The melanin pigment gene black mediates body pigmentation and courtship behaviour in the German cockroach Blattella germanica.

Genes involved in melanin production directly impact insect pigmentation and can affect diverse physiology and behaviours. The role these genes have on sex behaviour, however, is unclear. In the present study, the crucial melanin pigment gene black was functionally characterised in an urban pest, the German cockroach, Blattella germanica. RNAi knockdown of B. germanica black (Bgblack) had no effect on survival, but did result in black pigmentation of the thoraxes, abdomens, heads, wings, legs, antennae, and cerci due to cuticular accumulation of melanin. Sex-specific variation in the pigmentation pattern was apparent, with females exhibiting darker coloration on the abdomen and thorax than males. Bgblack knockdown also resulted in wing deformation and negatively impacted the contact sex pheromone-based courtship behaviour of males. This study provides evidence for black function in multiple aspects of B. germanica biology and opens new avenues of exploration for novel pest control strategies.

RNAi of yellow-y, required for normal cuticle pigmentation, impairs courtship behavior and oviposition in the German cockroach (Blattella germanica).

The insect cuticle plays a key role in maintaining the insect's physiological function and behavior. Herein, the yellow-y protein is required to produce black melanin, and is expressed in a pattern that correlates with the distribution of this pigment. However, yellow-y can also have other functions, for instance, in insect behavior, but not much is known. In this study, we have studied the yellow-y gene in one important model and pest species, namely the German cockroach (Blattella germanica), which is to our knowledge the first time reported. In essence, we identified the yellow-y gene (BgY-y) and characterized its function by using RNA interference (RNAi). Silencing of BgY-y gene led to different developmental abnormalities (body weight and wings) in both genders. Specifically, there was an abundant decrease in melanin, turning the body color in pale yellow and the cuticle softer and more transparent. Interestingly, we also observed that the knockdown of BgY-y impaired the male cockroaches to display a weaker response to female-emitted contact sex pheromones, and also that the oviposition ability was weakened in the RNAi females. This study comprehensively analyzed the biological functions of the yellow-y gene in German cockroaches from the perspectives of development, body color, courtship behavior and oviposition, and as a consequence, this may opens new avenues to explore it as a novel pest control gene.

Nanoparticle-delivered RNAi-based pesticide target screening for the rice pest white-backed planthopper and risk assessment for a natural predator.

Vacuolar-type (H+)-ATPase (vATPase) is a conserved multi-subunit eukaryotic enzyme composed of 14 subunits that form a functional complex consisting of an ATP-hydrolytic domain (V1) and a proton-translocation domain (V0). ATP hydrolysis and subsequent H+ translocation rely heavily on a fully assembled V1/V0 complex. Since vATPase is crucial for insect survival, it is a viable molecular target for pest control. However, detailed functional analyses of the 14 subunits and their suitability for pest control have not been fully explored in a single insect species. In this study, we identified 22 vATPase subunit transcripts that correspond to 13 subunits (A1, A2, B, C, D, E, F, G, H, a1, a2, c and d) in the white-backed planthopper (WBPH), Sogatella furcifera, a major hemipteran pest of rice. RNAi screens using microinjection and spray-based methods revealed that the SfVHA-F, SfVHA-a2 and SfVHA-c2 subunits are critical. Furthermore, star polymer (SPc) nanoparticles were utilized to conduct spray-induced and nanoparticle-delivered gene silencing (SI-NDGS) to evaluate the pest control efficacy of RNAi targeting the SfVHA-F, SfVHA-a2 and SfVHA-c2 transcripts. Target mRNA levels and vATPase enzymatic activity were both reduced. Honeydew excreta was likewise reduced in WBPH treated with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. To assess the environmental safety of the nanoparticle-wrapped dsRNAs, Cyrtorhinus lividipennis Reuter, a major natural enemy of planthoppers, was also sprayed with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. Post-spray effects of dsSfVHA-a2 and dsSfVHA-c2 on C. lividipennis were innocuous. This study identifies SfVHA-a2 and SfVHA-c2 as promising targets for biorational control of WBPH and lays the foundation for developing environment-friendly RNAi biopesticides.

