexes formed with different metal ions have potential interest for diagnostic applications, namely magnetic resonance imaging (MRI) and positron emission tomography (PET).

Bifunctional 3-Hydroxy-4-Pyridinones as Potential Selective Iron(III) Chelators: Solution Studies and Comparison with Other Metals of Biological and Environmental Relevance.

The binding ability of five bifunctional 3-hydroxy-4-pyridinones towards Cu and Fe was studied by means of potentiometric and UV-Vis spectrophotometric measurements carried out at = 0.15 mol L in NaCl = 298.15 K and 310.

Development of a rapid lateral flow immunochromatography assay for the detection of group-specific antibodies against VP7 protein of bluetongue virus in multiple species.

Bluetongue virus (BTV), the causative agent of bluetongue disease infects many domestic and wild ruminants. In the present study, colloidal gold nanoparticle-based lateral flow immunochromatography assay (LFIA) was developed to detect the group-specific antibodies to BTV in serum samples of sheep, goats, cattle, and camel. The recombinant VP7 protein of BTV conjugated to colloidal gold nanoparticles (GNPs) was used as a detector reagent.

A Minimalistic Coumarin Turn-On Probe for Selective Recognition of Parallel G-Quadruplex DNA Structures.

G-quadruplex (G4) DNA structures are widespread in the human genome and are implicated in biologically important processes such as telomere maintenance, gene regulation, and DNA replication. Guanine-rich sequences with potential to form G4 structures are prevalent in the promoter regions of oncogenes, and G4 sites are now considered as attractive targets for anticancer therapies. However, there are very few reports of small "druglike" optical G4 reporters that are easily accessible through one-step synthesis and that are capable of discriminating between different G4 topologies.

Genetic and phylogenetic characterization of polycistronic dsRNA segment-10 of bluetongue virus isolates from India between 1985 and 2011.

The smallest polycistronic dsRNA segment-10 (S10) of bluetongue virus (BTV) encodes NS3/3A and putative NS5. The S10 sequence data of 46 Indian BTV field isolates obtained between 1985 and 2011 were determined and compared with the cognate sequences of global BTV strains. The largest ORF on S10 encodes NS3 (229 aa) and an amino-terminal truncated form of the protein (NS3A) and a putative NS5 (50-59 aa) due to alternate translation initiation site.

Stabilization of G-quadruplex DNA structures in Schizosaccharomyces pombe causes single-strand DNA lesions and impedes DNA replication.

G-quadruplex (G4) structures are stable non-canonical DNA structures that are implicated in the regulation of many cellular pathways. We show here that the G4-stabilizing compound PhenDC3 causes growth defects in Schizosaccharomyces pombe cells, especially during S-phase in synchronized cultures. By visualizing individual DNA molecules, we observed shorter DNA fragments of newly replicated DNA in the PhenDC3-treated cells, suggesting that PhenDC3 impedes replication fork progression.

A site-specific self-assembled light-up rotor probe for selective recognition and stabilization of c-MYC G-quadruplex DNA.

Direct and unambiguous evidence of the formation of G-quadruplexes (G4s) in human cells have shown their implication in several key biological events and has emphasized their role as important targets for small-molecule cancer therapeutics. Here, we report on the first example of a self-assembled molecular-rotor G4-binder able to discriminate between an extensive panel of G4 and non-G4 structures and to selectively light-up (up to 64-fold), bind (nanomolar range), and stabilize the c-MYC promoter G4 DNA. In particular, association with the c-MYC G4 triggers the disassembly of its supramolecular state (disaggregation-induced emission, DIE) and induces geometrical restrictions (motion-induced change in emission, MICE) leading to a significant enhancement of its emission yield.

Deciphering type-specific neutralizing antibodies to bluetongue virus in goats of Andaman and Nicobar Islands, India.

The presence of antibodies to bluetongue virus (BTV) and the viral antigen is reported recently from the Andaman and Nicobar Islands, a group of islands at the juncture of the Bay of Bengal and the Andaman Sea. A retrospective study was conducted to investigate the presence of neutralizing antibodies to different BTV serotypes in the seroconverted goats of the Islands. Thirty six samples out of 186 serum samples tested were selected on the basis of high antibody titre as predicted in an indirect ELISA.

Quinazoline Ligands Induce Cancer Cell Death through Selective STAT3 Inhibition and G-Quadruplex Stabilization.

