TY - JOUR
T1 - The relations between the composition of liposomes and their interaction with triton X-100
AU - Hertz, Rachel
AU - Barenholz, Yechezkel
PY - 1977/6/1
Y1 - 1977/6/1
N2 - The interaction of Triton X-100 with phospholipid bilayers of multilamellar liposomes formed from mixtures of spinal cord sphingomyelin and egg yolk lecithin in various mole ratios (all containing 1 mole of dicetylphosphate per 10 moles of phospholipid) was studied. The results indicate that the process is time dependent and is much slower than the formation of simple micelles. The time to reach the final equilibrium state is dependent on the SPM to PC mole ratio, on the Triton to phospholipid mole ratio, and on the Tirton concentration. Titration with increasing Triton concentration shows that the behavior of Triton is biphasic for all the various lipid compositions tested. For low Triton to phospholipid mole ratio there is no mass formation of mixed micelles; in addition, the Triton seems to radically increase the leakage of glucose without reducing the turbidity. This range is limited by a turning point where most of the phospholipids and about half of the Triton coprecipitate. Above this Triton to phospholipid mole ratio formation of mixed Triton-phospholipid micelles occurred followed by a drastic decline in turbidity. This turning point as well as the exact profile of the Triton effect are strongly related to the SPM:PC mole ratio. The higher the mole fraction of SPM in the membrane, the less Triton is required to reach the turning point and to cause a complete solubilization. These effects can be explained by tighter packing and stronger phospholipid-phospholipid interactions imposed by SPM and expressed as apparent microviscosity which increases upon increasing the mole fraction of SPM in the bilayer.
AB - The interaction of Triton X-100 with phospholipid bilayers of multilamellar liposomes formed from mixtures of spinal cord sphingomyelin and egg yolk lecithin in various mole ratios (all containing 1 mole of dicetylphosphate per 10 moles of phospholipid) was studied. The results indicate that the process is time dependent and is much slower than the formation of simple micelles. The time to reach the final equilibrium state is dependent on the SPM to PC mole ratio, on the Triton to phospholipid mole ratio, and on the Tirton concentration. Titration with increasing Triton concentration shows that the behavior of Triton is biphasic for all the various lipid compositions tested. For low Triton to phospholipid mole ratio there is no mass formation of mixed micelles; in addition, the Triton seems to radically increase the leakage of glucose without reducing the turbidity. This range is limited by a turning point where most of the phospholipids and about half of the Triton coprecipitate. Above this Triton to phospholipid mole ratio formation of mixed Triton-phospholipid micelles occurred followed by a drastic decline in turbidity. This turning point as well as the exact profile of the Triton effect are strongly related to the SPM:PC mole ratio. The higher the mole fraction of SPM in the membrane, the less Triton is required to reach the turning point and to cause a complete solubilization. These effects can be explained by tighter packing and stronger phospholipid-phospholipid interactions imposed by SPM and expressed as apparent microviscosity which increases upon increasing the mole fraction of SPM in the bilayer.
UR - http://www.scopus.com/inward/record.url?scp=0001276998&partnerID=8YFLogxK
U2 - 10.1016/0021-9797(77)90270-3
DO - 10.1016/0021-9797(77)90270-3
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AN - SCOPUS:0001276998
SN - 0021-9797
VL - 60
SP - 188
EP - 200
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
IS - 1
ER -