RNA Interference-Screening of Potentially Lethal Gene Targets in the White-Backed Planthopper Sogatella furcifera via a Spray-Induced and Nanocarrier-Delivered Gene Silencing System.

RNA interference (RNAi) is a widespread post-transcriptional silencing mechanism that targets homologous mRNA sequences for specific degradation. An RNAi-based pest management strategy is target-specific and considered a sustainable biopesticide. However, the specific genes targeted and the efficiency of the delivery methods can vary widely across species. In this study, a spray-induced and nanocarrier-delivered gene silencing (SI-NDGS) system that incorporated gene-specific dsRNAs targeting conserved genes was used to evaluate phenotypic effects in white-backed planthopper (WBPH). At 2 days postspraying, transcript levels for all target genes were significantly reduced and knockdown of two gene orthologs, hsc70-3 and PP-α, resulted in an elevated mortality (>60%) and impaired ecdysis. These results highlight the utility of the SI-NDGS system for identifying genes involved in WBPH growth and development that could be potentially exploitable as high mortality target genes to develop an alternative method for WBPH control.

[Correlation between rhizosphere environment and content of medicinal components of Arnebia euchroma].

This study aimed to explore the correlation between rhizosphere soil microorganisms of wild Arnebia euchroma and the content of medicinal components to provide guidance for the selection of the ecological planting base. The total DNA of rhizosphere soil microorganisms of wild A. euchroma was extracted, and the microbial community structure of rhizosphere soil microorganisms was analyzed by IlluminaMiseq high-throughput sequencing technology. The content of total hydroxynaphthoquinone pigment and ß,ß'-dimethylacrylalkannin in medicinal materials was determined by high-performance liquid chromatography(HPLC). The physicochemical pro-perties of rhizosphere soil of wild A. euchroma in main producing areas were determined, and the correlation of soil microbial abundance with index component content and soil physicochemical properties was analyzed by SPSS software. The results showed that the species composition of rhizosphere fungi and bacteria in A. euchroma from different habitats was similar at the phylum and genus levels, but their relative abundance, richness index(Chao1), and community diversity(Simpson) index were different. Correlation analysis showed that the content of available phosphorus in soil was positively correlated with the content of total hydroxynaphthoquinone pigment and ß,ß'-dimethylacrylalkannin, and the abundance of five fungal genera such as Solicoccozyma and six bacterial genera such as Pseudo-nocardia and Bradyrhizobium was positively correlated with the content of medicinal components in medicinal materials. The abundance of Bradyrhizobium was significantly positively correlated with the content of ß,ß'-dimethylacrylalkanin. The abundance of fungi such as Archaeorhizomyces was significantly positively correlated with the content of available phosphorus in rhizosphere soil, and Bradyrhizobium was significantly negatively correlated with soil pH. Therefore, the abundance of fungi and bacteria in the rhizosphere of A. euchroma has a certain correlation with the medicinal components and the physicochemical properties of the rhizosphere soil, which can provide a scientific basis for the selection of ecological planting bases in the later stage.

Efficient DIPA-CRISPR-mediated knockout of an eye pigment gene in the white-backed planthopper, Sogatella furcifera.

Although CRISPR/Cas9 has been widely used in insect gene editing, the need for the microinjection of preblastoderm embryos can preclude the technique being used in insect species with eggs that are small, have hard shells, and/or are difficult to collect and maintain outside of their normal environment. Such is the case with Sogatella furcifera, the white-backed planthopper (WBPH), a significant pest of Oryza sativa (rice) that oviposits inside rice stems. Egg extraction from the stem runs the risk of mechanical damage and hatching is heavily influenced by the micro-environment of the rice stem. To bypass these issues, we targeted embryos prior to oviposition via direct parental (DIPA)-CRISPR, in which Cas9 and single-guide RNAs (sgRNAs) for the WBPH eye pigment gene tryptophan 2,3-dioxygenase were injected into the hemocoel of adult females. Females at varying numbers of days posteclosion were evaluated to determine at what stage their oocyte might be most capable of taking up the gene-editing components. An evaluation of the offspring indicated that the highest G0 gene-edited efficacy (56.7%) occurred in females injected 2 d posteclosion, and that those mutations were heritably transmitted to the G1 generation. This study demonstrates the potential utility of DIPA-CRISPR for future gene-editing studies in non-model insect species and can facilitate the development of novel pest management applications.

