(Color online) Density profile of solvent particles (solid blue line), lipid head particles (dashed red line), and lipid tail particles (dash-dot black line). is plotted as a function of , the distance from the membrane midplane.
Membrane tension (in units of ) as a function of the area per amphiphile molecule . Area per molecule is defined as two times the total area of the system cross section spanned by the membrane, divided by the number of lipids in the membrane. At , the membrane is compressed and develops ripples, thus the “true” area of the membrane (defined as the area of the midplane surface) is larger than the cross-section area. The error for each point is .
Dependence of the adhesion energy change per unit area of particle surface, (in units of ), on the repulsion coefficient between particle and solvent beads, . The error for each point is .
(Color online) Cross-section images of equilibrium membrane wrapping around particle at various values of adhesion energy and excess membrane area . Images (a)–(c) are for and images (d)–(f) are for . The adhesion energy is for (a) and (d) for (b) and (e) and for (c) and (f).
(Color online) Time sequence showing a cross section of the membrane “eyelid” which wraps the particle for . Image (d) shows the fully wrapped particle that remains attached to the membrane.
(Color online) System energy as a function of the relative excess membrane area , determined from the cross-section area, for a homogeneous membrane in contact with a particle for (blue circles), (red squares), (green triangles), (black crosses), (lavender inverted triangles), (yellow diamonds), and (light blue stars). The system energy is expressed as the average energy per bead over the entire system (including all solvent) and is expressed in units of . The rms error for each point is approximately .
Dependence of interfacial line tension (in units of ) on , the repulsion parameter between type-1 and type-2 lipids. The error for each point is .
(Color) Membrane with an adhesive raft partially wrapped around a particle.
(Color) Time sequence of membrane neck structure during fission (side view). The particle is represented by brown beads. A portion of the raft, near the membrane neck, is shown with red head beads and dark blue tail beads. In order to illustrate the location of the raft interface, only the bulk phase lipids which lie in close proximity to the raft lipids (within a distance of 1.5) are shown. These lipids have light blue head beads and black tail beads. (a) As the neck forms, a rip appears on the interface, in the region where no bulk phase lipids are present. (b) The neck size decreases. (c) The rip spreads across the interface, allowing the raft to further coat the particle and leaving only a small region of contact between the raft and the bulk phase. (d) Continued spreading of the interface rip causes complete fusion. The raft now fully coats the particle, although a small number of the raft lipids remain in the flat membrane.
(Color online) Time sequence of membrane neck structure during fission (cross-section view). These images correspond to those in Fig. 9. See the caption of that figure for further details.
Phase diagram describing the equilibrium state of a membrane raft interacting with a particle. Circles represent cases in which the membrane remained open and did not fully wrap the particle. Plusses represent cases in which the particle becomes fully wrapped but does not detach from the particle. Crosses represent cases where the particle is wrapped by the raft, which then undergoes fission, detaching from the membrane. The adhesion energy and the interfacial line tension are varied. The raft radius is and the particle radius is .
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