THE EFFECT OF ION CONCENTRATION AND pH ON THE THERMAL STABILITY OF A CANINE ADENOVIRUS

1967 ◽  
Vol 13 (9) ◽  
pp. 1139-1149 ◽  
Author(s):  
T. Yamamoto
Keyword(s):  
Thermal Stability ◽  
Salt Solution ◽  
Ion Concentration ◽  
Ph Adjustment ◽  
Ion Concentrations ◽  
Stabilizing Effect ◽  
High Concentrations ◽  
Ph Range ◽  
Thermal Stability Of

The inactivation of a canine adenovirus hemagglutinin and infectivity at 56 °C at varying times up to 1 h has been studied in the presence of various ions and concentrations of ions.Under conditions of uncontrolled pH 1–2 M NaCl and MgCl2 both stabilized the virus hemagglutinin and infectivity. Lower concentrations of these salts as well as 0.04 M phosphate, Hank's balanced salt solution, and minimal Eagle's medium had little stabilizing effect. Molar concentrations of phosphate and Tris butter were also found to stabilize the virus hemagglutinin.The pH adjustment of the suspending salt solution was found to be important since high concentrations of salts such as MgCl2 are quite acidic. Both 1 M MgCl2 and 1 M NaCl stabilized the virus in the pH range of 4–6, but inactivation was rapid at pH 3 and less rapid at pH 7. Ion concentrations lower than 1 M markedly reduced the hemagglutinin stabilization at optimun pH.

Thermal stability of ribosomes from a thermophilic and a mesophilic fungus

1973 ◽  
Vol 19 (6) ◽  
pp. 761-763 ◽  
Author(s):  
H. M. Miller ◽  
M. G. Shepherd
Keyword(s):  
Thermal Stability ◽  
Ion Concentration ◽  
Magnesium Ion ◽  
Penicillium Notatum ◽  
Ribosomal Subunits ◽  
Ion Concentrations ◽  
Thermal Stability Of

Ribosomes and ribosomal subunits from the thermophile Penicillium duponti were found to be more thermostable than the corresponding particles from the mesophile Penicillium notatum. The thermostability of the ribosomes from both organisms was dependent on magnesium ion concentration. The dissociation of the 80-S ribosomes into 60-S and 40-S subunits occurred at higher magnesium ion concentrations for the mesophile than the thermophile.

The chemical stability of mendipite, diaboleïte, chloroxiphite, and cumengéite, and their relationships to other secondary lead(II) minerals

1980 ◽  
Vol 43 (331) ◽  
pp. 901-904 ◽  
Author(s):  
D. Alun Humphreys ◽  
John H. Thomas ◽  
Peter A. Williams ◽  
Robert F. Symes
Keyword(s):  
Chloride Ion ◽  
Stability Diagram ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Stability Field ◽  
Cupric Ion ◽  
Free Energy Of Formation ◽  
High Concentrations ◽  
The Stability ◽  
Ph Range

SummaryThe chemical stabilities of mendipite, Pb3O2Cl2, diaboleïte, Pb2CuCl2(OH)4, chloroxiphite, Pb3CuCl2O2(OH)2, and cumengéite, Pb19Cu24Cl42 (OH)44, have been determined in aqueous solution at 298.2 K. Values of standard Gibbs free energy of formation, ΔGf°, for the four minerals are −740, −1160, −1129, and −15163±20 kJ mol−1 respectively. These values have been used to construct the stability diagram shown in fig. I which illustrates their relationships to each other and to the minerals cotunnite, PbCl2, paralaurionite, PbOHCl, and litharge, PbO. This diagram shows that mendipite occupies a large stability field and should readily form from cold, aqueous, mineralizing solutions containing variable amounts of lead and chloride ions, and over a broad pH range. The formation of paralaurionite and of cotunnite requires a considerable increase in chloride ion concentration, although paralaurionite can crystallize under much less extreme conditions than cotunnite. The encroachment of the copper minerals on to the stability fields of those mineral phases containing lead(II) only is significant even at very low relative activities of cupric ion. Chloroxiphite has a large stability field, and at given concentrations of cupric ion, diaboleïte is stable at relatively high aCl−. Cumengéite will only form at high concentrations of chloride ion.

scholarly journals Anionic surfactant sulfate dodecyl sodium (SDS)-induced thermodynamics and conformational changes of collagen by ultrasensitive microcalorimetry

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Jie Zhang ◽  
Chunhua Wang ◽  
Fengteng Zhang ◽  
Wei Lin
Keyword(s):  
Thermal Stability ◽  
Conformational Changes ◽  
Triple Helix ◽  
Striking Difference ◽  
Thermal Transition ◽  
Scanning Calorimetry ◽  
Helix Structure ◽  
Stabilizing Effect ◽  
Collagen Molecules ◽  
Thermal Stability Of

