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101.
102.
Spores from severalBacillus species displayed a strong affinity for hexadecane and other hydrophobic solvents. The binding ofBacillus subtilis spore suspensions to octyl-Sepharose was enhanced by ammonium sulfate and other salts, but was inhibited by detergents. Treatment of spore suspensions with strong denaturants promoted their adherence to hexadecane, presumably by exposing hydrophobic residues in coat proteins. The hydrophobic characteristics of spores may be important in the ecological adaptation of certain bacteria. 相似文献
103.
Protein phosphatase 2A (PP2A) consists of three types of subunits: a catalytic
(C), a scaffolding (A), and a regulatory (B) subunit. In Arabidopsis
thaliana and other organisms the regulatory B
subunits are divided into at least three non-related groups, B55, B’ and B″.
Flowering time in plants mutated in B55 or B''
genes were investigated in this work. The PP2A-b55α and
PP2A-b55β (knockout) lines showed earlier flowering than
WT, whereas a PP2A-b’γ (knockdown) line showed late flowering.
Average advancements of flowering in PP2A-b55 mutants were 3.4
days in continuous light, 6.6 days in 12 h days, and 8.2 days in 8 h days.
Average delays in the PP2A-b’γ mutant line were 7.1 days in 16
h days and 4.7 days in 8 h days. Expression of marker genes of genetically
distinct flowering pathways (CO, FLC, MYB33, SPL3), and the
floral integrator (FT, SOC1) were tested in WT, pp2a mutants,
and two known flowering time mutants elf6 and
edm2. The results are compatible with B55 acting at and/or
downstream of the floral integrator, in a non-identified pathway. B’
γ was involved in repression of FLC, the main
flowering repressor gene. For B’γ the results are consistent
with the subunit being a component in the major autonomous flowering pathway. In
conclusion PP2A is both a positive and negative regulator of flowering time,
depending on the type of regulatory subunit involved. 相似文献
104.
Toward High‐Temperature Stability of PTB7‐Based Bulk Heterojunction Solar Cells: Impact of Fullerene Size and Solvent Additive 下载免费PDF全文
Sadok Ben Dkhil Martin Pfannmöller Maria Ilenia Saba Meriem Gaceur Hamed Heidari Christine Videlot‐Ackermann Olivier Margeat Antonio Guerrero Juan Bisquert Germa Garcia‐Belmonte Alessandro Mattoni Sara Bals Jörg Ackermann 《Liver Transplantation》2017,7(4)
The use of fullerene as acceptor limits the thermal stability of organic solar cells at high temperatures as their diffusion inside the donor leads to phase separation via Ostwald ripening. Here it is reported that fullerene diffusion is fully suppressed at temperatures up to 140 °C in bulk heterojunctions based on the benzodithiophene‐based polymer (the poly[[4,8‐bis[(2‐ethylhexyl)oxy]‐benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl][3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]‐thieno[3,4‐b]thiophenediyl]], (PTB7) in combination with the fullerene derivative [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC70BM). The blend stability is found independently of the presence of diiodooctane (DIO) used to optimize nanostructuration and in contrast to PTB7 blends using the smaller fullerene derivative PC70BM. The unprecedented thermal stability of PTB7:PC70BM layers is addressed to local minima in the mixing enthalpy of the blend forming stable phases that inhibit fullerene diffusion. Importantly, although the nanoscale morphology of DIO processed blends is thermally stable, corresponding devices show strong performance losses under thermal stress. Only by the use of a high temperature annealing step removing residual DIO from the device, remarkably stable high efficiency solar cells with performance losses less than 10% after a continuous annealing at 140 °C over 3 days are obtained. These results pave the way toward high temperature stable polymer solar cells using fullerene acceptors. 相似文献
105.
