scholarly journals Effect of polyamines on the stability of brain-cortex ribosomes

1969 ◽  
Vol 114 (4) ◽  
pp. 847-854 ◽  
Author(s):  
R. K. Datta ◽  
Suchandra Sen ◽  
J. J. Ghosh
Keyword(s):  
Melting Temperature ◽  
Brain Cortex ◽  
Temperature Dependent ◽  
Enzymic Digestion ◽  
Ph Dependent ◽  
High Concentrations ◽  
The Stability ◽  
Goat Brain

1. Ribosomes isolated from the cortex tissue of goat brain contain very small amounts of spermidine and spermine. Ribosomes isolated from spermidine-treated slices have a higher spermidine content. 2. The polyamines partially prevent the temperature-dependent breakdown of ribosomes into acid-soluble nucleotides. 3. The ‘melting’ temperature of ribosomes rises slightly when the ribosomes are heated slowly in the presence of polyamines. 4. The pH-dependent breakdown of ribosomes into protein, RNA and acid-soluble nucleotide is markedly decreased by polyamines present in media in which ribosomes are suspended. 5. The breakdown of ribosomes in the presence of high concentrations of salts and EDTA is partially checked by the concurrent presence of polyamines. 6. Spermidine and spermine make ribosomes less susceptible to enzymic digestion by crystalline trypsin and ribonuclease.

scholarly journals Concentration- and pH-Dependent Oligomerization of the Thrombin-Derived C-Terminal Peptide TCP-25

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1572
Author(s):  
Ganna Petruk ◽  
Jitka Petrlova ◽  
Firdaus Samsudin ◽  
Rita Del Giudice ◽  
Peter J. Bond ◽  
...  
Keyword(s):  
Tryptophan Fluorescence ◽  
Helical Structure ◽  
High Concentration ◽  
Temperature Dependent ◽  
Preclinical Development ◽  
Intrinsic Tryptophan Fluorescence ◽  
Ph Dependent ◽  
High Concentrations ◽  
Dose Dependent Increase ◽  
Dose Dependent

Peptide oligomerization dynamics affects peptide structure, activity, and pharmacodynamic properties. The thrombin C-terminal peptide, TCP-25 (GKYGFYTHVFRLKKWIQKVIDQFGE), is currently in preclinical development for improved wound healing and infection prevention. It exhibits turbidity when formulated at pH 7.4, particularly at concentrations of 0.3 mM or more. We used biochemical and biophysical approaches to explore whether the peptide self-associates and forms oligomers. The peptide showed a dose-dependent increase in turbidity as well as α-helical structure at pH 7.4, a phenomenon not observed at pH 5.0. By analyzing the intrinsic tryptophan fluorescence, we demonstrate that TCP-25 is more stable at high concentrations (0.3 mM) when exposed to high temperatures or a high concentration of denaturant agents, which is compatible with oligomer formation. The denaturation process was reversible above 100 µM of peptide. Dynamic light scattering demonstrated that TCP-25 oligomerization is sensitive to changes in pH, time, and temperature. Computational modeling with an active 18-mer region of TCP-25 showed that the peptide can form pH-dependent higher-order end-to-end oligomers and micelle-like structures, which is in agreement with the experimental data. Thus, TCP-25 exhibits pH- and temperature-dependent dynamic changes involving helical induction and reversible oligomerization, which explains the observed turbidity of the pharmacologically developed formulation.

scholarly journals Mescaline-induced changes of brain-cortex ribosomes. Effect of mescaline on the stability of brain-cortex ribosomes

1970 ◽  
Vol 117 (5) ◽  
pp. 961-968 ◽  
Author(s):  
R. K. Datta ◽  
J. J. Ghosh
Keyword(s):  
Enzyme Activities ◽  
Brain Cortex ◽  
Rapid Degradation ◽  
Brain Cortex Slices ◽  
Cortex Slices ◽  
The Stability ◽  
Induced Changes ◽  
Goat Brain ◽  
Absorption Characteristics ◽  
Positive Materials

1. During the action of mescaline sulphate on goat brain-cortex slices the ribosomal particles become susceptible to breakdown, releasing protein, RNA, acidsoluble nucleotides and ninhydrin-positive materials, resulting in loss of ribosomal enzyme activities. 2. Ribosomes of the mescaline-treated cortex slices undergo rapid degradation in the presence of trypsin and ribonuclease. 3. Mescaline does not alter the chemical and nucleotide compositions or the u.v.-absorption characteristics of ribosomal particles, however.