Disitamab Vedotin plus anti-PD-1 antibody show good efficacy in refractory primary urethral cancer with low HER2 expression: a case report.

Primary urethral carcinoma (PUC) has a low incidence, but with high aggressiveness. Most of the patients are found in late stage, with poor prognosis. At present, chemotherapy is still the main treatment for metastatic PUC, but it has limited effect. Here, we report a case of metastatic PUC with low HER2 expression that developed disease progression after multiline therapy including chemotherapy, programmed death-1 (PD-1) inhibitors and multi-targeted receptor tyrosine kinase (RTK) inhibitor. After receiving Disitamab Vedotin(a novel antibody drug conjugate, ADC) and toripalimab (a PD-1 inhibitor), the patient achieved persistent PR, and the PFS exceeded 12 months up to now. Our report indicates that, despite the patient of metastatic PUC has low expression of HER2, it is still possible to benefit from Disitamab Vedotin combined with PD-1 inhibitor, which may reverse the drug resistance of PD-1 inhibitor and chemotherapy to a certain extent. But larger sample studies are needed to determine the efficacy of this treatment strategy and its impact on survival.

[Remediation of Petroleum-contaminated Soil by Highly Efficient Oil-degrading Bacteria and Analysis of Its Enhancement Mechanism].

A 120-day in situ remediation of oil-contaminated soil was carried out by using highly efficient oil-degrading bacteria. The effects of bio-enhanced remediation and changes in soil physicochemical properties and enzyme activities were investigated. Combined with metagenomic sequencing and bioinformatics analysis, the strengthening mechanism was revealed. The results showed that compared with the blank control group (Ctrl), the degradation rate of total petroleum hydrocarbons in the bioremediation group (Exp-BT) was significantly increased, reaching 81.23%. During enhanced bioremediation by highly efficient oil-degrading bacteria, the pH of the soil was stable, the oxidation capacity of the system was improved, and the electrical conductivity was in the range suitable for agricultural activities. Lipase and dehydrogenase maintained high activity during repair. In addition, the analysis of the initial contaminated soil (B0), the highly efficient oil-degrading bacteria obtained from domestication (GZ), and the soil samples after bioremediation (BT) in the obtained samples showed that, at the phylum level, the total proportion of Proteobacteria and Actinobacteria increased by 17.1%. At the genus level, the abundance of Nocardioides, Achromobacter, Gordonia, and Rhodococcus increased significantly. The species and function contribution analysis of COG and KEGG proved that the above bacterial genera had important contributions to the degradation of petroleum hydrocarbons. A high abundance of petroleum hydrocarbon-related metabolic enzymes and five petroleum hydrocarbon-related degradation genes was found in the soil after remediation:alkM, tamA, rubB, ladA, and alkB. The analysis showed that the introduction of the exogenous petroleum hydrocarbon-degrading bacteria group enhanced the metabolic activity of microorganism-related enzymes and the expression of corresponding functional genes.

Preferential capture of phosphate by an Enteromorpha prolifera-based biopolymer encapsulating hydrous zirconium oxide nanoparticles.

