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 to the fluid phase L R . For higher values of a hh , the transition from the L c to the L R phase occurs via the tilted gel phase L ′ and the rippled phase P ′ . The occurrence of the L ′ phase depends on tail length. We find that the rippled structure (P ′ ) occurs if the headgroups are sufficiently surrounded by water and that the ripple is a coexistence between the L c or L ′ phase and the L R phase. The anomalous swelling, observed at the P ′ f L R transition, is not directly related to the rippled phase, but a consequence of conformational changes of the tails.

Understanding the Phase Behavior of Coarse-Grained Model Lipid Bilayers through Computational Calorimetry

“…The Journal of Physical Chemistry B ARTICLE previously examined with the DPD model, 11 neither of the models was fully parametrized in order to match these phase phenomena. As such, we place these models on relatively even footing in this comparison, though it has already been established that DPD captures the range of structures characterizing the different bilayer phases.…”

Alcohol solubility in a lipid bilayer: Efficient grand-canonical simulation of an interfacially active molecule

“…16 Furthermore, alcohol models such as the one we use have been shown to induce interdigitation among the lipid tails in nonliquid crystal phases. 7 We predominantly simulate the system at T = 0.7 in order to remain in a purely liquid-crystalline phase regardless of the mole fraction of alcohol.…”

“…26 The coarse-grained model studied undergoes the relevant phase transitions, 16 and the "alcohol" model used has been shown to induce reasonable structure modification in the bilayer. 7 Therefore, we studied the temperature dependence of K p in our model in the hope of gaining insight into the structural drivers for this increase in partitioning.…”

Using spin polarised positive muons for studying guest molecule partitioning in soft matter structures

“…A phospholipid bilayer knows many different phases [53]. At low temperature, the subgel L c with highly ordered and tilted hydrophobic chains appears (Fig.…”