scholarly journals Effect of pH on thermal stability of collagen in the dispersed and aggregated states (Short Communication)

1974 ◽  
Vol 139 (1) ◽  
pp. 277-280 ◽  
Author(s):  
Allan E. Russell
Keyword(s):  
Thermal Stability ◽  
Short Communication ◽  
Dilute Solution ◽  
Thermal Stabilities ◽  
Effect Of Ph ◽  
Soluble Collagen ◽  
Insoluble Collagen ◽  
Acid Soluble Collagen ◽  
Collagen Molecules ◽  
Thermal Stability Of

Thermal stabilities of mature insoluble collagen, salt-precipitated fibrils of acid-soluble collagen and acid-soluble collagen in solution were compared as a function of acid pH. Both insoluble and precipitated collagens showed large parallel destabilization with decrease in pH, whereas the intrinsic stability of individual collagen molecules in dilute solution was comparatively unaffected.

scholarly journals Effect of compounds of the urea–guanidinium class on renaturation and thermal stability of acid-soluble collagen

1972 ◽  
Vol 127 (5) ◽  
pp. 855-863 ◽  
Author(s):  
A. E. Russell ◽  
D. R. Cooper
Keyword(s):  
Thermal Stability ◽  
Common Mechanism ◽  
Soluble Collagen ◽  
Activity Variation ◽  
Molar Activity ◽  
Acid Soluble Collagen ◽  
Skin Collagen ◽  
Thermal Stability Of ◽  
Calf Skin ◽  
Guanidinium Salts

The effects of guanidinium salts in decreasing the renaturation rate and lowering the thermal stability of acid-soluble calf-skin collagen have been compared with those of formamide and urea. With the exception of guanidinium sulphate at higher concentrations, no qualitative differences were apparent in the effects of these perturbants, which thus differed only in molar activity. Activity variation in the guanidinium salts reflected a net effect resulting from additivity of cation and anion contributions. As observed in other protein systems, lyotropic activity increased in the series formamide<urea<guanidinium ion, and in the guanidinium salts in the anion order fluoride<sulphate<chloride<bromide<nitrate<iodide. Low activities of guanidinium fluoride and sulphate were attributable to counter-effects of the anions, which acted as structural stabilizers. Changes in renaturation kinetics induced by either temperature or added perturbants appeared to conform with the Flory–Weaver model for the collagen transition. Additivity and non-specificity of the observed effects are discussed with particular reference to a common mechanism involving weak, non-saturated binding of perturbants at protein peptide groups.

scholarly journals Differential anion effects on thermal stability of collagen in the dispersed and aggregated states

1974 ◽  
Vol 137 (3) ◽  
pp. 599-602 ◽  
Author(s):  
A. E. Russell
Keyword(s):  
Thermal Stability ◽  
Acid Solution ◽  
Thermal Transition ◽  
Dilute Solution ◽  
Dilute Acid ◽  
Dilute Acid Solution ◽  
Skin Collagen ◽  
Collagen Molecules ◽  
Thermal Stability Of ◽  
Calf Skin

The effects of KCNS and KI on thermal transition temperatures of calf skin collagen molecules in dilute acid solution and precipitated collagen fibrils from the same source were compared as a function of salt concentration and pH. The two salts produced qualitatively similar effects on each collagen form, but the response shown by single collagen molecules in dilute solution differed from that observed for molecular aggregates present in native-type fibrils.

Syntheses, Crystal Structures and Thermal Stability of Co(II) and Zn(II) Complexes with Ethyl Carbazate

2005 ◽  
Vol 60 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Tong-Lai Zhang ◽  
Jiang-Chuang Song ◽  
Jian-Guo Zhang ◽  
Gui-Xia Ma ◽  
Kai-Bei Yu
Keyword(s):  
Thermal Stability ◽  
Aqueous Solutions ◽  
Diffraction Analysis ◽  
Single Crystals ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Thermal Stabilities ◽  
X Ray ◽  
Thermal Stability Of

Cobalt(II) and zinc(II) complexes of ethyl carbazate (ECZ), [Co(ECZ)3](NO3)2 and [Zn(ECZ)3] (NO3)2, were synthesized. Single crystals of these two compounds were grown from aqueous solutions using a slow evaporation method. Their structures have been determined by X-ray diffraction analysis. Both of them are monoclinic with space group P21/n. The complexes are further characterized by element analysis and IR measurements. Their thermal stabilities are studied by using TG-DTG, DSC techniques. When heated to 350 °C, only metal oxide was left for both complexes.

