Partial Molar Volumes and Adiabatic Compressibilities of Tetraalkylammonium and Aminium Salts in Water. II. Volume and Volume Change Relationships

1966 ◽  
Vol 70 (12) ◽  
pp. 3961-3969 ◽  
Author(s):  
R. E. Verrall ◽  
B. E. Conway
Keyword(s):  
Volume Change ◽  
Partial Molar Volumes ◽  
Molar Volumes

Use of Partial Molar Volumes of Model Compounds in the Interpretation of High-Pressure Effects on Proteins

1996 ◽  
Author(s):  
Kenneth E. Prehoda ◽  
John L. Markley
Keyword(s):  
Volume Change ◽  
Atmospheric Pressure ◽  
Protein Unfolding ◽  
Partial Molar Volumes ◽  
Bulk Water ◽  
Pressure Effects ◽  
Molar Volumes ◽  
Positive Term ◽  
Full Characterization ◽  
The Difference

The transfer of liquid hydrocarbons into water is accompanied by a large decrease in volume at 25 °C and atmospheric pressure, with typical values for ΔV°tr of — 2.0 ml mol methylene−1. Considering the large amount of apolar surface that is exposed when a globular protein unfolds, the hydrocarbon transfer results imply that the change in volume accompanying the unfolding process (ΔV°obs) should be highly negative under these conditions. However, experimental data on the pressure denaturation of proteins typically yield relatively small values of ΔV°obs at atmospheric pressure and 25 °C. We analyze this apparent inconsistency in terms of a simple thermodynamic dissection of the partial molar volume. This approach allows the volume effects that result from solute-solvent interactions to be determined from experimental partial molar volumes. The use of absolute quantities (partial molar volumes) circumvents assumptions associated with the use of results from transfer experiments. An important finding is that hydration of apolar species is less dense than bulk water. This discovery leads to the conclusion that the contribution to ΔV°obs for protein unfolding from the hydration of apolar surfaces is highly positive, contrary to predictions based on transfer data. Further, hydration of polar surfaces makes a positive contribution to ΔV°obs. The large, positive term from the differential hydration of the folded and unfolded states is compensated by the difference in free volume of the protein in the two states. This finding provides a new framework for interpreting pressure effects on macromolecules. The full characterization of a macromolecular system requires knowledge of the effect of pressure on the system. The thermodynamic information obtained from using pressure as a perturbation is a volume change for the particular reaction being studied. The observed volume change, ΔV°obs, for protein unfolding may provide insight into the mechanisms that determine the three-dimensional structure of the folded state. Pressure denaturation experiments have been demonstrated for a number of proteins, including ribonuclease A (Gill & Glogovsky, 1965; Brandts et al., 1970), chymotrypsinogen (Hawley, 1971), metmyoglobin (Zipp & Kauzmann, 1973), and, more recently, lysozyme (Samarasinghe et al., 1992) and staphylococcal nuclease (Royer et al., 1993).

Electrostriction volumes of α-amino acids from density measurements in water and in aqueous HCl and NaOH solutions at 25 °C

1993 ◽  
Vol 71 (12) ◽  
pp. 2150-2154 ◽  
Author(s):  
M. Abbate ◽  
G. Castronuovo ◽  
V. Elia ◽  
S. Puzziello
Keyword(s):  
Amino Acids ◽  
Hydrochloric Acid ◽  
Aqueous Solutions ◽  
Sodium Hydroxide ◽  
Volume Change ◽  
Pure Water ◽  
Partial Molar Volumes ◽  
Molar Volumes ◽  
Density Measurements ◽  
Alkyl Chains

The values of the limiting partial molar volumes, [Formula: see text], for some α-amino acids bearing alkyl chains, in pure water and in aqueous solutions of hydrochloric acid and sodium hydroxide, have been obtained from density measurements. From these data it is possible to determine the volume change, ΔVZW, due to the formation of the amphionic molecule from the corresponding neutral molecule.

The volume change on ionizatin of weak electrolytes

1954 ◽  
Vol 7 (4) ◽  
pp. 329 ◽  
Author(s):  
SD Hamann ◽  
SC Lim
Keyword(s):  
Volume Change ◽  
Solvent Effects ◽  
Partial Molar Volumes ◽  
Volume Changes ◽  
Molar Volumes ◽  
Weak Electrolytes

The standard partial molar volumes of some strong and weak electrolytes have been measured in water and three other solvents. The results have been used to estimate the volume changes which accompany the ionization of weak electrolytes. Solvent effects are discussed.

Partial Molar Volumes of Some Multicharged Electrolytes in Aqueous Dimethylformamide at Various Temperatures

1998 ◽  
Vol 63 (4) ◽  
pp. 507-514
Author(s):  
Madan L. Parmar ◽  
Ch. V. Nageshwara Rao ◽  
Suresh Chand Attri
Keyword(s):  
Partial Molar Volumes ◽  
Water Systems ◽  
Molar Volumes ◽  
Density Measurements ◽  
Solution Density ◽  
Aluminium Sulfate ◽  
Ion Interactions

Partial molar volumes of ammonium aluminium sulfate and potassium aluminium sulfate in DMF-water mixtures (5-20 wt.% of DMF) have been determined from solution density measurements at various temperatures and electrolyte concentrations. The data were evaluated by using Masson equation and the obtained parameters were interpreted in terms of ion-solvent and ion-ion interactions. Both electrolytes have been found to act as the structure makers/promotors in DMF-water systems.

On the calculation of partial molar volumes at infinite dilution from experimental density data

2020 ◽  
pp. 1-7
Author(s):  
Jorge Álvarez Juliá ◽  
María Del Carmen Grande ◽  
Carmen Raquel Barrero ◽  
Carlos Miguel Marschoff
Keyword(s):  
Infinite Dilution ◽  
Partial Molar Volumes ◽  
Density Data ◽  
Molar Volumes ◽  
Experimental Density
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