Figure 3. Model-generated organization (snapshots) of receptors diffusing on a cell membrane with low-diffusivity microdomains (lipid rafts): (A) monomer regime (k_mono = 10⁶ s⁻¹, k_dimer = 10³ s⁻¹), (B) dimer regime (k_mono = 10³ s⁻¹, k_dimer = 10⁶ s⁻¹), and (C) oligomer regime (k_mono = 10⁶ s⁻¹, k_dimer = 10⁶ s⁻¹).

Lipid raft regions are shown as nine small squares. Monomers and dimers are shown with blue and brown dots respectively. (D) The predicted enrichment ratio varies with k_mono and k_dimer. Diffusion coefficients in lipid raft and non-raft regions for A-D were set to 10⁻¹² and 10⁻¹⁰ cm²/s respectively. Simulation results with other values of diffusivity are shown in Supplementary Figure S3. Simulations were run to equilibrium with receptor density of 18%. In this set of simulations, rafts make up 20% of the simulated membrane and the raft diameter is 50 nm.