Standard Volumes of Transfer for Some α-Amino Acids from Water to Aqueous Sodium Acetate Solutions at 298.15 K

Author(s):  
Jianji Wang ◽  
Z. Yan ◽  
Kelei Zhuo ◽  
D. Liu

Apparent molar volumes, V

1999 ◽  
Vol 80 (3) ◽  
pp. 179-188 ◽  
Author(s):  
Jianji Wang ◽  
Zhenning Yan ◽  
Kelei Zhuo ◽  
Jinsuo Lu

1994 ◽  
Vol 72 (2) ◽  
pp. 362-368 ◽  
Author(s):  
Andrew W. Hakin ◽  
Michelle M. Duke ◽  
Sheri A. Klassen ◽  
Robert M. McKay ◽  
Kathryn E. Preuss

The thermodynamics of amino acid systems are key to the understanding of protein chemistry. We have found that many previous studies of the apparent molar volumes and heat capacities of aqueous solutions of amino acids were conducted at the standard temperature of 298.15 K. This does not allow for the fact that most biological processes occur at temperatures removed from this standard condition.In an attempt to address this imbalance we have measured densities and heat capacities for aqueous solutions of glycine, L-alanine, L-serine, and L-threonine at 288.15, 298.15, 313.15, and 328.15 K using a Picker flow microcalorimeter. Apparent molar volumes and heat capacities, and the associated standard state partial molar properties have been calculated. Constant pressure variations of revised Helgeson, Kirkham, and Flowers equations have been fitted to calculated standard state volumes and heat capacities over the temperature range 288.15 to 328.15 K. These equations may be used to estimate standard state volumes and heat capacities, and hence equilibrium constants, for aqueous amino acid systems at higher temperatures.


1989 ◽  
Vol 18 (2) ◽  
pp. 131-142 ◽  
Author(s):  
J. F. Reading ◽  
P. A. Carlisle ◽  
G. R. Hedwig ◽  
I. D. Watson

1999 ◽  
Vol 77 (3) ◽  
pp. 387-390 ◽  
Author(s):  
Xiaoling Ren ◽  
Ruisen Lin ◽  
Yaming Ni ◽  
Hanxing Zong

Densities of glycine, L-alanine, and L-serine have been measured with an oscillating-tube densimeter at 298.15 K in water + ethanol (EtOH) mixtures ranging from pure water to 45% ethanol by mass. From these densities, apparent molar volumes and limiting apparent molar volumes of the three amino acids in the mixtures have been calculated. Transfer volumes are interpreted in terms of the structure-making or structure-breaking effects of water on addition of these amino acids in the mixtures. The relative contributions of hydrophilic and hydrophobic interactions in these solutions have been inferred.Key words: glycine, L-alanine, L-serine, water + ethanol mixtures, densities.


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