Evaluation of bacteriophages during the treatment of sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 189-194 ◽  
Author(s):  
B. Mignotte-Cadiergues ◽  
C. Gantzer ◽  
L. Schwartzbrod
Keyword(s):  
Bacteroides Fragilis ◽  
Temperature Dependent ◽  
Treatment Methods ◽  
Somatic Coliphages ◽  
Viral Contamination ◽  
Log Reduction ◽  
Ph Dependent ◽  
Somatic Coliphage ◽  
Phage Inactivation

The aim of this work was to determine the effect of liming and composting on the fate of three bacteriophages (somatic coliphages, F-RNA phages, Bacteroides fragilis phages) considered as potential indicators of viral contamination. It was shown that the three bacteriophages studied exhibited variable densities in sludge. Somatic coliphages were most abundant (104 to 105 .10 g−1 DM) then F-RNA bacteriophages (102 to 104.10 g−1 DM) and Bacteroides fragilis phages (101 to 102.10 g−1 DM). The efficacy of liming was found to be pH dependent but also sludge dependent. The pH allowing 99% elimination of somatic coliphage is close to 9 for solid sludges and close to 13.5 for liquid sludges. For composting, our findings clearly demonstrated that phage inactivation is very clearly temperature-dependent. For temperatures reaching 70°, there is a 5 log reduction in somatic coliphages while for temperature in the 50-55°C range, the drop off is only 2 log. Considering the efficacy of the treatment methods, it is clear that the well-established industrial procedures that reach temperatures in the 60-70°C range totally inactivate all 3 phages tested and present in sludge before composting.

scholarly journals The potentional of plants to cleanup metals from an old landfill site

2017 ◽  
Author(s):  
Yahya Jani ◽  
Charlotte Marchand ◽  
William Hogland
Keyword(s):  
Contaminated Soils ◽  
Hazardous Materials ◽  
Average Concentration ◽  
Soil Samples ◽  
Landfill Site ◽  
Group Company ◽  
Timothy Grass ◽  
Xrf Scanning ◽  
High Concentrations ◽  
The Stability

Old landfill sites contain different hazardous materials like heavy metals which have the ability to affects the entire environment. These places are sometimes covered by plants to increase the stability of the soil and to reduce the effects of erosion. 15 soil samples (3 samples from each place) and 5-7 timothy-grass (Phleum pretense) plants from 5 different places were taken from an old landfill place in an active landfill site in Högbytorp /Sweden owned by Ragn-sells Group Company. XRF scanning was used to analyze the metal content of soil samples and of plants. High concentrations of metals were detected in the soil samples like Fe with an average of about 25000 ppm, Mn about 250 ppm and 2800 ppm of Ti. The plants results showed an average concentration of Fe in the shoots about 730 ppm, Mn about 60 ppm and Ti about 1760 ppm. On the other hand, the roots results showed an average concentration of about 10 000 ppm of Fe, about 160 ppm of Mn and 2200 ppm of Ti. These results gave the indication that the Timothy-grass has the ability to extract metals from contaminated soils and can help to cleanup these soils.

Selection for soyabeans with high and environmentally stable lutein concentrations

2014 ◽  
Vol 12 (S1) ◽  
pp. S12-S16 ◽  
Author(s):  
Krishna Hari Dhakal ◽  
Myoung-Gun Choung ◽  
Young-Sun Hwang ◽  
Felix B. Fritschi ◽  
J. Grover Shannon ◽  
...  
Keyword(s):  
Human Health ◽  
High Stability ◽  
Planting Dates ◽  
Early Maturity ◽  
Breeding Objective ◽  
Late Maturity ◽  
Selection For ◽  
High Concentrations ◽  
The Stability ◽  
Nutritional Benefits

