The first report of genetic variations in the chicken prion protein gene

ABSTRACT

Abnormal structural changes of the prion protein (PrP) are the cause of prion disease in a wide range of mammals. However, spontaneous infected cases have not been reported in chicken. Genetic variations of the prion protein gene (PRNP) may impact susceptibility to prion disease but have not been investigated thus far. Because an investigation of the chicken PRNP can improve the understanding of characteristics related to resistance to prion disease, research on the chicken PRNP is highly desirable. In this study, we investigated the genetic characteristics of the chicken PRNP gene. For this, we performed direct sequencing in 106 Dekalb White chickens and analyzed the genotype and allele frequencies of chicken PRNP gene. We found two insertion and deletion polymorphisms in the chicken PRNP: c.163_180delAACCCAGGGTACCCCCAT and c.268_269insC. The former is a U2 hexapeptide deletion polymorphism. Of the 106 samples, 13 (12.26%) were insertion homozygotes, 89 (83.96%) were heterozygotes, and 4 (3.77%) were deletion homozygotes in c.163_180delAACCCAGGGTACCCCCAT. In the c.268_269insC polymorphism, 102 (96.23%) were deletion homozygotes, and 4 (3.77%) were heterozygotes. Insertion homozygotes of c.268_269insC were not detected. Two polymorphisms were in perfect linkage disequilibrium (LD) with a D’ value of 1.0, and three haplotypes were identified. Furthermore, PROVEAN evaluates 163_180delAACCCAGGGTACCCCCAT as ‘deleterious’ with a score of – 13.173. Furthermore, single nucleotide polymorphisms (SNPs) in the open reading frame (ORF) of the PRNP gene were not found in the chicken. To the best of our knowledge, this was the first report on the genetic variations of the chicken PRNP gene.     

Repeated use of Bacillus subtilis cell walls for copper binding

Purified cell walls from Bacillus subtilis were repeatedly suspended in 5 mm CuCl₂ and, after removing unbound Cu, were suspended in 1% (v/v) HNO₃ to release bound Cu. The walls were then regenerated by washing in H₂O. After five cycles, copper binding actually increased slightly, probably due to enhanced exposure of binding sites in the walls. Thus bacterial walls may be used repeatedly for metal removal during bioremediation of heavy metal pollution.R.J.C. McLean is with the Department of Biology, Southwest Texas State University, 601 University Drive, San Marcos, TX 78666-4616, USA A.M. Campbell is with the Department of Chemical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada. P.T. Khu is with the Department of Mining Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada. A.T. Persaud, L.E. Bickerton and D. Beauchemin are with the Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada.     

Copper Oxide Nanomaterials Derived from Zanthoxylum armatum DC. and Berberis lycium Royle Plant Species: Characterization,Assessment of Free Radical Scavenging and Antibacterial Activity

Copper oxide nanomaterials were synthesized by a facile sustainable biological method using two plant species (Zanthoxylum armatum DC. and Berberis lycium Royle ). The formation of materials was confirmed by FT‐IR, ATR, UV‐visible, XRD, TEM, SEM, EDX, TGA and PL. The antibacterial activity was evaluated by agar well diffusion method to ascertain the efficacy of plant species extract and extract derived copper oxide nanomaterials against six Gram‐positive bacteria namely Staphylococcus aureus, Streptococcus mutans, Streptococcus pyogenes, Corynebacterium diphtheriae, Corynebacterium xerosis, Bacillus cereus and four Gram‐negative bacteria such as Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris against the standard drug, Ciprofloxacin for Gram‐positive and Gentamicin for Gram‐negative bacteria, respectively. In both cases, copper oxide nanomaterials were found to be sensitive in all the bacterial species. Sensitivity of copper oxide nanomaterials shows an be higher as compared to plant species extract against different bacteria. Scavenging activity of plant extracts along with nanomaterials have been accessed using previously reported protocols employing ascorbic acid as standard. Scavenging activity of copper oxide nanomaterials shows an increase with increase in concentration. The biological activity (bactericidal and scavenging efficiency) of plant derived copper oxide nanomaterials revealed that these materials can be used as potent antimicrobial agent and DPPH scavengers in industrial as well as pharmacological fields.     

Copper nanocluster‐based fluorescence enhanced determination of d‐penicillamine

Taking advantage of the compelling properties of d ‐penicillamine (d ‐PA) combined with copper, a method for the sensitive and selective determination of d ‐PA was established using copper nanocluster (Cu NC)‐based fluorescence enhancement. d ‐PA molecules containing a thiol compound showed a strong tendency to combine with the surface of Cu NCs, causing the re‐dispersion of nanoclusters and therefore fluorescence intensity was enhanced. Fluorescence enhancement efficiency of Cu NCs induced by d ‐PA was linear, with the d ‐PA concentration varying from 0.6–30 μg ml^?1 (R² = 0.9952) and with a detection limit of 0.54 μg ml^?1. d ‐PA content in human urine samples was detected with recoveries of 104.8–112.99%. Fluorescence‐enhanced determination of d ‐PA using Cu NCs was established for the first time and this rapid, easy and sensitive method should attract much attention for this application.     