Preferential removal of phosphate from aqueous was conducted by a novel biomass-based nanocomposite (EP-N+-Zr) with encapsulated hydrous zirconium oxide, and the biopolymer EP-N+-Zr features were described. EP-N+-Zr exhibited high selective sequestration toward phosphate when humic acid or other competing anions (Cl-, SO42-, NO3-, ClO4-) coexisted at relatively high levels. Such excellent performance of EP-N+-Zr was attributed to its specific two site structures; the embedded HZO nanoparticles and quaternary ammonia groups [N+(CH2CH3)3Cl-] bonded inside the biomass-Enteromorpha prolifera, which facilitated preferable capture towards phosphate through specific affinity and nonspecific preconcentration of phosphate ions on the basis of the ion exchange, respectively. The maximum adsorption capacity of phosphate (20 °C) as calculated by Langmuir model was 88.5 mg(P)/g. Regeneration tests showed that EP-N+-Zr could be recycled at least five times without noticeable capacity losses using binary NaOH-NaCl as eluent.

ABO blood type, smoking status, other risk factors and prognosis of pancreatic ductal adenocarcinoma.

The aim of this observational study was to test whether ABO blood type was a prognostic factor for pancreatic ductal adenocarcinoma (PDAC) patients and whether other risk factors could influence pancreatic cancer patients' survival. This study included 610 patients who were diagnosed as pancreatic cancer and had undergone radical surgery. Patients' characteristics included age, gender, tumor stage, tumor grade, adenosquamous carcinoma (ASC) status, preoperative serum carbohydrate antigen 19-9 (CA19-9) levels, preoperative serum carcinoembryonic antigen (CEA) levels, ABO blood type, smoking status, and drinking status were analyzed in this study. Cox proportional hazards regression model and Kaplan-Meier method were used to evaluate the role of prognostic factors. For pancreatic cancer patients undergoing radical surgery, the overall survival was worse for ASC patients than PDAC patients (Log-rank = 11.315, P < .001). Compared with ASC patients (Log-rank < 0.001, P = .996), PDAC patients can benefit from chemotherapy (Log-rank = 17.665, P < .001). For PDAC patients, O blood type had better overall survival than non-O blood type (Log-rank = 4.153, P = .042). Moreover, the group with higher serum levels of CA19-9 had poor prognosis compared to another group with low serum CA19-9 (Log-rank = 4.122, P = .042). Higher CEA levels indicated poor prognosis (Log-rank = 13.618, P < .001). In conclusion, ASC status was associated with overall survival of pancreatic cancer patients and cannot benefit from postoperative chemotherapy. Non-O blood type was a prognostic factor for PDAC patients.

Evaluation of the target genes of arsenic trioxide in pancreatic cancer by bioinformatics analysis.

The aim of the present study was to evaluate the potential network of arsenic trioxide (ATO) target genes in pancreatic cancer. The DrugBank, STITCH, cBioPortal, Kaplan-Meier plotter and Oncomine websites were used to analyze the association of ATO and its target genes with pancreatic cancer. Initially, 19 ATO target genes were identified, along with their associated protein-protein interaction networks and Kyoto Encyclopedia of Genes and Genomes pathways. ATO was found to be associated with multiple types of cancer, and the most common solid cancer was pancreatic cancer. A total of 6 ATO target genes (namely AKT1, CCND1, CDKN2A, IKBKB, MAPK1 and MAPK3) were found to be associated with pancreatic cancer. Next, the mutation information of the 6 ATO target genes in pancreatic cancer was collected. A total of 20 ATO interacting genes were identified, which were mainly involved in hepatitis B, prostate cancer, pathways in cancer, glioma and chronic myeloid leukemia. Finally, the genes CCND1 and MAPK1 were detected to be prognostic factors in patients with pancreatic cancer. In conclusion, bioinformatics analysis may help elucidate the molecular mechanisms underlying the involvement of ATO in pancreatic cancer, enabling more effective treatment of this disease.

High levels of serum glypican-1 indicate poor prognosis in pancreatic ductal adenocarcinoma.