The signal transducer and activator of transcription 3 (STAT3) protein is a master regulator of most key hallmarks and enablers of cancer, including cell proliferation and the response to DNA damage. G-Quadruplex (G4) structures are four-stranded noncanonical DNA structures enriched at telomeres and oncogenes' promoters. In cancer cells, stabilization of G4 DNAs leads to replication stress and DNA damage accumulation and is therefore considered a promising target for oncotherapy.

Subtle structural alterations in G-quadruplex DNA regulate site specificity of fluorescence light-up probes.

G-quadruplex (G4) DNA structures are linked to key biological processes and human diseases. Small molecules that target specific G4 DNA structures and signal their presence would therefore be of great value as chemical research tools with potential to further advance towards diagnostic and therapeutic developments. However, the development of these types of specific compounds remain as a great challenge.

Novel tacrine-benzofuran hybrids as potential multi-target drug candidates for the treatment of Alzheimer's Disease.

Pursuing the widespread interest on multi-target drugs to combat Alzheimer´s disease (AD), a new series of hybrids was designed and developed based on the repositioning of the well-known acetylcholinesterase (AChE) inhibitor, tacrine (TAC), by its coupling to benzofuran (BF) derivatives. The BF framework aims to endow the conjugate molecules with ability for inhibition of AChE (bimodal way) and of amyloid-beta peptide aggregation, besides providing metal (Fe, Cu) chelating ability and concomitant extra anti-oxidant activity, for the hybrids with hydroxyl substitution. The new TAC-BF conjugates showed very good activity for AChE inhibition (sub-micromolar range) and good capacity for the inhibition of self- and Cu-mediated Aβ aggregation, with dependence on the linker size and substituent groups of each main moiety.

Speciation Studies of Bifunctional 3-Hydroxy-4-Pyridinone Ligands in the Presence of Zn at Different Ionic Strengths and Temperatures.

The acid-base properties of two bifunctional 3-hydroxy-4-pyridinone ligands and their chelating capacity towards Zn, an essential bio-metal cation, were investigated in NaCl aqueous solutions by potentiometric, UV-Vis spectrophotometric, and H NMR spectroscopic titrations, carried out at 0.15 ≤ /mol ≤ 1.00 and 288.

A Light-up Logic Platform for Selective Recognition of Parallel G-Quadruplex Structures via Disaggregation-Induced Emission.

The design of turn-on dyes with optical signals sensitive to the formation of supramolecular structures provides fascinating and underexplored opportunities for G-quadruplex (G4) DNA detection and characterization. Here, we show a new switching mechanism that relies on the recognition-driven disaggregation (on-signal) of an ultrabright coumarin-quinazoline conjugate. The synthesized probe selectively lights-up parallel G4 DNA structures via the disassembly of its supramolecular state, demonstrating outputs that are easily integrable into a label-free molecular logic system.

Genetic studies of terminal regions of vaccine and field isolates of capripoxviruses.

Sheeppox and goatpox are two of the most important diseases associated with significant economic loss and impact on animal trade. In spite of the use of vaccines, outbreaks are being reported on several occasions. Therefore, deciphering the host specificity and virulence of sheeppox virus (SPPV) and goatpox virus (GTPV) is important in developing effective vaccines.

New strong extrafunctionalizable tris(3,4-HP) and bis(3,4-HP) metal sequestering agents: synthesis, solution and in vivo metal chelation.

Finding new multifunctional metal binders to be potentially used in diagnosis or therapy has been a subject of major challenge. Hydroxypyridinones have long been recognized as privileged chelating structures for the design of metal chelating drugs, especially towards hard metal ions, in view of their decorporation in metal overload disorders. Thus, pursuing our strategy of engineering new polydentate 3-hydroxy-4-pyridinones (3,4-HP) with extrafunctionalization capacity for sensing or targeting purposes, we report herein the synthesis and full characterization of a hexadentate (tris-3,4-HP) and a tetradentate (bis-3,4-HP) ligand, possessing three and two 3,4-HP arms N-attached to an aminomethanetrispropionic acid backbone, respectively.

Identification of putative G-quadruplex DNA structures in S. pombe genome by quantitative PCR stop assay.

In order to understand in which biological processes the four-stranded G-quadruplex (G4) DNA structures play a role, it is important to determine which predicted regions can actually adopt a G4 structure. Here, to identify DNA regions in Schizosaccharomyces pombe that fold into G4 structures, we first optimized a quantitative PCR (qPCR) assay using the G4 stabilizer, PhenDC3. We call this method the qPCR stop assay, and used it to screen for G4 structures in genomic DNA.