title: Phase behavior of model lipid bilayers.
abstract: We investigated the phase behavior of double-tail lipids, as a function of temperature, headgroup interaction and tail length. At low values of the head-head repulsion parameter a(hh), the bilayer undergoes with increasing temperature the transitions from the subgel phase L(c) via the flat gel phase L(beta) to the fluid phase L(alpha). For higher values of a(hh), the transition from the L(c) to the L(alpha) phase occurs via the tilted gel phase L(beta)(') and the rippled phase P(beta)('). The occurrence of the L(beta)(') phase depends on tail length. We find that the rippled structure (P(beta)(')) occurs if the headgroups are sufficiently surrounded by water and that the ripple is a coexistence between the L(c) or L(beta)(') phase and the L(alpha) phase. The anomalous swelling, observed at the P(beta)(') --> L(alpha) transition, is not directly related to the rippled phase, but a consequence of conformational changes of the tails.
authors.affiliation: The Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands.
authors.forename: Marieke
authors.initials: M
authors.lastname: Kranenburg
authors.forename: Berend
authors.initials: B
authors.lastname: Smit
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D002627:Chemistry, Physical / Q000379:methods*; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D015233:Models, Statistical; D008968:Molecular Conformation; D010743:Phospholipids / Q000737:chemistry; D011312:Pressure; D012984:Software; D055672:Static Electricity; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D010743:Phospholipids; D014867:Water