Somaye Shahraki Maryam Saeidifar Fereshteh Shiri Ameneh Heidari 《Journal of biomolecular structure & dynamics》2017,35(14):3098-3106
In this study, a cytotoxic Pt(IV) complex [Pt(5,5′-dmbpy)Cl4 (5,5′-dmbpy is 5,5′-dimethyl-2,2′-bipyridine) was selected to investigate its affinity to human serum albumin (HSA) by spectroscopy and molecular docking methods. This complex has a bidentate nitrogen donor ligand with four chloride anions attached to a Pt(IV) metal in a distorted octahedral environment. The ?uorescence data showed this complex quench the intrinsic ?uorescence of HSA through a static quenching mechanism. The binding constant (Kb) and the number of binding sites (n) were obtained based on the results of fluorescence measurements. UV–vis, circular dichroism spectroscopy, and three-dimensional fluorescence spectroscopy proved that the Pt(IV) complex could slightly change the secondary structure of protein. Thermodynamic parameters show that the Pt(IV) complex binds to HSA through electrostatic and Vander Waals interactions with one binding site. The molecular docking results confirmed the spectroscopic results and showed that Pt(IV) complex is embedded into subdomain IIA of protein. The aim of this study is to describe the performance of effective anti-cancer drugs when faced with proteins such as HSA. 相似文献
106.
Arash Rahafar Christoph Randler Juan F. Díaz-Morales Ali Kasaeian Zeinab Heidari 《Chronobiology international》2017,34(2):273-279
Morningness-Eveningness Stability Scale improved (MESSi) is a newly constructed measure to assess circadian types and amplitude. In this study, we applied this measure to participants from three different countries: Germany, Spain and Iran. Confirmatory factorial analysis (CFA) of MESSi displayed mediocre fit in the three countries. Comparing increasingly stringent models using multigroup confirmatory factor analyses indicated at least partial measurement invariance (metric invariance) by country for Morning Affect and Distinctness subscales. Age was positively related to Morning Affect (MA), and negatively related to Eveningness (EV) and Distinctness (DI). Men reported higher MA than women, whereas women reported higher DI than men. Regarding country effect, Iranian participants reported highest MA compared to Spaniards and Germans, whereas Germans reported higher DI compared to Iranians and Spaniards. As a conclusion, our study corroborated the validity and reliability of MESSi across three different countries with different geographical and cultural characteristics. 相似文献
107.
108.
Kovarik P Mangold M Ramsauer K Heidari H Steinborn R Zotter A Levy DE Müller M Decker T 《The EMBO journal》2001,20(1-2):91-100
109.
110.
Heidari R Devonshire AL Campbell BE Bell KL Dorrian SJ Oakeshott JG Russell RJ 《Insect biochemistry and molecular biology》2004,34(4):353-363
Resistance of the blowfly, Lucilia cuprina, to organophosphorus (OP) insecticides is due to mutations in LcalphaE7, the gene encoding carboxylesterase E3, that enhance the enzyme's ability to hydrolyse insecticides. Two mutations occur naturally, G137D in the oxyanion hole of the esterase, and W251L in the acyl binding pocket. Previous in vitro mutagenesis and expression of these modifications to the cloned gene have confirmed their functional significance. G137D enhances hydrolysis of diethyl and dimethyl phosphates by 55- and 33-fold, respectively. W251L increases dimethyl phosphate hydrolysis similarly, but only 10-fold for the diethyl homolog; unlike G137D however, it also retains ability to hydrolyse carboxylesters in the leaving group of malathion (malathion carboxylesterase, MCE), conferring strong resistance to this compound. In the present work, we substituted these and nearby amino acids by others expected to affect the efficiency of the enzyme. Changing G137 to glutamate or histidine was less effective than aspartate in improving OP hydrolase activity and like G137D, it diminished MCE activity, primarily through increases in Km. Various substitutions of W251 to other smaller residues had a broadly similar effect to W251L on OP hydrolase and MCE activities, but at least two were quantitatively better in kinetic parameters relating to malathion resistance. One, W251G, which occurs naturally in a malathion resistant hymenopterous parasitoid, improved MCE activity more than 20-fold. Mutations at other sites near the bottom of the catalytic cleft generally diminished OP hydrolase and MCE activities but one, F309L, also yielded some improvements in OP hydrolase activities. The results are discussed in relation to likely steric effects on enzyme-substrate interactions and future evolution of this gene. 相似文献