A novel fluorescent sensor based on electrosynthesized benzene sulfonic acid‐doped polypyrrole for determination of Pb(II) and Cu(II)

To develop conducting organic polymers (COPs) as luminescent sensors for determination of toxic heavy metals, a new benzene sulfonic acid‐doped polypyrrole (PPy‐BSA) thin film was electrochemically prepared by cyclic voltammetry (CV) on flexible indium tin oxide (ITO) electrode in aqueous solution. PPy‐BSA film was characterized by FTIR spectrometry, X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The optical properties of PPy‐BSA were investigated by ultraviolet (UV)‐visible absorption and fluorescence spectrometry in dimethylsulfoxide (DMSO) diluted solutions. PPy‐BSA fluorescence spectra were strongly quenched upon increasing copper(II) ion (Cu²⁺) and lead(II) ion (Pb²⁺) concentrations in aqueous medium, and linear Stern–Volmer relationships were obtained, which indicated the existence of a main dynamic fluorescence quenching mechanism. BSA‐PPy sensor showed a high sensitivity for detection of both metallic ions, Cu²⁺ and Pb²⁺, with very low limit of detection values of 3.1 and 18.0 nM, respectively. The proposed quenching‐fluorimetric sensor might be applied to the determination of traces of toxic heavy metallic ions in water samples.     

High‐Performance and Stable Perovskite Solar Cells Based on Dopant‐Free Arylamine‐Substituted Copper(II) Phthalocyanine Hole‐Transporting Materials

A power conversion efficiency (PCE) as high as 19.7% is achieved using a novel, low‐cost, dopant‐free hole transport material (HTM) in mixed‐ion solution‐processed perovskite solar cells (PSCs). Following a rational molecular design strategy, arylamine‐substituted copper(II) phthalocyanine (CuPc) derivatives are selected as HTMs, reaching the highest PCE ever reported for PSCs employing dopant‐free HTMs. The intrinsic thermal and chemical properties of dopant‐free CuPcs result in PSCs with a long‐term stability outperforming that of the benchmark doped 2,2′,7,7′‐Tetrakis‐(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐Spirobifluorene (Spiro‐OMeTAD)‐based devices. The combination of molecular modeling, synthesis, and full experimental characterization sheds light on the nanostructure and molecular aggregation of arylamine‐substituted CuPc compounds, providing a link between molecular structure and device properties. These results reveal the potential of engineering CuPc derivatives as dopant‐free HTMs to fabricate cost‐effective and highly efficient PSCs with long‐term stability, and pave the way to their commercial‐scale manufacturing. More generally, this case demonstrates how an integrated approach based on rational design and computational modeling can guide and anticipate the synthesis of new classes of materials to achieve specific functions in complex device structures.     

Altered Domain Structure of the Prion Protein Caused by Cu2+ Binding and Functionally Relevant Mutations: Analysis by Cross-Linking,MS/MS,and NMR

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铜处理对菠菜幼苗矿质营养吸收和细胞超微结构的影响

土壤重金属积累严重影响植物生长和生态系统平衡,探寻植物对重金属的耐性机理尤为重要.菠菜可能具有一定的耐铜性,但Cu对其矿质元素吸收、细胞超微结构等方面的耐性机理尚不明确.本研究以菠菜幼苗为研究对象,通过盆栽试验,探究不同浓度铜处理对菠菜幼苗生长、矿质元素吸收、叶片细胞超微结构等指标的影响.结果表明: 100 mg·L^-1 CuSO₄处理浓度时,菠菜幼苗根Cu²⁺积累量小于地上部,其根系生长量增加,地上部生长量稍有下降,继续增加铜处理浓度,植物体各器官生长参数均呈下降趋势.低浓度铜处理时(<400 mg·L^-1 CuSO₄),菠菜幼苗叶N、K、Ca、Mg、Fe含量增加,P含量减少;根N、P、K含量减少,Ca、Mg、Fe含量增加;叶片细胞内各细胞器清晰可见,基粒片层排列仍较为整齐,叶绿体内外膜完整.高浓度铜处理时(>600 mg·L^-1 CuSO₄),菠菜幼苗叶N含量增加,P、K、Ca、Mg、Fe含量减少;根N、P、K、Ca、Mg、Fe含量均减少;叶片细胞内叶绿体变圆,叶绿体膜变薄,基质、基粒片层变少,层堆积高度下降,细胞核解体,液泡、细胞壁中有黑色小点分布,可能是大量Cu²⁺聚集导致细胞内膨压增大所致.低浓度铜处理并未对菠菜幼苗的生长生理特性产生明显的负面影响,而高浓度铜处理并未终止菠菜幼苗的生长.说明菠菜幼苗具有一定的耐铜性.