Figure 4.

Binding of the N-terminal peptide of β2e to liposomes is strengthened in the presence of anionic poly-PIs. (A) Schematic diagram of FRET analysis. Binding was examined using FRET between peptide containing Trp (W) (donor) and liposomes labeled with dansyl-PE (acceptor). Fluorescence emitted from Trp is quenched by dansyl-PE, suggesting peptide binding to liposomes. The initial spectrum of Trp was determined in the absence of liposomes (F₀), and the subsequent spectrum was recorded after liposome addition (F). (B) FRET signals in the absence (black trace) or presence (red traces) of liposomes with no-liposome, 1% PIP₂, or both 1% PIP₂ and 15% PS. FRET is presented as F₀/F at 355 nm. A.U., absorbance units. (C) Summary of FRET changes with different lipid compositions on the liposomes. For no-liposome, 1% PIP₂, and both 1% PIP₂ and 15% PS, n = 3; *, P < 0.05; **, P < 0.01, compared with no liposome. Data are mean ± SEM.