Carbohydrate antigen 19-9 (CA19-9) fails to demonstrate the predictive value for early detection pancreatic ductal adenocarcinoma (PDAC). Glypican-1 (GPC1+) exosomes may serve as a noninvasive diagnostic tool to detect early stages of PDAC. Therefore, it is necessary to explore the serum GPC1 levels and determine whether serum GPC1 serves as a novel biomarker for PDAC patients. Blood samples were collected from 156 patients with PDAC, 199 non-cancer controls, and 240 patients with other cancers. Serological levels of GPC1 were examined by enzyme-linked immunosorbent assay (ELISA). Finally, a 5-year follow-up was monitored to evaluate the correlation between serum GPC1 levels and overall survival in 156 patients with PDAC. The results suggested that levels of serum GPC1 and CA19-9 were higher in PDAC patients than that of controls (P < 0.05). Serum GPC1 levels in PDAC were different from those in gallbladder carcinoma (P < 0.001), colorectal carcinoma (P < 0.001), gastric carcinoma (P < 0.001), and prostate cancer (P < 0.001), but not hepatocellular carcinoma (P = 0.395) and cholangiocarcinoma (P = 0.724). Receiver operating characteristic curve (ROC) analysis showed that serum CA19-9 was significantly better than serum GPC1 in distinguishing PDAC patients from the controls (AUC, 95% CI: 0.908, 0.868-0.947 vs 0.795, 0.749-0.841, respectively). The serum GPC1 cannot be used as a serum diagnostic biomarker for PDAC patients. The level of serum GPC1 decreased 2 days after surgery (P = 0.001), which were not different from serum GPC1 levels in healthy control (P = 0.381). The overall survival rate was shorter in patients with high levels of serum GPC1 compared to those with low levels of serum GPC1 (log-rank = 5.16, P = 0.023). Taken together, the results indicate that high levels of serum GPC1 predict poor prognosis in PDAC patients. Serum GPC1 may be a prognosis factor for PDAC patients.

Four Hybrid Materials Based on Preyssler P5W30 Polyoxometalate and First-Row Transition-Metal Complex.

Four Preyssler P5W30 based inorganic-organic hybrids, formulated as {[Cu12(pbtz)2(Hpbtz)2(OH)4(H2O)16][Na(H2O)P5W30O110]}·16H2O (1; H2pbtz = 5'-(pyridin-2-yl)-1H,2'H-3,3'-bi(1,2,4-triazole)), {[Cu10(ttbz)2(Httbz)4(OH)6(H2O)8][K(H2O)H2P5W30O110]}·30H2O (2; Httbz = 1-(tetrazo-5-yl)-4-(triazo-1-yl)benzene), {[Ni6(bpz)6(H2O)16][Na(H2O)H2P5W30O110]}·36H2O (3; bpz = 3,3',5,5'-tetramethyl-4,4-bipyrazole), {[Co4(bpz)6(H2O)9][K(H2O)H6P5W30O110]}·46H2O (4), have been isolated and structurally identified via microanalysis, thermogravimetry (TG), infrared (IR) spectroscopy, and X-ray single-crystal diffraction. Compound 1 exhibits a 3D binodal (3,6)-connected ant framework composed of dodeca-supported P5W30 polyoxometalate (POM) clusters and discrete [Cu6(pbtz)(Hpbtz)(OH)2(H2O)8] subunits. Compound 2 is a pillared-layer 3D network constructed from [Cu5(ttbz)(Httbz)2(OH)3(H2O)4] sheets pillared by individual P5W30 clusters. Compound 3 contains octa-supporting P5W30 POM clusters and novel [Ni6(bpz)6] crown-like metallamacrocycles, which construct a (4,4)-connected pts network. Compound 4 displays a complicated 3D (5,5)-connected {4(5)·6(4)·8}{4(5)·6(5)} network built by pentasupporting P5W30 POM clusters and discrete [Co4(bpz)6(H2O)9] subunits. In 1-4, the unified features are the Preyssler-type [P5W30O110] POM as the fundamental building block, which supports the transition-metal compounds with different modes to give the resultant diverse networks. The magnetism studies indicated antiferromagnetically coupled systems for the hexa- and pentanuclear Cu(II) units in 1 and 2, respectively. The electrochemical properties demonstrate that all compounds have electrocatalytic abilities toward the reduction of hydrogen peroxide. Furthermore, the catalytic activities of 1 in the cyanosilylation of aldehydes reaction have been investigated.

