Figure 1. Membrane fission and ring-raft formation in bud-mimicking architecture.

(a) Schematic representation of key budding steps (case I–case IV). (b) Closed ring-raft domain located around a bud-neck region with a negative curvature (c₀<0; radius r=1/c₀). (c) Formation of a nano-raft enriched with CHOL and SPM molecules in the outer leaflet by the bud-neck curvature.