Lutein has significant nutritional benefits for human health. Therefore, enhancing soybean lutein concentrations is an important breeding objective. However, selection for soybeans with high and environmentally stable lutein concentrations has been limited. The objectives of this study were to select soybeans with high seed lutein concentrations and to determine the stability of lutein concentrations across environments. A total of 314 genotypes were screened and 18 genotypes with high lutein concentrations and five genotypes with low lutein concentrations were selected for further examination. These 23 genotypes and two check varieties were evaluated under six environments (two planting dates for 2 years at one location and two planting dates for 1 year at another location). Lutein concentrations were influenced by genotype, environment and genotype × environment interactions. Genotypes with late maturity and low lutein concentrations were more stable than those with early maturity and high concentrations. Early (May) planting resulted in greater lutein concentrations than late (June) planting. Among the genotypes evaluated, PI603423B (7.7 μg/g) and PI89772 (5.8 μg/g) had the greatest mean lutein concentrations and exhibited medium and high stability across the six environments, respectively. Thus, these genotypes may be useful for breeding soybeans with high and stable seed lutein concentrations.

scholarly journals Temperature dependent chiroptical response of sigmoidal gold clusters: probing the stability of chiral metal clusters

2018 ◽  
Vol 9 (25) ◽  
pp. 5614-5622 ◽  
Author(s):  
Ping Guo ◽  
Biao Yang ◽  
Li Zhang ◽  
Liang Zhao
Keyword(s):  
Metal Clusters ◽  
Gold Cluster ◽  
Gold Clusters ◽  
Cluster Compounds ◽  
Structural Factors ◽  
Temperature Dependent ◽  
Cluster Stability ◽  
The Stability

Three chiral gold cluster compounds are herein selected to probe how structural factors influence the cluster stability upon heating.

Transitions in Dictyostelium discoideum behaviour: influence of calcium and fluoride on slug phototaxis and thermotaxis

1984 ◽  
Vol 65 (1) ◽  
pp. 111-121
Author(s):  
U. Dohrmann ◽  
P.R. Fisher ◽  
M. Bruderlein ◽  
K.L. Williams
Keyword(s):  
Dictyostelium Discoideum ◽  
Temperature Gradients ◽  
Sensory Transduction ◽  
Inorganic Salts ◽  
Transition Temperatures ◽  
Temperature Dependent ◽  
High Concentrations

Phototaxis and thermotaxis by slugs of Dictyostelium discoideum show transitions that result in bimodality in phototaxis and temperature-dependent orientation up or down temperature gradients. New steps in the sensory transduction chain for these kinds of behaviour are elucidated from studies using inorganic salts (Ca2+, EGTA, KF) and several mutants. KF enhances bimodality of phototaxis, improves the accuracy of thermotaxis, and affects the transition temperatures from positive to negative thermotaxis. Changing the Ca2+ concentration has effects on both phototaxis and thermotaxis. At low Ca2+ concentrations phototaxis and thermotaxis are enhanced. In the presence of EGTA or high concentrations of Ca2+ phototaxis becomes bimodal, thermotaxis is impaired and spontaneous turning is suppressed. These results obtained by changing Ca2+ concentrations are analogous to those obtained previously with sensory transduction mutations, which coordinately affect phototaxis and thermotaxis.

Temperature-Dependent Mechanical Stability of Retained Austenite in Thermomechanically Processed 3Mn Steel

2021 ◽  
Vol 1016 ◽  
pp. 762-767
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański
Keyword(s):  
Retained Austenite ◽  
Mechanical Stability ◽  
Electron Backscatter Diffraction ◽  
Tensile Tests ◽  
Trip Effect ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Static Tensile ◽  
The Stability ◽  
Backscatter Diffraction

The temperature-dependent mechanical stability of retained austenite in medium-Mn transformation induced plasticity 0.17C-3.3Mn-1.6Al-1.7Al-0.22Si-0.23Mo thermomechanically processed steel was investigated using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) methods. Specimens were deformed up to rupture in static tensile tests in a temperature range 20–200°C. It was found that deformation temperature affects significantly the intensity of TRIP effect. In case of specimens deformed at temperatures higher than 60°C, a gradual temperature-related decrease in the stability of γ phase was noted. It indicates a progressive decrease of the significance of the TRIP effect and at the same time the growing importance of the thermally activated processes affecting a thermal stability of retained austenite.

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