Abstract In this communication, sulfate dodecyl sodium (SDS)-induced thermodynamics and conformational changes of collagen were studied. We used ultrasensitive differential scanning calorimetry (US-DSC) to directly monitor the thermal transition of collagen in the presence of SDS. The results show that SDS affects the conformation and thermal stability of collagen very differently depending on its concentrations. At CSDS ≤ 0.05 mM, the enhanced thermal stability of collagen indicates the stabilizing effect by SDS. However, a further increase of SDS leads to the denaturation of collagen, verifying the well-known ability of SDS to unfold proteins. This striking difference in thermodynamics and conformational changes of collagen caused by SDS concentrations can be explained in terms of their interactions. With increasing SDS, the binding of SDS to collagen can be dominated by electrostatic interaction shifting to hydrophobic interaction, and the latter plays a key role in loosening and unfolding the triple-helix structure of collagen. The important finding in the present study is the stabilizing effect of SDS on collagen molecules at extreme low concentration. Graphical abstract

scholarly journals Influence of High-Concentration LLDPE on the Manufacturing Process and Morphology of Pitch/LLDPE Fibres

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1099
Author(s):  
Salem Mohammed Aldosari ◽  
Muhammad A. Khan ◽  
Sameer Rahatekar
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Modulus ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
High Concentration ◽  
Scanning Electron Microscope Study ◽  
High Concentrations ◽  
Thermal Stability Of

A high modulus of elasticity is a distinctive feature of carbon fibres produced from mesophase pitch. In this work, we expand our previous study of pitch/linear low-density polyethylene blend fibres, increasing the concentration of the linear low-density polyethylene in the blend into the range of from 30 to 90 wt%. A scanning electron microscope study showed two distinct phases in the fibres: one linear low-density polyethylene, and the other pitch fibre. Unique morphologies of the blend were observed. They ranged from continuous microfibres of pitch embedded in linear low-density polyethylene (occurring at high concentrations of pitch) to a discontinuous region showing the presence of spherical pitch nodules (at high concentrations of linear low-density polyethylene). The corresponding mechanical properties—such as tensile strength, tensile modulus, and strain at failure—of different concentrations of linear low-density polyethylene in the pitch fibre were measured and are reported here. Thermogravimetric analysis was used to investigate how the increased linear low-density polyethylene content affected the thermal stability of linear low-density polyethylene/pitch fibres. It is shown that selecting appropriate linear low-density polyethylene concentrations is required, depending on the requirement of thermal stability and mechanical properties of the fibres. Our study offers new and useful guidance to the scientific community to help select the appropriate combinations of linear low-density polyethylene/pitch blend concentrations based on the required mechanical property and thermal stability of the fibres.

scholarly journals The Thermal Stability of theFusarium solani pisiCutinase as a Function of pH

2001 ◽  
Vol 1 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Steffen B. Petersen ◽  
Peter Fojan ◽  
Evamaria I. Petersen ◽  
Maria Teresa Neves Petersen
Keyword(s):  
Thermal Stability ◽  
Enzymatic Activity ◽  
Fusarium Solani ◽  
Ph Variation ◽  
Electrostatic Contribution ◽  
Molecular Interpretation ◽  
Ph Range ◽  
Thermal Stability Of

We have investigated the thermal stability of theFusarium solani pisicutinase as a function of pH, in the range from pH 2–12. Its highest enzymatic activity coincides with the pH-range at which it displays its highest thermal stability. The unfolding of the enzyme as a function of pH was investigated by microcalorimetry. The ratio between the calorimetric enthalpy (ΔHcal) and the van′t Hoff enthalpy (ΔHv) obtained, is far from unity, indicating that cutinase does not exhibit a simple two state unfolding behaviour. The role of pH on the electrostatic contribution to the thermal stability was assessed using TITRA. We propose a molecular interpretation for the pH-variation in enzymatic activity.

