Fig. 6
From: Single molecule dynamics in a virtual cell combining a 3-dimensional matrix model with random walks
Single molecule movements in the presence of lipid rafts. (A) Projected SD image generated from a movie sequence (500 frames, 20 fps) simulating fluorescent molecules moving at Kdiff = 0.1 µm2⋅s−1 in cellular membrane (20 × 20 × 2 µm3, voxel size 5 × 5 × 5 µm3) containing 1000, randomly positioned, circular lipid rafts, Ø220 nm (surface area 400 µm2, 10% raft coverage, viscosity × 10 of surrounding membrane). (B) Thresholded map showing the distribution of lipid rafts on the cell membrane shown in (A). (C) Projected SD image generated using the same conditions as in (A), but without lipid rafts. Scale bars are 2 µm. (D) MSD vs dT plots produced by tracking the paths of 1195 individual fluorophores moving on the membrane containing lipid rafts (red line) and 958 molecules moving on plain membrane (green line). The linear fit of the first 40 data points (up to 2 s time interval) gives Kdiff = 0.056 and 0.102 µm2⋅s−1 respectively. (E) Distribution of diffusion constants, measured from the initial gradient of MSD v dT plots of individual molecules; cell with lipid rafts (red line); plain membrane (green line). Note: same data set as D.
