The structure and stability of phospholipid bilayers by atomic force microscopy

摘要: Atomic force microscopy (AFM) was used to investigate the structure, stability, and defects of hydrophilic surfaces Langmuir-Blodgett bilayer films distearoylphosphatidylcholine (DSPC) dipalmitoylphosphatidylethanolamine (DPPE) in solid phase, dilinoleoylphosphatidylethanolamine (DLPE) fluid phase. Their relative resilience external mechanical stress by scanning tip exchange were also investigated. DPPE monolayers showed parallel ridges at surface with a period 0.49 nm, corresponding rows aligned headgroups consistent known crystallographic structure. DSPC DLPE did not show any periodic order. The stable continued rastering AFM tip; however, stability depended on pH aqueous environment. Structural form monolayer gaps holes observed after exchange, but 11 during consecutive scanning. At 9 below, induced over more extensive deformed easily 10 nN. dependence explained increasing bending energy or frustration due high spontaneous curvature low pH. tangential exerted deformable eventually produced ripple pattern, which could be described as buckling Shallamach waves.