The Effects of ASMase Mediated Endothelial Cell Apoptosis in Multiple Hypofractionated Irradiations in CT26 Tumor Bearing Mice.

BACKGROUND: To investigate the effects of ASMase mediated endothelial cell apoptosis in multiple hypofractionated irradiations in CT26 tumor bearing mice. MATERIALS AND METHODS: Thirty-five CT26 tumor bearing mice were subjected to single ionizing radiation (IR) of 0, 3, 6, 9, 12, 15, 18 Gy. Eight hours after IR, the mice were sacrificed and tumor tissues were used for CD31 immunohistochemistry staining, TUNEL and CD31 double staining, ASMase activity assay. Then 6 and 12 Gy were chosen for multiple hypofractionated IR experiments according to the above results. Each time after IR, 5 mice were sacrificed and assayed as above. RESULTS: The ASMase activities were increased significantly after a single IR of 12 Gy or higher which was accompanied with remarkable increased endothelial cell apoptosis and decreased MVD. For 6 Gy which was not high enough to trigger ASMase activation, after 2 or more times of IR, the ASMase activities were significantly increased accompanied with remarkable increased endothelial cell apoptosis and decreased MVD. While for 12 Gy, after 2 or more times of IR, the ASMase activities and endothelial cell apoptosis rates were maintained without remarkable increase; however, the MVD was significantly decreased. What's more, the cancer cell apoptosis rates were significantly increased after multiple IR for both 6 Gy and 12 Gy. CONCLUSIONS: ASMase mediated endothelial cell apoptosis may play an important role in the process of multiple hypofractionated IR for CT26 colorectal carcinoma.

Controlled in situ reaction for the assembly of Cu(II) mixed-ligand coordination polymers: synthesis, structure, mechanistic insights, magnetism and catalysis.

It has been a challenge to decipher the in situ ligand reaction mechanism in assembly processes, involving metals and ligands. The present study shows two crystalline mixed-ligand Cu(II) coordination polymers isolated by controlled in situ ligand reactions under the same hydrothermal conditions. Two closely related examples provide a precious chance to access the in-depth mechanistic issues surrounding in situ reactions. The solid structure of 1 demonstrated that maleic acid was completely transformed to malic acid, whereas when fumaric acid was used in the same reaction conditions, an incomplete transformation from fumaric acid to malic acid was observed in the solid structure of 2. Compound 1 exhibits a 3D 6-connected sni network based on a binuclear copper(ii) secondary building unit, whereas the 3D network of 2 is classified to a (6,8)-connected topology network. The difference in steric hindrance between maleic acid and fumaric acid dictates the degree of the in situ nucleophilic addition reaction. The comparison of synthesis and final solid structures indicates that the one-step nucleophilic addition mechanism for in situ generated malic acid under the current reaction conditions of 1 is plausible. The magnetic sensitivity measurements of 1 demonstrated that overall antiferromagnetic coupling exists between Cu1 and Cu2 ions and between Cu3 and Cu4 ions. Furthermore, the obtained 1 can be an active catalyst for the solvent-free silylcyanation of aromatic aldehydes under mild conditions.

A platonic solid templating Archimedean solid: an unprecedented nanometre-sized Ag37 cluster.