Simulation of Thermal Stability and Friction: A Lubricant Confined Between Monolayers of Wear Inhibitors on Iron Oxide

1998 ◽  
Vol 543 ◽  
Author(s):  
T. Çağin ◽  
Y. Zhou ◽  
E. S. Yamaguchi ◽  
R. Frazier ◽  
A. Ho ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Thermal Stability ◽  
Quantum Chemical ◽  
Md Simulations ◽  
Atomic Level ◽  
The Self ◽  
Self Assembled Monolayer ◽  
Thermal Stabilities ◽  
Frictional Forces ◽  
Thermal Stability Of

AbstractTo understand antiwear phenomena in motor engines at the atomic level and provide evidence inselecting future ashless wear inhibitors, we studied the thermal stability of the self-assembled monolayer(SAM) model for dithiophosphate (DTP) and dithiocarbamate (DTC) molecules on the iron oxidesurface using molecular dynamics. The interactions for DTP, DTC and Fe2O3 are evaluated based on aforce field derived from fitting to ab initio quantum chemical calculations of dimethyl DTP (and DTC)and Fe(OH)2(H2O)2-DTP (DTC) clusters. MD simulations at constant-NPT are conducted to assesrelative thermal stabilities of the DTP and DTC with different pendant groups (n-propyl, i-propyl, npentyl.and i-pentyl). To investigate frictional process, we employ a steady state MD method, in whichone of the Fe2O3 slabs maintained at a constant linear velocity. We obtain the time averaged normaland frictional forces from the interatomic forces. Then, we calculated the friction coefficient at theinterface between SAMs of DTP and the confined lubricant, hexadecane, to assess the shear stability ofDTPs with different pendant groups.

The effect of pH ont he thermal stability ofa-actin isoforms

2005 ◽  
Vol 82 (1) ◽  
pp. 281-285 ◽  
Author(s):  
G. Papp ◽  
Beáta Bugyi ◽  
Z. Ujfalusi ◽  
Sz. Halasi ◽  
J. Orbán
Keyword(s):  
Thermal Stability ◽  
Font Size ◽  
Actin Isoforms ◽  
Effect Of Ph ◽  
Thermal Stability Of

Thermal Stability of GaAs/InGaP and InGaP/(In)GaAs Interfaces

1995 ◽  
Vol 405 ◽  
Author(s):  
F. Hyuga ◽  
T. Nittono ◽  
K. Watanabe ◽  
T. Furuta
Keyword(s):  
Thermal Stability ◽  
Quantum Wells ◽  
Annealing Time ◽  
High Performance ◽  
High Reliability ◽  
Half Maximum ◽  
Single Quantum ◽  
Thermal Stabilities ◽  
Temperature Range ◽  
Thermal Stability Of

AbstractThermal stabilities of GaAs/InGaP and InGaP/(In)GaAs interfaces are investigated using InGaP/(In)GaAs/InGaP single quantum wells. Annealing is performed at a temperature range between 600 and 900 °C for 10 min. Positions and the full widths at half maximum (FWHM) of photoluminescence (PL) peaks are almost identical to those of as-grown ones up to 800 °C. Blue shifts of PL peaks and increased widths of their FWHM observed after 900 °C annealing are suppressed by shortening the annealing time to 0.1 sec. Annealing at 900 ‘C for 0.1 sec is sufficient to activate Si ions implanted into (In)GaAs layers. As a result, these thermal stabilities are able to provide high reliability and high performance of InGaP/(In)GaAs heterostructure MESFET ICs.

Thermal stability of ribosomes from a psychrophilic and a mesophilic yeast

1969 ◽  
Vol 15 (9) ◽  
pp. 1116-1118 ◽  
Author(s):  
C. H. Nash ◽  
D. W. Grant
Keyword(s):  
Thermal Stability ◽  
Candida Utilis ◽  
Thermal Stabilities ◽  
Similar Treatment ◽  
Psychrophilic Yeast ◽  
Ribosomal Function ◽  
Physical Degradation ◽  
Thermal Stability Of

Ribosomes from the obligately psychrophilic yeast, Candida gelida, are rendered completely non-functional after exposure to 40 C for 5 minutes. This heat-induced impairment of ribosomal function is characterized by a reduced capacity to bind charged sRNA and is accompanied by physical degradation. Ribosomes from the mesophilic yeast, Candida utilis, however, are functionally and physically unaffected when subjected to similar treatment. The dissimilar thermal stabilities may be attributed to marked differences in the ribonucleoproteins present in the two species.

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

The effect of pH on the thermal stability of fibrous hard alpha-keratins

2013 ◽  
Vol 98 (2) ◽  
pp. 542-549 ◽  
Author(s):  
Dan Istrate ◽  
Crisan Popescu ◽  
Meriem Er Rafik ◽  
Martin Möller
Keyword(s):  
Thermal Stability ◽  
Effect Of Ph ◽  
Thermal Stability Of
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