Interaction of antimycin with cytochrome b-561: A study in secretory granules and in plasma membrane isolated from chromaffin cells of bovine adrenal medulla

Cytochrome b-561 in chromaffin granules interacts with antimycin and its -peak shifts 1 nm towards red. When chromaffin granules were treated with Triton X-100 antimycin no effect was observed. Cytochrome b-561 is located in the plasma membrane isolated from the chromaffin cells. The plasma membrane b-561 does not seem to interact with antimycin. A number of NADH or NADPH (acceptor) oxidoreductase activity has been observed in isolated plasma membrane providing clues to the origin of plasma membrane dehydrogenase. The possible role of cytochrome b561 in secretory granules other than its accredited energy conserving electron transport property is projected.     

Difference of two dependent sensitivities and specificities: Comparison of various approaches

In diagnostic studies, a new diagnostic test is often compared with a standard test and both tests are applied on the same patients, called paired design. The true disease state is in general given by the so‐called gold standard (most reliable method for classification), which has to be known for all patients. The benefit of the new diagnostic test can be evaluated by sensitivity and specificity, which are in fact proportions. This means, for the comparison of two diagnostic tests, confidence intervals for the difference of the dependent estimated sensitivities and specificities are calculated. In the literature, many comparisons of different approaches can be found, but none explicitly for diagnostic studies. For this reason we compare 13 approaches for a set of scenarios that represent data of diagnostic studies (e.g., with sensitivity and specificity ?0.8). With simulation studies, we show that the nonparametric interval with normal approximation can be recommended for the difference of two dependent sensitivities or specificities without restriction, the Wald interval with the limitation of slightly anti‐conservative results for small sample sizes, and the nonparametric intervals with t‐approximation, and the Tango interval with the limitation of conservative results for high correlations.     

A New Monoclonal Antibody Enables BAR Analysis of Subcellular Importin β1 Interactomes

Importin β1 (KPNB1) is a nucleocytoplasmic transport factor with critical roles in both cytoplasmic and nucleocytoplasmic transport, hence there is keen interest in the characterization of its subcellular interactomes. We found limited efficiency of BioID in the detection of importin complex cargos and therefore generated a highly specific and sensitive anti-KPNB1 monoclonal antibody to enable biotinylation by antibody recognition analysis of importin β1 interactomes. The monoclonal antibody recognizes an epitope comprising residues 301-320 of human KPBN1 and strikingly is highly specific for cytoplasmic KPNB1 in diverse applications, with little reaction with KPNB1 in the nucleus. Biotinylation by antibody recognition with this novel antibody revealed numerous new interactors of importin β1, expanding the KPNB1 interactome to cytoplasmic and signaling complexes that highlight potential new functions for the importins complex beyond nucleocytoplasmic transport. Data are available via ProteomeXchange with identifier PXD032728.     

Spectral lights trigger biomass accumulation and production of antioxidant secondary metabolites in adventitious root cultures of Stevia rebaudiana (Bert.)

Stevia rebaudiana (S. rebaudiana) is the most important therapeutic plant species and has been accepted as such worldwide. It has a tendency to accumulate steviol glycosides, which are 300 times sweeter than marketable sugar. Recently, diabetic patients commonly use this plant as a sugar substitute for sweet taste. In the present study, the effects of different spectral lights were investigated on biomass accumulation and production of secondary metabolites in adventitious root cultures of S. rebaudiana. For callus development, leaf explants were excised from seed-derived plantlets and inoculated on a Murashige and Skoog (MS) medium containing the combination of 2,4-dichlorophenoxy acetic acid (2, 4-D, 2.0 mg/l) and 6-benzyladenine (BA, 2.0 mg/l), while 0.5 mg/l naphthalene acetic acid (NAA) was used for adventitious root culture. Adventitious root cultures were exposed to different spectral lights (blue, green, violet, red and yellow) for a 30-day period. White light was used as control. The growth kinetics was studied for 30 days with 3-day intervals. In this study, the violet light showed the maximum accumulation of fresh biomass (2.495 g/flask) as compared to control (1.63 g/flask), while red light showed growth inhibition (1.025 g/flask) as compared to control. The blue light enhanced the highest accumulation of phenolic content (TPC; 6.56 mg GAE/g DW), total phenolic production (TPP; 101 mg/flask) as compared to control (5.44 mg GAE/g DW; 82.2 mg GAE/g DW), and exhibited a strong correlation with dry biomass. Blue light also improved the accumulation of total flavonoid content (TFC; 4.33 mg RE/g DW) and total flavonoid production (TFP; 65 mg/flask) as compared to control. The violet light showed the highest DPPH inhibition (79.72%), while the lowest antioxidant activity was observed for control roots (73.81%). Hence, we concluded that the application of spectral lights is an auspicious strategy for the enhancement of the required antioxidant secondary metabolites in adventitious root cultures of S. rebaudiana and of other medicinal plants.     

