Benzimidazolium-Based Self-Assembled Fluorescent Aggregates for Sensing and Catalytic Degradation of Diethylchlorophosphate

The unregulated use of chemical weapons has aroused researchers to develop sensors for chemical warfare agents (CWA) and likewise to abolish their harmful effects, the degradation through catalysis has great advantage. Chemically, the CWAs are versatile; however, mostly they contain organophosphates that act on inhibition of acetyl cholinesterase. In this work, we have designed and synthesized some novel benzimidazolium based fluorescent cations and their fluorescent aggregates were fabricated using anionic surfactants (SDS and SDBS) in aqueous medium. The prepared fluorescent aggregates have shown aggregation induced emission enhancement, which was further used as detection of chemical warfare agent in aqueous medium. The aggregates (<b>Benz-2/SDBS</b> and <b>Benz-3/SDBS</b>) have shown significant changes in emission profile upon interaction with diethylchlorophosphate. Contrarily, the pure dipodal receptor <b>Benz-4</b> has not shown any response in emission after interaction with organophosphate, and consequently, it was concluded that benzimidazolium cation plays a decisive role in sensing. The mechanism of sensing was fully validated using ³¹P NMR spectroscopy as well as GC-MS, which highlights the transformation of diethylchlorophosphate into diethylhydrogen phosphate. The aggregates selectively interact with diethylchlorophosphate over other biological important phosphates

Polyamine Based Ratiometric Fluorescent Chemosensor for Strontium Metal Ion in Aqueous Medium: Application in Tap Water, River Water, and in Oral Care

A pyrene-based polymer, <b>2</b>, was synthesized via one step condensation reaction between pyrene-1-carboxaldehyde and polyamine in methanol. Organic nanoparticles (ONPs) of polymeric compound <b>2</b> were developed using a reprecipitation method and investigated for their chemosensor application using fluorescence spectroscopy. Nanoaggregates of polymer compound <b>2</b> exhibit efficient and selective chemosensor properties for detection of strontium ions in an aqueous medium, with a detection limit of 9 nM. To analyze the practical utility of the sensor, it was successfully employed to detect the amount of Sr²⁺ in tap water, river water, and strontium based toothpastes

Rad4 mainly functions in Chk1-mediated DNA damage checkpoint pathway.

<p><b>A</b>, wild type cells or cells with the integrated mutations were treated with (+) or without (−) MMS at 30°C for 1 hour. Phosphorylation of Chk1 was monitored by the mobility shift assay as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092936#s2" target="_blank">Materials and Methods</a>. A section of the Ponceau S stained membrane is shown for the loading (bottom). <b>B</b>, Rad3-dependent phosphorylation of Cds1-Thr¹¹ was examined by phosphor-specific antibody (top panel). Loading of Cds1 is shown in the lower panel. <b>C</b>, sensitivity of the cells to acute HU (left) or MMS (right) treatment. Cells were treated with the drugs in YE6S medium at 30°C. At each time point, an aliquot of the culture was removed and spread on YE6S plates for the cells to recover. Colonies were counted and viability was presented as percentages of the untreated cells. Each data point represents an average of three independent experiments for each mutant. <b>D</b>, synthetic effects of the double mutants containing Δ<i>cds1</i> or Δ<i>chk1</i> with the indicated <i>rad4</i> mutations were examined by spot assay.</p

ATP Induced Modulation in π–π Stacking Interactions in Pyrene Based Zinc Complexes: Chemosensor Study and Quantitative Investigation of Apyrase Activity

Fluorescent zinc complexes of 1,2-disubstituted benzimidazole (<b>R1–R3</b>) have been synthesized and characterized using single crystal X-ray diffraction. The ligands <b>L1–3</b> were found to be less emissive due to photoinduced electron transfer (PET) mechanism originated from the electron pair of benzimidazole nitrogen. The complexation of ligands with Zn­(II) not only enhances the fluorescent intensity; it also orients the ligands to a new packing. It was observed that the aromatic unit plays a decisive role in the packing of the molecules. The complex <b>R1</b> has extended the coordination through C–H···π interaction, whereas complex <b>R2</b> involved C–H···π interaction and C–H···Br interaction for packing in supramolecular architecture. Among these complexes, <b>R3</b> showed the most interesting noncovalent interaction pattern involving C–H···π interaction, C–H···Br interaction, and π–π stacking between pyrene rings. These noncovalent interactions govern photophysical properties that are sensitive toward the microenvironment. Thus, by altering these interactions, the selective sensing for a particular analyte can be achieved. The complexes <b>R1</b> and <b>R2</b> have shown enhanced emission intensity upon interacting with adenosine triphosphate (ATP) competitively in the presence of some other tested anions. A ratiometric change in emission spectra of the complex <b>R3</b> was observed upon binding with ATP in semiaqueous medium offering the lowest detection limit of 15 nM. Upon interaction with ATP, the π<b>–</b>π stacking between pyrene rings breaks and results in a decrease in excimer emission at 470 nm and increases in monomeric emission intensity at 410 nm. The AFM (Atomic force microscopy) images of receptor <b>R3</b> show that upon addition of ATP to the <b>R3</b> solution, solvent mediated aggregation takes place, which results in the ratiometric detection. In the dimethylformamide solvent system, aggregates were formed, whereas in a water/tetrahydrofuran solvent system the clear solution was converted to a highly viscous gel. To investigate the applications of the prepared sensor, the fluorescence response of HeLa cells enriched with ATP was observed using fluorescence microscopy. The fluorescence modulation of the sensor in living cells makes the receptor practically applicable in a biological environment. Quantitative analysis of apyrase activity has shown that the presented sensor <b>R3</b> is capable of monitoring the hydrolysis process in the biological system

