Stomatocyte–discocyte–echinocyte sequence of the human red blood cell: Evidence for the bilayer– couple hypothesis from membrane mechanics

Red-cell shape is encoded in the mechanical properties of the membrane. The plasma membrane contributes bending rigidity; the protein-based membrane skeleton contributes stretch and shear elasticity. When both effects are included, membrane mechanics can reproduce in detail the full stomatocyte–discocyte–echinocyte sequence by variation of a single parameter related to the bilayer couple originally introduced by Sheetz and Singer [Sheetz, M. P. & Singer, S. J. (1974) Proc. Natl. Acad. Sci. USA 71, 4457–4461].