Synthesis,characterization and biological studies of Schiff bases derived from heterocyclic moiety

Some new Schiff bases (H₁-H₇) have been synthesized by the condensation of 2-aminophenol, 2-amino-4-nitrophenol, 2-amino-4-methylphenol, 2-amino benzimidazole with thiophene-2-carboxaldehyde and pyrrole-2-carboxaldehyde. The structures of newly synthesized compounds were characterized by elemental analysis, FT-IR, ¹ H NMR, UV–VIS, and single crystal X-ray crystallography. The in vitro antibacterial activity of the synthesized compounds has been tested against Salmonella typhi, Bacillus coagulans, Bacillus pumills, Escherichia coli, Bacillus circulans, Pseudomonas, Clostridium and Klebsilla pneumonia by disk diffusion method. The quantitative antimicrobial activity of the test compounds was evaluated using Resazurin based Microtiter Dilution Assay. Ampicillin was used as standard antibiotics. Schiff bases individually exhibited varying degrees of inhibitory effects on the growth of the tested bacterial species. The antioxidant activity of the synthesized compounds was determined by the 1,1-diphenyl-2-picrylhydrazyl(DPPH) method. IC₅₀ value of synthesized Schiff bases were calculated and compared with standard BHA.     

New targeted approaches for the quantification of data‐independent acquisition mass spectrometry

The use of data‐independent acquisition (DIA) approaches for the reproducible and precise quantification of complex protein samples has increased in the last years. The protein information arising from DIA analysis is stored in digital protein maps (DIA maps) that can be interrogated in a targeted way by using ad hoc or publically available peptide spectral libraries generated on the same sample species as for the generation of the DIA maps. The restricted availability of certain difficult‐to‐obtain human tissues (i.e., brain) together with the caveats of using spectral libraries generated under variable experimental conditions limits the potential of DIA. Therefore, DIA workflows would benefit from high‐quality and extended spectral libraries that could be generated without the need of using valuable samples for library production. We describe here two new targeted approaches, using either classical data‐dependent acquisition repositories (not specifically built for DIA) or ad hoc mouse spectral libraries, which enable the profiling of human brain DIA data set. The comparison of our results to both the most extended publically available human spectral library and to a state‐of‐the‐art untargeted method supports the use of these new strategies to improve future DIA profiling efforts.     

格氏栲种群数量动态的谱分析研究

运用谱分析数学方法,研究分析格氏栲林格氏栲种群动态规律．结果表明：格氏栲种群数量动态的周期波动性是明显的,与格氏栲天然更新过程有关;不同生境、人为干扰均对辂氏栲种群数量动态的波动产生影响;格氏栲生长量的周期波动与其种群数量动态的周期波动特征基本一致,表明格氏栲种群数量动态呈周期波浪式发展,即表征格氏栲林优势种群的稳定性。     

珍稀濒危植物南方铁杉种群动态研究

以种群生命表及生存分析理论为基础,编制南方铁杉种群静态生命表,绘制存活曲线、死亡率曲线、亏损度曲线、死亡密度函数曲线、积累死亡函数曲线和危险率函数曲线,分析种群生命过程。结果表明,南方铁杉有一个死亡最低峰,存活曲线趋于Deevey-Ⅱ型。并应用谱分析方法研究南方铁杉种群动态,结果表明,在南方铁杉种群自然更新过程中并没有表现出明显的周期性。     

Dinuclear copper(I) complexes containing diimine and phosphine ligands: Synthesis, copper-copper separation and photophysical properties

Dinuclear copper(I) complexes with bridging bis(dicyclohexylphosphino)methane (dcpm) or bis(diphenylphosphino)methane (dppm) and 2,2′-bipyridine or 2-[N-(2-pyridyl)methyl]amino-5,7-dimethyl-1,8-naphthyridine (L), [Cu₂(bpy)₂(dppm)₂](BF₄)₂ (1), [Cu₂(bpy)₂(dcpm)](BF₄)₂ (2), [Cu₂(L)(dppm)](BF₄)₂ (3) and [Cu₂(L)(dcpm)](BF₄)₂ (4) were prepared, and their structures were determined by X-ray crystal analysis. Two-, three-, and four-coordinate copper(I) centers are found in these complexes. Compounds 3 and 4 show close Cu^I?Cu^I separations of 2.664(3) and 2.674(1) Å, respectively, whereas an intramolecular copper-copper distance of 3.038 Å is found in 2 having only dcpm as an additional bridge. Powdered samples of 1, 3, and 4 display intense and long-lived phosphorescence with λ_max at 533, 575, and 585 nm at room temperature, respectively. In the solid state, 2 exhibits only a weak emission at 555 nm. The time-resolved absorption and emission spectra of these complexes were investigated. The difference in the emission properties among complexes 1-4 suggests that both Cu^I?Cu^I distances and coordination environment of the copper(I) centers affect the excited-state properties.     

A simple workflow to increase MS2 identification rate by subsequent spectral library search

Searching a spectral library for the identification of protein MS/MS data has proven to be a fast and accurate method, while yielding a high identification rate. We investigated the potential to increase peptide discovery rate, with little increase in computational time, by constructing a workflow based on a sequence search with Phenyx followed by a library search with SpectraST. Searching a consensus library compiled from the search results of the prior Phenyx search increased the number of confidently matched spectra by up to 156%. Additionally matched spectra by SpectraST included noisy spectra, spectra representing missed cleaved peptides as well as spectra from post‐translationally modified peptides.