Additional file 3: of Trichoderma polysporum selectively inhibits white-nose syndrome fungal pathogen Pseudogymnoascus destructans amidst soil microbes

Flow chart of Pd and Tp (1:10 and 1:100 ratio) interaction in AC soil samples. (TIF 324 kb

The C13Y and K56R mutations abolish the scaffolding function of Rad4 <i>in vitro</i>.

<p><b>A</b>, schematic diagram of the Rad4 fragments used in this experiment. Each fragment was fused with a GST tag for protein purification and detection in the binding assay using anti-GST antibodies. <b>B</b>, preferential binding of the N- and C-terminal pair of BRCT repeats of Rad4 to Crb2 and Rad9, respectively. Recombinant GST or GST-tagged Rad4 fragments were incubated with immunopurified Crb2 (middle panels) or Rad9 (right panels) bound to the anti-HA antibody beads. The bound proteins were released from the beads in gel loading buffer and analyzed by Western blotting. The membrane was striped and reprobed with anti-HA antibody for Crb2 and Rad9 (bottom panels). Aliquots of the binding reaction were analyzed separately by SDS PAGE as the input (left panel). <b>C</b>, equal amount of the Rad4 fragment b with or without the C13Y-K56R mutation was incubated with Crb2 bound on beads. The input and the Rad4 protein bound to Crb2 were analyzed as in B. <b>D</b>, fragment e with or without the E368K mutation was similarly tested for binding to phosphorylated Rad9. Phosphorylation of Rad9-Thr⁴¹² was detected by blotting of the same membrane with the phospho-specific antibody.</p

The C13Y and K56R mutations abolish the scaffolding function of Rad4 <i>in vivo</i>.

<p><b>A</b>, Rad9 was IPed from the lysates of MMS-treated cells with the indicated mutation (bottom panel). Wild type or mutant Rad4 (top two panels) Co-IPed with Rad9 was detected by Western blotting using anti-Rad4 antibodies. Phosphorylated Rad9-Thr⁴¹² was shown in the third panel from the top. <b>B</b>, Co-IP of Rad4 containing the indicated mutations with phosphorylated Rad9 from HU-treated cells. <b>C</b>, Co-IP of Rad4 and Rad9 with Crb2 from MMS-treated cells.</p

Additional file 7: of Trichoderma polysporum selectively inhibits white-nose syndrome fungal pathogen Pseudogymnoascus destructans amidst soil microbes

DESeq2 analysis of changes in the abundance of fungal genera in soil from bat hibernacula with or without Tp treatment. (XLSX 97 kb

Additional file 11: of Trichoderma polysporum selectively inhibits white-nose syndrome fungal pathogen Pseudogymnoascus destructans amidst soil microbes

Fungi recovered from BHM soil and assessed for growth inhibition by Tp. (DOCX 20 kb

Genetic screen of novel <i>rad4</i> mutants with enhanced sensitivities to HU and MMS in the <i>rad4⁺</i> shut-off strain.

<p><b>A</b>, thiamine-controlled cell growth of the shut-off strain (nmt-rad4) in which the endogenous promoter of <i>rad4⁺</i> was replaced with a thiamine repressive <i>nmt81</i> promoter. Logarithmically growing cells were diluted in fivefold steps and spotted on EMM6S plates with (+) or without (-) thiamine. The plates were incubated at 30°C for 3 days before being photographed. <b>B</b>, thiamine-regulated expression of Rad4 was examined by Western blotting. Untagged Rad4, Rad4 with the deletion of whole C-terminus (ΔC) and HA-tagged Rad4 were expressed on a vector in the shut-off strain. Expression of Rad4 in the presence (+) or absence (-) of thiamine was examined by using anti-Rad4 antibodies (Top). The same membrane was stripped and blotted with anti-HA antibody (bottom). Asterisks indicate the cross-reacting materials. <b>C</b>, molecular architecture of Rad4 with relative locations of the newly isolated (solid circles) and previously reported (open circles) mutations and the AAD domain. The four BRCT repeats are marked by roman numerals. The regions covered by mutational PCRs in the genetic screening are also shown. <b>D</b>, sensitivities of the <i>rad4</i> mutants to HU and MMS were assessed by spot assay in the shut-off strain. The newly screened (top part) and the previously reported (lower part) mutations are marked on the right. Wild type cells, Δ<i>rad3</i> mutant, and the shut-off strain carrying an empty vector or the vector expressing wild-type Rad4 were used as controls.</p