Tripeptides in aqueous solution: Model compounds for the evaluation of the partial molar heat capacities of amino acid side-chains in proteins

Partial molar volumes and heat capacities of the N-acetyl amide derivatives of the amino acids asparagine, glutamine, tyrosine, and lysine monohydrochloride in aqueous solution at temperatures from T=288.15K to T=328.15K

“…For consistency, the same approach is adopted in this work. The values chosen for C p ðHÞ were those calculated using a polynomial in temperature reported previously [37]. The values of the partial molar heat capacities for AcglyNH 2 used in the calculations were also taken from previous work [6].…”

“…The solid curves given in the figure represent the side-chain heat capacities calculated from heat capacity data determined using differential scanning calorimetry (d.s.c.) [8,37]. For the protonated lysyl side-chain, values of C p ðlysH þ Þ at all temperatures in the range T = (288.15 to 328.15) K were obtained by the addition to the quantities fC p ðlysH þ ÞÀ C p;2 ðH þ Þg reported previously [8], a value for C p;2 ðH þ Þ of À63.…”

Apparent and partial molar heat capacities and volumes of the amino acids l -lysine monohydrochloride andl -arginine monohydrochloride in aqueous solution at temperatures from T= 288.15 K to T= 328.15 K

“…The partial molar heat capacities of aqueous hydrochloric acid solutions at infinite dilution were calculated using an equation for the temperature dependence of C ∞ p,m,φ given by Ballerat-Busserolles et al, (30) and the C ∞ p,m,φ (gly) values were taken from Hakin et al (28) . Values of C ∞ p,m,φ (H) were calculated using a polynomial in temperature as derived in previous work (31) . The values of {C ∞ p,m,φ (R + ) − C ∞ p,m,φ (H + )}, together with their root-mean-square uncertainties, are given in table 7.…”

Temperature, pressure, and electrochemical constraints on protein speciation: Group additivity calculation of the standard molal thermodynamic properties of ionized unfolded proteins

“…The latter values were calculated from the standard molal Gibbs energies and enthalpies of ionization ( G • ion and H • ion ) of these charged species taken from Goldberg et al ( ) Kikuchi et al, 1995;( ) Kharakoz, 1991; ( ) Mizuguchi et al, 1997;( ) Yasuda et al, 1998;and (×) Millero et al, 1978. ( ) Vogl et al (1995); ( ) Häckel et al (1998); (♦) Häckel et al (1999a); ( ) Downes and Hedwig, 1995;( ) ( ) Vogl et al (1995); ( ) Häckel et al (1998); (♦) Häckel et al (1999b). www.biogeosciences.net/bg/0000/0001/ Biogeosciences, 0000, 0001-26, 2006 together with the properties of the corresponding neutral species given in Table 2.…”

“…The polynomial equations representing the experimental measurements of C • P and V • of the Gly-X-Gly tripeptides given by Vogl et al (1995), Häckel et al (1998), andHäckel et al (1999a) were used to generate the values at 15, 25, 40, 55, 70, 80, 90, and 100 • C shown in Figs. 2d and e.…”