Fig. 4: Vesicle division arising from constriction forces generated by spontaneous curvature.
From: Controlled division of cell-sized vesicles by low densities of membrane-bound proteins
a Constriction force f compressing the closed membrane neck as a function of the curvature difference m − Mne. The straight line corresponds to Eq. (2) with κ = 48kBT. For comparison, the plot also includes literature values for the constriction forces as generated by the specialized protein complexes of dynamin4, ESCRT-III5, and FtsZ6. b Neck fission and division of a symmetric dumbbell with a closed membrane neck on the left to the two-vesicle state on the right. The free energy barrier between these two states is provided by the intermediate state with two daughter vesicles, each of which has a small membrane pore arising from the broken neck. The radius R of the pores is determined by the neck size before fission. c Average vesicle diameter of LUVs measured by dynamic light scattering as a function of GFP concentration X. Error bars indicate standard deviations from six measurements on the same sample. In total, two independent repeat experiments were performed. The upper x-axis with the spontaneous curvature m is obtained from the calibration curve in Supplementary Fig. 1 and the data in Fig. 2a, as described by Eq. (1). d Size distribution of LUVs obtained for GFP concentration X = 0.7 and 3 nM by dynamic light scattering. These two X-values generate a spontaneous curvature of about 1.5 and 5.5 μm−1. The data in c and d were obtained for 1 mol% anchor-lipids. Source data for panels a, c, and d are provided in the Source Data file.
