ABSTRACT

The apparent molar volumes, apparent molar adiabatic compressibilities, and heats of dilution of glycyl-glycine (gly-gly), glycyl-glycyl-glycine (gly-gly-gly), glycyl leucine (gly-leu), and glycyl-glycyl-leucine (gly-gly-leu) have been determined in aqueous trimethylamine N-oxide (TMAO) at T = 298.15 K. These data have been used to calculate the values of infinite dilution standard partial molar volume, standard partial molar isoentropic compressibility, standard molar enthalpy of dilution, and the corresponding transfer thermodynamic properties from water to aqueous TMAO solutions. The results on transfer thermodynamic properties of peptides from water to aqueous TMAO solutions have been interpreted in terms of ion-ion, ion-polar, hydrophilic-hydrophilic, hydrophilic-hydrophobic and hydrophobic-hydrophobic group interactions. The results obtained in this work suggest strengthening of polar solute-solvent interactions in case of peptides compared to those in case of amino acids and support the experimental observations on the effect of TMAO on the thermodynamic and conformational stability of proteins.

Compounds

#	Formula	Name
1	C3H9NO	trimethylamine oxide
2	C4H8N2O3	glycylglycine
3	C6H11N3O4	glycylglycylglycine
4	C8H16N2O3	glycyl-L-leucine
5	C10H19N3O4	glycylglycyl-L-leucine
6	H2O	water

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	2 6	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	titration calorimetry	24
POMD	3 6	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	titration calorimetry	24
POMD	4 6	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	titration calorimetry	24
POMD	6 5	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	titration calorimetry	24
POMD	2 1 6	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Solvent: Molality, mol/kg - 1; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	isothermal titration calorimetry	24
POMD	2 1 6	Speed of sound, m/s ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 2; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	14
POMD	2 1 6	Mass density, kg/m3 ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 2; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Vibrating tube method	14
POMD	3 1 6	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Solvent: Molality, mol/kg - 1; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	isothermal titration calorimetry	24
POMD	3 1 6	Speed of sound, m/s ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 3; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	15
POMD	3 1 6	Mass density, kg/m3 ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 3; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Vibrating tube method	15
POMD	4 1 6	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Solvent: Molality, mol/kg - 1; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	isothermal titration calorimetry	24
POMD	4 1 6	Speed of sound, m/s ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 4; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	14
POMD	4 1 6	Mass density, kg/m3 ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 4; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Vibrating tube method	14
POMD	1 6 5	Molar enthalpy of dilution, kJ/mol ; Liquid	Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Solvent: Molality, mol/kg - 1; Liquid Initial molality of solute, mol/kg; Liquid Pressure, kPa; Liquid	Liquid	isothermal titration calorimetry	24
POMD	1 6 5	Speed of sound, m/s ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 5; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	15
POMD	1 6 5	Mass density, kg/m3 ; Liquid	Solvent: Molality, mol/kg - 1; Liquid Molality, mol/kg - 5; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Vibrating tube method	15

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Interactions of some short peptides with the osmolyte trimethylamine N-oxide in aqueous solution: physico-chemical insights

Choudhary, S.[Sinjan], Kishore, N.[Nand]

ABSTRACT