Archaebacterial lipids: highly proton-impermeable membranes from 1,2-diphytanyl-sn-glycero-3-phosphocholine.
Unlike ordinary glycero-lipids such as egg-yolk lecithin, 1,2-diphytanyl-sn-glycero-3-phosphocholine, which was employed as a model lipid of archaebacterial acidophiles, gave liposomal membranes which were highly resistant to proton permeation in a wide temperature range (about 10-50 degrees C); the permeability coefficient and activation energy of the flux were 0.7 x 10(-5) cm/s at 20 degrees C and 24.5 kcal/mol, respectively. The high resistance to proton flow was attributed to a fluid and bulky isoprenoid chain-layer of the membrane.
Department of Bioapplied Chemistry, Faculty of Engineering, Osaka City University, Japan.
K
K
Yamauchi
K
K
Doi
Y
Y
Yoshida
M
M
Kinoshita
D015060:1,2-Dipalmitoylphosphatidylcholine; D001105:Archaea / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000737:chemistry*; D010539:Permeability; D010713:Phosphatidylcholines / Q000737:chemistry*; D011522:Protons; D013696:Temperature
D008081:Liposomes; D010713:Phosphatidylcholines; D011522:Protons; D015060:1,2-Dipalmitoylphosphatidylcholine; C021016:1,2-diphytanoylphosphatidylcholine