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.

scholarly journals The effects of certain glycols, substituted glycols and related organic solvents on the thermal stability of soluble collagen

1971 ◽  
Vol 125 (2) ◽  
pp. 599-604 ◽  
Author(s):  
G. J. Hart ◽  
A. E. Russell ◽  
D. R. Cooper
Keyword(s):  
Thermal Stability ◽  
Optical Rotation ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Thermal Transition ◽  
Denaturation Temperature ◽  
Rotation Measurement ◽  
Skin Collagen ◽  
Positional Isomerism ◽  
Thermal Stability Of

The effects of a number of related diols, substituted diols and glycerol on the thermal stability of acid-soluble calf skin collagen were investigated. Thermal transition temperatures were determined by optical rotation measurement. Short-chain diols with terminal hydroxyl groups, i.e. ethylene glycol and propane-1,3-diol, stabilized the protein at all accessible concentrations. Stabilization was also observed with glycerol and diethylene glycol. Higher homologues in the diol series produced various effects, as did hydroxyl-group positional isomerism. Monoalkyl substitution of diols progressively lowered the denaturation temperature of collagen. Results are discussed in relation to possible mechanisms of perturbant action.

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 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 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.

Thermal stability of calf skin collagen type I in salt solutions

1996 ◽  
Vol 1297 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Regina Komsa-Penkova ◽  
Rumiana Koynova ◽  
Georgi Kostov ◽  
Boris G. Tenchov
Keyword(s):  
Thermal Stability ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Salt Solutions ◽  
Skin Collagen ◽  
Thermal Stability Of ◽  
Calf Skin

Semiautomated Method for the Analysis of Formulations of Chlorpheniramine Maleate and Brompheniramine Maleate

1979 ◽  
Vol 62 (3) ◽  
pp. 552-555
Author(s):  
Don C Cox ◽  
Ross D Kirchhoefer
Keyword(s):  
Acid Solution ◽  
Active Ingredient ◽  
Dilute Acid ◽  
Chlorpheniramine Maleate ◽  
Precision Data ◽  
Dilute Acid Solution ◽  
Aqueous Layer ◽  
Brompheniramine Maleate ◽  
Semiautomated Method

Abstract The determination of chlorpheniramine maleate and brompheniramine maleate in tablets, capsules, injections, and elixirs has been automated. The active ingredient is dissolved in dilute HCl. The dilute acid solution is sampled, made basic with dilute NaOH, and extracted with isooctane. The isooctane phase is resampled and the drug is re-extracted into dilute HCl. The absorbance of the acidic aqueous layer is monitored at 265 nm. The method is an automated version of the general USP XIX assay for salts of organic nitrogenous bases. The results from the semiautomated procedure agree well with the USP XIX and NF XIV official methods. Recoveries were 100% from an authentic tablet material. The system is linear from 0 to 300% of declared potency. The procedure is free from common excipient and dye interferences. Precision data are included for both the automated and official methods.

Apparent Molecular Weight of Insulin in Dilute Acid Solution

Nature ◽  
1963 ◽  
Vol 197 (4872) ◽  
pp. 1104-1105 ◽  
Author(s):  
P. D. JEFFREY ◽  
J. H. COATES
Keyword(s):  
Molecular Weight ◽  
Acid Solution ◽  
Apparent Molecular Weight ◽  
Dilute Acid ◽  
Dilute Acid Solution
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