ABSTRACT

To compare the counteracting effects of methylamines trimethylamine N-oxide (TMAO) and betaine on the actions of urea, we have determined the apparent transfer free energies ( G tr) of zwitterionic glycine peptides: glycine (Gly), diglycine (Gly2), triglycine (Gly3), and tetraglycine (Gly4) from water to methylamine and urea, and also the blends of methylamine and urea at a 1:2 ratio as well as various urea concentrations (0.5 8M) in the presence of 1M methylamine. The G tr values of the blends of methylamine with urea revealed that the methylamine strongly counteracted the urea actions on glycine peptides. However, the methylamine partially counteracted the deleterious effects of urea on the Gly4 in the cases of higher urea concentrations (4 8M) in the presence of 1M methylamine. The experimental results were further used to estimate the transfer free energies ( g tr) of the peptide backbone unit ( CH2C ONH ) contributions.

Compounds

#	Formula	Name
1	C2H5NO2	2-aminoacetic acid
2	C8H14N4O5	glycylglycylglycylglycine
3	C4H8N2O3	glycylglycine
4	C6H11N3O4	glycylglycylglycine
5	CH4N2O	urea
6	C3H9NO	trimethylamine oxide
7	C5H11NO2	(trimethylammonio)acetate
8	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	1 6 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 1	Vibrating tube method	4
POMD	1 6 8	Mass ratio of solute to solvent - 1 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 1	Determined from density measurements	4
POMD	1 7 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 1	Vibrating tube method	4
POMD	1 7 8	Mass ratio of solute to solvent - 1 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 1	Determined from density measurements	4
POMD	1 5 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 1	Vibrating tube method	5
POMD	1 5 8	Mass ratio of solute to solvent - 1 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 1	Determined from density measurements	5
POMD	3 6 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 3	Vibrating tube method	4
POMD	3 6 8	Mass ratio of solute to solvent - 3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 3	Determined from density measurements	4
POMD	7 3 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 3	Vibrating tube method	4
POMD	7 3 8	Mass ratio of solute to solvent - 3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 3	Determined from density measurements	4
POMD	5 3 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 3	Vibrating tube method	5
POMD	5 3 8	Mass ratio of solute to solvent - 3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 3	Determined from density measurements	5
POMD	4 6 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 4	Vibrating tube method	4
POMD	4 6 8	Mass ratio of solute to solvent - 4 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 4	Determined from density measurements	4
POMD	7 4 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 4	Vibrating tube method	4
POMD	7 4 8	Mass ratio of solute to solvent - 4 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 4	Determined from density measurements	4
POMD	5 4 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 4	Vibrating tube method	5
POMD	5 4 8	Mass ratio of solute to solvent - 4 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 4	Determined from density measurements	5
POMD	2 6 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 2	Vibrating tube method	4
POMD	2 6 8	Mass ratio of solute to solvent - 2 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 2	Determined from density measurements	4
POMD	7 2 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 2	Vibrating tube method	4
POMD	7 2 8	Mass ratio of solute to solvent - 2 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 7; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 2	Determined from density measurements	4
POMD	5 2 8	Mass density, kg/m3 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 2	Vibrating tube method	5
POMD	5 2 8	Mass ratio of solute to solvent - 2 ; Liquid	Solvent: Amount concentration (molarity), mol/dm3 - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal - 2	Determined from density measurements	5
POMD	1 8	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 1	Vibrating tube method	1
POMD	1 8	Mass ratio of solute to solvent - 1 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 1	Determined from density measurements	1
POMD	3 8	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 3	Vibrating tube method	1
POMD	3 8	Mass ratio of solute to solvent - 3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 3	Determined from density measurements	1
POMD	4 8	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 4	Vibrating tube method	1
POMD	4 8	Mass ratio of solute to solvent - 4 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 4	Determined from density measurements	1
POMD	2 8	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 2	Vibrating tube method	1
POMD	2 8	Mass ratio of solute to solvent - 2 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid Crystal - 2	Determined from density measurements	1

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Counteracting effects of trimethylamine N-oxide and betaine on the interactions of urea with zwitterionic glycine peptides

Venkatesu, P.[Pannur], Lin, H. M.[Ho-Mu], Lee, M. J.[Ming-Jer]

ABSTRACT