Theoretical analysis of opening-up vesicles with single and two holes

Abstract

Cuplike lipid vesicles with a single hole and tubelike vesicles with two holes were theoretically analyzed by taking into account the line tension of membrane holes and the bending energy of membranes, using the area difference elasticity model. We numerically solved the Euler-Lagrange equation and the boundary conditions holding on the membrane edge to obtain axisymmetric vesicle shapes that minimize the total energy. The numerical results showed that when the line tension is very low, and for appropriate values of the relaxed area difference between the two monolayers of bilayer membranes, the model yields cup-, tube-, and funnel-shaped vesicles that closely resemble previously observed shapes of opening-up vesicles with additive guest molecules such as the protein talin and some detergents. This strongly suggests that these additive molecules greatly reduce the line tension of lipid membranes. The effect of the Gaussian bending modulus on the shape of the opening-up vesicles was also evaluated and the effect is greatest when the size of hole is small.

Dynamics of vesicle self-assembly and dissolution

“…However, the behavior of membranes with edges depends on . 56,57 In the meshless membrane model, and ⌫ can essentially be varied independently. 42 The bending rigidity increases linearly with k ␣ and is almost independent of , with…”

Stepwise Shrinkage of Liposomes Driven by Thermal Fluctuations of the Membranes

“…Theoretically, opening-up shapes can only be established when the spontaneous curvature, as well as the line tension, is within a certain range. [14] Furthermore, some other combinations cause inside-out topological inversion of vesicles, [2] which suggests a large negative spontaneous curvature. It has been reported that some detergents (including Triton X-100) are able to accelerate phospholipid flip-flop.…”

Peptide-induced membrane curvature in edge-stabilized open bilayers: A theoretical and molecular dynamics study

“…The general solution of this formidable problem is very difficult and several papers dealing with this issue have been written over the time. [25][26][27][28][29] Here, we follow a simple approximate procedure that retains most of the relevant physics. A similar procedure, that does not include the relevant spontaneous curvature effects, has been developed some time ago.…”