Lipid phase behavior and calcium-induced fusion of phosphatidylethanolamine-phosphatidylserine vesicles. Calorimetric and fusion studies

Synaptotagmin 1 Modulates Lipid Acyl Chain Order in Lipid Bilayers by Demixing Phosphatidylserine

“…It is well known that PC and PS do not form ideal mixtures (42,43) and are, therefore, prone to demix. However, PS and PE are reported to form nearly ideal lipid mixtures (44). The addition of PE to a PC:PS mixture resulted in a lower level of fluorescence quenching when the syt1 C2 domains were added and by inference an incomplete level of demixing or phase separation (Fig.…”

Mixing behavior of symmetric chain length and mixed chain length phosphatidylcholines in two-component multilamellar bilayers: evidence for gel and liquid-crystalline phase immiscibility

“…Of relevance to the current study are the studies on the saturated phosphatidylcholine series (12)PC, and C( 18)C( 1O)PC. Bilayers composed of C( 18)C-(18)PC or C( 18)C(16)PC do not show significant interdigitation of the phospholipid's hydrocarbon chains across the bilayer center in the gel phase (Stumpel et al, 1983;Huang & Mason, 1986). Raman spectroscopic and X-ray diffraction (Hui et al, 1984) studies indicate that the acyl chains of the C(18)C(14)PC molecules do not interdigitate in the gel phase of this bilayer system.…”

“…The properties of binary mixtures of phospholipids that differ in their headgroup type or acyl chain composition have been studied by a variety of techniques. These include DSC' (Mabrey & Sturtevant, 1976;Silvius, 1986;van Dijck et al, 1977;Silvius & Gagnd, 1984a,b), dilatometry (Wilkinson & Nagle, 1979;Schmidt & Knoll, 1986), ESR and NMR spectroscopy (Shimshick & McConnell, 1973;Wu & McConnell, 1975;Blume et al, 1982), freeze-fracture electron microscopy (Luna & McConnell, 1978), and Raman and IR spectroscopy (Mendelsohn & Maisano, 1978;Jaworsky & Mendelsohn, 1985). Theoretical descriptions of binary mixtures of phospholipids have also appeared (Jacobs et al, 1977;Priest, 1980;Sugar & Monticelli, 1985;Lee, 1977).…”

“…These systems are characterized by complete miscibility of the phospholipid components in the liquid-crystalline phase and complete or limited miscibility of the phospholipid components in the bilayer gel phase. Examples include binary mixtures of PC and PE (Silvius, 1986), PC and PS and also PE and PS in the absence of calcium (Silvius & Gagnb, 1984a,b), and PC and PG (Findlay & Barton, 1978). The mixing behavior of phospholipids in the gel phase of two-component bilayers is strongly influenced by differences in the acyl chain composition of the two phospholipid components.…”

Targeting of anionic membrane species by lanthanide(iii) complexes: towards improved MRI contrast agents for apoptosis

“…Here we present a study of 19 or by hydrophobic interactions into Eu-bearing micelles. 20 We propose that intermolecular energy transfer may be used to detect the With the reasonable presumption of an even distribution of DOPS between inner and outer leaflets of the membrane bilayer in vesicles of this size, 21 it was possible to construct a Job's plot consistent with 1:1 binding (Fig. 3, inset).…”