Studies in the Physical Chemistry of Amino Acids, Peptides and Related Substances. I. The Apparent Molal Volume and the Electrostriction of the Solvent

Abstract

5) Details of preparation and criteria of purity of these compounds will be reported in subsequent papers of this series.(6) Traube, Samml. chem. und chem.-techn. Vortr., 4, 255 (1 899). NHt CH2 COOH NH2CH2COOHVol. of groups, cc.7.7 16.1 18.9 42.7°Traube believed that a second hydroxyl group, or the second oxygen in a carboxyl group, occupied less space than the first.

Volume changes of the molten globule transitions of horse heart ferricytochrome c: A thermodynamic cycle

“…This would give rise to an electrostatic attraction for anions, and the protein is known to bind anions, including chloride (Stellwagen & Babul, 1975;Taborsky & McCollum, 1979;Osherhoff et al, 1980). Electrostatic interactions would release electrostricted water, which would cause a net rise in volume (Cohn et al, 1934;Cohn & Edsall, 1943). A V is negative, however, so if release of electrostricted water occurs, its effect is masked by another.…”

Thermodynamics of transfer of glycine, diglycine, and triglycine from water to aqueous solutions of urea, glycerol, and sodium nitrate

“…We have therefore calculated AG? (cav) by the widely used procedure (12, 13, 24) using the "scaled particle theory (SPT)" (27), taking the diameter of G , DG, and TG as 5.64 (28), 8.0 (29), and 1 1.5 (29), respectively and those of the cosolvent molecules as given in refs. 12 and 13.…”

“…12 and 13. Notably, since the radius of equivalent hard sphere of DG and TG will be quite uncertain and also since DG and TG may be best considered according tooCohn et al (29) to be cylindrical of length 8.0 and 1 1.5 A, respectively, we have tentatively assumed the excluded volume of diameter of the same magnitudes for the respective species to be equivalent to their hard-sphere model.…”

“…(int) values. But since Kirkwood (28) and Cohn et al (29) have ajready considered glycine as a spherical solute of radii 2.82 A (and hence amenable for SPT calculations), the AG:(int)-composition profile for glycine should by no means be considered to be an artifact but rather fairly meaningful. Likewise, the same profile for diglycine should also be taken as something real.…”

A simple method for displaying the hydropathic character of a protein

“…We have used both the water-vapor transfer free energies and the interior-exterior distribution of amino acid side-chains determined by Chothia (1976) The apparent molal volumes (4) at 25°C of model compounds for the side-chains (Wolfenden et al, 1979) of the structure RH, where R is the side-chain of a given amino acid (+HaNCH(R)COO-) are either the observed values (a) tabulated by Cohn et al (1934) or values calculated (b) by the methods of Cohn et al (1934), which themselves were adapted from Traube (1899). The water-vapor partition coefficients for the various model compounds are available in the Tables published by (c) Hine & Mookerjee (1975) or (d) Wolfenden et al (1979).…”