The effect of selected anions on dipalmitoylphosphatidylcholine phase transitions.
The effect of three anions, Cl-, Br- and I-, on the phase transitions of dipalxnitoylphosphatidyicholine (DPPC) was measured. Main phase transition was modestly affected by these anions in the salt concentration range 0.2 M. For Cl- and Br- the temperature of main phase transition was lower (by about 0.5 degrees C), its half-width modestly larger and enthalpy practically unchanged, all three parameters were altered to a much larger deuce. Main phase transition temperature was 1.5 degrees C lower and the peak hall-width significantly smaller. These changes were not accompanied by any alteration in main phase transition enthalpy. Iodide shifted the pretransition temperature toward lower values and increased its half-width to such an extent that at concentrations above 100 mM it was practically undetectable. Besides cations, the presence of anions also has a distinct effect on lipid bilayer interface properties.
Przyczyna
Adriana
A
Department of Physics and Biophysics, Agricultural Academy, Wrocław, Poland. mucha@ozi.ar.wroc.pl
Rózycka-Roszk
Bozenna
B
Langner
Marek
M
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000838:Anions; D001965:Bromides / Q000737:chemistry; D002152:Calorimetry, Differential Scanning / Q000379:methods; D002725:Chloroform; D007202:Indicators and Reagents; D012965:Sodium Chloride / Q000737:chemistry; D017670:Sodium Compounds / Q000737:chemistry; D012974:Sodium Iodide / Q000737:chemistry; D013816:Thermodynamics
D000838:Anions; D001965:Bromides; D007202:Indicators and Reagents; D017670:Sodium Compounds; D015060:1,2-Dipalmitoylphosphatidylcholine; D012965:Sodium Chloride; D002725:Chloroform; D012974:Sodium Iodide; C027938:sodium bromide