Fig. 4.

DIM aggregate in a POPC-POPE-cholesterol-sphingomyelin lipid mixture. Simulations of a 28 × 28-nm² patch of a macrophage-like membrane constituted of POPC/POPE/cholesterol/sphingomyelin (ratio 4:3:2:1) at 310 K with 5% of DIM (A) or 2.5% of DIM (B). For each system, at the end of 10 µs of simulations, 1 or several aggregates were formed in the center of the bilayer. Here, we focus on the largest aggregate. (Top illustration) DIM aggregates after 10 µs of simulation. POPC molecules are colored in red. POPE molecules are colored in blue. Cholesterol molecules are colored in green. Sphingomyelin molecules are colored in purple. DIM molecules are colored in yellow. (Second and Third row) The density profile for both leaflets (top view of the membrane) of DIM and POPE lipids obtained by centering the DIM aggregates for the last 2.5 µs. Dashed lines broadly define the periphery of DIM aggregates where POPE lipids tend to be enriched while they seem to be depleted in the center of the aggregate.