The spontaneous formation of discrete spherical nanosized molecules is prevalent in nature, but the authentic structural mimicry of such highly symmetric polyhedra from edge sharing of regular polygons has remained elusive. Here we present a novel ball-shaped {(HNEt3)[Ag37S4(SC6H4(t)Bu)24(CF3COO)6(H2O)12]} cluster () that is assembled via a one-pot process from polymeric {(HNEt3)2[Ag10(SC6H4(t)Bu)12]}n and CF3COOAg. Single crystal X-ray analysis confirmed that is a Td symmetric spherical molecule with a [Ag36(SC6H4(t)Bu)24] anion shell enwrapping a AgS4 tetrahedron. The shell topology of belongs to one of 13 Archimedean solids, a truncated tetrahedron with four edge-shared hexagons and trigons, which are supported by a AgS4 Platonic solid in the core. Interestingly, the cluster emits green luminescence centered at 515 nm at room temperature. Our investigations have provided a promising synthetic protocol for a high-nuclearity silver cluster based on underlying geometrical principles.

Atom-precise polyoxometalate-ag2 s core-shell nanoparticles.

Atomically precise polyoxometalate-Ag2 S core-shell nanoparticles were generated in a top-down approach under solvothermal conditions and structurally confirmed by X-ray single-crystal diffraction as an interesting core-shell structure comprising an in situ generated Mo6 O22 (8-) polyoxometalate core and a mango-like Ag58 S38 shell. This result demonstrates the possibility to integrate polyoxometalate and Ag2 S nanoparticles into a core-shell heteronanostructure with precisely controlled atomical compositions of both core and shell.

Anion-induced supramolecular isomerism in two Preyssler P5W30 polyoxometalate-based hybrid materials.

Two extended Preyssler P5W30 polyoxometalate-based inorganic-organic hybrid materials exhibiting anion-induced supramolecular isomerism were reported. Because of the cis-trans isomerism in the octahedral CoN2O4 coordination geometry, the Preyssler P5W30 polyoxometalates are extended by double O-Co-O bridges in 1α and a single O-Co-O bridge in 1ß to form the isomeric 2D 4-connected 4(4)-sql and 3D 8-connected bcu networks, respectively. Both compounds show electrocatalytic abilities on the reduction of H2O2.

Simultaneous encapsulation of an infinite T4(0)A(0)6(0) water tape and discrete water hexamers in a hydrogen-bonded Ag(I) supramolecular framework.

Self-assembly of Ag2O, 1,4-bis(pyrid-4-yl)benzene (dpb) and 1,3-benzenedicarboxylic acid (H2bdc) resulted in a one-dimensional mixed-ligand Ag(I) coordination polymer [Ag2(dpb)2(bdc)·9H2O]n (1), in which infinite 1D T4(0)A(0)6(0) water tapes and discrete water hexamers were simultaneously encapsulated. Chair-like water hexamers and D2h water tetramers with two dangling water molecules were alternately hydrogen-bonded into the unprecedented 1D T4(0)A(0)6(0) water tape. Additionally, results on the thermal stability, UV-Vis absorption and photoluminescence spectra of 1 were discussed.

The biochemical effect of Ser166 phosphorylation on Euplotes octocarinatus centrin.

Centrin is a member of the EF-hand superfamily that is phosphorylated during mitosis and is associated with alterations of contractile fibers. To obtain insight into the structural basis for the functional effects of phosphorylation, we found that the serine residue at position 166 of Euplotes octocarinatus centrin (EoCen) can be phosphorylated by protein kinase A (PKA) in the absence or presence of metal ions using (31)P-NMR spectroscopy. Cations of Ca(2+) and Tb(3+) bound to EoCen resulted in an important structural transition from a closed to an open state. EoCen in both the closed and the open state can be phosphorylated by PKA. After phosphorylation, secondary and tertiary structural changes of EoCen, mainly on its C-terminal domain (C-EoCen), were noted through circular dichroism spectroscopy, native polyacrylamide gel electrophoresis, and 2-p-toluidinylnaphthalene-6-sulfonate fluorescence. After the protein was phosphorylated, the α-helix content and the extent of the exposed hydrophobic surface on EoCen were decreased. Phosphorylated EoCen has higher affinity for the peptide melittin than nonphosphorylated EoCen. In addition, binding of melittin with phosphorylated C-EoCen was enthalpy-driven.