NaCl-dependent formation of the highly crystalline phase in sufficiently hydrated dimyristoylphosphatidylglycerol bilayers.
We investigated the low-temperature phase behavior of dimyristoylphosphatidylglycerol (DMPG) bilayers in the presence of high concentration of NaCl (>or=100 mM). Differential scanning calorimetry showed that the highly crystalline (HC) phase grew after an initial delay period when DMPG bilayers were sufficiently hydrated and incubated at 1 degree C in the presence of more than 100 mM NaCl. The HC phase formation reached a plateau, the level of which depended on NaCl concentration; all the lipids were unable to be in the HC phase at the plateau stage without a quite high concentration of NaCl. Since electron microscopic observations suggested that the HC phase formed coexists with the precursor phases in a closed vesicle, elastic constrain and/or shortage of free sodium ions in the inside of the closed vesicle may prevent the complete transition into the HC phase.
Kinoshita
Masanao
M
Department of Physics, School of Science and Technology, Kwansei-Gakuin University, Sanda, Hyogo, 669-1337, Japan. aul81636@kwansei.ac.jp
Kato
Satoru
S
Takahashi
Hiroshi
H
D003080:Cold Temperature; D003460:Crystallization; D007700:Kinetics; D044367:Phase Transition; D010715:Phosphatidylglycerols / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
D010715:Phosphatidylglycerols; D014867:Water; D012965:Sodium Chloride; C002773:dimyristoylphosphatidylglycerol