Maillard-Reacted Whey Protein Isolates Enhance Thermal Stability of Anthocyanins over a Wide pH Range

2018 ◽  
Vol 66 (36) ◽  
pp. 9556-9564 ◽  
Author(s):  
Xinguang Qin ◽  
Dan Yuan ◽  
Qi Wang ◽  
Zhongze Hu ◽  
Yang Wu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Whey Protein ◽  
Protein Isolates ◽  
Wide Ph Range ◽  
Ph Range ◽  
Whey Protein Isolates ◽  
Thermal Stability Of

scholarly journals Macromolecular Crowding Enhances Catalytic Efficiency and Stability of α-Amylase

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jay Kant Yadav
Keyword(s):  
Thermal Stability ◽  
Relative Effectiveness ◽  
Macromolecular Crowding ◽  
Catalytic Efficiency ◽  
Crowding Effect ◽  
Functional Attributes ◽  
Marginal Change ◽  
High Concentrations ◽  
Thermal Stability Of

In the present study an attempt was made to investigate the macromolecular crowding effect on functional attributes of α-amylase. High concentrations of sugar based cosolvents, (e.g., trehalose, sucrose, sorbitol, and glycerol) were used to mimic the macromolecular crowding environment (of cellular milieu) under in vitro conditions. To assess the effect of macromolecular crowding, the activity and structural properties of the enzyme were evaluated in the presence of different concentrations of the above cosolvents. Based on the results it is suggested that the macromolecular crowding significantly improves the catalytic efficiency of the enzyme with marginal change in the structure. Out of four cosolvents examined, trehalose was found to be the most effective in consistently enhancing thermal stability of the enzyme. Moreover, the relative effectiveness of the above cosolvents was found to be dependent on their concentration used.

scholarly journals Synthesis and study of aroylethyl(ethyl)-xanthates as stabilizers of polymeric materials

2021 ◽  
Author(s):  
Tanzila Akchurina ◽  
Sabira Sardarova ◽  
Khuraman Efendiyeva ◽  
Irada Eyvazova ◽  
Vagif Farzaliyev ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Intermediate Product ◽  
Cumene Hydroperoxide ◽  
Polymeric Materials ◽  
Transformation Products ◽  
Oxidative Destruction ◽  
Ethyl Xanthate ◽  
Stabilizing Effect ◽  
Oxidation Chain ◽  
Thermal Stability Of

AbstractThe number of aroylethyl (ethyl)xanthates have been synthesized by the reaction of the exchange decomposition of β-dimethylaminopropiophenone hydrochlorides with potassium xanthate containing several functional groups (C=O, C=S, C–OH), which determine the use of these xanthates as stabilizers with internal synergy to polymeric materials. It was shown that the thermal stability of the compounds, depending on the nature of the substituent in the benzene ring of the molecule was observed in the temperature range of 149–196 °C. It was revealed that aroylethyl(ethyl)xanthates had a stabilizing effect due to the suppression of thermo-oxidative destruction of polyethylene; they increased the induction period of polyethylene oxidation by 2–6 times, and the oxidation rate was reduced by about 3–9 times. Among the studied compounds, 4-hydroxybenzoylethyl (ethyl)xanthate had the greatest stabilizing effect. The study of the mechanism of the stabilizing action of the compounds showed that xanthates react with cumene hydroperoxide (CHP), which proceeded through the stage of formation of an intermediate product that actively decomposed CHP, i.e., the oxidation chain was terminated by the decomposition of the CHP not by the initial xanthates but by their transformation products.

scholarly journals The Effect of Divalent Metal Ions on the Temperature Stability of Poly(I:C) Duplex

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Evgeniya Usenko ◽  
Vladimir Valeev ◽  
Alexander Glamazda ◽  
Victor Karachevtsev
Keyword(s):  
Thermal Stability ◽  
Metal Ions ◽  
Concentration Dependence ◽  
Temperature Stability ◽  
Ion Concentration ◽  
Poly I:C ◽  
Divalent Metal Ions ◽  
Buffer Solution ◽  
Solution Ph ◽  
Thermal Stability Of

The effect of divalent ions on the thermal stability of the double-stranded polynucleotide polyinosinic:polycytidylic acid (poly(I:C)) in a buffer solution (pH 7) was studied by UV absorption spectroscopy and thermal denaturation by measuring the absorbance at 260 nm. The concentration dependence of the polynucleotide melting temperature (Tm) in the presence of metal ions (2.5 × 10−6–10−2 M) was obtained. It was found that the duplex thermal stability grew gradually upon an increase of Ca2+ and Mn2+ concentration. The thermal stability of the duplex in the presence of Cd2+, Ni2+, and Zn2+ rises up to an ion concentration of about 10−4 M and further falls. In contrast to these ions, the addition of Cu2+ to the solution leads to a sharp decline in Тm of the duplex at a concentration above 10−5 M. The observed difference in the influence of metal ions on the poly(I:C) thermal stability is explained by the different affinity of these ions to both the phosphate groups and the nitrogenous bases of the polynucleotides. Based on the analysis of the Tm concentration dependence, the dominant binding of each ion to the specific polynucleotide components was proposed.

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