MD/DPD Multiscale Framework for Predicting Morphology and Stresses of Red Blood Cells in Health and Disease
Fig 2
Schematic representation of the two-component composite CGMD model (A & C) and whole-cell DPD model (B & D) of H-RBCs and Pf-RBCs.
For the composite CGMD model, the red, blue, and grey particles represent clusters of lipid molecules, actin junctions, and actin filaments of cytoskeleton, respectively; the black and yellow particles signify band-3 complexes, of which one third (yellow ones) are connected to the spectrin network; the green patches represent the rigid knobs in the Pf-RBC membrane; the purple particles refer to the spectrin octamers. For the whole-cell DPD model, the lipid bilayer and cytoskeleton are rendered in red and grey triangular networks, respectively. Only half of the triangular network of the lipid bilayer is shown for clarity. The rigid knobs in lipid bilayer of the Pf-RBC is rendered in green, while the enhanced spectrin network of T-RBC and deficient spectrin network of S-RBC are highlighted in purple bonds and visible holes in the triangular network of the cytoskeleton. The knob density in the whole-cell DPD model is set to be lower than that in the composite CGMD model due to different levels of coarse-graining applied to these two-component models. In the whole-cell DPD model, the average size of a knob (Aknob,DPD) is around 0.04 μm2 and 0.036 μm2 for T-RBC and S-RBC, respectively, which is around 2–5 times bigger than that (Aknob,CGMD) used in the composite CGMD model. Thus, ρknob,DPD ≈ (0.2–0.5)ρknob,CGMD.